Protective effects of ascorbic acid and garlic extract against neurogenesis inhibition caused by developmental lead exposure in the dentate gyrus of rat

Abstract

Lead is a well-known neurotoxin that affects the developing central nervous system and may potentially inhibit neurogenesis in adults. We investigated the effect of ascorbic acid and garlic extract against lead-induced neurotoxicity in developing rat dentate gyrus. Female Wistar rats were divided randomly into five groups: lead-treated (L; 1,500 ppm lead acetate in drinking water) group, lead plus ascorbic acid-treated (L + AA; 500 mg/kg, ip) group, lead plus garlic juice-treated (L + G; 1 ml /100 g BW, gavage) group, sham group (sh), and controls. All treatments were administered to female rats during pregnancy and lactation. At the end of the treatment, dentate gyrus neurogenesis were determined using Doublecortin (DCX) immunohistochemistry in the hippocampus of 50-day-old male pups. DCX-positive cells in the dentate gyrus were counted and compared between the groups. Lead exposure caused a significant increase in blood and brain lead concentration vs. control (P < 0.001); whereas, co-administration of ascorbic acid or garlic + lead was effective in reducing blood and brain lead levels (P < 0.01). The number of DCX-positive cells in the dentate gyrus of the lead-exposed group was significantly lower, when compared with controls. A statistically significant increase in number of DCX-positive cells in ascorbic acid and garlic groups compared with lead-exposed rats was noted (P < 0.05). This study provides evidence of the beneficial role of ascorbic acid and garlic in early status of dentate gyrus neurogenesis in rats against lead exposure.