Publications internationales
Résumé: Many Helianthemum species (Cistaceae) are recognized for their various medicinal virtues. Helianthemum ruficomum is an endemic species to the septentrional Sahara on which no report is available so far. The purpose of this work was to investigate the chemical composition and the radical scavenging capacity of this species and its isolated components. Collected from Mougheul (south-west of Algeria), the aerial parts were macerated with 80% EtOH/H2O, after evaporation, the remaining extract was diluted with H2O and extracted with petroleum ether, chloroform, ethyl acetate and n-butanol. EtOAc and n-BuOH extracts were evaluated for their free radical scavenging capacity by on-line HPLC-ABTS•+ assay. The obtained data which were confirmed by TEAC and ORAC assays, allowed guiding the fractionation of these extracts by CC, TLC and reverse phase HPLC. Among the components, 14 were isolated and identified by spectroscopic analyses: protocatechuic acid (1), trans-tiliroside (2), cis-tiliroside (3), astragalin (4), picein (7), vanillic acid 4-O-β-D-glucopyranoside (8), lavandoside (9), 4-hydroxybenzoic acid 4-O-β-D-glucopyranoside (10), nicotiflorin (11), rutin (12), vicenin-2 (13), narcissin (14) and stigmasterol (5) and β-sitosterol (6) as a mixture (71% and 29%, respectively). Compounds 5, 7, 8, 9, 10 and 14 were new for the genus Helianthemum. The antioxidant power of all the isolated compounds was also evaluated by HPLC-ABTS•+ , TEAC and ORAC assays. The results clearly indicated high antioxidant potent
Résumé: The objective of the current study was led to reveal the possible protective effects of n-butanol extract of Helianthemum confertum (H. confertum) against doxorubicin (DOX) induced liver damage and its implication on the integrity of liver cells. Adult male rats were randomly divided into groups treated with plant extract (50 mg/kg, 100 mg/kg) for 10 days and/or injected with a single dose of DOX (10 mg/kg). Liver function as well as oxidative stress parameters and histological study were estimated. DOX treated rat’s induced hepatic dysfunction revealed by a significant increase in biochemical parameters (serum transaminases, cholesterol and triglycerides) and disturbance in oxidative stress parameters described by an increase in malondialdehyde (MDA) levels, providing information on the loss of cellular integrity. This later elicited histopathological changes in the liver which was confirmed on histological section chowing necrotic cells. Altghout the DOX-treatment reduced significantly the reduced glutathione (GSH) level and the glutathione peroxidase (GPx) activity. The pretreatment of the animals with n-butanol extract of H. confertumat 50 mg/kg and 100 mg/kg counteracted almost all adverse effects induced by DOX. The results showed a considerable decrease in serum markers of liver function and lipid peroxides. There was significant increase in the GSH level and the activity of antioxidant enzyme (GPx), which allowed the normalization of redox status in liver cells. Data suggest that DOX-induced an oxidative stress in rat’s liver and nbutanol extract of H. confertum exerted antioxidant properties.