An assessment of phytochemical constituents and antioxidant potential of Delphinium malabaricum (Huth) Munz

Abstract

Objective: The aim of the study was to examine the efficiency of different extraction methods for the determination of total phenolics, flavonoids and alkaloid contents contributing to antioxidant capacity of Delphinium malabaricum. Methods: The extracts of different plant parts (roots, stems and leaves) of Delphinium malabaricum were prepared in aqueous and various organic solvents and the extracts were evaluated for phenolics, flavonoids and alkaloid contents as the equivalents of gallic acid, rutin, and colchicine; respectively. The antioxidant capacity of the extracts was also assessed by 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity and ferric reducing antioxidant power assays in both fresh and dry plant tissues and the difference in fresh and dry extracts on phytochemical constituents and antioxidant activities were compared. Results: The aqueous extracts of roots exhibited the highest total phenolic (4.94 mg gallic acid/g fresh weight, 13.4 mg gallic acid/g dry weight) and total alkaloid content (8.05 mg colchicine/g fresh weight, 20.4 mg colchicine/g dry weight) as compared to stem, leaves and other solvent extracts. Whereas, flavonoid contents were found to be highest in the leaf extracts (5.36 mg rutin/g fresh weight, 7.88 mg rutin/g dry weight). Interestingly the aqueous extracts of all the plant parts exhibited highest yield of phenolic, flavonoids and alkaloids as compare to the other solvents used for the extraction. Antioxidant activity assays exhibited considerable antioxidant potential and showed expected significant positive correlation with the phytochemical compounds. Conclusion: The study specified that aqueous extracts are more effective to extract phenols, flavonoids, alkaloids and antioxidants from Delphinium malabaricum than organic extracts and roots have higher level and the alkaloids were found to be higher comparing to that of phenolics and flavonoids content per gram dry weight of plant tissue.