The carotenoid extract from Dunaliella salina was identified and quantitated. The effects against cadmium (Cd)-induced hepatotoxicity
and transforming growth factor β1 (TGF-β1)-induced activation of hepatic stellate cells (HSCs) were evaluated. All-trans- β-carotene (474.82 mg/g extract) and 9- or 9′-cis-β-carotene (425.64 mg/g extract) were major carotenoids in the extract, accounting for 90.30% of total carotenoids (997.17 mg/g extract). Other carotenoids were all-trans-lutein (22.77 mg/g extract), all-trans-zeaxanthin (39.26 mg/g extract), 13- or 13′-cis-β-carotene (17.18 mg/g extract), all-trans-α-carotene (9.26 mg/g extract) and 9- or 9′-cis-α- carotene (8.24 mg/g extract). The algal extract had a higher effect (p < 0.05) than all-trans-β-carotene in the reduction of cytotoxicity for CdCl2-treated Clone 9 cells and expression of smooth muscle α-actin (αSMA) for TGF-β1-treated HSC-T6 cells. These effects were shown to be concentration-dependent.