본 연구에서 WEC를 제조하고 이의 항산화 활성과 멜라닌 생성 억제 효과를 측정하였다. 항산화 활성으로는 DPPH 라디칼 소거능, 환원력 및 총 폴리페놀 함량을 측정하였으며, DPPH 라디칼 소거능에서 73.98%의 높은 소거능을 나타냈으며, WEC의 환원력은 42.11 μM으로 Cu<SUP>2+</SUP>을 Cu<SUP>1+</SUP> 이온으로 환원하였고, 이는 항산화 활성이 높은 ascorbic acid와 유사한 수준을 나타냈다. 또한, WEC의 총 폴리페놀 함량은 1.74, 4.05, 6.77, 11.36 및 19.24 μg GAE/mL로 농도가 증가함에 따라 증가하였고, 이는 DPPH 라디칼 소거능과 환원력과의 연관성이 있음을 확인하였다. 게다가 B16F10 세포에서 WEC의 멜라닌 생합성 억제 활성은 농도가 증가함에 따라 유의적으로 저해하였다. 본 연구 결과를 종합해 볼 때, 백년초 열매의 항산화 효과를 증명하였으며, 멜라닌 형성 억제 소재로서의 기능성이 있음을 시사하였다.
Opuntia ficus-indica var. saboten, commonly known as cactus, is recognized for its bioactive component, β-cyanin, which has been found to have beneficial effects on pain relief, blood circulation, and detoxification. In this study, we investigated the antioxidant and anti-melanogenic activities of the hot water extracts of Opuntia ficus-indica var. saboten. Various in vitro assays were conducted, including evaluation of total phenolic content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and reducing potential. The total phenolic content of the hot water extract (WEC) was determined to be 1.74, 4.05, 6.77, 11.36, and 19.24 μg GAE/mL (w/w-hot water extract) at concentrations of 10 to 400 μg/mL. The results revealed significant antioxidant activity of WEC through the effective scavenging of DPPH radicals. WEC exhibited DPPH radical scavenging activity ranging from 7.24% to 73.98% compared to the control (no treatment) at concentrations of 10 to 400 μg/mL. Additionally, the WEC demonstrated robust reducing potential comparable to the positive control (ascorbic acid) at concentrations of 200 and 400 μg/mL. The cytotoxicity of WEC was evaluated using the thiazolyl blue tetrazolium bromide (MTT) assay, and subsequent tests were conducted on B16F10 cells using WEC concentrations ranging from 10 to 400 μg/mL. Remarkably, the WEC treatment exhibited inhibitory effects on melanin accumulation in B16F10 cells, as observed through microscopic examination. These findings indicate that WEC possesses antioxidant and anti-melanogenic effects, making it a potential functional food ingredient.