Department of Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University, Pathumthani 12120, Thailand.
Center of Excellence in Applied Thai Traditional Medicine Research, Thammasat University, Pathumthani 12120, Thailand.
J Integr Med. 2017 Jul;15(4):310-319. doi: 10.1016/S2095-4964(17)60334-0.
To investigate the antioxidant activities as well as phytochemical constituents of Antidesma thwaitesianum Müll. Arg. leaf extracts.
The leaves of A. thwaitesianum were extracted using three different methods: blending with distilled water, maceration with ethanol and decoction. The chemical antioxidant activity of the plant leaf extracts was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) radical and 2,2'-azinobis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS⁺) radical scavenging assays, as well as the ferric reducing antioxidant power assay. Cellular antioxidant activity was determined by superoxide and nitric oxide scavenging assays. The cytotoxicity of the leaf extracts in RAW 264.7 and differentiated HL-60 cells was tested in parallel using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays, respectively. The total phenolic and flavonoid contents were also assessed by spectrophotometric analysis. Phytochemical constituents of the most potent extract were investigated by liquid chromatography with an electrospray ionization quadrupole time-of-flight mass spectrometer (LC-ESI-QTOF-MS/MS).
The ethanolic (ME) and decoction (LW) extracts of dried leaves had the highest chemical scavenging activity against DPPH and ABTS⁺ free radicals with half maximal effective concentration (EC) values ranging from 3.54 to 6.44 μg/mL. ME and LW exerted moderate ferric reducing activity, with ferric reducing antioxidant power values of 847.41 and 941.26 mg Fe/g extract, respectively. Similarly, ME showed potent cellular scavenging activity against superoxide and nitric oxide radicals with EC values of 58.12 and 71.90 μg/mL, respectively. However, LW exhibited only strong nitric oxide scavenging activity with an EC value of 91.20 μg/mL. The cell viability of RAW 264.7 and HL-60 cells was greater than 70% in all tested concentrations of both extracts, thus confirming the absence of their cytotoxicity. ME and LW contained high total phenolic contents of 231.14 and 274.42 mg gallic acid equivalents per gram, respectively, as well as high total flavonoid contents of 18.82 and 22.17 mg quercetin equivalents per gram, respectively. LC-ESI-QTOF-MS/MS analysis revealed the presence of 52 structurally characterized compounds in ME, 43 of which were tentatively identified. Hydroxycinnamic acids such as caffeic acid and its derivatives were the predominant phenolic compounds.
This is the first report describing potent chemical and cellular antioxidant effects of the ethanolic leaf extract of A. thwaitesianum. The extract contained high total phenolic and flavonoid contents. LC-ESI-QTOF-MS/MS analysis further revealed an abundance of caffeic acid derivatives and flavonoids. These data support its potential use as dietary supplements in oxidative stress prevention.
研究 Antidesma thwaitesianum Müll. Arg. 叶提取物的抗氧化活性和植物化学成分。
采用水混合、乙醇浸提和水煮三种方法从 A. thwaitesianum 叶片中提取植物提取物。采用 2,2-二苯基-1-苦基肼（DPPH）自由基和 2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS⁺）自由基清除实验，以及铁还原抗氧化能力（FRAP）测定法评估植物叶提取物的化学抗氧化活性。通过超氧阴离子和一氧化氮清除实验测定细胞抗氧化活性。同时采用 3-(4,5-二甲基-2-噻唑基)-2,5-二苯基-2H-四唑溴盐（MTT）和 3-(4,5-二甲基噻唑-2-基)-5-(3-羧基甲氧基苯基)-2-(4-磺基苯基)-2H-四唑（XTT）测定法分别平行测定 RAW 264.7 和分化 HL-60 细胞中叶片提取物的细胞毒性。采用分光光度法评估总酚和总黄酮含量。采用液相色谱-电喷雾电离四极杆飞行时间质谱联用仪（LC-ESI-QTOF-MS/MS）分析最有效提取物的植物化学成分。
干叶的乙醇（ME）和水煮（LW）提取物对 DPPH 和 ABTS⁺自由基具有最高的化学清除活性，半数最大有效浓度（EC）值在 3.54 至 6.44 μg/mL 之间。ME 和 LW 具有适度的铁还原活性，铁还原抗氧化能力值分别为 847.41 和 941.26 mg Fe/g 提取物。同样，ME 对超氧阴离子和一氧化氮自由基具有较强的细胞清除活性，EC 值分别为 58.12 和 71.90 μg/mL。然而，LW 仅对一氧化氮具有较强的清除活性，EC 值为 91.20 μg/mL。在所有测试浓度下，RAW 264.7 和 HL-60 细胞的细胞活力均大于 70%，这证实了提取物没有细胞毒性。ME 和 LW 分别含有 231.14 和 274.42 mg 没食子酸当量/克的高总酚含量，以及 18.82 和 22.17 mg 槲皮素当量/克的高总黄酮含量。LC-ESI-QTOF-MS/MS 分析表明，ME 中存在 52 种结构特征明确的化合物，其中 43 种被推测为其结构。羟基肉桂酸类如咖啡酸及其衍生物是主要的酚类化合物。
这是首次报道 Antidesma thwaitesianum 乙醇叶提取物具有强大的化学和细胞抗氧化作用。提取物含有丰富的总酚和总黄酮。LC-ESI-QTOF-MS/MS 分析进一步揭示了丰富的咖啡酸衍生物和类黄酮。这些数据支持其作为预防氧化应激的膳食补充剂的潜在用途。
