Phytochemical Profiling, GC-MS Analysis, and Antioxidant Activity of Polar Solvent Extracts of Conoclinium coelestinum Leaves

The importance of medicinal plants as source of potent drugs for therapeutic purposes is currently of global interest to researchers. Phytochemicals are compounds from plants used for prevention and treatment of health disorders. Antioxidants are molecules that inhibit free radicals. This research aimed to investigate the phytochemical profile, and antioxidant activity of polar solvent extracts of Conoclinium coelestinum leaves. The pulverized leaves was extracted with methanol, ethanol, and water using Soxhlet apparatus. Phytochemical screening of the extracts was done using chemical methods and by gas chromatography-mass spectrometry (GC-MS). Antioxidant activity was evaluated using DPPH, FRAP, ABTS, lipid peroxidation, H₂O₂, nitric oxide, and superoxide radical scavenging assays. Phytochemical screening revealed the presence of alkaloids, glycosides, saponins, flavonoids, terpenoids, and steroids in all three solvent extracts. GC-MS analysis identified twenty-seven (27) bioactive compounds, with hexadecanoic acid ethy lester (8.89%), 2(3H)-furanone, dihydro-5-pentyl (6.52%), and butanal oxime (5.18%) as the major compounds. Of all the three extracts, the methanol extract significantly (p < 0.05) demonstrated exceptional antioxidant activity, achieving 94.15% DPPH inhibition at 400 µg/mL (IC50 = 95.65 µg/mL) and FRAP activity of 81.12% (IC50 = 100.90 µg/mL). The methanol extract also demonstrated significant (P < 0.05) lipid peroxidation inhibitory activity, H₂O₂, superoxide, and nitric oxide scavenging activities, with percentage inhibition of 64.07%, 76.12%, 90.12%, and 60.07%, respectively at 400 µg/mL, highlighting its capacity to neutralize reactive oxygen species and protect against oxidative damage. These findings affirm C. coelestinum as a potential source of natural antioxidants, supported by its rich bioactive compounds profile.