संस्कृत नाम- पलाण्डुः
Botanical name - Allium cepa
Description - Foetid scapigerous biennial bulbous herb; lower part of the plant swollen at maturity to form a large bulb, bulbs vary in size, colour (white, yellow, red, brown), shape (round, flat, conical), firmness, keeping quality, period of maturity and strength of flavour; leaves subdistichous, green, linear, fleshy, hoHow cylindrical; scape inflated; umbels bear flowers and bulbils; flowers pedicellate, white, trimerous; capsules 3-chambered containing small black seeds.
Chemical_Constituents- Fresh onion contains fructosan and also several oligosaccharides, several gama -glutamyl peptides. Bulbs contain essential oil known as Onion oil containing alkyl and trisulphides, several phenolic acids, cepanone, nor-cepanone, neodecanoic acid, flavonoids, calchrymatory principle thiopropanol-S-oxide. Onion juice contains several soluble carbohydrates and sugars. Leaves and flowers contain essential oil, quercetin, phenolic acids and sterol glycosides. Seeds contain fatty oil; alkaloid protoberberine Bharatamine, glycoside seposide D. Flavonoids in the bulb include quercetin-4'-glucoside, quercetin 3, 4'- diglucoside and possibly quercetin-3, 5-diglucoside and peonidin 3-glucoside and cyanidin-3-laminaribioside. Bulb - diphenylamine, steroid glycoside - alliospiroside B, phytoalexins. Roots contain flavone glycoside - isookanin-7-O-rhamnoside From lexicon Onion: 1.2% proteins, 11.6% carbohydrates, lesser than 1% fat, 0.18% Ca, 0.5% P.O., Fe, vitamins A, B and C; Bulb : caffeic acid, ferulic acid, polyphenols, protocatechuic acid, kaempferol, quercetin and its derivatives; Onion skin: kaempferol; Dried skin : quercetin, sterols, cholesterol, beta-sitosterol, stigmasterol; Bulb and Fresh herb; on steam distillation yield an essential oil, called onion oil, chief constituent of onion oil-various mono-, di-, tri- and tetra-sulphides, thiols and thiophene derivatives.
Uses - SANTAL : bulb-paste with that of black pepper in malarial fever; BHOXA (a tribe of Garhwal): Fresh onion-paste : on blister, boils, eye complaints; TRIBES OF SAGAR DISTRICT (Madhya Pradesh) : Bulb as diuretic, expectorant, rubifacient, skin diseases, sedative, in insect bites, wounds; Bulb-juice : applied in bleeding from nose, ear complaints, in vomiting and on piles; RURAL FOLK OF INDIA : fresh onion in faintness, convulsions, epileptic fits, applied on insect sting and circular alopecia; Seed-paste (with that of root of Punica granatum, Cajanus cajan, Piper rubrum and honey) is given for abortion. UPAVARHANA SAMHITA : Stem delicious, energiser, stimulant; CHARAKA SAMHITA and SHUSHRUTA SAMHITA : destroyer of wind, stimulant, helps in digestion but increases bile and phlegm; AYURVEDA : Tuber is aphrodisiac, pungent, taste-improver, tonic useful in biliousness, bleeding piles, body pain, tumours, vomiting; Seed: fattening, useful in caries of teeth and urinary discharges. UNANI : Bub is appetiser, pungent, stomachic, tonic, used in asthma, spleen disorders, vomiting, scabies, piles and night blindness. HOMEOPATHY : For different ailments of eye, conjuctivitis and for relaxation of colic pains. Modern use: Bulb: antimalarial, antirheumatic, antidiabetic, antibacterial, antiatherogenic, antihypertensive, diuretic, expectorant, stimulant, useful in flatulence and dysentery, hypocholesteremic. increases clotting time and fibrinolytic activity in man; Onion without peel: remedy for circular alopecia; Onion-extract: reduces blood sugar.