In vitro evaluation and comparison of antioxidant activities of various extracts of leaves and stems of Kalanchoe pinnatum

Abstract

Aim: Many diseases are associated with oxidative stress caused by free radicals. The present research was carried out to evaluate the total phenolic contents, flavonoid contents and in vitro evaluation of antioxidant potentials by five different assay method of various (benzene, chloroform, acetone, and ethanol) extracts of leaves and stems of Kalanchoe pinnatum as the plant is an ingredient of various traditional preparations used in the treatment of various diseases. Materials and Methods: Antioxidant and free radical scavenging activity was determined by using five different in vitro antioxidant assays including 2, 2‑Diphenyl‑1‑Picrylhydrazyl (DPPH), hydrogen peroxide, nitric oxide, ferric reducing antioxidant power and phosphomolybdenum assays. In the present investigation, quantitative estimation of flavonoid content and phenolic content was carried out by colorimetric methods using aluminium chloride and Folin‑Ciocalteu reagent methods respectively to establish relationship between antioxidant activity and total phenolic and flavonoid contents. Results and Conclusions: The plant powder (100 mg) yielded 0.49, 0.64, 0.99, 1.17 %w/w total phenolic content in leaves and 0.18, 0.27, 0.48, 0.62 %w/w total phenolic content in the benzene, chloroform, acetone, ethanol extracts of stems respectively using gallic acid as standard and plant contains about 0.24, 0.37, 0.56, 0.75 %w/w of total flavonoids content in leaves and 0.15, 0.22, 0.42, 0.54 %w/w of total flavonoids content in the benzene, chloroform, acetone, ethanol extracts of stems respectively using quercetin as standard. The extracts showed significant antioxidant activity in dose dependent manner in all the assays. The result obtained in the present study indicated that leaves and stems of K. pinnatum could be a potential source of natural antioxidant and justified the traditional use of herb in preventing disease induced by oxidative stress. Key words: DPPH scavenging activity, Kalanchoe pinnatum, no scavenging activity, phytochemical screening