In vitro analysis of anti-diabetic and anti-oxidative potential of pedicles of fruit-vegetable bottle gourd.

The fruit-vegetable Lagenaria siceraria is well known for its ethnomedicinal applications. While other parts of the plant have been studied for their medicinal properties, its fruit pedicles have not been yet explored. The present study therefore aimed to investigate their phenolics, flavonoids, antioxidant potential and alpha-amylase inhibitory properties. The bioactivities of this neglected part of the fruit were promising. Ethyl acetate fraction had the highest total phenolic content (TPC), 4.4μg/mL Gallic acid equivalent (GAE). The TPC of chloroform and n-butanolic fractions were 3.6 and 2.5 GAE, respectively. Chloroform fraction displayed the highest total flavonoid content (TFC, 295μg/mL Rutin equivalent). The trend of TFC among the fractions was chloroform > hexane > ethyl acetate > n-butanolic > aqueous. Ethyl acetate fraction was most potent as a DPPH radical scavenger, and showed notable activity even at very low concentration (IC50 2.65mg/mL). It was more potent than ascorbic acid (IC50 4.9mg/mL), the standard used in the study. The methanolic extract itself was more powerful than ascorbic acid. The residual aqueous fraction was the strongest inhibitor of alpha-amylase with IC50 1.35mg/mL, which was comparable to the antidiabetic drug Acarbose (IC50 1.26 mg/mL). The IC50 (mg/mL) of ethyl acetate, hexane and n-butanolic fractions were 2.16,2.05 and 2.44, respectively. The findings indicated that the pedicles of L. siceraria fruits have remarkable antioxidant and alpha-amylase inhibitory potential. Subject to verification by in vivo analysis and clinical trial, consumption of the pedicles of this fruit may be advised to diabetic people. As the aqueous fraction was the most potent inhibitor, a water decoction of the fruit part may safely be recommended for the purpose.