Parboiled Germinated Brown Rice Decreases Inflammatory Cytokines Levels in Various Regions of Brain in Rats Induced by Carbon Tetrachloride

Abstract

Parboiled germinated brown rice (PGBR) from the Khao Dawk Mali 105 (KDML 105) Thai rice strain is well-known for its nutrients and bioactive compounds. This research was conducted to determine the protective effect of PGBR on carbon tetrachloride (CCl4)-induced brain inflammation. Thirty-five male Sprague-Dawley rats were randomly divided into five groups: (I) control group (basal diet); (II) CCl4 group (basal diet); (III) white rice + CCl4 group; (IV) brown rice + CCl4 group, and (V) PGBR + CCl4 group. PGBR, brown rice and white rice diets were produced by replacing cornstarch in basal diet with cooked PGBR, brown rice, and white rice, respectively. Twice weekly, each rat was orally administrated with 1 mL/kg of CCl4 in olive oil (1:1, v/v). After eight weeks, all rats were subjected to carbon dioxide euthanasia. The cerebral cortex, hippocampus and cerebellum were dissected and homogenised to evaluate the levels of tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β), and interleukin 6 (IL-6). It was observed that the administration of CCl4 induced the elevation of the TNF-α and IL-1β levels in all brain tissues, as well as the blood ammonia and serum liver functions also rose. However, there was a significant reduction in the levels of TNF-α and IL-1β in the cerebral cortex, hippocampus and cerebellum in the PGBR + CCl4 group compared to the CCl4 group (P<0.05), whereas the blood ammonia and serum liver functions were also decreased. These findings suggest that regular consumption of PGBR may prevent CCl4-induced brain inflammation.