Antibacterial, antioxidant and acute toxicity tests on flavonoids extracted from some medicinal plants

Abstract

Flavonoids are well-known for their many therapeutic and pharmaceutical effects. In this study, we tested the antibacterial activity of 11 flavonoids extracted from some medicinal plants by the agar diffusion method. Then, we measured their antioxidant activity using the DPPH (2,2'-diphenyl-1-picrylhydrazyl) radical assay and we also tested their acute toxicity effect on mice. The results showed that apigenin-7-O-glucoside was more active against the Gram-positive bacteria and quercetin was more active against the Gram-negative ones. Also, quercetin and diosmin showed the best antioxidant activity. Quercetin, apigenin-7-O-glucoside, luteolin-7-O-glucoside and luteolin-3'-O-glucuronide gave the best acute toxicity values. It can be concluded that quercetin was the most interesting compound for all the tested activities. Also, we observed that the presence or the absence of substitutions in flavonoids influenced significantly the results obtained, whereas the substitution type had a low impact.

Phenolic compounds in black currant leaves – an interaction between the plant and foliar diseases?

“…quercetin-3-O-glucoside) have been reported by Razavi et al (2009), whereas other authors showed a synergistic efficacy of the antibacterial activity of quercetin-3-O-glucoside and kaempferol-3-O-glucoside (Akroum et al 2009). …”

Composition, antimicrobial and antioxidant activity of the extracts of Eryngium palmatum Pančić and Vis. (Apiaceae)

“…The methanol extract of aerial parts contained apigenin and its glycosides as well as kaempferol glycoside. Apigenin and kaempferol exert antimicrobial activity [23] and probably have multiple cellular targets. Phenolic compounds inhibit microbial adhesions and inactivate enzymes and cell envelope transport proteins [24].…”

Antimicrobial screening of some Egyptian plants and active flavones from Lagerstroemia indica leaves

“…More than 90% of the cases of food poisoning or food-related infection each year are caused by Gram-positive bacteria such as Staphylococcus aureus and Listeria monocytogenes or Gram-negative bacteria such as Escherichia coli and Salmonella enteritidis (4)(5)(6)(7). In recent years, the effects of plant extracts and phytochemicals on food pathogenic bacteria have been studied (8)(9)(10)(11). Candidiasis is an infection caused by Candida yeast, especially Candida albicans, and is associated with skin infection and other health problems.…”