Antioxidant and antimicrobial activities of Bauhinia racemosa L. stem bark

The present study was carried out to evaluate the antioxidant and antimicrobial activities of a methanol extract of Bauhinia racemosa (MEBR) (Caesalpiniaceae) stem bark in various systems. 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical, superoxide anion radical, nitric oxide radical, and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract. The antioxidant activity of the methanol extract increased in a concentration-dependent manner. About 50, 100, 250, and 500 æg MEBR inhibited the peroxidation of a linoleic acid emulsion by 62.43, 67.21, 71.04, and 76.83 percent, respectively. Similarly, the effect of MEBR on reducing power increased in a concentration-dependent manner. In DPPH radical scavenging assays the IC50 value of the extract was 152.29 æg/ml. MEBR inhibited the nitric oxide radicals generated from sodium nitroprusside with an IC50 of 78.34 æg/ml, as opposed to 20.4 æg/ml for curcumin. Moreover, MEBR scavenged the superoxide generated by the PMS/NADH-NBT system. MEBR also inhibited the hydroxyl radical generated by Fenton's reaction, with an IC50 value of more than 1000 æg/ml, as compared to 5 æg/ml for catechin. The amounts of total phenolic compounds were also determined and 64.7 æg pyrocatechol phenol equivalents were detected in MEBR (1 mg). The antimicrobial activities of MEBR were determined by disc diffusion with five Gram-positive, four Gram-negative and four fungal species. MEBR showed broad-spectrum antimicrobial activity against all tested microorganisms. The results obtained in the present study indicate that MEBR can be a potential source of natural antioxidant and antimicrobial agents.

Antitumor activity of Hygrophila spinosa on Ehrlich ascites carcinoma and sarcoma-180 induced mice.

Petroleum ether extract from H. spinosa root exhibited antitumor activity in Ehrlich ascites carcinoma and Sarcoma-180 bearing mice Processed extract suppressed significantly the tumor fluid volume at the end of 3 weeks experiment. It decreased about 50% of packed cell volume and increased life span of EAC/S-180 bearing mice in a day dependent manner. Red blood cell count, hemoglobin content and white blood cell count were more or less normal after processed extract treatment of the tumor bearing mice. In tumor control animals, neutrophils increased (273.7% in EAC and 263.4% in S-180 bearing mice respectively with respect to normal mice) whereas lymphocytes decreased (60.0% in EAC and 56.5% in S-180 bearing mice respectively with respect to normal mice). It also inhibited the rapid increase of body weight of tumor bearing mice.

Effect of petroleum ether extract from Hygrophila spinosa on hematological parameters and hepatorenal functions in mice.

Multiple doses of H. spinosa were administered, ip once in a week for 4 weeks (20, 40 and 80 mg/kg body weight) and daily for one month (2, 4 and 8 mg/kg body weight). No alteration in biochemical parameters at low and moderate dose level of daily and low dose level of weekly treatment of petroleum ether extract was observed. However, the extract at moderate dose level in weekly treatment changed serum aminotransferase, alkaline phosphatase and plasma cholesterol significantly. High dose level of the extract changed all the above parameters of weekly treated mice including total bilirubin, nonprotein nitrogen, blood urea and plasma protein. High dose level of daily treatment and moderate and high dose level of weekly treatment of the root extract increased only the white blood cell count significantly. The results reveal that the weekly moderate and high dose (above 40 mg/kg body weight) and daily/therapeutic high dose (8 mg/kg) of the petroleum ether extract of H. spinosa affects liver and kidney functions and metabolism and hematological parameters whereas low weekly dose (20 mg/kg) and low and moderate daily/therapeutic dose (2 and 4 mg/kg) does not exhibit any appreciable toxic action.