Antioxidant efficacy of Kalanchoe daigremontiana bufadienolide-rich fraction in blood plasma in vitro

Abstract

Context: The main source of bufadienolides is toad venom; however, plants such as members of Kalanchoe Adans. (Crassulaceae) genus may also synthesize these bioactive substances. Objective: This is the first study on antioxidant effects and cytotoxicity of bufadienolide-rich fraction isolated from Kalanchoe daigremontiana Raym.-Hamet & H. Perrier. Materials and methods: The methanolic fraction was extracted from the plant roots and contained 0.48 mg bufadienolides/mg of dry mass (11a,19-dihydroksytelocinobufagin, bersaldegenin-1-acetate, bersaldegenin-1,3,5-orthoacetate, 19-(acetyloxy)-3b,5b,11a,14-tetrahydroxyl-12-oxo-bufa-20,22-dienolide and 19-(acetyloxy)-1b,3b,5b,14-tetrahydroxyl-bufa-20,22-dienolide, mainly). The cytotoxicity of K. daigremontiana fraction was evaluated in an in vitro experimental model of blood platelets. The viability of blood platelets was determined on the basis of a release of lactate dehydrogenase. Results: The fraction scavenged DPPH radicals, with EC 50 of 21.80 lg/mL. Studies on an experimental model of blood plasma under peroxynitrite-induced oxidative stress revealed that the plant preparation had moderate antioxidant properties. Levels of 3-nitrotyrosine and thiol groups indicated that the protective effect of K. daigremontiana was significant mainly for its concentration of 50 lg/mL. No effect was found in prevention of oxidation of low-molecular plasma thiols (glutathione, cysteine and cysteinylglycine). Simultaneously, measurements of lipid hydroperoxides and thiobarbituric acid-reactive substances (TBARS) indicated that the examined fraction might be effective antioxidant at broader concentration range, that is 1-5 and 25-50 lg/mL for hydroperoxides and TBARS generation, respectively. No cytotoxicity was observed at the concentration range of 1-50 lg/mL. Conclusions: Based on the obtained results, we suggest that antioxidant activity may additionally contribute to beneficial properties of K. daigremontiana-derived extracts.ARTICLE HISTORY

Bufadienolides of Kalanchoe species: an overview of chemical structure, biological activity and prospects for pharmacological use

“…It should be emphasized that earlier results, obtained by other authors in analogous experiments on different Kalanchoe plants indicated on significantly lower antioxidant efficacy of extracts, originated from different organs of Kalanchoe species (Sharker et al 2012 ; Quazi Majaz et al 2011a , b ). Furthermore, antioxidant action of the mentioned bufadienolide-rich extract of Kalanchoe daigremontiana was also confirmed using an experimental model of blood plasma exposed to peroxynitrite-induced oxidative stress (Kolodziejczyk-Czepas et al 2016 ).…”

“…Moreover, this group of compounds may be a base for development of new derivatives with enhanced antioxidant properties and decreased toxicity (obtained by chemical alterations of the pyrone moiety) (Aucamp 2014 ). Recent studies on bufadienolide-rich fraction of Kalanchoe daigremontiana roots demonstrated that its DPPH · scavenging ability was characterized by EC 50 = 21.80 μg/ml (Kolodziejczyk-Czepas et al 2016 ). Under the same experimental conditions, for the reference compounds, i.e.…”

Identification of Flavonoids and Bufadienolides and Cytotoxic Effects of Kalanchoe daigremontiana Extracts on Human Cancer Cell Lines

“…Kalanchoe daigremontiana has anti-inflammatory, antimicrobial, antioxidant, and cytotoxic activities [9][10][11][12]. However, the effect of extracts of this plant on cancer cells was tested only on human lymphoblastic leukemia T cells (H9 and J45 cell lines) with estimation of inhibitory concentration values [11].…”

Contribution of Individual Polyphenols to Antioxidant Activity of Cotoneaster bullatus and Cotoneaster zabelii Leaves—Structural Relationships, Synergy Effects and Application for Quality Control

“…Human blood buffy coats (from eight healthy volunteers) were purchased from the Regional Centre of Blood Donation and Blood Treatment in Lodz (Poland). The blood plasma samples were obtained by centrifugation according to previously described procedures [15]. All experiments were accepted by the committee on the Ethics of Research at the Medical University of Lodz RNN/347/17/KE.…”

“…The concentrations of nitrated proteins were estimated from the standard curve of 3-nitrotyrosine-containing fibrinogen (3-NT-Fg) and expressed as the 3NT-Fg equivalents (in nmol/mg of plasma proteins). The concentration of free -SH groups in plasma samples was measured spectrophotometrically according to the Ellman s method, as described earlier [15], and -SH concentrations were expressed in µmol/mL of plasma. The TBARS levels were determined as described previously [16] and expressed in µmol TBARS/mL of plasma.…”