Laizuman Nahar

Comparative study of antidiabetic activity of Cajanus cajan and Tamarindus indica in alloxan-induced diabetic mice with a reference to in vitro antioxidant activity

Background: Oxidative stress not only develops complications in diabetic (type 1 and type 2) but also contributes to beta cell destruction in type 2 diabetes in insulin resistance hyperglycemia. Glucose control plays an important role in the pro-oxidant/antioxidant balance. Some antidiabetic agents may by themselves have antioxidant properties independently of their role on glucose control. Objective: The present investigation draws a comparison of the protective antioxidant activity, total phenol content and the antihyperglycemic activity of the methanolic extract of Cajanus cajan root (MCC) and Tamarindus indica seeds (MTI). Materials and Methods: Antidiabetic potentials of the plant extracts were evaluated in alloxan-induced diabetic Swiss albino mice. The plant extracts at the doses of 200 and 400 mg/kg body weight was orally administered for glucose tolerance test during 1-hour study and hypoglycemic effect during 5-day study period in comparison with reference drug Metformin HCl (50 mg/kg). In vitro antioxidant potential of MCC and MTI was investigated by using 1, 1- diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity at 517 nm. Total phenolic content, total antioxidant capacity and reducing power activity was also assayed. Results: There was a significant decrease in fasting serum glucose level (P < 0.001), reduction in blood glucose level (P < 0.001) in 5-days study, observed in the alloxan-induced diabetic mice. The reduction efficacy of blood glucose level of both the extracts is proportional to their dose but MCC is more potent than MTI. Antioxidant study and quantification of phenolic compound of both the extracts revealed that they have high antioxidant capacity. Conclusion: These studies showed that MCC and MTI have both hypoglycemic and antioxidant potential but MCC is more potent than MTI. The present study suggests that both MCC and MTI could be used in managing oxidative stress.

Evaluation of Antioxidant and Antitumor Activities of Wrightia arborea

Wrightia arborea (Br.) (Family-Apocynaceae), locally known as Sathkurchi, is a small deciduous tree with small branches and densely velvety leaves. This study was designed to investigate the antioxidant and anti tumor activities of leaves of W. arborea. Antioxidant potential was evaluated in vitro by DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging- and reducing power- assay method which was concentration dependent that was 25-200 � g/ml. The extract showed scavenging activity with IC50 value of 15.23 ± 4.10 � g/ml for DPPH and also showed reducing activity in dose dependent manner. In addition, total phenol and flavonoid content were determined by Folin-Ciocalteu reagent and were found to be 112.54 ± 9.74 mg/g plant extract (in GAE) and 247.14 ± 15.45 mg/g plant extract (in quercetin equivalent), respectively. The antioxidant capacity was evaluated by phosphomolybdenum method and was found to be 117.27 ± 12.36 mg/g plant extract (in ascorbic acid equivalents). The anti tumor effect of the methanol extract was determined with doses of 5, 10 and 20 mg/kg b.wt against Ehrlich ascites carcinoma (EAC) in mice with respect to the determination of tumor volume, tumor weight, % of cell growth inhibition, % increase in life span (%ILS), and hematological parameter (WBC, RBC and hemoglobin). The methanol extract of W. arborea decreased the tumor weight significantly compared to control group at all the mentioned doses and the highest was observed at the dose of 20 mg/kg b. wt. (1.28 ± 0.15 g). The % of cell growth inhibition increased in dose dependent manner like 36.43 ± 7.45, 58.76 ± 9.43 and 98.43 ± 12.45 at the doses of 5, 10, 20 mg/kg b.wt. respectively. The %ILS was also enhanced in all the doses where 20 mg/kg b.wt showed maximum effect (105.5 ± 3.57). Heamoglobin (Hb) content was significantly increased 8.12 ± 2.6, 10.23 ± 1.62 and 12.12 ± 2.09 g/dL at the doses of 5, 10 and 20 mg/kg b.wt. respectively, compared to EAC control mice (4.95 ± 1.80 g). There was a significant (p< 0.05, p< 0.01, p<0.001) decrease in RBC count and increase in WBC counts in extract treated animals when compared to EAC control animals.