Antiinflammatory, analgesic and hypoglycemic effects of Mangifera indica Linn. (Anacardiaceae) stem-bark aqueous extract

Previous studies in our laboratories and elsewhere have shown that some members of Anacardiaceae family possess antiinflammatory, analgesic and hypoglycemic effects in man and mammalian experimental animals. The present study was, therefore, undertaken to examine the antiinflammatory, analgesic and antidiabetic properties of the stem-bark aqueous extract of Mangifera indica Linn., M. indica a member of the Anacardiaceae family, in rats and mice. The stem-bark powder of M. indica was Soxhlet extracted with distilled water and used. The analgesic effect of the plant's extract was evaluated by the hot-plate and acetic acid test models of pain in mice, while the antiinflammatory and antidiabetic effects of the stem-bark extract were investigated in rats, using fresh egg albumin-induced paw edema, and streptozotocin (STZ)-induced diabetes mellitus, respectively. Morphine (MPN, 10 mg/kg i.p.), diclofenac (DIC, 100 mg/kg i.p.), and chlorpropamide (250 mg/kg p.o.) were used respectively as reference analgesic, antiinflammatory, and hypoglycemic agents for comparison. M. indica stem-bark aqueous extract (MIE, 50-800 mg/kg i.p.) produced dose-dependent and significant (p < 0.05-0.001) analgesic effects against thermally and chemically induced nociceptive pain stimuli in mice. MIE (50-800 mg/kg i.p.) also significantly (p < 0.05-0.001) inhibited fresh egg albumin-induced paw edema, and caused significant (p < 0.05-0.001) hypoglycemic effects in rats. It is suggested that the analgesic effects of MIE (50-800 mg/kg i.p.) may be peripherally and centrally mediated. The different chemical constituents of the plant, especially the polyphenolics, flavonoids, triterpenoids, mangiferin, and other chemical compounds present in the plant may be involved in the observed antiinflammatory, analgesic, and hypoglycemic effects of the plant's extract. However, the results of this experimental animal study lend pharmacological credence to the suggested folkloric uses of the plant in the management and control of painful, arthritic and other inflammatory conditions, as well as in the management of adult-onset type 2 diabetes mellitus in some rural African communities.