부산대학교 도서관

Apart from boosting flavor, herbs and spices are also known for their preservative, antioxidant, antimicrobial and other medicinal properties. Bioactive metabolites with aspiring prospect have guided the present study to screen for antibacterial and antioxidant activity of three Zingiberplants available in Bangladesh. For that purpose, rhizomes of Zingiber officinale, Z. montanumand Z. zerumbetwere extracted with ethanol as solvent system for bioactivity analysis. Antioxidant activity was assessed by employing DPPH free radical scavenging assay, reducing power assay and ferric reducing antioxidant power (FRAP) assay. Z. officinaleextract demonstrated the highest free radical scavenging activity (IC50: 43.65 µg/ml), reducing power (EC50: 189.026 µg/ml) and FRAP value (137.18 ± 0.116 µM Fe(II)/100 µg dry weight of extract). Moreover, total phenolic, flavonoid and tannin content were determined which significantly correlated (Pearson correlation) with the antioxidant activities. For the evaluation of antibacterial activity, zone of inhibition (ZOI) was measured by disc diffusion bioassay against four Gram positive bacteria Bacillus megaterium, Staphylococcus aureus, Micrococcusspp., and S. epidermidisas well as ten Gram negative bacteria Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, S. paratyphi, Vibrio cholera, Shigella dysenteriae, S. flexneri, Proteusspp., Mycobacteriumspp., and Campylobacterspp. Z. montanumextract exhibited significant activity against E. coli(13.67 ± 0.577 mm ZOI) and Micrococcusspp. (14.33 ± 0.763 mm ZOI) if compared to standard erythromycin with ZOI 15.33 ± 0.577 mm and 15.67 ± 0.577 mm, respectively. Furthermore, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Z. montanumextract were determined against B. megaterium, Micrococcusspp., E. coliand S. paratyphi.Thus, Z. officinaleand Z. montanumextracts could be utilized as source and template for the synthesis of potential drugs and food supplements as well.