EVALUATION OF AQUEOUS EXTRACT OF Costus speciosus (J.König)Sm. LEAF FOR HEPATIC AND RENAL TOXICITIES: BIOCHEMICAL AND HISTOPATHOLOGICAL PERSPECTIVES

Hewa Walpola Amila Sewwandi Subasinghe*, Lakshmi Menik Hettihewa, Sampath Gunawardena and Thushari Liyanage

ABSTRACT

Costus speciosus is popular among Sri Lankans as an antidiabetic agent. Various parts of Costus speciosus plant are widely used in traditional medicine. Many of its pharmacological properties have scientifically proved. The objective of this study was to investigate the consequences of long-term use of Costus speciosus leaf aqueous extract (CSlwex) with respect to hepatic and renal functions of Wistar rats. Wistar rats (170-250 g) were divided into 9 groups (n=5 each) and labelled A to I. Groups A,B and C were kept as normal healthy rats. Insulin resistance was induced in six groups D to I. Costus speciosus leaf aqueous extract oral treatment was conducted for 12 weeks as given next. Group A and D- 1 mL of Distilled water, Group B and E- 1500 mg/kg CSlwex, Group F- 2000 mg/kg CSlwex, Group G- 2500 mg/kg CSlwex, Group C and H- 3000 mg/kg CSlwex, Group I- 20 mg/kg pioglitazone. After the therapy, serum ALT, AST and Creatinine were analyzed. Histopathology of liver and kidney were assessed for toxicity. No significant increase in ALT (34.77±6.19 IU/L, p=0.304) or AST (137.55±9.83 IU/L, p=0.928) were found in insulin resistant rats. Also, Costus speciosus leaf aqueous extract did not change ALT and AST significantly in healthy rats. Serum creatinine of either insulin resistant or healthy rats treated with CSlwex did not increase significantly compared to the respective controls (insulin resistant- 34.53±1.38 μmol/L; healthy- 42.56±3.27 μmol/L). No features of liver or renal toxicity were observed histopathologically in CSlwex treated rats or controls. In conclusion, 1500-3000 mg/kg doses of C. speciosus leaf aqueous extract did not initiate hepatic or renal toxicity after 12 weeks continuous therapy.

Keywords: Costus speciosus, aqueous extract, Wistar rats, renal toxicity, hepatic toxicity.