# Antibacterial Activity of Hydroethanolic Extracts of Artemisia annua L., Hibiscus sabdariffa L., and Paronychia argentea Lam. Against Some Clinically Relevant Gram-Positive and Gram-Negative Bacteria

## TL;DR

This study tests plant extracts for their ability to fight antibiotic-resistant bacteria and finds some are effective against common pathogens.

## Contribution

The study provides new evidence on the antibacterial potential of three plant species against clinically relevant bacteria.

## Key findings

- H. sabdariffa L. showed the strongest antibacterial activity against tested bacteria.
- All plant extracts exhibited varying levels of bacterial inhibition.
- Phytochemical analysis identified compounds like fatty acids and terpenoids in the extracts.

## Abstract

Background: Antimicrobial resistance is one of the major challenges in healthcare, leading to more severe infections, higher mortality, and increased healthcare costs. Therefore, exploring new alternatives, such as plant extracts with antimicrobial properties helps to reduce bacterial resistance. Artemisia annua L., Hibiscus sabdariffa L., and Paronychia argentea Lam. are traditionally used for their biological properties, including antimicrobial activity. However, scientific evidence regarding their antibacterial effects against clinically important bacteria remains limited. Methods: Extracts were obtained from the mentioned plants and phytochemically characterized by GC/MS. Phytochemical analysis revealed the presence of fatty acids, phenolic compounds, aliphatic compounds, and terpenoids. Antibacterial activity was evaluated using the diffusion method with a modified Kirby-Bauer technique and the microdilution method employing the massive plate sealing drop approach. Results: All extracts exhibited bacterial inhibition, with H. sabdariffa L. showing the strongest activity against E. coli (256 mg/mL), K. pneumoniae (256 mg/mL), P. aeruginosa (128 mg/mL), Salmonella sp. (128 mg/mL), and S. aureus (64 mg/mL). Conclusions: Hydroethanolic extracts of A. annua L., H. sabdariffa L., and P. argentea Lam. exhibit antibacterial activity against clinically relevant bacteria and represent promising candidates for future preclinical studies.