Hernandezine induces autophagic cell death in human pancreatic cancer cells via activation of the ROS/AMPK signaling pathway.

Hernandezine (Her) is a bisbenzylisoquinoline alkaloid extracted from the traditional Chinese herbal medicine Thalictrum glandulosissimum. Evidence shows that Her is a natural agonist of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and induces apoptosis and autophagy in tumor cells. In this study, we investigated the role of autophagy in Her-induced cell death in human pancreatic cancer cell lines. We showed that Her dose-dependently suppressed cell proliferation, promoted autophagy and induced autophagic death in pancreatic ductal adenocarcinoma (PDAC) cell lines Capan-1 and SW1990. The IC50 values of Her in inhibition of Capan-1 and SW1990 cells were 47.7 µM and 40.1 µM, respectively. Immunoblotting showed that Her (1-40 µM) promoted the conversion of LC3-I to LC3-II, and Her exerted concentration-dependent and time-dependent effects on autophagy activation in PDAC cells. In transmission electron microscopy and fluorescence image analysis, we found that autophagic vacuoles were significantly increased in Her-treated cells. Knockdown of ATG5, a key gene in the autophagy pathway, alleviated the activation of autophagy by Her. These results demonstrated that Her induced autophagy in PDAC cells. Intensely activated autophagy could promote cell death. The autophagy inhibitors, BafA1 and HCQ significantly inhibited Her-induced cell death, implying that Her induced autophagic cell death in PDAC cells. Moreover, we showed that Her activated autophagy by increasing the phosphorylation of AMPK and decreasing the phosphorylation of mTOR/p70S6K. Knockdown of AMPKα relieves the autophagic cell death induced by Her. Furthermore, Her concentration-dependently enhanced reactive oxygen species (ROS) generation in PDAC cells. Antioxidants could reduce the phosphorylation of AMPK and suppress autophagic cell death induced by Her. Our study provides evidence for the development of Her as a therapeutic agent for the treatment of pancreatic cancer.

[Effect of Ginkgo biloba extract on the function of alveolar polymorphonuclear neutrophils in severe acute pancreatitis rats complicated with lung injury].

OBJECTIVE: To explore the effect of Ginkgo biloba extract (GBE) on the function of alveolar polymorphonuclear neutrophils (PMN) in severe acute pancreatitis (SAP) rats complicated with lung injury (LI). METHODS: Forty-eight adult SD rats were randomly divided into three groups, i.e., the sham-operation group, the SAP group, and the GBE treatment group, 16 in each group. The SAP model was successfully induced by retrograde injection of 5% sodium taurocholate solution into the biliopancreatic duct. Rats in the sham-operation group only received flipping of the duodenum. Those in the GBE treatment group received GBE intervention based on SAP model. Equal volume of normal saline was given to rats in the sham-operation group and the SAP group. Rats were sacrificed at 6 and 12 h after operation respectively. The lung tissue was sampled to evaluate the LI score. The wet/dry ratio (W/D) of lung tissues was detected. The activity of myeloperoxidase (MPO) was measured. Alveolar PMN was harvested by bronchoalveolar lavage. The content of neutrophil elastase (NE) in bronchoalveolar lavage fluid (BALF) was measured by enzyme-linked immunoabsorbent assay (ELISA). The percentage of CD11b/CD18 double positive PMN was detected using flow cytometry. The expression of intercellular adhesion molecule-1 (ICAM-1) and NE protein in the lung tissue was detected by Western blot. RESULTS: Compared with the sham-operation group, significant pathologic lesion occurred in the lung tissue of rats in the SAP group; the pathologic LI score, lung tissue W/D ratio, MPO, and NE content in BALF significantly increased, the expression of ICAM-1 and NE in the lung tissue was obviously up-regulated, and the percentage of CD11b/CD18 double positive PMN significantly increased (P < 0.01). Compared with the SAP group, pathological lesion of the lung tissue was obviously attenuated, and the above indices were all significantly declined in the GBE treatment group (P < 0.01). CONCLUSIONS: Expression of ICAM-1 in the lung tissue and the percentage of D11b/ CD18 double positive PMN were up-regulated in SAP rats complicated with LI, resulting in the adherence of PMN to pulmonary vascular endothelial cells, and then activating PMN to release NE and aggravate LI. GBE could alleviate LI through down-regulating the expression ICAM-1 and CD11b/CD18, and hindering the adherence and activation of PMN to pulmonary vascular endothelial cells.

Effects of phytoestrogen on mitochondrial structure and function of hippocampal CA1 region of ovariectomized rats.

The present study was undertaken to evaluate whether estrogen deprivation might lead to mitochondrial alteration of hippocampal neurons of ovariectomized (OVX) rats, and to evaluate the protective effect of estrogen and phytoestrogen on the mitochondrial alteration. First, OVX rats were used to mimic the pathologic changes of neurodegeneration of postmenopausal female, and we looked into the alteration of the mitochondrial ultrastructure and ATP content of hippocampal CA1 region after ovariectomy on different phase by transmission electron microscope (TEM) and reversed-phase high-performance liquid chromatography (HPLC), and found the best phase points of the alteration of the mitochondrial ultrastructure and ATP content. Next, estrogen and phytoestrogen were administered to the OVX rats for the protective effects on the mitochondrial ultrastructure and ATP content. Meanwhile, the density, size, shape, and distribution parameters of mitochondrial ultrastructure were analyzed according to the morphometry principle. The experimental results presented that (1) The alteration of mitochondrial ultrastructure elicited by ovariectomy worsened with the days going on, and the changes were the most noteworthy in volume density (Vv), average surface area (S), specific surface area (delta), and particle dispersity (Clambdaz) on 12th day (P < 0.05 or P < 0.01). Moreover, there was no statistical significance of the numerical density (Nv) among the five groups in the first step experiment. (2) The treatment with estrogen, genistein (Gs), and ipriflavone (Ip) significantly reversed the effect elicited by ovariectomy on Vv, S, delta, Clambdaz, Nv, and particle average diameter (D) of mitochondria of hippocampal CA1 region (P < 0.05). (3) Furthermore, ATP content of hippocampal CA1 region after ovariectomy declined significantly on 7th day (P < 0.05), and estrogen and phytoestrogen could reverse the alteration (P < 0.05). Taken together, these results revealed that phytoestrogen may have a protective role against the neurodegeneration after menopause via protecting mitochondrial structure and functions. Phytoestrogen may be a good alternative as a novel therapeutic strategy for menopausal syndrome.