Antioxidant and In Vitro Antidiabetic Activity of Methanol Extract of Piper cubeba L

Objective- The study was carried out to evaluate invitro antioxidant and antidiabetic activity of methanol extract of medicinal plant Piper cubeba L. Methods- In vitro antioxidant activity of various concentrations of plant extract (20-100 μg/ml) was carried out by using DPPH free radical scavenging assay. The reduced color intensity was measured by using UV visible spectrophotometer at 517 nm. The ascorbic acid was used as a reference drug. In vitro antidiabetic activity of various concentrations of plant extract was investigated by α-amylase inhibitory assay and glucose uptake in yeast cells assay. Results- There was dose dependent percentage inhibition of DPPH free radical scavenging activity. The maximum 79.56% inhibition was observed at 1000 μg/ml and the IC50 value found at 58.75 μg/ml, indicating potent antioxidant action. The maximum 80.59% α-amylase activity inhibition was observed at concentration 250 µg/ml of plant extract. The standard drug acarbose exhibited 86.16% inhibition. Similarly, maximum 65.19% increase in glucose uptake by yeast cell was reported at 250 µg/ml of plant extract. Conclusion- Methanol extract of fruits of medicinal plant Piper cubeba exhibited potential antioxidant and antidiabetic activity. This would attribute to presence of bioactive substances polyphenols and flavonoids.