Kazinol B protects H9c2 cardiomyocytes from hypoxia/reoxygenation-induced cardiac injury by modulating the AKT/AMPK/Nrf2 signalling pathway.

CONTEXT: Kazinol B (KB), an isoprenylated flavan derived from Broussonetia kazinoki Sieb. (Moraceae) root, has long been used in folk medicine. OBJECTIVE: This study examines the protective effects of KB and its underlying mechanisms in hypoxia and reoxygenation (H/R)-induced cardiac injury in H9c2 rat cardiac myoblasts. MATERIALS AND METHODS: H9c2 cells were incubated with various concentrations of KB (0, 0.3, 1, 3, 10 and 30 µM) for 2 h and then subjected to H/R insults. The protective effects of KB and its underlying mechanisms were explored. RESULTS: KB significantly elevated cell viability (1 µM, 1.21-fold; 3 µM, 1.36-fold, and 10 µM, 1.47-fold) and suppressed LDH release (1 µM, 0.77-fold; 3 µM, 0.68-fold, and 10 µM, 0.59-fold) in H/R-induced H9c2 cells. Further, 10 µM KB blocked apoptotic cascades, as shown by the Annexin-V/PI (0.41-fold), DNA fragmentation (0.51-fold), caspase-3 (0.52-fold), PARP activation (0.27-fold) and Bax/Bcl-2 expression (0.28-fold) assays. KB (10 µM) downregulated reactive oxygen species production (0.51-fold) and lipid peroxidation (0.48-fold); it upregulated the activities of GSH-Px (2.08-fold) and SOD (1.72-fold). KB (10 µM) induced Nrf2 nuclear accumulation (1.94-fold) and increased ARE promoter activity (2.15-fold), HO-1 expression (3.07-fold), AKT (3.07-fold) and AMPK (3.07-fold) phosphorylation. Nrf2 knockdown via using Nrf2 siRNA abrogated KB-mediated protective effects against H/R insults. Moreover, pharmacological inhibitors of AKT and AMPK also abrogated KB-induced Nrf2 activation and its protective function. DISCUSSION AND CONCLUSIONS: KB prevented H/R-induced cardiomyocyte injury via modulating the AKT and AMPK-mediated Nrf2 induction. KB might be a promising drug candidate for managing ischemic cardiac disorders.

Curcumin prevents As3+-induced carcinogenesis through regulation of GSK3ß/Nrf2.

BACKGROUND: Arsenic (As3+) is a carcinogen with considerable environmental and occupational relevancy. Its mechanism of action and methods of prevention remain to be investigated. Previous studies have demonstrated that ROS is responsible for As3+-induced cell transformation, which is considered as the first stage of As3+ carcinogenesis. The NF-E2 p45-related factor-2 (Nrf2) signaling pathway regulates the cellular antioxidant response, and activation of Nrf2 has recently been shown to limit oxidative damage following exposure to As3+ METHODS AND RESULTS: In this study, molecular docking was used to virtually screen natural antioxidant chemical databases and identify molecules that interact with the ligand-binding site of Keap1 (PDB code 4L7B). The cell-based assays and molecular docking findings revealed that curcumin has the best inhibitory activity against Keap1-4L7B. Co-immunoprecipitation (Co-IP) results indicated that curcumin is a potent Keap1 Kelch domain-dependent Nrf2 activator that stabilizes Nrf2 by hindering its ubiquitination. The increased activation of Nrf2 and its target antioxidant genes by curcumin could significantly decrease As3+-generated ROS. Moreover, curcumin induced autophagy in As3+-treated BEAS-2B via inducing autophagy by the formation of a p62/LC-3 complex and increasing autophagic flux by promoting transcription factor EB (TFEB) and lysosome-associated membrane protein 1 (LAMP1) expression. Knockdown of Nrf2 abolished curcumin-induced autophagy and downregulated ROS. Further studies showed that inhibition of autophagosome and lysosome fusion with bafilomycin a1 (BafA1) could block curcumin and prevented As3+-induced cell transformation. These results demonstrated that curcumin prevents As3+-induced cell transformation by inducing autophagy via the activation of the Nrf2 signaling pathway in BEAS-2B cells. However, overexpression of Keap-1 showed a constitutively high level of Nrf2 in As3+-transformed BEAS-2B cells (AsT) is Keap1-independent regulation. Overexpression of Nrf2 in AsT demonstrated that curcumin increased ROS levels and induced cell apoptosis via the downregulation of Nrf2. Further studies showed that curcumin decreased the Nrf2 level in AsT by activating GSK-3ß to inhibit the activation of PI3K/AKT. Co-IP assay results showed that curcumin promoted the interaction of Nrf2 with the GSK-3ß/ß-TrCP axis and ubiquitin. Moreover, the inhibition of GSK-3ß reversed Nrf2 expression in curcumin-treated AsT, indicating that the decrease in Nrf2 is due to activation of the GSK-3ß/ß-TrCP ubiquitination pathway. Furthermore, in vitro and in vivo results showed that curcumin induced cell apoptosis, and had anti-angiogenesis and anti-tumorigenesis effects as a result of activating the GSK-3ß/ß-TrCP ubiquitination pathway and subsequent decrease in Nrf2. CONCLUSIONS: Taken together, in the first stage, curcumin activated Nrf2, decreased ROS, and induced autophagy in normal cells to prevent As3+-induced cell transformation. In the second stage, curcumin promoted ROS and apoptosis and inhibited angiogenesis via inhibition of constitutive expression of Nrf2 in AsT to prevent tumorigenesis. Our results suggest that antioxidant natural compounds such as curcumin can be evaluated as potential candidates for complementary therapies in the treatment of As3+-induced carcinogenesis.

Bismuth chelate as a contrast agent for X-ray computed tomography.

BACKGROUNDS: Due to the unexpected side effects of the iodinated contrast agents, novel contrast agents for X-ray computed tomography (CT) imaging are urgently needed. Nanoparticles made by heavy metal elements are often employed, such as gold and bismuth. These nanoparticles have the advantages of long in vivo circulation time and tumor targeted ability. However, due to the long residence time in vivo, these nanoparticles may bring unexpected toxicity and, the preparation methods of these nanoparticles are complicated and time-consuming. METHODS: In this investigation, a small molecular bismuth chelate using diethylenetriaminepentaacetic acid (DPTA) as the chelating agent was proposed to be an ideal CT contrast agent. RESULTS: The preparation method is easy and cost-effective. Moreover, the bismuth agent show better CT imaging for kidney than iohexol in the aspect of improved CT values. Up to 500 µM, the bismuth agent show negligible toxicity to L02 cells and negligible hemolysis. And, the bismuth agent did not induce detectable morphology changes to the main organs of the mice after intravenously repeated administration at a high dose of 250 mg/kg. The pharmacokinetics of the bismuth agent follows the first-order elimination kinetics and, it has a short half-life time of 0.602 h. The rapid clearance from the body promised its excellent biocompatibility. CONCLUSIONS: This bismuth agent may serve as a potential candidate for developing novel contrast agent for CT imaging in clinical applications.

Neferine alleviates memory and cognitive dysfunction in diabetic mice through modulation of the NLRP3 inflammasome pathway and alleviation of endoplasmic-reticulum stress.

Accumulating clinical and epidemiological evidence indicates a close relationship between diabetes mellitus and dysfunction in memory and cognition. Neferine (NE) is a unique bis-benzylisoquinoline alkaloid derived from the seed embryo of Nelumbo nucifera (Lotus), an herbal medicine with a long history of use in used in China. NE has been reported to ameliorate diabetes mellitus and exert considerable protective effects on the central nervous system. Thus, this study aimed to investigate the effects of NE on memory and cognitive dysfunction in db/db mouse model of diabetes. First, we found that NE treatments significantly ameliorated behavioral impairment and cognitive dysfunction in the Morris water maze, Y-maze, and fear conditioning test in db/db mice. Additionally, in these diabetic mice, NE decreased fasting glucose and insulin resistance while promoting lipid metabolism. Furthermore, NE treatments alleviated oxidative stress and inhibited inflammatory responses in the hippocampus. Further investigations showed that NE suppressed the NOD-like receptor protein 3 (NLRP3) inflammasome pathway via down-regulating the levels of thioredoxin-interacting protein (TXNIP), NLRP3 inflammasomes, apoptosis-associated speck-like protein containing a CARD (ASC), and mature interleukin-1ß (IL-1ß) in the hippocampus. Moreover, NE alleviated endoplasmic-reticulum (ER) stress via down-regulating the levels of immunoglobulin heavy-chain-binding protein (GRP78), C/EBP homologous protein (CHOP), proteins kinase R-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1), and activating transcription factor 6 (ATF6) in the hippocampus. In conclusion, these results suggest that NE ameliorated memory and cognitive dysfunction, possibly through modulating the NLRP3 inflammasome pathways and alleviating ER stress.

Effects of furanodiene on 95-D lung cancer cells: apoptosis, autophagy and G1 phase cell cycle arrest.

Furanodiene (FUR) is a natural terpenoid isolated from Rhizoma curcumae, a well-known Chinese medicinal herb that presents anti-proliferative activities in several cancer cell lines. Herein, we systematically investigated the effects of FUR on the significant processes of tumor progression with the relatively low concentrations in 95-D lung cancer cells. FUR concentration-dependently inhibited cell proliferation and blocked the cell cycle progressions in G1 phase by down-regulating the protein levels of cyclin D1 and CDK6, and up-regulating those of p21 and p27 in 95-D cells. FUR also affected the signaling molecules that regulate apoptosis in 95-D cells revealed by the down-regulation of the protein levels of full PARP, pro-caspase-7, survivin, and Bcl-2, and the up-regulation of cleaved PARP. Further studies showed that FUR enhanced the expression of light chain 3-II (LC3-II) in the protein level, indicating that autophagy is involved in this process. Besides, the adhesion ability of 95-D cells to matrigel and fibronectin was slightly inhibited after FUR treatment for 1 h in our experimental condition. FUR also slightly suppressed cell migration and invasion in 95-D cells according to the data from wound healing and Transwell assays, respectively. Taken together, FUR activated the signal molecules regulating G1 cell cycle arrest, apoptosis and autophagy, while slightly affecting the key steps of cell metastasis in 95-D lung cancer cells in the relatively low concentrations.

Furanodiene presents synergistic anti-proliferative activity with paclitaxel via altering cell cycle and integrin signaling in 95-D lung cancer cells.

Furanodiene (FUR) is a natural terpenoid isolated from Rhizoma Curcumae, a well-known Chinese medicinal herb that presents anti-proliferative activities in several cancer cell lines. Recently, we found that the combined treatment of FUR with paclitaxel (TAX) showed synergetic anti-proliferative activities in 95-D lung cancer cells. Herein, we showed that FUR reduced the cell numbers distributed in mitosis phase induced by TAX while increased those in G1 phase. The protein levels of cyclin D1, cyclin B1, CDK6 and c-Myc were all down-regulated in the group of combined treatment. The dramatically down-regulated expression of integrin ß4, focal adhesion kinase and paxillin might partially contribute to the synergic effect. Though FUR alone obviously induced endoplasmic reticulum stress, this signaling pathway may not contribute to the synergetic anti-proliferative effect as the protein expression of CHOP and BIP was similar in FUR alone and combined treatment group.

Furanodiene induces endoplasmic reticulum stress and presents antiproliferative activities in lung cancer cells.

Furanodiene (FUR) is a natural terpenoid isolated from Curcumae Rhizoma, a well-known Chinese medicinal herb that presents antiproliferation activities in several cancer cell lines. In this study, we demonstrated that FUR concentration dependently inhibits the cell proliferation of A549, NIH-H1299, and 95-D lung cancer cells. ß-elemene, another terpenoid isolated from Curcumae Rhizoma, exhibited weaker antiproliferative effects in A549 and NIH-H1299 cells and activities similar to FUR in 95-D cells. FUR significantly inhibited colony formation in A549 and 95-D cells and upregulated both the mRNA and protein expression levels of binding immunoglobulin protein (BIP) and C/EBP homologous protein (CHOP), indicating that endoplasmic reticulum (ER) stress is induced. FUR treatment led to the accumulation of CHOP in the nucleus, which further confirms induction of ER stress. Furthermore, combined treatment of FUR with paclitaxel showed significant synergetic activities in NIH-H1299 and 95-D cells, suggesting its potential roles in combination therapy. These findings provide a basis for the further study of the anticancer effects in vivo and the internal mechanisms of FUR.

Anti-cancer properties of terpenoids isolated from Rhizoma Curcumae--a review.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhizoma Curcumae is a popular type of traditional Chinese medicine whose essential oils are widely used in the treatment of cancer in China. This review aims to systematically summarize and analyze the anti-cancer properties of terpenoids, the main components of essential oils in Rhizoma Curcumae, and thus enable the development of new anti-cancer drugs. MATERIALS AND METHODS: Information on the recent progress of anti-cancer studies on terpenoids isolated from Rhizoma Curcumae, including ß-elemene, δ-elemene, furanodiene, furanodienone, curcumol, and germacrone, was gathered and analyzed. RESULTS: Among these terpenoids, ß-elemene is the most widely studied, whereas δ-elemene, furanodiene, furanodienone, curcumol, and germacrone have just recently attracted the attention of researchers. The anti-cancer effects of these terpenoids are related to the retardation of cell cycle arrest, the induction of apoptosis, and the inhibition of metastasis or tissue invasion, among others. CONCLUSIONS: Most studies have focused on the in vitro data, and in vivo data is urgently needed. Further insight into the anti-cancer activity and the molecular basis of these compounds, combined with efforts in pharmaceutical chemistry and/or pharmaceutics, will potentially enable the development of new anti-cancer agents.

Ganoderic acid DM, a natural triterpenoid, induces DNA damage, G1 cell cycle arrest and apoptosis in human breast cancer cells.

Ganoderic acid DM (GADM) is a triterpenoid isolated from Ganoderma lucidum, a well-known edible medicinal mushroom. In the present study, we found that GADM effectively inhibited cell proliferation and colony formation in MCF-7 human breast cancer cells, which was much stronger than that of MDA-MB-231 breast cancer cells. GADM both concentration- and time-dependently mediated G1 cell cycle arrest and significantly decreased the protein level of CDK2, CDK6, cycle D1, p-Rb and c-Myc in MCF-7 cells. Moreover, GADM obviously induced DNA fragmentation and cleavage of PARP which are the characteristics of apoptosis and decreased the mitochondrial membrane potential in MCF-7 cells. Besides, we also showed that GADM elicited DNA damage as measured by comet assay which is a sensitive method for DNA damage detection. γ-H2AX, a marker of DNA damage, was also slightly up-regulated after treated with GADM for 6h, suggesting that the G1 cell cycle arrest and apoptosis induced by GADM may be partially resulted from GADM-induced DNA damage. These results have advanced our current understandings of the anti-cancer mechanisms of GADM.

Preparative isolation and purification of six volatile compounds from essential oil of Curcuma wenyujin using high-performance centrifugal partition chromatography.

Six volatile compounds, curdione (1), curcumol (2), germacrone (3), curzerene (4), 1,8-cineole (5) and beta-elemene (6), were successfully isolated from the essential oil of Curcuma wenyujin by high-performance centrifugal partition chromatography using a nonaqueous two-phase solvent system consisting of petroleum ether-acetonitrile-acetone (4:3:1 v/v/v). A total of 8 mg of curdione (1), 4 mg of curcumol (2), 10 mg of germacrone (3), 18 mg of curzerene (4), 9 mg of 1,8-cineole (5) and 17 mg of beta-elemene (6) were isolated from the essential oil (300 mg) in 500 min. Their structures were determined by comparison of their retention times and MS data with those of the authentic samples as well as NMR spectroscopic analysis.