Investigation of the in vitro antioxidant activity, in vivo antidiabetic efficacy and safety of Capparis tomentosa roots aqueous extracts

Abstract

Capparis tomentosa has been used traditionally to manage several diseases including diabetes, however, its efficacy and safety is not well evaluated. The aim of this study was to determine the in vitro antioxidant activity, in vivo antidiabetic efficacy and safety of the aqueous root extract of C. tomentosa. The in vitro antioxidant activity was assessed using 1,1 – dipheny – 2 – picrylhydrazyl method,phosphomolybdate assay and by total reducing power assay. The in vivo antidiabetic efficacy was performed in alloxan – induced diabetic male Balb/C mice using oral route of administration of the plant extract and reference drug (glibenclamide). The safety of the extract was studied in mice that were grouped into two; one group orally administered with 1g/kg body weight of plant extract daily while the second group orally administered with 0.1ml physiological saline daily for 28 days and changes in body weight recorded weekly. Comparison in organ weights and biochemical parameters were also studied. Phytochemical screening of the aqueous root extract was also done using standard procedures. C. tomentosa aqueous root extracts displayed antioxidant activity. Antioxidant activity by 1,1 – dipheny – 2 – picrylhydrazyl was 35.50 ± 0.02%, phosphomolybdate assay was 41.22± 0.17mg/kg ascorbic acid equivalent and the total reducing power increased with increase in extract concentration up to a maximum of 800µg/ml. The extract showed hypoglycemic activity at dose levels of 50,100 and 200mg/kg body weight. Administration of 1g/kg body weight of the extract decreased body weight gain in Balb/C mice and also altered organ weights of the mice, such as reduction in kidney, liver and increase in size of spleen. C. tomentosa at 1g/kg body weight also caused increased levels of Alkaline phosphatase and Aspartate aminotransferase/Glutamic – oxaloacetic transaminase and decreased levels of creatinine and Alanine aminotransferase. The extracts contained alkaloids, tannins, flavonoids, terpenoids and saponins. The observed antioxidant activity, hypoglycemic activity and slight toxicity could be associated with the phytochemicals present in this plant extract.