Abstract
Background: Novel chemical molecules recovered from endangered medicinal plants have wide applications and have the potential to cure different diseases caused by microorganisms. The aim of this study was to investigate In vitro antimicrobial, alpha-glucosidase inhibition and antioxidant activity of different solvent extracts of Epaltes divaricata L.
Methods: Antimicrobial activity of hexane, ethyl acetate and methanol extract of Epaltes divaricata was determined against bacteria and fungi using disc diffusion and microdilution method respectively. alpha-glucosidase inhibition, Total phenolic content (TPC), Reducing power activity, DPPH radical scavenging assay, hydroxyl radical scavenging activity, nitric oxide scavenging activity, superoxide scavenging activity and lipid peroxidation assay of plant extracts were performed according to standard protocol. Compound detection from the potential solvent extract was done through GC-MS analysis.
Results: Epaltes divaricata ethyl acetate extracts (EDEa) (1.25 mg/disc) showed significant inhibition for E. lentum (23 mm), E. aerogenes (18 mm), P. fluorescence (15 mm) and A. baumanii (15 mm). Minimum inhibitory concentration (MIC) of EDEa was found to be 31.25 mu g/ml, 62.5 mu g/ml and 62.5 mu g/ml against A. flavus, A. niger and T. rubrum respectively. EDEa showed more alpha-glucosidase inhibition and antioxidant activity compared to hexane and methanol. EDEa showed 50% alpha-glucosidase inhibition at the concentration of 525.20 +/- 2.37 mu g/ml. The TPC of EDEa was 412.0 +/- 2.21 mg of catechol equivalents/g extract. EDEa showed great scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC50 560 +/- 2.02 mu g/ml), hydroxyl (IC50 314.75 +/- 2.56 mu g/ml), nitric oxide (IC50 648.20 +/- 2.09 mu g/ml) and superoxide (IC50 361.14 +/- 1.45 mu g/ml) radicals, as well as high reducing power. EDEa also showed a more suppressive effect on lipid peroxidation. Using Antioxidant beta-carotene linoleate method, the scavenging values of EDEa was significantly lower than BHT. GC-MS analysis of EDEa showed maximum amount of 2-butenamide, N-(4-fluorophenyl)-3-methyl trans-cinnamyl tiglate silane and trichlorocyclohexyl silane (36.86%).
Conclusion: The results obtained in this study clearly indicate that EDEa can be used as a natural antimicrobial, alpha-glucosidase inhibition and antioxidant agent.