Discovery of Potent Antibacterial and Anticancer Flavonoids from Beehive-Associated Streptomyces griseoaurantiacus HNF214

Thongchai Taechowisan, Thanaporn Chuen-Im and Waya Phutdhawong

Background and Objective: Actinomycetes from beehives are a potential source of bioactive compounds. This study aimed to isolate actinomycetes from Apis florea beehives, characterize their compounds and evaluate their antibacterial and anticancer properties, including underlying mechanisms. Materials and Methods: Actinomycetes were isolated from Apis florea beehives in Nakhon Pathom, Thailand. The most active isolate, HNF214, was identified by 16S rRNA gene sequencing and characterized morphologically. Bioactive compounds were extracted, purified and identified using spectroscopy. Antibacterial (MIC/MBC) and anticancer (MTT assay on various cell lines) activities were tested. Molecular docking predicted interactions with MEK1/MEK2 and in silico ADMET properties were assessed. ERK1/2 phosphorylation was measured by ELISA. One-way ANOVA and Tukey’s post hoc test were employed, with significance defined as p<0.05. Results: Thirty-two isolates yielded Streptomyces griseoaurantiacus HNF214, which showed potent antibacterial activity against Gram-positive bacteria. Two compounds, quercetin and isoquercetin, were purified. They demonstrated significant cytotoxicity against breast, cervical and liver cancer cells (IC₅₀ 234-811 μg/mL) with lower toxicity to normal cells. Docking revealed favorable binding to MEK1/MEK2 and ELISA confirmed reduced ERK1/2 phosphorylation. The ADMET predictions were mostly favorable, but compound 1 showed potential carcinogenicity/mutagenicity. Conclusion: Streptomyces griseoaurantiacus HNF214 from beehives produces quercetin and isoquercetin, exhibiting both antibacterial and anticancer activities, likely via MAPK/ERK pathway inhibition. While promising, further safety and in vivo studies are crucial before therapeutic development.

View Fulltext Back