Effect of total phenolic and flavonoid contents of Ampelocissus martini on radical scavenging and antibacterial activities
Ampelocissus martini Planch., an edible plant belonging to the Vitaceae family, is used in traditional medicine to cure certain conditions. However, the biological activities of the vine and rhizome extracts of A. martini have not been investigated; hence, the objective of this work was to extract and investigate the bioactive substances of the vine and rhizome of A. martini. Three organic solvents (hexane, ethyl acetate, methanol) were used and all the extracts were analyzed to determine the total phenolic and flavonoid contents, using a Folin-Ciocalteu assay and the colorimetric aluminum chloride method, respectively. The results showed that the ethyl acetate and methanol extracts of vine and rhizome had significantly higher total phenolic and flavonoid contents than the hexane extracts. The correlation coefficients between total phenol and flavonoid contents (r = 0.96) were positive. In addition, the ethyl acetate and methanolic extracts of vine and rhizome had a higher percentage of radical scavenging activity than the hexane extracts when measured using the 1,1-diphenyl-2-picrylhydrazyl method and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonate free radical scavenging assay. The antibacterial screening was carried out using disc diffusion with Gram-positive and Gram-negative bacterial strains. Good antibacterial activity was indicated with the ethyl acetate and methanol extracts of vine and rhizome and was supported by the analysis of the total phenolic and flavonoid contents. The present study provided evidence that the ethyl acetate and methanol extracts of vine and rhizome of A. martini contained extremely important medicinal bioactive substances, such as phenolics and flavonoids, in large quantities that had good biological activity.