This herb is approved for mucosal inflammation therapy and to reduce the tendency toward infection. In Asian medicine it treats wounds fungal, bacterial, and helminthic infections. The active compounds include alliins (alkylcysteine sulphoxides), polysaccharides, saccharose, flavonoids, and steroid saponins. In addition to anti-inflammatory effects, this herb inhibits gram-negative bacteria and thrombocytes and has anti-allergic effects. Onion rarely produces contact irritant reactions.
This herb effectively modulates scars and keloid formation in two human trials when formulated with allantoin (16,17). In a study for treatment of patchy alopecia areata of 23 patients, re-growth of terminal coarse hairs started after two weeks of treatment with crude onion juice. At six weeks, the hair re-growth was observed in 20 patients. The tap – water-treated control group experienced hair re-growth in only two patients at eight weeks of treatment (p <0.0001) versus the onion juice group (47).