Pau‐Ling Tee, Salmah Yusof and Suhaila Mohamed
A study was conducted to determine the antioxidative properties of roselle (Hibiscus sabdariffa L.) methanol extract by monitoring the formation of diene‐conjugated compounds and…
Abstract
A study was conducted to determine the antioxidative properties of roselle (Hibiscus sabdariffa L.) methanol extract by monitoring the formation of diene‐conjugated compounds and thiobarbituric acid reactive substances (TBARS) in linoleic acid model system. The properties were compared to those of butylated hydroxy‐anisole (BHA) and α‐tocopherol. Results indicated that the roselle extract showed stronger antioxidant properties than BHA or α‐tocopherol. A total of 200 parts per million (ppm) of the extract inhibited more than 85 per cent of diene‐conjugated compounds after seven days of incubation at 40○C. The total phenolic compound was found to be 2.96mg/g calyx as gallic acid equivalent. This indicates that roselle is a good source of natural antioxidants which may protect the body from damage by free radicals and lipid peroxidation. The protective effect is probably through the action of highly bioavailable ascorbic acid, β‐carotene and phenolic compounds, especially the anthocyanins.
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Pau‐Ling Tee, Salmah Yusof, Suhaila Mohamed, Nor Aimi Umar and Noordin Mohamed Mustapha
The efficacy of roselle as a functional food has been revealed lately, especially for its antioxidant bioactivity. In this study, the benefits of roselle were further studied in…
Abstract
The efficacy of roselle as a functional food has been revealed lately, especially for its antioxidant bioactivity. In this study, the benefits of roselle were further studied in vivo using the model of male Sprague Dawley rats fed with normal diets (C), 2.5 percent roselle (R), 2.5 percent roselle with 15 percent soybean oil (RO) and 15 percent soybean oil (O) for 25 weeks. The results demonstrated that supplementation of roselle in the diets significantly (p < 0.05) reduced the gross body weight and increased the high‐density lipoproteins cholesterol (HDL‐C) compared to the rats fed with normal diets and oil diets, and reduced the level of triglycerides in the serum. Serum total cholesterol of R group decreased compared to C but increased in RO compared to O group. Significant increase (p < 0.05) of serum uric acid was observed in R group at week 15 and 20. Addition of roselle in oil diet significantly decreased (p < 0.05) the malondialdehyde formation at week 20 and 25 but there was no significant effect of roselle on the catalase activity among the treatments at all time points. Suggests that roselle might play a role in the prevention of atherosclerosis and obesity.