Phytochemical profiling and biological activity of the ethanolic extract of Phragmites australis.

Abstract

Background: Phragmites australis, a grass species of the Poaceae family, was studied here for the first time in Libya, marking its initial documented phytochemical and biological evaluation. In traditional folk medicine, P. australis has a promising therapeutic potential.

Aim: This study analyzed and identified phytochemical compounds and the antioxidant, cytotoxic, antimicrobial, and antiviral activities of Phragmites australis ethanolic extract (PAEE).

Methods: Phytochemical profiling was conducted using liquid chromatography-mass spectrometry. Antioxidant properties were evaluated using ferric reducing antioxidant power, 2,2-diphenyl-1-picrylhydrazyl, nitric oxide, total antioxidant capacity, and Trolox equivalent antioxidant capacity assays. The cytotoxic effects of the extracts on the breast (MCF-7), hepatocellular (Hep-G2), and colon (Caco-2) cancer cell lines were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Antimicrobial effects were tested against four bacterial strains and three fungi, and the antiviral activities of the extracts against herpes simplex virus type 1 (HSV-1) and hepatitis A virus (HAV) were assessed.

Results: The PAEE contained 65.94 mg/gallic acid equivalents g of total phenolics and 22.7 mg/RE g of total flavonoids. Phytochemical analysis revealed the presence of key bioactive compounds, including flavonoids such as rutin, quercetin, luteolin-7-O-glucoside, caffeic acid, and apigenin-6-C-glucoside, as well as phenolic acids, such as protocatechuic acid, coumaric acid, and feruloyl-quinic acid derivatives.The extract exhibited significant antioxidant activity. Additionally, the extract exhibited potent antimicrobial efficacy, particularly in counteracting Bacillus subtilis and Klebsiella pneumoniae.

Conclusion: This study is the first to investigate P. australis from Benghazi, Libya, revealing its rich diversity of polyphenols and flavonoids, along with its strong antioxidant, antibacterial, and antiviral activities. Notably, this is the first report evaluating Libyan-sourced PAEE for its antiviral activity against HSV-1 and HAV, alongside its cytotoxic effects on colorectal adenocarcinoma (Caco-2) cells.