Background and Objective: In recent years, the trend of using natural compounds in cosmetics and drugs is increasing as it has proved to be effective with fewer side effects. Although many herbs have been studied, there has not really been a study on the Wedelia trilobata plant about the ability to treat melasma, more specifically, toxicity on the epithelial cancer cell line. This study aimed to evaluate the total content of flavonoids and phenolic in the Wedelia trilobata and specifically to evaluate the tyrosinase inhibitory activity, anti-UV activity and cytotoxicity of plant extract. Materials and Methods: In this study, Wedelia trilobata were planted and treated with salinity to obtain an ethanolic extract of the Wedelia trilobata plant in different experimental treatments. Quantitation of total flavonoid content (TFC) and total phenolic content (TPC) was done using the aluminum chloride colorimetric assay and Folin and Ciocalteu’s phenol reagent, respectively. The SPF value of the extracts was determined by ultraviolet spectrophotometry. Results: Three salinity treatments of Wedelia trilobata showed that the highest levels of flavonoids and phenolic were 3.48 mg QE g–1 and 2.81 mg GA g–1, respectively. At a sample concentration of 256 μg mL–1, three extract samples were found to have the strongest cytotoxicity on cancer cells with the inhibitory rate ranging from 17-25%. Extract samples grown in 0‰ salinity of this plant have shown a significant SPF value of 22.992. Furthermore, it also performs greatly in inhibiting tyrosinase with the lowest IC50 value (27.98 μg mL–1). The mentioned findings have proved that Wedelia trilobata can also be a promising source of organic yet inexpensive compounds for both cosmetology and pharmaceutical products. Conclusion: This paper provides the foundation for future research to find more potential botanical sources for the treatment of carcinoma.