title: Robustaside B and para‑hydroxyphenol: phenolic and antioxidant compounds purified from Cnestis ferruginea D.C induced membrane permeability transition in rat liver mitochondria.
abstract: The antioxidant properties of robustaside B and para‑hydroxyphenol isolated from Cnestis ferruginea were measured as the rate of inhibition of thiobarbituric acid reactive substance (TBARS) production in the Fe2+/ascorbate system. The modulatory effects of the compounds on mitochondrial membrane permeability transition (MMPT) were monitored spectrophotometrically as decreases in light scattering at 540 nm. The varying concentrations of robustaside B and para‑hydroxyphenol (0.05, 0.1, 0.2, 0.25, 0.5, 0.75 and 1 mM) significantly reduced (P<0.05) the amount of TBARS generated by the Fe2+/ascorbate system by 85.3, 86.4, 86.0, 86.1, 86.0, 86.0 and 86.0% and 86.7, 81.3, 81.3, 80, 80, 82.6 and 83.1%, respectively. Similarly, quercetin, a standard antioxidant, was found to induce an 80% reduction in the amount of TBARS produced. The same IC50 value of 0.025 mM was observed for robustaside B, para‑hydroxyphenol and quercetin. Pre‑incubation of varying concentrations of robustaside B (0.125, 0.2, 0.5 and 1 mM) with succinate‑energized mitochondria induced MMPT pore opening by 0, ‑33.3, ‑59.3 and ‑218.5%, compared with control mitochondria. Para‑hydroxyphenol at 0.1, 0.2, 0.25 and 0.5 mM induced MMPT pore opening in a concentration‑dependent manner up to 0.25 mM by ‑21, ‑54.4 and ‑107.0%, respectively. Quercetin at 0.05, 0.1, 0.25, 0.5, 0.75 and 1 mM also induced MMPT pore opening in the absence of calcium in a concentration‑dependent manner by 5, 3.7, ‑42.6, ‑81.5, ‑187 and ‑161.1%, respectively. The current observations confirm the antioxidant properties of robustaside B and para‑hydroxyphenol, and indicate a potential therapeutic use of the compounds for the treatment of diseases requiring the induction of cell death, including cancer.
authors.affiliation: Laboratories for Biomembrane Research and Biotechnology, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan 200284, Nigeria.
authors.forename: Rahmat A
authors.initials: RA
authors.lastname: Adisa
authors.forename: Olufunso O
authors.initials: OO
authors.lastname: Olorunsogo
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002122:Calcium Chloride / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects*; D031961:Connaraceae / Q000737:chemistry*; D006027:Glycosides / Q000494:pharmacology*; D006873:Hydroquinones / Q000494:pharmacology*; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins / Q000187:drug effects*; D000083162:Mitochondrial Permeability Transition Pore; D010636:Phenols / Q000494:pharmacology*; D011794:Quercetin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D006027:Glycosides; D006873:Hydroquinones; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D010636:Phenols; C578580:robustaside B; D011794:Quercetin; D002122:Calcium Chloride; C031927:hydroquinone