The effects of the Caribbean medicinal plant Argemone mexicana on Gardnerella vaginalis using a co-culture method with vaginal Lactobacillus spp.

Bacterial vaginosis (BV) is caused by vaginal microbiome dysbiosis, when beneficial Lactobacillus species are no longer dominant and are replaced by harmful anaerobic bacteria such as Gardnerella vaginalis. In Caribbean cultures, women use plants topically, such as Argemone mexicana, to treat several vaginal infections, including BV. There has been little research into how traditional botanical extracts affect the vaginal microbiota, especially as these extracts are often prepared in different ways for the same condition. This study aims to evaluate the effect of botanical preparations using an in vitro co-culture assay with beneficial Lactobacillus species and BV-causing Gardnerella vaginalis. This is an application of an in vitro co-culture assay to assess the effect of botanical preparations on the vaginal microbiota. We hypothesized that variations in the chemical composition of these preparations would affect the composition of vaginal microbiota. Argemone mexicana extractions were tested using an in vitro co-culture method with Gardnerella vaginalis and one of three vaginal Lactobacillus species and evaluated by UPLC-qToF-MS for metabolomic chemical analysis. Aqueous extractions that did not have significant antibacterial effect compared to the control in monoculture suppressed the growth of Gardnerella vaginalis in co-culture with Lactobacillus, supporting the traditional Dominican use of this plant. These results are likely related to the presence of berberine and polysaccharides in the aqueous extractions.