Curcumin alleviates lung injury in diabetic rats by inhibiting nuclear factor‐κB pathway

Curcumin is a polyphenolic compound that is extracted from Curcuma longa. It has broad anti‐inflammation and anti‐tumor activities. Curcumin was previously reported to exert beneficial effects on diabetes. However, the effect of curcumin on diabetes‐induced lung injury is not yet clear. In this study, the effects of curcumin on lung injury induced by diabetes was explored using quantitative real time polymerase chain reaction (PCR), enzyme‐linked immunosorbent assay (ELISA), immunohistochemistry and electrophoretic mobility shift assay. The results of this study showed that curcumin reduced oxidative stress level, inhibited the synthesis of nitric oxide and prostaglandin E2, and reduced inflammatory responses in the lungs of diabetic rats, thereby alleviating diabetes‐induced lung injury. Further study of the mechanism revealed that curcumin inhibited the activation of nuclear factor (NF)‐κB which is a key player in inflammatory responses. In summary, our study demonstrated that curcumin inhibited the activation of NF‐κB in the lungs of diabetic rats, thus reducing pulmonary inflammatory responses and oxidative stress, and ultimately relieving diabetes‐induced lung injury. This study suggests that curcumin may be a promising agent to alleviate diabetic lung injury and also provides theoretical foundation for the development of diabetes therapy.     

姜黄素预处理对急性缺血再灌注模型大鼠肝脏的保护作用

目的：建立姜黄素预处理的大鼠急性肝脏缺血再灌注模型,初步探讨姜黄素对急性缺血再灌注后大鼠肝脏的保护作用。方法：10只SD大鼠随机分为假手术组（n=3）、溶剂对照组（n=3）和实验组（n=4）。实验组和溶剂对照组大鼠在进行急性肝脏缺血再灌注前分别腹腔注射姜黄素和1%羧甲基纤维素钠（CMC）进行预处理。假手术组大鼠不进行急性肝脏缺血再灌注。采用超高效液相色谱-质谱（UPLC-MS）联用法分析各组大鼠血清中姜黄素水平,胆管导管术和荧光分析法检测各组大鼠胆汁流量,丙二醛（MDA）试剂盒检测各组大鼠肝脏组织中MDA水平。结果：腹腔注射200mg·kg^-1姜黄素1h后大鼠血清中姜黄素水平达到（0.17±0.05）mg·L^-1,并在注射3h后降到检测线以下。实验组大鼠肝脏组织中MDA水平为（9.18±1.78）mmol·g^-1,低于溶剂对照组（527.54mmol·g^-1±237.38mmol·g^-1）和假手术组（162.73mmol·g^-1±90.50 mmol·g^-1）。实验组大鼠在缺血再灌注后胆汁流量恢复到基线的40%左右,与溶剂对照组比较差异无统计学意义（P>0.05）,假手术组大鼠胆汁流量则保持在基线水平。结论：姜黄素腹腔注射给药后能迅速进入大鼠血液循环,并在体内较快代谢,其水平在给药3h后降到检测线以下。姜黄素预处理能有效降低缺血再灌注后肝脏组织中MDA水平,对肝脏起到保护作用,但对恢复胆汁流量的效果不明显。     

Propoxur-induced oxidative DNA damage in human peripheral blood mononuclear cells: protective effects of curcumin and α-tocopherol

The present study enumerates the attenuating effects of curcumin and α-tocopherol against propoxur induced oxidative DNA damage in human peripheral blood mononuclear cells (PBMC). Cultured cells were isolated from peripheral blood of healthy volunteers, and were exposed to varying concentrations of propoxur (0–21?μg/ml) for 6, 12, and 24?h, and in combination with curcumin (9.2?μg/ml) or α-tocopherol (4.3?μg/ml) or both. Cytotoxic effect of propoxur was examined by MTT assay. The role of oxidative stress beneath the cytotoxicity of propoxur was evaluated by the measurement of reduced glutathione (GSH), malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OH-dG) levels in cell lysate. A concentration-dependent cell death, depletion of GSH, an increase in the level of both MDA and 8-OH-dG were observed. Co-treatment with curcumin or α-tocopherol significantly attenuates depleted GSH, decrease in MDA and 8-OH-dG levels in propoxur exposed cells (p?curcumin and α-tocopherol following propoxur exposure.     

Enhanced selective cellular uptake and cytotoxicity of epidermal growth factor-conjugated liposomes containing curcumin on EGFR-overexpressed pancreatic cancer cells

Pancreatic cancer is one of the most malignant cancers with a high mortality rate. Some types of pancreatic cancer cells overexpress epidermal growth factor receptor (EGFR), which is a potential target for anticancer agents. In this study, we examined the effect of epidermal growth factor (EGF)-conjugated liposomes containing curcumin (EGF-LP-Cur) on three different EGFR-expressed human pancreatic cancer cell lines, BxPC-3, Panc-1 and Mia Paca-2. We have demonstrated that it is feasible to prepare liposomal vesicles of EGF-LP-Cur and that it is stable in the liquid vehicle at ambient conditions for three weeks. In addition, the formulation of curcumin had higher cytotoxicity on BxPC-3 than on any other cells. It is also shown that the cellular uptake of curcumin on BxPC-3, which is essential for the cytotoxicity, is associated with EGFR-mediated mechanism of action. In summary, our results have showed that targeting EGFR with EGF-conjugated curcumin liposomes enhanced the antitumor activity of curcumin against human pancreatic cancer cells.