Neem leaves mainly yield the flavanoid quercetin and nimbosterol as well as a number of limonoids. Quercetin, a polyphenolic flavonoid, is known to have antibacterial and antifungal properties.
The flowers also yield a waxy material consisting of several fatty acids. The bark contains various tannins in different forms. The seed is very important both because of its high lipid content and the presence of a large number of bitter principals such as azadirachtin, azadiradione, fraxinellone, nimbin, salannin, salannol, vepinina and vilasinin.
Skin disorders: Neem is mentioned in most Ayurvedic formulations for the treatment of skin disorders, because of its detoxifying properties. The growth of acne-causing bacteria such as propionibacterium acnes (P. acnes) and staphylococcus epidermidis is also inhibited by Neem. The role of Neem in acne is further supported by studies which have shown that it exhibits anti-inflammatory activity by suppressing P. acnes-induced reactive oxygen species (ROS) and the pro-inflammatory cytokines TNF-a and IL-8.
Gastrointestinal: The antioxidant, antisecretory and proton-pump inhibitory (reduction of gastric acid production) properties of the Neem leaf extract work as a gastroprotective and are effective in healing ulcers.
Acne vulgaris (pimples)
Skin allergies & infections