Phytochemical Analysis and Biological Evaluation of Andrographis paniculata (Burm.f.) Wall. ex Nees, from Nigeria

The medicinal plant, Andrographis paniculata (Burm.f.) Wall. ex Nees, used in Nigeria's ethno-medicine, was investigated for its radical scavenging and antimicrobial properties, as well as its phytochemical composition, using gas chromatography-mass spectrometric (GC-MS) analysis. In vitro antioxidant activity of the methanol extract of the whole plant was tested through four different assays: DPPH, ABTS, FRAP, and NOx. The GC-MS analysis revealed the presence of neophthadiene (29.42%), followed by ergost-5-en-3-ol (10.57%), and methyl sterate (7.29%) as the major compounds present in the methanol extract of Andrographis paniculata. The methanol extract showed promising antioxidant activity compared with the reference (ascorbic acid). It was observed that the activity was concentration dependent, and values of 86.12±0.03, 90.18±0.03, 80.20±0.04, and 92.15±0.06 were obtained for DPPH, ABTS, FRAP, and NOx, respectively, under the same condition. All the tested bacteria (gram positive and gram negative) were inhibited by the methanol extract of Andrographis paniculata, except Proteus mirabilis, which showed a resistance at lower concentrations (0.25 mg/ml and 0.50 mg/ml). These findings suggest the bioactive potentials of Andrographis paniculata (Burm.f.) Wall. ex Nees, supporting its traditional use in Nigerian ethnomedicine and highlighting potential applications in pharmaceuticals.