Polyphenol-rich fraction of Parquetina nigrescens mitigates dichlorvos-induced neurotoxicity and apoptosis

Abstract

BackgroundParquetina nigrescens (Afzel.) Bullock of the family Asclepiadaceae is known for its antioxidant effects with wide range of uses in Southwestern Nigeria especially in traditional medicine. This study was undertaken to explore if polyphenol-rich fraction (prf) from P. nigrescens will ameliorate dichlorvos-induced neurotoxicity and apoptosis. The exploration utilized evaluation of markers of oxidative stress, apoptosis and serum acetylcholinesterase (AchE) levels.MethodsForty Wistar rats randomly placed in four groups were utilized for the study. Animals in Group A received corn oil, group B- dichlorvos (16 mg/kg), groups C and D- dichlorvos + 100 and 200 mg/kg prf of P. nigrescens respectively. Markers of oxidative stress, antioxidants and apoptosis were assessed in the serum and brain tissues using biochemical assay and immunohistochemistry.ResultsExposure to dichlorvos caused significant decreases in AchE, catalase, superoxide dismutase, glutathione peroxidase (GPx) and increases in hydrogen peroxide (H2O2) generation and malondialdehyde levels. Histopathology and immunohistochemistry of the cerebellum and cerebrum of rats exposed to dichlorvos revealed greater neurotoxic effects in the cerebellum as well as decreased expressions of AchE with a concomitant increase in Bax (proapototic) compared to prf of P. nigrescens treated rats.ConclusionThis study showed that dichlorvos caused cellular and tissue neurotoxicity by inhibiting AchE activity, induced oxidative stress and apoptosis in rats with prominent effects on the cerebellum than cerebrum. The prf of P. nigrescens showed amelioration of neurotoxicity by its antioxidative and antiapoptotic properties in rats exposed to dichlorvos.

Anti-diabetic Activity of Convallatoxin Isolated from the Root Bark of Parquetina nigrescens (Afzel.) Bullock (Asclepiadaceae)

“…Some of its isolated chemical constituents reported include strophanthidin, strophanthidin glycoside, cymarin and Isorhoifolin [15,25]. The chloroform soluble extract of the leaves was reported to ameliorate dichlorvos-induced cardio-and nephrotoxicity, neurotoxicity, oxidative stress and apoptosis in rats [26,27].…”

Quercetin-3-O-β-D-Glucopyranoside-Rich Fraction from Spondias mombin Leaves Halted Responses from Oxidative Stress, Neuroinflammation, Apoptosis, and Lipid Peroxidation in the Brain of Dichlorvos-Treated Wistar Rats

“…Therefore, the DDVP-induced oxidative stress that resulted in the activities of catalase, SOD and GPx in the hippocampus, striatum, and prefrontal cortex of rats coupled with the increase in level of H 2 O 2 in the present study is an indication of oxidative damage suggesting impairment of the antioxidant status. Ajiboye [69] and Sharma and Singh [70] reported a similar decrease in the activities of catalase and SOD in the brain of rats following DDVP intoxication, while Ojo et al [14] and Ochigbo et al [71] reported the decreased activity of GPx in the brain of rats exposed to DDVP. The restoration in the activities of catalase, SOD and GPx in the hippocampus, striatum, and prefrontal cortex of rats as well as the level of H 2 O 2 suggest the chemoprotective potential of Q3G-RF by suppressing lipid peroxidation in the brain tissues.…”

“A Review of Parquetina nigrescens (Afzel.) Bullock, A Plant for Traditional Medicine: Phytochemical and Pharmacological Properties”

“…The pulverized stem bark is applied to the skin surface to treat wounds and rheumatism. The leaf sap is used to treat jaundice and conjunctivitis [ 31 ]. The latex and leaf sap are externally used to treat burns and abscesses, applied to thorns in the skin to extract them [ 32 ].…”

“…Jaundice and conjunctivitis [31] Latex White, hardening to black Arrow poison for hunting bush meat and production of black rubber [33] source: Summary of claim traditional uses of parts of the plant was generated by Authors'.…”