Phytochemical Screening and Evaluation of Antioxidant, Antibacterial Activities of Ethanol Extract from Combretum quadrangulare Collected in Vietnam

Abstract

— Combretum quadrangulare Kurz has long been considered a precious herb, which is very useful in treating various kinds of diseases on humans and aquatic animals. The study was conducted to evaluate the antioxidant and antibacterial effects of ethanol extracts from Combretum quadrangulare Kurz fruit collected in Kien Giang province, Vietnam. Research results showed that ethanol extract from Combretum quadrangulare Kurz fruit contained bioactive compounds such as alkaloids, flavonoids, steroids and triterpenoids, tannins, and phenolics. In the ethanol extract of Combretum quadrangulare Kurz fruit, the content of total phenolics and total flavonoids were recorded at 230.89 ± 2.36 mg GAE/g extract and 165.35 ± 5.80 mg QE/g extract, respectively. The survey results of in vitro antioxidant capacity through four methods of DPPH, ABTS ●+ , RP and TAC indicated that the extracts of Combretum quadrangulare Kurz fruit showed its good activity with EC 50 values of 103.90 ± 0.40 µg/mL, 24.18 ± 0.06 µg/mL, 128.58 ± 0.20 µg/mL and 79.30 ± 1.40 µg/mL, respectively. The investigation results of in vivo antioxidant activity on fruit fly Drosophila melanogaster model showed that the fruit flies raised in the medium supplemented with 1 mg/mL extract of Combretum quadrangulare Kurz fruit had in vivo antioxidant effect under the conditions of oxidative stress induced by Paraquat and H 2 O 2 . In addition, the extract from Combretum quadrangulare Kurz fruit also had the ability to against the bacteria causing diseases in aquatic animals such as Edwardsiella ictaluri, Aeromonas hydrophila and Streptococcus agalactiae .