| dc.description.abstract | Background: Hyperpigmentation can occur due to sun exposure, hormonal imbalances, and inflammation. The lerak plant has the potential for research and development as a natural depigmentation product. Previous in vitro studies have stated that lerak seed extract is helpful for anti-hyperpigmentation by providing inhibition effects on tyrosinase enzyme, free radical scavenging, and anti-proliferation. Therefore, further in vivo, research is needed on animal models to determine the inhibitory effects of lerak seed extract on melanin pigments.
Objective: To determine the effect of lerak seed extract (S. rarak) on inhibiting the number of melanin pigments on the guinea pig skin (C. porcellus) model induced by sunlight exposure.
Subjects and methods: This experimental laboratory study uses a post-test-only controlled group design. Twenty-four male guinea pigs were divided into six experimental groups, each consisting of four guinea pigs. All groups of guinea pigs were then induced with sunlight exposure three times a week for 60 minutes from 10:00 a.m. to 12:00 p.m. in good weather (no rain) for three weeks to stimulate melanin formation on the guinea pigs' skin. At the end of the third week, group P1 (normal control) was terminated, and histological preparations were made using Masson-Fontana staining. Group P2 (negative control: base cream), Group P3 (positive control: 4% hydroquinone), Group P4 (0.5% lerak seed extract), Group P5 (1% lerak seed extract), and Group P6 (2% lerak seed extract) then had the cream applied every morning and evening and continued to be exposed to sunlight until a total of eight weeks of irradiation had been completed. Groups P2, P3, P4, P5, and P6 were terminated at the end of the eighth week, and histological preparations were made using Masson-Fontana staining. The histopathological preparations of all groups were examined in four fields of view, and the mean value of the number of melanin pigments in guinea pig skin was calculated using ImageJ® software. All data obtained were analyzed using ANOVA and followed by Post hoc tests.
Results: The group of guinea pigs that received treatment with lerak seed extract with the lowest melanin pigmentation was found in group P6 (2% lerak seed extract) with a mean melanin pigmentation of 3%. Guinea pigs in group P5 (1% lerak seed extract) had a mean melanin pigmentation of 3.77%, and those in group P4 (0.5% lerak seed extract) had a mean melanin pigmentation of 5.54%. The results of the one-way ANOVA test showed a significant difference in the amount of melanin pigmentation among the six treatment groups (p<0.001). The post hoc test using the Bonferroni test showed that applying 1% and 2% lerak seed extract cream on the guinea pig skin can significantly inhibit melanin pigmentation compared to the group that only received the base cream (p<0.05).
Conclusion: The application of a cream containing lerak seed extract (S. rarak) at concentrations of 0.5%, 1%, and 2% has been proven to inhibit the increase of melanin pigments in the skin of guinea pig model (C. porcellus) induced by exposure to sunlight. The higher the concentration of the cream used, the greater the inhibitory effect on the increase in the amount of melanin pigments that occur. | en_US |
