Phytochemical Content, Antibacterial Activity, and Antioxidant, Anti-Inflammatory, and Cytotoxic Effects of Traditional Medicinal Plants against Respiratory Tract Bacterial Pathogens.

Respiratory tract infections (RTIs) are frequent ailments among humans and are a high burden on public health. This study aimed to determine the antibacterial, anti-inflammatory, and cytotoxic effects of indigenous medicinal plants used in the treatment of RTIs, namely, , , , and . Dried leaves were extracted using various organic solvents. Antibacterial activity was quantified using the microbroth dilution assay. Protein denaturation assays were used to evaluate anti-inflammatory activity. The cytotoxicity of the extracts towards THP-1 macrophages was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Antioxidant activity was determined using free radical scavenging activity and ferric-reducing power. Total polyphenolics were quantified. Liquid chromatography mass spectrometry was used to evaluate the acetone plant extracts. Nonpolar extracts had noteworthy antibacterial activity against , , , and where MIC values ranged between 0.16 and 0.63 mg/mL. At 100 g/mL, , , and had a nonsignificant effect on the viability of the THP-1 macrophages. The LC-MS analysis of the leaf extracts of detected Hercynine, L-Lysine citrate, and Gamma-Linolenate. A pentacyclic triterpenoid, cochalate, was detected in Two flavonoids 7-hydroxy-2-(4-methoxyphenyl)-4-oxo-chroman-5-olate and (3R)-3-(2,4-dimethoxyphenyl)-7-hydroxy-4-oxo-chroman-5-olate were detected in the extract. The findings from this study indicated that the leaves of the selected plant extracts possess antioxidant, anti-inflammatory, and antibacterial activity. Therefore, they may serve as good candidates for further pharmaceutical investigations.