本研究將虎杖飲片分別以0%、10%、70%與95%等不同濃度的乙醇及甘油進行萃取,在萃取的過程中施加伽瑪照射(0、5、25與50 kGy),並將照射後的萃取物進行白藜蘆醇的定量分析以及抗氧化與抑制酪氨酸酶活性能力的評估探討。實驗結果顯示,虎杖乙醇萃取物(EEPC)中以70%EEPC 25 kGy的總白藜蘆醇含量最高,為2771.61 μg/g;另外,虎杖甘油萃取物(GEPC)中以70%GEPC 0 kGy所得的總白藜蘆醇含量最高,為2451.06 μg/g。在抗氧化能力測定實驗結果顯示,自由基清除能力隨濃度的提高而增加,呈現濃度效應,在濃度12.5 μg/mL時,EEPC中以95%EEPC 5 kGy對DPPH自由基清除能力最佳,為85.05%;另外,在濃度0.25%時,GEPC中以95%GEPC 0 kGy對DPPH自由基清除能力最佳,為60.60%。在抑制酪胺酸酶活性測定實驗結果顯示,在濃度1000 μg/mL時,EEPC中以70%EEPC 25 kGy對酪胺酸酶活性的抑制能力最佳,為62.25%;另外,在濃度10%時,GEPC中以95%GEPC 5 kGy對酪胺酸酶活性的抑制能力最佳,為65.88%。
The resveratrol (Res) contents, anti-oxidative (DPPH-free-radical-scavenging effect) and antityrosinase activities of Polygonum cuspidatum extracts (PCE) with 0%, 10%, 70% and 95% ethanol and glycerol solutions (defined as 0%, 10%, 70% and 95% EEPC and GEPC for PCE, respectively) under γ-ray irradiation (0, 5, 25 and 50 kGy) were investigated in this study. The maximum Res content (2771.61 ?g/g) was obtained from 70%EEPC under 25 kGy γ-ray irradiation (defined as 70%EEPC 25 kGy), while that (2451.06 ?g/g) was obtained from 70%GEPC without γ-ray irradiation (defined as 70%GEPC 0 kGy). Among the EEPC and GEPC dilutions of the PCE, the DPPH-scavenging effects of EEPCs and GEPCs first gradually increased to a certain value as increasing their sample concentrations or Res contents. When the sample concentration was at 12.5 ?g/mL, the most optimal value (85.05%) of DPPH-scavenging effect of EEPCs was obtained from 95%EEPC 5 kGy, while that of GEPCs was 60.60% from 95%GEPC 0kGy at 0.25% sample concentration. In addition, the best anti-tyrosinase activity (%) of EEPCs was about 62% for 70%EEPC 25 kGy when the sample concentration was at 1000 ?g/mL, while that of GEPCs was about 66% from 95%GEPC 5 kGy at 10% sample concentration.