Programme of Biomedical Science, Centre of Applied and Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
Asian Pac J Cancer Prev. 2020 Nov 1;21(11):3381-3386. doi: 10.31557/APJCP.2020.21.11.3381.
Traditional cooling rice powder (bedak sejuk) is a fermented rice-based cosmetic that is applied topically on one's skin, as an overnight facial mask. According to user testimonies, bedak sejuk beautifies and whitens skin, whereby these benefits could be utilised as a potential melanoma chemopreventive agent.
Hence, this study aimed to determine the effects of bedak sejuk made from Oryza sativa ssp. indica (Indica) and Oryza sativa ssp. japonica (Japonica) on UVB-induced B164A5 melanoma cells, and also identify the antioxidant capacities of both types of bedak sejuk.
The optimum dose of Indica and Japonica bedak sejuk to treat the cells was determined via the MTT assay. Then, the antioxidant capacities of both types of bedak sejuk were determined using the FRAP assay.
From the MTT assay, it was found that Indica and Japonica bedak sejuk showed no cytotoxic effects towards the cells. Hence, no IC50 can be obtained and two of the higher doses, 50 and 100 g/L were chosen for treatment. In the FRAP assay, Indica bedak sejuk at 50 and 100 g/L showed FRAP values of 0.003 ± 0.001 μg AA (ascorbic acid)/g of bedak sejuk and 0.004 ± 0.0003 μg AA/g of bedak sejuk. Whereas Japonica bedak sejuk at 50 g/L had the same FRAP value as Indica bedak sejuk at 100 g/L. As for Japonica bedak sejuk at 100 g/L, it showed the highest antioxidant capacity with the FRAP value of 0.01 ± 0.0007 μg AA/g of bedak sejuk which was statistically significant (p < 0.05) when compared to other tested concentrations.
In conclusion, Japonica bedak sejuk has a higher antioxidant capacity compared to Indica bedak sejuk despite both being not cytotoxic towards the cells. Regardless, further investigations need to be done before bedak sejuk could be developed as potential melanoma chemoprevention agents.
传统的爽身粉（bedak sejuk）是一种发酵的米粉化妆品，涂在皮肤上，作为过夜面膜。根据用户的证言，爽身粉可以美化和美白皮肤，因此这些好处可以用作潜在的黑色素瘤化学预防剂。
因此，本研究旨在确定来自 Oryza sativa ssp. indica（Indica）和 Oryza sativa ssp. japonica（Japonica）的爽身粉对 UVB 诱导的 B164A5 黑色素瘤细胞的影响，并确定这两种爽身粉的抗氧化能力。
通过 MTT 测定法确定治疗细胞的 Indica 和 Japonica 爽身粉的最佳剂量。然后，使用 FRAP 测定法测定这两种爽身粉的抗氧化能力。
从 MTT 测定中发现，Indica 和 Japonica 爽身粉对细胞没有细胞毒性作用。因此，无法获得 IC50，选择了两个较高的剂量，50 和 100 g/L 进行治疗。在 FRAP 测定中，Indica 爽身粉在 50 和 100 g/L 时的 FRAP 值分别为 0.003 ± 0.001 μg AA（抗坏血酸）/g 爽身粉和 0.004 ± 0.0003 μg AA/g 爽身粉。而 Japonica 爽身粉在 50 g/L 时与 Indica 爽身粉在 100 g/L 时具有相同的 FRAP 值。至于 Japonica 爽身粉在 100 g/L 时，其 FRAP 值最高，为 0.01 ± 0.0007 μg AA/g 爽身粉，与其他测试浓度相比具有统计学意义（p < 0.05）。
总之，尽管两种爽身粉对细胞均无细胞毒性作用，但 Japonica 爽身粉的抗氧化能力高于 Indica 爽身粉。然而，在爽身粉可以开发为潜在的黑色素瘤化学预防剂之前，还需要进一步的研究。
