Antibacterial and Biological Evaluation of Selected Medicinal Plants Against Multi Drug Resistant Bacteria Streptococcus Pneumoniae

Abstract

Streptococcus pneumoniae is a prominent respiratory infection associated with rising antibiotic resistance, necessitating the quest for new bioactive sources. Phenolic and flavonoid chemicals with potential biological action have been found in a number of medicinal plants that have historically been used to treat respiratory and throat-related conditions; nevertheless, there has been little experimental confirmation against S. pneumoniae. The purpose of this study was to examine the phytochemical composition, antioxidant capacity, and in vitro antibacterial activity of nine ethnomedicinal plants that have historically been linked to respiratory health. Ethanolic extracts of Sisymbrium officinale, Syzygium aromaticum, Fumaria officinalis, Hyssopus officinalis, Lepidium sativum, Strychnos nux-vomica, Ephedra gerardiana, Cinnamomum zeylanicum, and Myristica fragrans were prepared and evaluated for total phenolic content (TPC) and total flavonoid content (TFC). The DPPH radical-scavenging test was used to measure antioxidant activity, and the agar-well diffusion method was used to screen for antibacterial activity against S. pneumoniae. The reference control was ciprofloxacin (5 µg/mL). The results were statistically compared and analyzed as mean ± SD. The phytochemical content and extract yield varied significantly. Syzygium aromaticum and Cinnamomum zeylanicum exhibited relatively higher TPC and stronger DPPH activity, whereas Ephedra gerardiana and Hyssopus officinalis produced comparatively larger inhibition zones against S. pneumoniae in agar diffusion screening. Ciprofloxacin produced greater inhibitory activity than all extracts, as expected. Moderate correlations were observed between TPC and antioxidant activity. The findings provide preliminary in vitro evidence supporting the biological relevance of selected traditionally used plants; however, they do not confirm therapeutic efficacy. The study is limited by the use of a single antioxidant assay and the absence of MIC/MBC determination and susceptibility profiling of the bacterial strain. Future research should include broth microdilution MIC/MBC testing, cytotoxicity evaluation, bioactive compound characterization, and in vivo validation to substantiate pharmacological potential.