Drug delivery resistance of blood-brain-barrier: Cajanus cajan and Lycopersicon Esculentum down-regulated multi-drug resistance expression in cerebrum of rats

Abstract

P-glycoprotein (multi-drug resistance 1 protein) is a brain endothelial cell protein which functions as a drug efflux transporter and strengthens the shielding effect of the blood brain barrier making drug delivery to the brain a challenging task. This study examined neuroprotective potential of two ethnomedicinal plants, Cajanus cajan and Lycopersicon esculentum, on P-glycoprotein expression in ethidium bromide-induced neurotoxicity. Ethidium bromide-induced toxicity was achieved via application of 0.5 ml of a solution of 0.5 g/100 ml ethidium bromide in ethanol to the scraped ventral skin of 23 groups (n = 5) of adult rats (day 1). Groups 1 and 2 were post-treated with normal saline and tamsulosin hydrochloride, respectively (days 1-28). Nine groups (CC3-11) were post-treated with Cajanus cajan (aqueous, butanolic and ethanolic extracts of seeds, stems and leaves) (days 1-28). Twelve groups (LE3-14) were post-treated with Lycopersicon esculentum (aqueous, butanolic, ethanolic and n-hexane extracts of roots, stems and leaves) (days 1-28). Concentrations of P-glycoprotein in homogenates of cerebral cortices were determined using ELISA following anaesthetization using diethyl ether. Data were analysed using ANOVA with Tukey post-hoc test at p ≤ 0.05. Post-treatments with Cajanus cajan and Lycopersicon esculentum extracts resulted in significant downregulations of MDR1 in CC3, CC4, CC6-11 and LE3-14 compared with group 1. Cajanus cajan and Lycopersicon esculentum possess neuroprotective and anti-drug resistance potential.