Antioxidant and antidiabetic activities of Holarrhena antidysenterica

Abstract

Introduction and Aim:Holarrhena antidysenterica (Kutaja) belonging to the Apocynaceae family is widely grown in India and used in traditional systems of medicine. Presence of polyphenols, flavonoids and alkaloids make the plant useful in treating metabolic disorders.This study presents comparison of antioxidant property between leaf and bark of H. antidysenterica followed by in vivo experimental validation of antidiabetic properties of leaf extracted in methanol. Materials and Methods: Bark and leaf of H.antidysentericaextracted in methanol by Soxhlet apparatus and quantified the phytochemicals present with respective standards. Antioxidant properties was estimated by DPPH scavenging assay. High Fat Diet C57BL/6 mice model was established and treated with leaf extract of H.antidysenterica. Levels of TNF alpha and blood glucose were monitored. Results:The IC50 values of bark and leaf of H.antidysentericawere 10.15 and 8.56 µg/ml respectively on DPPH scavenging assay. The established Sandwich ELISA would detect TNF alpha with the detection limit of 0.011 µg/ml. This ELISA was used to estimate TNF alpha in the mice serum, and found that there was an increase in TNF alpha level in HFD animals (29.76±5.1 µg/ml) which was lowered by the treatment of leaf extract (22.08±2.08 µg/ml). The blood glucose levels were also reduced upon treatment with leaf extract from 130.83± 6.43 mg/dl to 111±2.9 mg/dl. Conclusion:Presence of high amount of phenolic compounds in leaf is responsible for its antioxidant property, whereas high amount of fat content in bark with moderate amount of phenolic compounds are the likely cause of its close-matched hydroxyl radical scavenging activity despite lesser content of phenolic compounds than leaf. Leaf also has anti-diabetic activity, having shown by reduction in TNF alpha and blood glucose levels by in vivo mice model. Phenols, flavonoids and tannins are the abundant phytochemicals found when leaves were extracted in methanol which might be responsible for its antidiabetic activity.