Evaluation of Antioxidant Activity of R. Slooffiae, R. Mucilaginosa Extracts

Antioxidants are health beneficial compounds that can protect cells and macromolecules from the damage of reactive oxygen species (ROS). The aims of this study were to compare the total antioxidant and carotenoid production in R. Slooffiae and R. Mucilaginosa.

To isolate the carotenoid pigment, cells were suspended in acetone and broken using a homogenizer, followed by centrifugation, and supernatant was separated. For analytical method, pigments were measured spectrophotometrically at 450 nm. The B-carotene bleaching and 1, 1-diphenyl-2-picrylhdrazyl (DPPH) assay were used to determine antioxidant properties of R. Slooffiae and R. Mucilaginosa by measuring the decrease in absorbance at 470 and 517 nm.

The results showed that the content of total carotenoid in R. Slooffiae was higher than R. Mucilaginosa and it presented higher ability to show antioxidant activity. The mean total antioxidant activity of ascorbic acid was the highest (97.11 ± 6.11%), followed by BHT (64.71 ± 5.41%), R. sloofias extract (57.91 ± 7.34%) and R. Mucilaginosa (39.32 ± 5.85%). The EC50 of ascorbic acid was the strongest (0.252 ± 0.000 mg/ml), followed by BHT (0.612 ± 0.009 mg/ml) and R. Slooffiae (0.658 ± 0.033 mg/ml). There was significant difference observed between the EC50 of R. Slooffiae and BHT.

It was found that both strains have ability to produce carotenoid and show antioxidant ability; however, R. Slooffiae had more potential in producing carotenoid and showing antioxidant ability than R. Mucilaginosa. Further study is required, in order to utilize this strain in the food, pharmaceuticals and cosmetics industries.