冇骨消葉萃取物之抗氧化及抗發炎活性探討

冇骨消 (Sambucus formosana) 為原住民間常用於治療骨折疼痛及跌打挫傷之中草藥。然而目前台灣產之冇骨消科學文獻相當稀少，因此進而研究其抗氧化活性、抗發炎能力及分析生物活性成分。將冇骨消葉以95oC熱水及不同濃度乙醇 (25%、50%、75%) 進行萃取，經減壓濃縮後分析其抗氧化能力及對 LPS誘導小鼠巨噬細胞RAW264.7發炎反應之影響。實驗結果顯示，總酚以75%乙醇萃取含量為最高達124.42 mg/g；總類黃酮含量75%乙醇萃取物為227.92 mg/g、50%乙醇萃取物216.25 mg/g；DPPH自由基清除能力以95oC熱水萃取、50%及75%乙醇萃取三者效果皆相當，於100 μg/mL時，三者清除率皆達93%；ABTS自由基清除能力以熱水萃取為最佳其清除率為81%；還原能力以75%乙醇萃取的效果為最佳，於1000 μg/mL其還原力為81%。冇骨消葉萃取物經HPLC-DAD分析並與標準品之滯留時間比對，發現冇骨消葉具有兒茶素、綠原酸、咖啡酸、芸香苷、楊梅素及槲皮素。而冇骨消葉萃取物於濃度800 μg/mL以下對 RAW264.7巨噬細胞處理24小時不具有細胞毒性，且與LPS (1 μg/mL) 共處理24小時下也不具有細胞毒性。以LPS (1 μg/mL)誘導RAW264.7 巨噬細胞發炎，測定冇骨消葉萃取物對巨噬細胞之NO生成量。結果顯示50%及75%之乙醇萃取物具有較佳之抑制NO生成能力，且對降低NO之含量具有濃度依賴性，於600 μg/mL時，抑制NO生成量分別達到6.1 μM及6.3 μM 。冇骨消葉75%乙醇萃取物亦可顯著抑制促發炎因子TNF-α、IL-1β、IL-6及PGE2之生成量，且於西方墨點法中亦可顯著抑制iNOS及COX-2之蛋白表現量。綜合上述結果冇骨消葉具有顯著之抗氧化能力及抑制發炎介質生成之效果，未來冇骨消可做為保健食品之開發。

關鍵字

冇骨消；小鼠巨噬細胞；脂多醣；抗氧化；發炎

並列摘要

Sambucus formosana is most used as a traditional herb medicine in Taiwan. However, the scientific literature study on Sambucus formosana is quite scarce. Thus, the objective of this study was to determine phytochemical contents, antioxidant activities and the effect on LPS-induced inflammatory response in murine RAW264.7 macrophages of Sambucus formosana. The leaves were extracted with 95oC hot water and different concentrations of ethanol (25%, 50%, 75%). The results showed that the highest total phenolic and total flavonoid contents were observed in 75% ethanol extract, which were 124.42 mg/g and 227.92 mg/g, respectively. The results illustrated that extract, using hot water, possessed the greatest ABTS radical scavenge, its capacity is above 81%. Sambucus formosana leaf extracts demonstrated the great inhibition rate to scavenge DPPH free radical is up to 93% by hot water, 50% ethanol and 75% ethanol extracts at 100 μg/mL. The extract presented the best reducing power in 75% ethanol, at 1000 μg/mL, which up to 76%. The phenolic compounds of Sambucus formosana leaf extracts were analyzed by HPLC and found containing catechin, chlorogenic acid, caffeic acid, rutin, myricetin and quercetin. In cell test, MTT cell viability assay showed that Sambucus formosana leaf extracts indicated little cytotoxic effect either to RAW264.7 macrophages treated for 24 hours at concentrations below 800 μg/mL or co-treated with LPS (1 μg/mL). Using LPS (1 μg/mL) to induce inflammation in RAW264.7 macrophages and effect of Sambucus formosana leaf extracts on NO production was measured. The results illustrated that 50% and 75% exhibition NO production was observed. The 75% ethanol extracts from Sambucus formosana leaf extracts was found significantly to inhibit on the production of TNF-α, IL-1β, IL-6, PGE2 and COX-2, iNOS protein expression. Conclusively, Sambucus formosana leaf extracts exposed not only the potential natural antioxidant sources but also inhibited the production of inflammatory mediators and could be developed as a nutraceutical food.