The in vitro antioxidant activity of the successive extracts (ethyl acetate, ethanol, methanol and water) of the leaves of Lagerstroemia speciosa L. (Lythraceae) were studied by examining their superoxide, hydroxyl ion scavenging and by measuring lipid peroxidation. The ethyl acetate and ethanol extracts were found to possess greater antioxidant property than the methanol and water extracts. Anti-inflammatory activity of the ethyl acetate and ethanol extracts were examined using the carrageenan-induced acute inflammation and formalin-induced (chronic) paw edema models. In acute and chronic inflammation models, the ethyl acetate extract reduced the paw edema significantly in a dose-dependent manner. Whereas, ethanol extract did not show dose-dependent activity. This results suggests that the anti-inflammatory activity is possibly attributed to its free radical scavenging activity. It was found that ethyl acetate extract reduced the inflammation more significantly than the ethanol extract.

We studied an ethyl acetate (EtoAC) extract of leaves obtained from the medicinal and ornamental tree, Lagerstroemia speciosa L, for nephroprotective activity in cisplatin-induced acute renal injury in Balb/C mice. The EtoAC extract at dose levels of 50 and 250 mg/kg showed a dose-dependent reduction in cisplatin-induced elevations in urea and creatinine concentrations. Additionally, treatment with the EtoAC extract prevented the cisplatin-induced decline of the renal antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and reduced glutathione. The findings suggest that the EtoAC extract from L. speciosa possesses marked nephroprotective activity and could offer a promising role in the treatment of acute renal injury caused by a nephrotoxin like cisplatin.

This study was carried out in order to investigate the potential and antioxidant effects of polyphenols from Mangifera indica stem bark against gastric damage induced by ethanol and cold-restraint stress. The polyphenols possess good capacity for scavenging nitric oxide (NO) radical and ferric-reducing antioxidant power (FRAP) assay in vitro. Rats were sacrificed after the experiment, and their stomachs were removed for biochemical and histopathological analysis. The severity of lesions was found to markedly decrease by the administration of polyphenols in both models. The increased gastric nitrite level of ethanol administered rats were significantly (p < 0.001) reduced by polyphenol treatment. Administration of polyphenols reduced thiobarbituric acid reactive substance (TBARS) level and increased the GSH level significantly in a dose-dependent manner in both models. Our study revealed the ulcer-protective effects of the polyphenols and could possibly reside for the most part on its anti-radical effects.

The aqueous and methanolic extract of a preparation; Diabo-SS (100 mg/kg b.wt) was administered to streptozotocin-induced diabetic animals. The aqueous Diabo-SS extract showed significantly (P < .001) higher anti-diabetic activity than the methanolic extract. Continuous administration of the aqueous extract of Diabo-SS reduced the plasma glucose level by 40% on 60th day. The tail flick latency (TFL) and gastric transit percentages were significantly higher in diabetic controls versus normal control animals.