L’effet protecteur de la plante Centaurea africana vis-à-vis la neurotoxicité et l’apoptose induits par la roténone chez le rat.

Abstract

Parkinson's disease (PD) is a chronic neurodegenerative disorder that develops in a slowly progressive manner with no identifiable cause. The aim of this investigation is the study of the biological potential of the n-BuOH and EtOAc fractions extracted from the plant Centaurea africana and elucidate the modulatory effect of the n-BuOH extract in rats (Wistar Albinos) treated with rotenone. In vitro studies (DPPH°, reducing power of iron, inhibition of LPO) have shown that C. africana is endowed with antioxidant properties. Anti-inflammatory studies have shown that nBuOH extract has this effect which is resulting in the inhibition of paw edema induced by carrageenan in rats and decreased activity of MPO and MDA levels in paw tissues. In vivo studies have investigated the modulatory effect of n-BuOH extract of C. africana (200 mg/kg) against biochemical, neurochemical, histopathological and behavioural alterations induced by rotenone (1 mg/kg; ip) in rats. Rotenone causes behavioral and motor deficits and also activates neuroinflammation. The mitochondrial dysfunction induced by ROT is expressed by the decrease in the activity of complex I of the mitochondrial respiratory chain and by the alteration of the oxidant/antioxidant status of the brain, which activates the intrinsic apoptotic pathway. This study revealed that the n-BuOH extract acts by several mechanisms: neutralization of oxidative stress, modulation of markers of apoptosis (Bcl-2, Bax and caspase 3) and neurochemical markers (dopamine and glutamate), and reduction of neuroinflammation which results in decreased MPO activity and lower levels of NO and TNF. The antioxidant and anti-inflammatory properties of this plant are probably explained by its richness in polyphenols and flavonoids, which have been revealed by phytochemical screening and LC-MS/MS analysis, and/or by the synergistic interactions of the isolated phenolics.