Screening and comparative study ofin vitroantioxidant and antimicrobial activities of ethanolic extracts of selected Vietnamese plants

Abstract

This study aimed to screen the in vitro antioxidant and antimicrobial activities of ethanolic extracts from 20 plants and three herbal commercial products empirically used for aquaculture improvement in Vietnam. The results of 2,2-diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging assays showed that Phyllanthus amarus extract was the strongest antioxidant, followed by four extracts in the subsequent order: Piper betle > Psidium guajava > Euphorbia hirta > Mimosa pudica. These five plant extracts were very active in a DPPH radical scavenging assay with concentrations needed to scavenge half of the DPPH (IC 50) below 30 µg/mL. Seven plant extracts showed an IC 50 ranging from 31.9 to 59.7 µg/mL, while eleven extracts showed an IC 50 above 70 µg/mL. A positive association was found between phenolic content (expressed as gallic acid equivalents) and antioxidant activity of the plant extracts. Concerning in vitro antimicrobial activities, P. amarus extract showed the highest activity against two different strains of Aeromonas hydrophila as demonstrated by its low minimal inhibitory concentration (MIC) of 156 and 625 µg/mL, respectively; whereas, P. betle displayed a moderate activity against Edwardsiella ictaluri with a MIC value of 625 µg/mL. Tannins were observed as significant factors contributing to antioxidant and antimicrobial properties of the plant extracts tested.

Investigation of chemical composition and evaluation of antioxidant, antibacterial and antifungal activities of ethanol extract from Bidens pilosa L.

“…It may be because the composition of the extract contained groups of compounds that act on the cell wall (peptidoglycan) of Gram (+) bacteria. Besides, the resistance to A. hydrophila of Bidens pilosa L. ethanol extract in this study was lower than that of the methanol extract of P. amarus (MIC = 128 μg/mL, according to Britto et al, 2011) and ethanol extract of Piper betle leaves (MIC = 25 μg/mL, according to Caruso et al, 2017), but higher than other extracts of Combretum quadrangulare, Kalanchoe pinnata, Premna corymbosa, Wedelia chinensis, Zingiber officinale, Houttuynia cordata and Ageratum conyzoides (Dao et al, 2020;Tran et al, 2021).…”

Properties of active packaging of PLA-PCL film integrated with chitosan as an antibacterial agent and syzygium cumini seed extract as an antioxidant agent

“…This difference is due to structural differences in bacterial cell walls. Gram-negative bacteria have an outer lipopolysaccharide membrane, whereas Gram-positive bacteria have a peptidoglycan structure with a single layer ([ 50 , 51 ]). Furthermore, when the proportion of SCSE exceeded that of chitosan, a higher percentage of colony reduction was observed for both types of bacteria.…”

A comprehensive study in efficacy of Vietnamese herbal extracts on whiteleg shrimp (Penaeus vannamei) against Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease (AHPND)

“…35,36 In Vietnam, the effectiveness of herbal species in aquaculture has been evaluated. [37][38][39][40] H. sabdariffa, M. pirga, and E. globulus are well-known to possess bioactive compounds to release human sickness; however, there are only a few studies in aquaculture. These herbs grow wildly or are planted.…”