Protective effect of Dunaliella salina -: A marine micro alga, against carbon tetrachloride-induced hepatotoxicity in rats

This is the first report on the hepatoprotective potentials of marine micro algae Dunaliella species. Dunaliella salina, halotolarent green alga was cultivated in modified autotrophic medium. The alga was subjected to light and nutrient stress in order to accumulate (P-carotene, along with other carotenoids. Such P-carotene enriched yellow cells were fed to rats by mixing with regular feed at the dose of 2.5 and of 5.0 a kg(-1) b.w. for 2 weeks. The degree of hepatoprotection was measured up on challenging animals with toxin (2.0 g kg-1 of carbon tetrachloride) by estimation of biochemical parameters like, serum transaminases (serum aspartate transaminase (S)AST and serum alanine transaminase (S)ALT), serum alkaline phosphatase and total protein. The results were compared to animals on normal diet and with group fed with 100 mu g kg(-1) b.w. of standard all trans beta-carotene. Among the three test groups the group fed with algae of 5.0 g kg(-1) body weight, showed maximum protection. The levels of (S)AST and (S)ALT was found to be 61.3 +/- 6.4 and 80.7 +/- 5.6%, against 90.8 +/- 10.5 and 144.7 +/- 13.9% in case of standard beta-carotene. The protein contents were increased in case of control to 6.1 +/- 0.7 and the same was found to be significantly less in case of 5.0 g kg(-1) Dunaliella fed group, which shown 5.6 +/- 0.8% total protein. However, the activity of 2.5 g kg(-1) was also significant comparatively (P < 0.05). The results indicate that Dunaliella, which contains isomeric forms of beta-carotene can act as good antihepatotoxic when compared to synthetic all trans beta-carotene. Dunaliella has shown the presence of both cis and trans isomeric forms of P-carotene, where as synthetic compounds contain only trans isomer. Hepatoprotectivity may be due to presence of various isomeric forms of carotene and other oxygenated carotenoids (xanthophylls) in algae. (c) 2005 Published by Elsevier Ireland Ltd.