Antioxidant Activity, Total Phenols, Flavonoids and LCMS Profile of Chamaecrista hildebrandtii (Vatke) Lock and Clerodendrum rotundifolium (Oliv.)

Aims: The purpose of the study was to determine the antioxidant activity, quantify total phenols and total flavonoids and characterize the secondary metabolites present in methanolic extracts of Chamaecrista hildebrandtii and Clerodendrum rotundifolium using liquid chromatography coupled to mass spectrometry (LC-MS).

Methodology: The total phenol and flavonoid contents were determined spectrophotometrically while the antioxidant activity was evaluated using the 2, 2-Diphenyl-1-Picrylhydrazyl (DPPH) free radical scavenging method. The secondary metabolites present in the methanolic leaves extracts were evaluated using LC-MS.

Results: The extracts of C. hildebrandtii showed a significantly higher antioxidant activity (IC50 = 8.7 mg/mL) compared to C. rotundifolium (IC50= 28.5 mg/mL). Both methanolic extracts of C. hildebrandtii and C. rotundifolium had common and different types of flavonoids such as quercetin, rutin, (+)-catechin 3-O-gallate and luteolin 6-C-glucoside among others that could be responsible for the observed antioxidant activity. The total phenolic content of C. hildebrandtii (1.33±0.07 mg/g tannic acid equivalents) was significantly higher than that of C. rotundifolium (0.25±0.00 mg/g tannic acid equivalents). However, there was no statistically significant difference (p>0.05) in total flavonoid content of C. hildebrandtii (2.69±0.33 mg/g catechin equivalents) and C. rotundifolium (2.36±0.16 mg/g catechin equivalents).

Conclusion: The results of the present study suggested that the good antioxidant activity exhibited by C. hildebrandtii may probably have been brought about by various secondary metabolites functioning in synergy.