Sub-acute Toxicity of Brown Rice Kefir Powder

Abstract

The present study was designed to determine sub-acute toxicity of kefir powders from Khao Dawk Mali 105 (KDMLKP), Red Hawm (RHKP) and Hawm Nil (HNKP) brown rice. Kefir powders at the doses of 500, 1,000 and 2,000 mg/kg were given orally to the rats every 2 days for 14 days. The results showed that all the doses of the kefir powders did not produce mortality and any symptoms of toxicity. And also, kefir powders did not alter relative organ weight in the treated rats. Increasing KDMLKP significantly increased body weight gain in contrast to RHKP and HNKP. Kefir powders produced feed conversion ratio better than that PBS, but this did not KDMLKP at the doses of 500 and 1,000 mg/kg. Kefir powders at the doses of 1,000 and 2,000 mg/kg decreased blood sugar and affected renal and/or hepatic functions as KDMLKP significantly increased globulin, RHKP significantly decreased creatinine and uric acid but increased globulin, serum aspartate aminotransferase (AST), and serum alanine aminotransferase (ALT) and HNKP significantly decreased blood urea nitrogen, uric acid, and albumin but increased globulin, AST and ALT. Kefir powder also significantly decreased neutrophils, but  increased lymphocytes.

These findings indicate that kefir powders at the dose of 500 mg/kg exert non sub-acute toxicity when the doses of 1,000 and 2,000 mg/kg administering every 2 days for 14 days decreased blood sugar and may cause renal and hepatic dysfunctions.