Curcumin, the Main Part of Turmeric, Prevents Learning and Memory Changes Induced by Sodium Metabisulfite, a Preservative Agent, in Rats

Abstract

Sodium metabisulfite is used as a disinfectant, antioxidant, and preservative agent in the food, beverage, and drug industries. Neurons are highly sensitive to sulfite toxicity. Curcumin is the main part of turmeric and has neuroprotective effects on a variety of nervous system damages. The present study aimed to investigate the possible protective role of curcumin in learning and memory after exposure to sulfite in rats. The rats were divided into five groups receiving distilled water (solvent of the sulfite), olive oil (solvent of the curcumin), sodium metabisulfite (25 mg/kg/day), curcumin (100 mg/kg/day), and sulfite + curcumin. All the animals received daily gavages for 8 weeks. At the end of the 8th week, learning and memory were assessed in a partially-baited eight arm radial maze. The animals treated with sulfite showed fewer correct choices and more reference and working memory errors during the learning phase, at the end of the learning phase, and during the retention testing (p<0.001). The study results demonstrated that sulfite-exposure was associated with impaired learning and memory in rats. Adding curcumin to the rat nutrition plays a protective role in learning and memory after exposure to sulfite.