College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China.
J Agric Food Chem. 2011 Jul 27;59(14):7948-53. doi: 10.1021/jf2016368. Epub 2011 Jun 22.
Loach protein hydrolysates (LPH) prepared by papain digestion were fractionated into four fractions, LPH-I (MW > 10 kDa), LPH-II (MW = 5-10 kDa), LPH-III (MW = 3-5 kDa), LPH-IV (MW < 3 kDa), and the in vitro antioxidant and antiproliferative (anticancer) activities of all fractions were determined. LPH-IV showed the lowest IC(50) value (16.9 ± 0.21 mg/mL) for hydroxyl radical scavenging activity and the highest oxygen radical scavenging capacity (ORAC) value (reaching 215 ± 5.9 mM Trolox/100 g loach peptide when the concentration was 60 μg/mL). Compared with other fractions, LPH-IV also exhibited stronger antiproliferative activity for human liver (HepG2), breast (MCF-7), and colon (Caco-2) cancer cell lines in a dose-dependent manner. When the protein concentration was 40 mg/mL, the HepG2 and MCF-7 cell proliferation of LPH-IV reached 7 and 4%, respectively, with no significant difference from those of LPH (8 and 7%, p > 0.05), with significantly less growth than those of LPH-I, LPH-II, and LPH-III, respectively (p < 0.05). The Caco-2 colon cell proliferation of LPH-IV was 12.8- and 8.7-fold smaller than those of LPH-I and LPH-II, respectively (p < 0.05). All of the fractions had a greater ability to inhibit Caco-2 colon cancer cell proliferation than to inhibit HepG2 liver cancer and MCF-7 breast cancer cell proliferation. The ORAC values of most of the fractions correlated (R(2) > 0.86, p < 0.01) with the antiproliferative activity of the three cancer cell lines, suggesting that higher antioxidant activity leads to better antiproliferative activity. However, further mechanistic and human clinical studies of the anticancer activity of loach protein hydrolysate fractions are needed.
泥鳅蛋白水解物（LPH）经木瓜蛋白酶消化后分为四个部分，LPH-I（MW>10 kDa）、LPH-II（MW=5-10 kDa）、LPH-III（MW=3-5 kDa）和 LPH-IV（MW<3 kDa），并测定了所有部分的体外抗氧化和抗增殖（抗癌）活性。LPH-IV 对羟基自由基清除活性的 IC50 值（16.9±0.21mg/mL）最低，氧自由基清除能力（ORAC）值最高（当浓度为 60μg/mL 时，达到 215±5.9mM Trolox/100g 泥鳅肽）。与其他部分相比，LPH-IV 对人肝癌（HepG2）、乳腺癌（MCF-7）和结肠癌（Caco-2）癌细胞系的增殖也具有更强的剂量依赖性抑制活性。当蛋白质浓度为 40mg/mL 时，LPH-IV 对 HepG2 和 MCF-7 细胞的增殖分别达到 7%和 4%，与 LPH 相比无显著差异（分别为 8%和 7%，p>0.05），与 LPH-I、LPH-II 和 LPH-III 相比，生长明显减少（分别为 p<0.05）。LPH-IV 对 Caco-2 结肠癌细胞的增殖抑制作用分别比 LPH-I 和 LPH-II 低 12.8 倍和 8.7 倍（p<0.05）。所有部分抑制 Caco-2 结肠癌的增殖能力均大于抑制 HepG2 肝癌和 MCF-7 乳腺癌的增殖能力。大多数部分的 ORAC 值与三种癌细胞系的增殖抑制活性相关（R2>0.86，p<0.01），表明更高的抗氧化活性导致更好的增殖抑制活性。然而，需要进一步对泥鳅蛋白水解物部分的抗癌活性进行机制和人体临床研究。
