Acute Oral Toxicity (LD50) of Crude Exopolysaccharide from Rhodotorula minuta BIOTECH 2178 in ICR Mice

Abstract

Acute toxicity study on lyophilized exopolysaccharide (EPS) produced from Rhodotorula minuta BIOTECH 2178 EPS was evaluated using laboratory mice. In this study, 20 male ICR mice were divided into four (4) groups: Group I received 0.5 ml saline solution; Group II was treated with 50mg EPS/kg body weight; Group III was treated with 225mg EPS/kg body weight; and Group IV was treated with 400 mg EPS/kg body weight. Blood samples were collected via orbital sinus for hematological analysis. Body weight, feed and water consumption were recorded daily. Liver and kidney were collected for histopathological analysis after 15 days administration of EPS. Blood chemistry analysis showed that mice fed with crude EPS had comparable BUN, creatinine and ALT values with that of the control. Liver histopathological analysis of the control and treated group showed normal hepatic architecture with intact hepatic cells, nucleus, sinusoidal spaces and a central vein. Histopathological analysis of the kidney showed normal renal structure of cortex, indicating a normal architecture of renal glomeruli, proximal convoluted tubule and distal convoluted tubules. Moreover, the tubules showed a relatively regular distinct lumen of both control and treated groups. Thus, crude EPS from R. minuta BIOTECH 2178 is neither hepatotoxic nor nephrotoxic and likely to be safe for human consumption. Moreover, its safety property lays a good foundation for application of EPS in food and pharmaceutical industries.