Phytochemical Profiling and In Vitro Evaluation of Biological Activities of Osbeckia stellata Buch.-Ham. ex D. Don Extracts From the Uttarakhand Himalayas, India.

Osbeckia stellata Buch.-Ham. ex D. Don (family: Melastomataceae) has been traditionally used to treat asthma, arthritis, diabetes, skin diseases, and toothaches. Therefore, we evaluated the phytochemical profile, antioxidant, in vitro anti-inflammatory, and antibacterial properties using various solvents. The methanol extract exhibited high levels of total phenolic (933.11 ± 37.29 milligram of gallic acid equivalents per gram [mg GAE/g]), flavonoid (253.05 ± 6.35 milligram of quercetin equivalent per gram [mg QE/g]), and tannin content (163.13 ± 14.91 mg tannin acid equivalents [TAE]/g). Antioxidant activity was potent with low IC50 values in 2,2-diphenyl-1-picrylhydrazyl (DPPH) (7.91 ± 0.57 µg/mL), ABTS (8.13 ± 1.78 µg/mL) and ferric-reducing antioxidant power (FRAP) (16.48 ± 0.21 mg AAE g-1), and metal-chelating activity (MCA) (23.53 ± 2.48 µg/mL) assays. In vitro anti-inflammatory activity was significant, with an IC50 of 90.82 ± 2.34 µg/mL. The methanol extract showed antibacterial activity, particularly against Pseudomonas aeruginosa. Liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS) analysis identified bioactive compounds, including flavonoids, triterpenoids, phenolic acids, glycosides, amino acids, and steroid compounds. The results indicate that the solvent's polarity enhances the biological activity of the extracts, supporting the traditional use of this plant as natural medicine.