TWI HERBAL MEDICINE GLOSSARY

Neem extracts have shown potential hypoglycaemic properties. Oral administration of the leaf
extracts reduced blood sugar levels in normal and streptozocin-induced of diabetic models, with the
hypoglycaemic effect comparable to glibenclamide (Khosla et al., 2000). The leaf extract blocked
the effects of adrenaline on glucose metabolism and reduced peripheral glucose utilization in
diabetic and normal rats (Chattopadhyay, 1996).

The anti-inflammatory properties of the plant have also been demonstrated in various studies. The water-soluble part of the alcoholic leaf extract showed anti-inflammatory activity in the cotton pellet granuloma assay in vivo (Chattopadhway, 1998). Neem extracts have shown a dose-dependent anti-gastric ulcer activity in stressed rats. The extracts also caused a decrease in ethanol-induced gastric mucosal damage, an increase in the amount of adherent gastric mucus in stressed animals, and showed significant anti-histaminic potential (Garg et al., 1993). Bandyopadhyay et al (2002) have investigated the gastroprotective properties of the stem bark extract of A. indica. The gastroprotective effect was attributed to the ability to inhibit acid secretion via blockage of H+/K+-ATPase activity as well as the inhibition of oxidative damage of the gastric mucosa by blocking lipid peroxidation and scavenging endogenous hydroxyl radicals.

Leaf extracts of A. indica exhibited significant immune-stimulating effects in vivo (Ray et al, 1996). A. indica potentiated the antibody titres following typhoid H. antigen immunization and induced delayed hypersensitivity following administration of tuberculin and DNCB to animals. In human trials, extracts stimulated humoral immunity by increasing antibody levels and cell-mediated immunity by increasing total lymphocyte and T-cell count in 21 days (Ansari et al., 1997). Aqueous leaf extract was found to lower raised levels of serum liver enzymes and paracetamol-induced liver necrosis (Bhanwra et al., 2000).