Plain words

Glossary

Health can come with big words. Here are simple, friendly meanings for terms you'll see around RemedyRank — no jargon, just clear language.

Looking for the scientific vocabulary instead? Jump to the technical terms — 356 of them.

Antioxidant: A helpful substance found in colorful fruits and vegetables that protects the tiny parts of your body's cells from everyday wear and tear.
Anti-inflammatory: A food or habit that helps calm swelling and redness in the body. Many plants, like ginger and turmeric, are gently anti-inflammatory.
Decoction: A way of making a strong herbal drink by simmering tougher plant parts — like roots or bark — in water for a while, instead of just steeping them.
Digestion: The way your body breaks food down into pieces small enough to use for energy and building blocks. It starts in your mouth and continues in your stomach and gut.
Electrolyte: Tiny minerals — like sodium, potassium, and magnesium — that help your muscles and nerves work right. You lose some when you sweat, so water and whole foods help replace them.
Essential oil: A very strong, concentrated oil pressed or steamed out of a plant, like eucalyptus or tea tree. Because it's so strong, it usually needs to be watered down (diluted) before use.
Fiber: The part of plant foods your body can't fully break down. It keeps your digestion moving smoothly and helps you feel full. Fruits, vegetables, beans, and whole grains are full of it.
Herb: A plant — or part of a plant, like a leaf, root, or flower — used for flavor, food, or gentle health support. Peppermint and chamomile are common herbs.
Holistic: Looking at the whole person — body, mind, and spirit — instead of just one symptom. RemedyRank takes a holistic view of health.
Hydration: Giving your body enough water to work well. Good hydration helps your energy, skin, digestion, and almost everything else.
Immune system: Your body's built-in defense team. It fights off germs and helps you heal. Rest, good food, water, and sunshine all help it do its job.
Inflammation: The body's natural response to injury or illness — like redness, swelling, or heat around a sore spot. A little is helpful for healing; too much over time isn't good for us.
Infusion: A gentle herbal drink made by steeping soft plant parts, like leaves or flowers, in hot water. A cup of herbal tea is an infusion.
Mineral: A natural building block your body needs in small amounts, like calcium for bones or magnesium for muscles. Whole plant foods are full of them.
NEWSTART: An easy way to remember the eight laws of health: Nutrition, Exercise, Water, Sunshine, Temperance, Air, Rest, and Trust in God. These simple habits support your whole self.
Plant-based: Eating mostly or only foods that come from plants — fruits, vegetables, beans, grains, nuts, and seeds. It's the way of eating we encourage on RemedyRank.
Probiotic: Friendly tiny living things (good bacteria) that help keep your gut healthy. You'll find them in foods like plant yogurt and sauerkraut.
Remedy: A simple, natural way people try to ease everyday discomforts — like sipping ginger tea for an upset stomach. On RemedyRank, remedies are for small concerns, not serious illness.
Temperance: One of the eight laws of health. It means balance and self-control — enjoying good things in healthy amounts and steering clear of what harms us.
Topical: Something you put on the outside of your body — on your skin — rather than swallow. Aloe gel on a sunburn is a topical remedy.
Vitamin: A natural substance your body needs in small amounts to stay healthy, like vitamin C from fruit or vitamin D from sunshine. Whole foods are the best source.
Whole foods: Foods that are close to how they grow in nature, with little or no processing — like an apple instead of apple candy. They keep more of their natural goodness.

🔬 Technical terms

The words behind “Let's get technical”

The remedy pages carry a scientific section where constituents and mechanisms are reported the way a professional monograph would put them. Those pages underline the technical words and define them on hover; here they all are in one place, plainly stated.

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1,8-cineole: Also called eucalyptol, the dominant aromatic compound in eucalyptus oil.
11-beta-hydroxysteroid dehydrogenase type 2: An enzyme that normally inactivates cortisol in certain tissues, and is inhibited by licorice compounds.
5-alpha-reductase: An enzyme that converts testosterone into dihydrotestosterone, a hormone linked to prostate tissue growth.
5-ht3 receptor: A serotonin receptor subtype involved in triggering nausea and the vomiting reflex.
5-lipoxygenase: An enzyme that converts arachidonic acid into leukotrienes, inflammatory signaling molecules.

A

acetic acid: The sour-tasting acid that gives vinegar its characteristic smell and taste.
acetylcholinesterase: An enzyme that breaks down the nerve-signaling chemical acetylcholine after it has done its job.
adaptogen: A traditional term for herbs thought to help the body handle stress; the label is descriptive, not a regulatory category.
adsorption: The process by which molecules stick to a surface, as distinct from absorption, where they are taken up into a material.
alkaloid: A nitrogen-containing plant compound, often strongly active in the body.
alkylamide: A type of lipid-soluble plant compound built around a fatty acid chain linked to an amine group.
allantoin: A plant compound that promotes skin cell growth and is used to support wound healing.
allicin: The sulfur compound formed when fresh garlic is crushed.
alliin: An odorless sulfur-containing compound stored in intact garlic cells.
alliinase: An enzyme released when garlic is cut or crushed that converts alliin into allicin.
alpha-amylase: A digestive enzyme, found in saliva and the pancreas, that breaks starch down into sugars.
alpha-linolenic acid: A plant-based omega-3 fatty acid found in flaxseed and other seeds and oils.
alpha-pinene: A minor aromatic terpene compound found in eucalyptus and other conifer-family oils.
analgesic: Something that relieves pain.
anethole: The main aromatic compound in fennel and anise oil, responsible for their licorice-like scent.
anthocyanin: A class of purple-red plant pigments with antioxidant activity, abundant in elderberries.
antiemetic: A substance that prevents or reduces nausea and vomiting.
antigen: A substance the immune system recognizes and can mount a response against, such as a pollen protein.
antimicrobial: Active against microbes such as bacteria or fungi.
antiplatelet: Describes an effect that reduces the tendency of blood platelets to clump together and form clots.
antispasmodic: Reducing muscle spasm, particularly of the smooth muscle in the gut wall.
antitussive: Something that calms or suppresses coughing.
anxiolytic: Something that reduces anxiety.
apigenin: A calming flavonoid found in chamomile.
apoptosis: A form of programmed cell death the body uses to remove damaged or unneeded cells.
arabinose: A simple sugar commonly found in plant mucilage and fiber structures.
arabinoxylan: A soluble plant fiber made of linked sugar units that forms a thick gel in water.
arctigenin: A lignan compound derived from burdock, studied in laboratory settings for anti-inflammatory activity.
ascorbic acid: The chemical name for vitamin C, a water-soluble vitamin required for collagen synthesis and antioxidant function.
astragaloside: One of a group of triterpenoid compounds found in astragalus root, studied for antioxidant and immune-related effects.
astringent: Causing tissue to contract or tighten, often reducing weeping or minor bleeding.
aucubin: An iridoid glycoside found in eyebright and related plants, studied for anti-inflammatory and antimicrobial properties.
autogenic inhibition: A reflex in which rising tension detected by the Golgi tendon organ causes the same muscle to relax.
avenanthramide: A phenolic compound unique to oats that has shown anti-inflammatory and antioxidant activity in laboratory studies.

B

bacteriocin: A protein made by one bacterium that inhibits or kills competing bacterial strains.
beeturia: The harmless passing of red or pink urine after eating beetroot, caused by excretion of betalain pigments.
benign prostatic hyperplasia: A common, non-cancerous enlargement of the prostate gland.
benzodiazepine-binding site: A specific site on the GABA-A receptor where certain calming drugs, and some plant compounds, can attach to enhance the receptor's effect.
berberine: A yellow alkaloid found in goldenseal and related plants with documented antimicrobial activity in laboratory studies.
beta-carotene: An orange plant pigment that the body can convert into vitamin A.
beta-glucan: A soluble fiber polysaccharide found in oats and some other grains, known for forming a gel-like texture in water.
beta-sitosterol: A plant sterol structurally similar to cholesterol that can reduce cholesterol absorption in the gut.
betalain: A class of red and yellow pigment compounds found in beetroot and related plants.
bile acid: A compound made by the liver from cholesterol and released into the gut to help digest fat; some fibers bind bile acids and carry them out of the body.
bioavailability: How much of a substance actually reaches the bloodstream in active form.
biofilm: A protective layer formed by communities of bacteria that increases their resistance to antimicrobial agents.
blood-brain barrier: A selective boundary of tightly joined cells that limits which substances can pass from the bloodstream into brain tissue.
boswellic acid: A class of resin compounds from Boswellia trees studied for anti-inflammatory activity.
bulk-forming laxative: A fiber-based laxative that works by adding volume and water to stool rather than by chemical stimulation.
butyrate: A short-chain fatty acid produced when gut bacteria ferment fiber, used as fuel by cells lining the colon.

C

calcidiol: The storage form of vitamin D circulating in blood, measured by lab tests to assess vitamin D status.
calcitriol: The fully activated hormone form of vitamin D that acts on the intestine, bone, and immune cells.
capsaicin: The compound responsible for the burning heat of chili peppers, including cayenne.
carminative: Something that eases gas and cramping in the digestive tract.
carnosic acid: An antioxidant compound found in sage and rosemary.
carotenodermia: A harmless yellow-orange skin discoloration caused by high intake of carotenoid pigments such as beta-carotene.
carotenoid: A class of yellow, orange, and red plant pigment compounds, some of which the body can convert to vitamin A.
casein: The main protein found in dairy milk.
catecholamine: A family of stress-and-arousal hormones and neurotransmitters, including epinephrine and norepinephrine, released during physical or emotional exertion.
chelate: To bind a mineral ion tightly, as certain plant compounds do to iron and zinc in the gut.
chemoreceptor trigger zone: A region in the brainstem that detects chemical signals in the blood and can initiate vomiting.
chemotaxis: The directed movement of cells, such as immune cells, toward a chemical signal.
chemotype: A chemically distinct variant within a plant species that produces a different balance of compounds.
chlorogenic acid: A phenolic acid found in dandelion and coffee, studied for antioxidant and mild choleretic activity.
choleretic: Describing a substance that increases the production or flow of bile from the liver.
cholinesterase: An enzyme that breaks down the neurotransmitter acetylcholine, relevant to nerve signaling and memory.
chrysin: A flavonoid in passionflower studied for its interaction with GABA-A receptors in the brain.
circadian rhythm: The roughly 24-hour internal clock that governs sleep-wake timing and many other body functions.
citral: A lemon-scented volatile compound made up of two related molecules, geranial and neral.
clear liquid diet: A short-term eating pattern limited to transparent fluids that leave little residue in the digestive tract.
cobalamin: The chemical name for vitamin B12.
coenzyme: A small molecule that binds to an enzyme and is required for it to function.
cohort study: A type of research that follows a group of people over time to see how their habits relate to health outcomes, without controlling who does what.
collagen: A structural protein that forms much of the body's connective tissue, skin, and blood vessel walls.
colloidal: Describes particles ground fine enough to stay suspended evenly in a liquid rather than settling out.
colonic fermentation: The bacterial breakdown of undigested fiber in the large intestine, producing gas and short-chain fatty acids.
colonocyte: A cell lining the inner surface of the colon.
conductive heat: Heat transferred by direct contact between a warm object and the skin, as opposed to heat delivered by light or air.
conjunctival: Relating to the conjunctiva, the thin clear membrane covering the white of the eye and inner eyelid.
contact dermatitis: A skin reaction, such as redness or irritation, caused by direct contact with a substance.
contrast hydrotherapy: Alternating hot and cold water application to a body part, used to influence local blood flow.
cortisol: A hormone involved in the stress response and in the body's natural wake-up signal each morning.
cucurbitacin: A bitter triterpenoid compound found in pumpkin seed, studied for anti-parasitic activity.
curcumin: The yellow pigment in turmeric, the most-studied of its active compounds.
cutaneous: Relating to the skin.
cyanogenic glycoside: A plant compound that can release cyanide compounds when broken down, present in raw elderberry parts and destroyed by cooking.
cyclooxygenase: An enzyme involved in producing inflammatory signaling compounds called prostaglandins.
cytokine: A signaling protein immune cells use to talk to each other.
cytokinin: A class of plant hormone that regulates cell division and growth; present in small amounts in coconut water.
cytotoxic: Toxic or damaging to living cells.

D

dark adaptation: The process by which the eyes become more sensitive to light in dim conditions.
defunctionalization: A temporary reduction in a nerve fiber's responsiveness after repeated or intense stimulation.
demulcent: A substance that forms a soothing, protective film over an irritated mucous membrane.
dental pulp: The soft inner tissue of a tooth, containing nerves and blood vessels.
diallyl disulfide: One of several sulfur compounds formed as allicin breaks down after garlic is crushed.
distal nephron: The final segment of the kidney's filtering unit, where fine adjustments to sodium and potassium balance occur.
diuretic: Something that increases urine output.
dose-dependent: An effect that grows or shrinks with the amount taken.

E

edema: Swelling caused by excess fluid accumulating in tissue.
effleurage: A light, gliding massage stroke often used to warm tissue at the start of a session.
eicosanoid: A signaling molecule derived from fatty acids that plays a role in inflammation and other physiological processes.
electrolyte: A mineral that carries an electric charge in body fluids and is needed for functions like nerve signaling and muscle contraction.
ellagitannin: A polyphenol compound found in walnuts and certain fruits, broken down by gut bacteria into urolithins.
emollient: A substance that softens and soothes the skin or other surface tissue.
endorphin: A naturally produced brain chemical that binds opioid receptors and is associated with pain relief and improved mood, notably during exercise.
endothelial function: How well the thin layer of cells lining blood vessels performs its role in regulating blood flow and clotting.
endothelium: The thin layer of cells lining the inside of blood vessels.
entero-salivary pathway: The route by which dietary nitrate is processed by oral bacteria and the gut before conversion to nitric oxide.
enterolignan: A compound produced by gut bacteria from plant lignans, such as those in flaxseed.
epithelial cell differentiation: The process by which unspecialized cells mature into the specific lining cells of tissues such as skin or gut.
equol: A compound some gut bacteria produce from the soy isoflavone daidzein, with stronger estrogenic activity than its source.
estragole: A minor aromatic compound found in fennel and some other herbs, shown to be genotoxic and carcinogenic in rodent studies at high doses.
estrogen receptor: A protein inside cells that binds estrogen or estrogen-like compounds and triggers hormone-related changes in gene activity.
eugenol: The main aromatic compound in clove oil, responsible for its numbing and antimicrobial effects.
expectorant: Something that helps loosen and clear mucus from the airways.

F

faradiol: A triterpenoid compound found in calendula flowers, esters of which are linked to its anti-inflammatory activity.
fenchone: A minor aromatic compound in fennel oil, contributing to its characteristic smell.
ferritin: A protein that stores iron inside cells and is used as a lab marker of the body's iron reserves.
fibroblast: A skin cell type responsible for producing collagen and connective tissue during wound healing.
flavonoid: A large family of plant pigments, many studied for antioxidant activity.
flavonolignan: A class of plant compounds combining flavonoid and lignan chemical structures.
food challenge: A controlled, staged reintroduction of a food used to confirm or rule out a reaction.
formononetin: An isoflavonoid compound found in astragalus with weak estrogen-like activity, studied for antioxidant properties.

G

gaba transaminase: An enzyme that breaks down GABA, the brain's main calming neurotransmitter.
gaba-a receptor: A receptor in the brain and nervous system that, when activated, produces a calming, inhibitory effect on nerve activity.
galacturonic acid: A sugar acid that forms part of the backbone of slippery elm's mucilage polysaccharide.
gallic acid: A plant-derived acid that is a building block of many tannins and has antioxidant properties.
gamma-aminobutyric acid (gaba): The brain's main inhibitory neurotransmitter, associated with calming and sedative effects.
gamma-carboxylation: A vitamin K-dependent chemical modification required to activate several blood-clotting proteins.
gamma-linolenic acid: An omega-6 fatty acid, found in spirulina and a few other plant sources, studied for its role in anti-inflammatory signaling pathways.
gastric emptying: The rate at which food or liquid moves out of the stomach into the small intestine.
gate-control mechanism: A theory describing how certain sensory input, such as warmth, can reduce the perception of pain signals in the nervous system.
gate-control theory: A model describing how certain nerve signals can block pain signals from reaching the brain.
genistein: The main isoflavone in soy, studied for its weak estrogen-receptor-binding activity.
gingerol: The pungent active compound family in fresh ginger.
gingivitis: Inflammation of the gums, typically caused by bacterial buildup.
glucose oxidase: An enzyme in honey that slowly produces hydrogen peroxide when the honey is diluted with moisture.
glucosinolate: A sulfur-containing plant compound, found in cruciferous vegetables, that is converted to isothiocyanates when plant tissue is damaged.
glycemic response: How much and how quickly blood sugar rises after eating or after a metabolic intervention.
glycoprotein: A protein molecule with sugar chains attached, often involved in cell signaling and immune recognition.
glycoside: A compound in which a sugar is bonded to another active molecule; the body often splits it to release the active part.
glycyrrhetinic acid: The active metabolite of glycyrrhizin responsible for licorice's hormone-like physiological effects.
glycyrrhizin: The primary sweet-tasting saponin compound in licorice root, metabolized by gut bacteria into glycyrrhetinic acid.
golgi tendon organ: A sensory receptor in tendons that detects muscle tension and can trigger reflex relaxation of the muscle.
gut-associated lymphoid tissue: Clusters of immune tissue embedded in the intestinal wall that sample gut contents and coordinate immune responses.

H

hamamelitannin: A tannin compound characteristic of witch hazel, contributing to its astringent, protein-binding action.
heart rate variability: The natural beat-to-beat variation in heart rate, used as an indirect marker of nervous-system balance between stress and relaxation states.
hemoglobin: The iron-containing protein in red blood cells that carries oxygen through the bloodstream.
hemorrhoidectomy: A surgical procedure to remove hemorrhoids.
hepatocyte: A liver cell, the main functional cell type of the liver.
hexose: A simple sugar built on six carbon atoms (glucose is one).
histamine: A chemical released by the immune system that triggers itching, swelling, and other allergic-type responses.
hmg-coa reductase: An enzyme the body uses to manufacture cholesterol, and the target that statin medications block.
homocysteine: An amino acid whose blood levels rise when B-vitamin metabolism is impaired.
hydrastine: An alkaloid found in goldenseal root, historically noted for mild vasoconstrictive effects.
hydrostatic pressure: The pressure a fluid exerts due to gravity and pumping force, such as blood pressure within veins and capillaries.
hydroxytyrosol: A phenolic antioxidant compound found in olive oil, related to oleuropein.
hyperemia: An increase in blood flow to a tissue, such as the reddening seen after heat application to skin.
hypertonic: Describing a solution with a higher concentration of dissolved particles than the fluid inside nearby cells, which draws water out of them.
hypothalamic-pituitary-adrenal axis: The signaling pathway linking the brain and adrenal glands that governs the body's stress-hormone response.

I

ige-mediated: An immune reaction driven by antibody type E, associated with rapid-onset classic allergic responses.
in vitro: Observed in laboratory glassware or cell cultures, not in a living body.
in vivo: Observed in a living organism.
innate immune: Relating to the body's fast, nonspecific first-line immune defenses, as opposed to the slower, pathogen-specific adaptive immune response.
insoluble fiber: Plant fiber that does not dissolve in water and adds bulk to stool, helping move waste through the colon.
interstitial fluid: The fluid that surrounds and bathes cells in body tissue, outside the blood vessels.
intracellular cation: A positively charged ion, such as potassium, found mainly inside rather than outside cells.
inulin: A fermentable, prebiotic fiber (a fructan-type polysaccharide) concentrated in dandelion root.
iridoid: A class of plant compounds, including nepetalactone, often found in aromatic volatile oils.
iridoid glycoside: A class of plant compounds, including aucubin and catalpol, associated with anti-inflammatory and antimicrobial activity.
ischemia: A restriction of blood supply to tissue, reducing oxygen and nutrient delivery.
isoflavone: A type of plant compound, abundant in soy, with a chemical structure similar to estrogen.
isoquinoline alkaloid: A class of plant alkaloids sharing a specific two-ring chemical structure, including berberine and hydrastine.
isothiocyanate: A class of compounds, such as sulforaphane, produced from glucosinolates and studied for effects on the body's detoxification enzymes.
isotonic: Having a similar concentration of dissolved particles to blood plasma, so fluid moves in and out of cells without a net shift.

K

keratin: A tough structural protein that makes up the outer layer of skin, hair, and nails.
keratinocyte: The main type of cell found in the outer layer of skin.

L

lactase: A digestive enzyme that breaks down lactose, the sugar found in milk.
ldl cholesterol: A cholesterol-carrying particle in blood often called 'bad cholesterol' because higher levels are linked to cardiovascular disease risk.
leukotriene: An inflammatory mediator involved in recruiting immune cells to a site of injury or irritation.
lignan: A class of plant compounds, concentrated in flaxseed, that gut bacteria convert into weakly estrogen-like molecules.
limbic system: A group of interconnected brain structures involved in emotion and the sense of smell.
linalool: A fragrant monoterpene compound and a major component of lavender essential oil.
linalyl acetate: An ester compound and major component of lavender oil, related to linalool.
lipid peroxidation: A damaging chain reaction in which reactive molecules degrade the fatty components of cell membranes.
lipophilic: Able to dissolve in fats and oils rather than water, which affects how a compound crosses cell membranes.
luminal: Relating to the lumen, the open interior space of a hollow organ such as the intestine.
lutein: A carotenoid pigment from leafy greens that concentrates in the retina of the eye.
lymphatic flow: The movement of lymph fluid through the body's lymphatic vessels, which helps clear tissue fluid and support immune function.

M

macrophage: A white blood cell that engulfs pathogens and debris as part of the immune response.
macula: The central part of the retina responsible for sharp, detailed vision.
macular pigment: The yellow pigment, made largely of lutein and related carotenoids, concentrated in the central retina.
malic acid: A tart organic acid found in apples and other fruits, present in smaller amounts in vinegar.
mast cell: An immune cell that releases histamine and other inflammatory mediators during allergic reactions.
matrix metalloproteinase: An enzyme that breaks down proteins in connective tissue, active in tissue remodeling and inflammation.
mechanoreceptor: A nerve ending that responds to physical pressure or stretch.
medium-chain triglyceride: A type of fat made of shorter carbon chains than most dietary fats, which the body absorbs and processes somewhat differently.
melatonin: A hormone released by the pineal gland in response to darkness that signals the body it is time to sleep.
menthol: The main cooling, minty-smelling compound in peppermint oil.
methylation: A chemical reaction that adds a small carbon-based group to a molecule, used throughout metabolism and gene regulation.
methylglyoxal: A reactive compound found at high levels in some honeys, particularly manuka, associated with added antibacterial activity.
methylpentose: A five-carbon sugar carrying an extra methyl group -- a common building block of plant mucilage.
microcystin: A toxin sometimes produced by cyanobacteria under certain growing conditions, relevant to spirulina quality control.
mineralocorticoid: A class of hormone, such as aldosterone, that regulates sodium and potassium balance in the body.
monoamine oxidase: An enzyme that breaks down neurotransmitters such as serotonin; its inhibition can alter mood-related brain chemistry.
monoterpene: A class of small, volatile plant compounds built from two isoprene units, common in essential oils.
mucilage: A thick, slippery gel of long-chain sugars that some plants produce; it coats and soothes tissue.
mucoadhesive: Able to physically adhere to and coat a mucous membrane surface.
mucociliary clearance: The process by which tiny hair-like cilia sweep mucus and trapped particles out of the airway.
mucolytic: Describing a substance that thins or breaks down mucus.
mucosal / mucosa: The moist tissue lining body cavities and passages, such as the throat.
mucous membrane: The moist lining of the mouth, throat, stomach, gut, and other passages.
muscarinic acetylcholine receptor: A type of receptor for the signaling molecule acetylcholine, involved in memory and other functions.
muscle spindle: A sensory receptor inside muscle tissue that detects changes in muscle length and speed of stretch.
myelin: The fatty sheath that insulates nerve fibers and speeds electrical signaling.
myelin sheath: The fatty insulating layer that wraps nerve fibers and speeds up electrical signaling along them.

N

nasal airway resistance: A measurable value of how much the nasal passages resist airflow during breathing.
nepetalactone: The main volatile compound in catnip, well known for its effect on cats and little investigated in humans.
nerve conduction velocity: The speed at which electrical signals travel along a nerve, including pain signals.
neural tube defect: A birth defect of the brain or spinal cord that can result from inadequate folate intake in early pregnancy.
neutrophil: A type of white blood cell that is among the first immune cells to respond to infection.
nf-kappa b: A protein complex inside cells that switches on genes involved in immune and inflammatory responses.
nf-κb: A protein complex that switches on genes for inflammation-related molecules inside cells.
nitrate: A nitrogen-containing compound found in leafy greens that can be converted in the body to nitric oxide.
nitric oxide: A gas molecule made by blood vessel lining cells that relaxes surrounding muscle and widens the vessel.
nitric oxide synthase: An enzyme that produces nitric oxide, a molecule involved in blood-vessel dilation and inflammatory signaling.
nitrite: A nitrogen-containing compound formed from nitrate that serves as an intermediate step toward nitric oxide production.
nmda receptor: A nerve-cell receptor involved in transmitting excitatory signals; its activity is influenced by calcium and magnesium ion levels.
nociceptive: Relating to the nerve fibers and pathways that detect and transmit pain signals.
non-heme iron: Plant-based dietary iron, which is less readily absorbed than the iron found in animal tissue.
nuclear receptor: A protein inside a cell's nucleus that, when activated by a hormone, turns specific genes on or off.

O

occlusive: A substance that forms a physical film on the skin to reduce water evaporation from its surface.
oleic acid: A monounsaturated fatty acid found in high amounts in avocado and olive oil.
oleocanthal: A pungent phenolic compound in extra-virgin olive oil with enzyme-inhibiting, anti-inflammatory activity.
oleuropein: A bitter phenolic compound in olives and olive oil studied for antioxidant activity.
olfactory receptor: A sensory protein in the nose that detects specific smell molecules.
one-carbon metabolism: A network of biochemical reactions, dependent on folate and related nutrients, needed for DNA synthesis and cell division.
onychomycosis: A fungal infection of the nail.
oral food challenge: A supervised, structured procedure of reintroducing a food to confirm or rule out a suspected food allergy.
oral immunotherapy: Gradual, repeated oral exposure to an allergen intended to build tolerance over time.
oral rehydration solution: A precisely balanced mixture of water, salts, and sugar designed to replace fluids and electrolytes lost through illness.
organosulfur compound: A chemical compound in which sulfur is bonded to carbon, a class especially common in garlic and other allium plants.
osmolality: A measure of how concentrated a fluid is, based on the number of dissolved particles it contains.
osmotic gradient / osmosis: The tendency of water to move across a membrane toward the side with a higher concentration of dissolved particles.

P

p-fimbriae: Hair-like protein structures on certain bacteria that let them attach to cell surfaces such as the bladder wall.
parasympathetic nervous system: The branch of the autonomic nervous system that promotes rest, digestion, and recovery, generally acting opposite to the fight-or-flight sympathetic branch.
pentose: A simple sugar built on five carbon atoms.
perineal: Relating to the perineum, the area of the body between the anus and the genitals.
peristalsis: The wave-like muscle contractions that move food through the digestive tract.
petrissage: Kneading strokes that lift and squeeze muscle tissue.
petrolatum: A semi-solid petroleum-derived substance widely used as a skin-protecting moisturizer base, also known as petroleum jelly.
phagocytic: Describes an immune cell's ability to engulf and destroy bacteria, debris, or other foreign particles.
phagocytosis: The process by which a cell engulfs and digests particles such as bacteria or debris.
phenolic: A broad class of plant compounds, many with antioxidant activity.
phycocyanin: A blue pigment-protein complex found in spirulina, studied for antioxidant and anti-inflammatory activity.
phylloquinone: The chemical name for vitamin K1, the form of vitamin K found in leafy green vegetables.
phytic acid: A compound in seeds and grains that binds minerals such as iron and zinc, reducing their absorption.
phytoestrogen: A plant compound that can weakly bind to and activate estrogen receptors in the body.
phytosterol: A plant-derived compound structurally similar to cholesterol, studied for effects on prostate tissue and blood lipids.
plasma volume: The amount of the liquid, non-cell portion of blood circulating in the body.
platelet aggregation: The clumping together of platelets in blood, an early step in clot formation.
polyphenolic: Belonging to polyphenols, a large family of plant compounds built from multiple linked phenol rings, many with antioxidant activity.
polysaccharide: A large molecule made of many sugar units linked together.
polysomnography: An overnight recording of brain waves, breathing, and other signals used to study or diagnose sleep disorders.
positive inotropic: Describing an effect that increases the force of heart muscle contraction.
postprandial: Occurring after a meal, as in blood sugar levels measured after eating.
prebiotic: A dietary substance that selectively nourishes beneficial gut bacteria.
proanthocyanidin: A type of plant flavonoid compound formed from linked units, studied for anti-adhesive and antioxidant activity.
procyanidin: A class of plant flavonoid compounds made of linked catechin units, related to proanthocyanidins.
prolyl hydroxylase: An enzyme, dependent on vitamin C, that helps stabilize the structure of collagen.
prostaglandin: A short-lived local messenger molecule involved in inflammation, pain, and many normal functions.
pseudoaldosteronism: A condition mimicking excess aldosterone hormone activity, marked by sodium retention, potassium loss, and high blood pressure.
pterostilbene: A stilbene compound related to resveratrol, found in blueberries and studied for antioxidant activity.
pyrolysis: Heating a material at high temperature without much oxygen so it chemically breaks down, here used to produce raw charcoal.
pyrrolizidine alkaloid: A class of plant alkaloids, present in comfrey and some other plants; the 1,2-unsaturated forms can damage the liver when absorbed into the body.

R

reactive oxygen species: Unstable oxygen molecules that damage cells when they build up -- what antioxidants neutralize.
relative humidity: The amount of water vapor in the air compared to the maximum the air could hold at that temperature.
renin-angiotensin-aldosterone system: A hormonal signaling system that regulates blood pressure and fluid balance via the kidneys.
resistant starch: A type of starch that resists digestion in the small intestine and instead reaches the colon, where gut bacteria ferment it.
resting membrane potential: The baseline electrical charge difference across a cell membrane that allows nerve and muscle cells to fire.
retinal: An intermediate compound in the conversion of beta-carotene to active vitamin A, also involved directly in vision.
retinoic acid: An active form of vitamin A involved in cell growth and differentiation.
rhamnose: A simple sugar that is a component of the mucilage found in slippery elm bark.
rhodopsin: A light-sensitive pigment in the retina's rod cells that is essential for vision in low light.
rod photoreceptor: A type of light-sensing cell in the retina specialized for vision in low light rather than color.
rosmarinic acid: A phenolic plant compound with antioxidant and anti-inflammatory activity.

S

salicin: A compound in willow bark that the body converts to salicylic acid, aspirin's relative.
saponin: A plant compound that foams in water and can affect cholesterol absorption and immunity.
sarcomere: The basic repeating contractile unit inside a muscle fiber.
satiety: The feeling of fullness that follows eating, which influences how much is eaten afterward.
sebum: The oily substance produced by skin glands that lubricates skin and hair follicles.
sesquiterpene: A class of plant compounds built from three linked isoprene units, common in aromatic and medicinal plants.
sesquiterpene lactone: A bitter-tasting class of plant compounds, found in dandelion and related plants, linked to digestive-stimulating effects.
short-chain fatty acid: A small fatty acid molecule (such as butyrate) produced when gut bacteria ferment fiber, used as fuel by colon cells and studied for broader metabolic effects.
silibinin: The principal and most-studied active compound within silymarin, also called silybin.
silymarin: The mixture of flavonolignan compounds extracted from milk thistle seed.
singlet oxygen: A reactive, high-energy form of oxygen that can damage cells and is neutralized by certain antioxidants.
skin protectant: An FDA regulatory category for ingredients that form a barrier to protect irritated skin from further damage.
sleep latency: The amount of time it takes to fall asleep after lying down to sleep.
smooth muscle: The involuntary muscle lining organs such as the intestine, as opposed to the muscle that moves the skeleton.
sodium bicarbonate: The chemical name for baking soda, a mildly alkaline compound.
soluble fiber: Plant fiber that dissolves in water to form a gel, slowing digestion and affecting cholesterol and blood sugar absorption.
stat3: A signaling protein inside cells that, once activated, turns on genes linked to cell growth and division.
steroidal lactone: A ring-shaped organic compound with a steroid-like structure, the chemical class withanolides belong to.
stratum corneum: The tough outermost layer of skin that acts as the body's main barrier to substances entering from outside.
substance p: A signaling molecule released by nerves that helps transmit pain signals to the central nervous system.
sulfhydryl group: A chemical group containing sulfur and hydrogen that many reactive plant sulfur compounds interact with.
surface area: The total exposed area of a material's surface, including its internal pores, which determines how much it can adsorb.
synovial fluid: The lubricating fluid found inside joints that reduces friction between cartilage surfaces.

T

t-cell: A type of white blood cell that helps direct and carry out the body's immune responses.
tannin: A plant compound with a drying, tightening (astringent) action on tissue.
tapotement: Rhythmic tapping or percussion strokes used in massage.
terpinen-4-ol: The main active monoterpene compound in tea tree oil, credited with most of its antimicrobial activity.
thermoregulation: The body's set of processes for maintaining a stable internal temperature.
thromboxane: A signaling molecule produced from fatty acids that promotes blood platelet clumping and vessel constriction.
thujone: A volatile oil compound found in sage and a few other herbs that can affect the central nervous system at high exposure.
tocopherol: One of several related forms of vitamin E, a fat-soluble antioxidant vitamin.
tocotrienol: A less common form of vitamin E, structurally related to tocopherols.
transcription factor: A protein that binds DNA and controls whether nearby genes are turned on or off.
transdermal: Describes a substance passing through the skin into underlying tissue or the bloodstream.
transepidermal water loss: The natural evaporation of water from inside the skin through to the outside air.
trichome: A small hair-like structure on a plant's surface; in nettle, these contain irritant compounds that cause a stinging sensation on contact.
triterpenoid: A class of plant compounds built from six isoprene units, including many saponins and related esters.
trpm8: A nerve receptor that responds to cold temperature and to menthol, producing a cooling sensation.
trpv1: A nerve receptor that responds to heat and to capsaicin, producing the sensation of burning.
tumor necrosis factor (tnf-alpha): A signaling protein released by immune cells that drives inflammation.
tumor necrosis factor-alpha: A cytokine that acts as a major signaling driver of inflammation in the body.

U

urolithin: A compound produced when gut bacteria metabolize ellagitannins, studied for antioxidant and anti-inflammatory activity.
uropathogenic: Describing a microorganism capable of causing infection in the urinary tract.
urothelium: The specialized tissue lining the inner surface of the bladder and urinary tract.
urushiol: The oily resin in poison ivy and related plants responsible for triggering allergic skin reactions.

V

vagal tone: A measure of activity in the vagus nerve, the main channel of the parasympathetic ('rest and digest') nervous system; higher vagal tone is linked to calmer heart rhythm and slower stress recovery time.
valepotriate: An unstable class of iridoid compounds found in fresh valerian root, studied for mild sedative activity.
valerenic acid: A sesquiterpene compound in valerian root studied for its activity at GABA-A receptors in the brain.
van der waals forces: Weak physical attractions between molecules that allow substances to stick to a surface like activated carbon.
vascular endothelial function: The health and responsiveness of the cells lining blood vessels, often used as a marker of cardiovascular health.
vasoconstriction: The narrowing of blood vessels, which reduces blood flow to the surrounding tissue.
vasodilation: The widening of blood vessels, which increases blood flow to the surrounding tissue.
venous return: The flow of blood back toward the heart through the veins.
verbascoside: A phenylethanoid glycoside compound found in mullein and other plants, studied for antioxidant activity.
viscoelastic: Describes a material that shows both fluid-like (viscous) and solid-like (elastic) behavior when stretched, so it deforms under load and only partly springs back.
vitexin: A flavonoid compound found in hawthorn and other plants.
volatile oil: The aromatic, easily-evaporating oil fraction of a plant -- what you smell.
voltage-gated sodium channel: A protein in nerve cell membranes that controls the electrical signal underlying pain transmission.

W

washout period: A time interval used to let a substance or its effects clear from the body before further testing.
water activity: A measure of how much water in a substance is available for microbial growth; low water activity discourages bacteria.
wind-pollinated: Describing pollen spread by air currents rather than insects; typically lighter and more likely to trigger hay fever.
withaferin a: A specific withanolide compound studied for anti-inflammatory and stress-axis activity.
withanolide: A class of naturally occurring steroid-like compounds found in ashwagandha and related plants.

X

xerophthalmia: A progressive eye condition caused by vitamin A deficiency, beginning with night blindness and dryness.

Z

zeaxanthin: A carotenoid, related to lutein, that concentrates in the retina and is studied for eye health.

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