Phytochemical and Biological Activities of the Wild Grape Fruit Extracts Using Different Solvents

Aims: To investigate the phytochemical, antioxidant and antibacterial activities of the solvent extracts of wild grape fruits in different colors.
Study Design: The solvent extracts of wild grape (Ampelocissus martinii Planch.) fruits were prepared by mixing grinded fruit in each solvent. The filtrates were evaporated using a rotary evaporation at 45ºC until the weight of evaporated filtrate were less than 10% of the original weight.
Place and Duration of Study: Department of Chemistry, Faculty of Science, Mahasarakham University, Thailand, between August 2012 and May 2013.
Methodology: All extracts were investigated for their total phenolic (TPC) and flavonoid contents (TFC) by Folin-Ciocalteu and colorimetric aluminum chloride assays, respectively as well as antioxidant activity using 2,2΄-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. They also tested for their antibacterial activity against infective bacteria using agar well diffusion method.
Results: Methanolic extracts showed the highest of TPC comparison to other. The methanolic extract from green wild grape has the highest of TPC, followed by ethanolic extract. The ethanolic extracts of red and black wild grape fruits found the highest of TFC whereas the green wild grape using methanol showed the highest TFC. All methanolic extracts showed the lowest of IC50 values when compared to other solvents in the same color. Among them, the methanolic extract from green wild grape has the lowest of IC50 values which considered to be the highest powerful of antioxidant activity. The obtained results were directly trend with the FRAB values. However, the ethanolic extract showed antioxidant activity similar as the methanolic extract. The methanolic extract from green wild grape showed good antibacterial activity. All ethanolic extracts showed widely and similarly inhibition of selected bacteria, but no activity in all water extracts. The MIC and MBC of all extracts were arranged of 500-250 µg/mL.
Conclusion: Methanol and ethanol should be used as good solvent extraction of wild grape fruits to obtain high TPC and TFC and good biological activities.