Anti-Hypertensive Effect of Solanum muricatum Aiton Leaf Extract In Vivo and In Vitro.

Hypertension is a global health problem and leads to cardiovascular disease and renal injury. Solanum muricatum Aiton leaf extract, rich in flavonoids, is known for its antioxidant capacity. However, the effects of Solanum muricatum Aiton leaf extract on hypertension combined with inflammatory complications were unknown. This study aimed to investigate the impact of Solanum muricatum Aiton leaf extract on hypertension in vivo and in vitro. In vivo, Solanum muricatum Aiton leaf extract led to decrease high blood pressure, improve heart, aorta, and kidney pathology, and enhance the antioxidative activity in spontaneously hypertensive rats (SHR). Our study demonstrated Solanum muricatum Aiton leaf extract inhibited angiotensin-converting enzyme (ACE), epithelial sodium channel (ENaC), sodium glucose co-transporters-1 (SGLT-1), nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6). In vitro, Solanum muricatum Aiton leaf extract improved the angiotensin II-induced reactive oxygen species (ROS) and mitochondrial membrane depolarization in NRK-52E cells. Besides, Solanum muricatum Aiton leaf extract could also decrease the expressions of ENaC, SGLT-1, and NF-κB in angiotensin II-treated NRK-52E cells. Solanum muricatum Aiton leaf can be suggested as a novel antihypertensive agent ameliorating hypertension via ACE inhibition, inflammation reduction, and ROS. PLE is a novel anti-hypertensive agent to ameliorate hypertension and its complications, including inflammation.

The Nephroprotective Effects of Hibiscus sabdariffa Leaf and Ellagic Acid in Vitro and in Vivo Models of Hyperuricemic Nephropathy.

Hyperuricemic nephropathy (HN) is caused by urate crystals that get deposited in the kidney and contribute to renal fibrosis. Uric acid (UA) has been proven to directly cause renal mesangial cell oxidative stress and fibrosis in the pathogenesis of HN. Some antioxidants can be used as chemopreventive agents of HN. Hibiscus sabdariffa leaf extracts (HLE), rich in polyphenol, have been shown to possess hypoglycemic, antioxidant, hypolipidemic, antiatherosclerotic, and anticancer effects. The aim of the study is to examine the inhibitory effect of HLE and its main component ellagic acid (EA) on renal fibrosis. In vitro, mouse renal glomerular mesangial SV40MES13 cells pretreated with UA were demonstrated to trigger obvious morphological changes and viability loss, as well as affect matrix metalloproteinases (MMPs) activities. Noncytotoxic doses of HLE and EA abolished the UA-induced cell injury and MMP-2/9 secretion. In addition, HLE and EA exhibited antioxidant and anti-inflammatory effects on the UA-treated cells with a reduction in transforming growth factor-beta (TGF-ß) production. Next, the UA-activated pro-fibrotic factors, extracellular matrix (ECM) deposition, and epithelial-mesenchymal-transition (EMT) were inhibited by HLE or EA. Mechanistic assays indicated that antifibrotic effects of HLE might be mediated via TGF-ß/Smad signaling, as confirmed by the transfection of Smad7 siRNA. In vivo, HLE and EA supplementations significantly alleviated HN development, which may result from inhibiting adenine-induced TGF-ß production accompanying oxidative stress and inflammation, as well as fibrogenesis. Our data imply that EA-enriched HLE regulates the TGF-ß/Smad signaling, which in turn led to reduced renal mesangial cell injury and fibrosis in HN and provided a new mechanism for its nephroprotective activity.

Anti-Melanogenesis Effects of Lotus Seedpod In Vitro and In Vivo.

Melanogenesis has many important physiological functions. However, abnormal melanin production causes various pigmentation disorders. Melanin synthesis is stimulated by α-melanocyte stimulating hormone (α-MSH) and ultraviolet (UV) irradiation. Lotus seedpod extract (LSE) has been reported as possessing antioxidative, anti-aging, and anticancer activities. The present study examined the effect of LSE on melanogenesis and the involved signaling pathways in vitro and in vivo. Results showed that non-cytotoxic doses of LSE and its main component epigallocatechin (EGC) reduced both tyrosinase activity and melanin production in the α-MSH-induced melanoma cells. Western blotting data revealed that LSE and EGC inhibited expressions of tyrosinase and tyrosinase-related protein 1 (TRP-1). Phosphorylation of p38 and protein kinase A (PKA) stimulated by α-MSH was efficiently blocked by LSE treatment. Furthermore, LSE suppressed the nuclear level of cAMP-response element binding protein (CREB) and disturbed the activation of melanocyte inducing transcription factor (MITF) in the α-MSH-stimulated B16F0 cells. The in vivo study revealed that LSE inhibited melanin production in the ear skin of C57BL/6 mice after exposure to UVB. These findings suggested that the anti-melanogenesis of LSE involved both PKA and p38 signaling pathways. LSE is a potent novo natural depigmenting agent for cosmetics or pharmaceutical applications.

Aqueous extract from Pepino (Solanum muricatum Ait.) leaves ameliorated insulin resistance, hyperlipidemia, and hyperglycemia in mice with metabolic syndrome.

Solanum muricatum Ait. (Pepino) is a plant food commonly cultivated in the Penghu Island, Taiwan. This present study aimed to investigate the protective effects of aqueous extract of Pepino leaves (AEPL) in mice with metabolic syndrome. Metabolic syndrome animal model was induced by continuous high-fat diet feeding and low-dose streptozotocin (40 mg/ml) for 5 days. A 1% AEPL or metformin were given for 6 weeks after streptozotocin injection. The results revealed that 1% AEPL effectively reduced fasting blood glucose, insulin resistance, and hyperlipidemia in metabolic syndrome mice. Histologic examination revealed lipid accumulation in liver decreased by 1% AEPL treatment. Further, western blot analysis revealed 1% AEPL treatment managed enzymes related to lipid synthesis and oxidation pathways and hepatic glucose production. Besides, 1% AEPL treatment increased liver antioxidant activities to against oxidative stress. These results concluded that AEPL treatment attenuated insulin resistance, hyperlipidemia, and hyperglycemia of metabolic syndrome. PRACTICAL APPLICATIONS: Metabolic syndrome (MS) is a multifactorial chronic disease which is characterized by dyslipidemia, insulin resistance, and hyperglycemia. However, there is no single drug or defined medication for MS so far. The present study revealed that AEPL treatment was able to regulate lipid metabolism and glycemic control at the molecular level to alleviate MS. AEPL has the potential to be a novo complementary medication for metabolic syndrome.

Flavonoids Identification and Pancreatic Beta-Cell Protective Effect of Lotus Seedpod.

Oxidative stress is highly associated with the development of diabetes mellitus (DM), especially pancreatic beta-cell injury. Flavonoids derived from plants have caused important attention in the prevention or treatment of DM. Lotus seedpod belongs to a traditional Chinese herbal medicine and has been indicated to possess antioxidant, anti-age, anti-glycative, and hepatoprotective activities. The purpose of this study was to demonstrate the pancreatic beta-cell protective effects of lotus seedpod aqueous extracts (LSE) against oxidative injury. According to HPLC/ESI-MS-MS method, LSE was confirmed to have flavonoids derivatives, especially quercetin-3-glucuronide (Q3G). In vitro, LSE dose-dependently improved the survival and function of rat pancreatic beta-cells (RIN-m5F) from hydrogen peroxide (H2O2)-mediated loss of cell viability, impairment of insulin secretion, and promotion of oxidative stress. LSE showed potential in decreasing the H2O2-induced occurrence of apoptosis. In addition, H2O2-triggered acidic vesicular organelle formation and microtubule-associated protein light chain 3 (LC3)-II upregulation, markers of autophagy, were increased by LSE. Molecular data explored that antiapoptotic and autophagic effects of LSE, comparable to that of Q3G, might receptively be mediated via phospho-Bcl-2-associated death promoter (p-Bad)/B-cell lymphoma 2 (Bcl-2) and class III phosphatidylinositol-3 kinase (PI3K)/LC3-II signal pathway. In vivo, LSE improved the DM symptoms and pancreatic cell injury better than metformin, a drug that is routinely prescribed to treat DM. These data implied that LSE induces the autophagic signaling, leading to protect beta-cells from oxidative stress-related apoptosis and injury.

Lotus Seedpod Extracts Reduced Lipid Accumulation and Lipotoxicity in Hepatocytes.

Non-alcoholic fatty liver disease (NAFLD) is closely associated with metabolic disorders, including hepatic lipid accumulation and lipotoxicity. Plant-derived polyphenols have attracted considerable attention in the prevention of NAFLD. Lotus seedpod, rich in polyphenols, is a traditional Chinese herbal medicine. Previous studies have showed that lotus seedpod possess radioprotective, antioxidant, anti-cancer, and anti-inflammatory activities. In this study, the in vitro hepatoprotective effect of lotus seedpod extract (LSE) and its main component epigallocatechin (EGC) was examined. Firstly, oleic acid (OA), an unsaturated fatty acid, was used to induce the phenotype of NAFLD in human hepatocytes, HepG2 cells. LSE dose-dependently improved the OA-induced viability loss of HepG2 cells. Non-cytotoxic concentrations of LSE or EGC abolished intracellular lipid accumulation and oxidative stress in the OA-treated cells. In addition, LSE and EGC showed a minor effect on autophagy, and potential in reducing OA-induced occurrence of apoptosis confirmed by morphological and biochemical features, including an increase in the formation of apoptotic bodies, the exposure of phosphatidylserine, and activation of caspases. Molecular data showed the anti-apoptotic effect of LSE might be mediated via downregulation of the mitochondrial pathway. Our data imply that EGC-enriched LSE potentially could be developed as an anti-NAFLD agent.

In Vitro and In Vivo Protective Effects of Flavonoid-Enriched Lotus Seedpod Extract on Lipopolysaccharide-Induced Hepatic Inflammation.

Endotoxin lipopolysaccharide (LPS) plays an important role in the acceleration of hepatic inflammation. Natural medicinal plants that can prevent inflammation by targeting LPS have potential therapeutic clinical application. The aim of the study is to examine the anti-inflammatory effects of lotus seedpod extract (LSE), used as a traditional Chinese herbal medicine with hemostasis function and for eliminating bruise, on the LPS-induced hepatic inflammation and its underlying molecular mechanisms in vitro and in vivo. In vitro, LSE and its purified compound (-)-epigallocatechin (EGC) dose-dependently inhibited the expressions of pro-inflammatory cytokines and mediators, including tumor necrosis factor (TNF)- α , interleukin (IL)-6, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), without affecting cell viability in LPS-stimulated human hepatoma cell line HepG2. Molecular studies showed the anti-LPS effect of HLP or EGC might be mediated via downregulation of Toll-like receptor 4. (TLR4)-mediated both NF- κ B and p38 signaling, as demonstrated by the usage of pyrrolidine dithiocarbamate (PDTC), a specific NF- κ B inhibitor. In vivo, LPS-induced hepatic inflammation was significantly ameliorated in LSE-fed mice as gauged by dose-dependent inhibition of serum levels of biochemical markers of liver damage, the changes of hepatic lobular architecture and the secretion of pro-inflammatory mediators, as well as induction of anti-oxidant enzymes. As a result, our data presented the first evidence of EGC-enriched LSE as an anti-inflammatory agent in LPS-stimulated HepG2 cells and mice, and these findings may open interesting perspectives to the strategy in treatment for hepatic inflammation.

Aqueous Extract of Pepino (Solanum muriactum Ait) Leaves Ameliorate Lipid Accumulation and Oxidative Stress in Alcoholic Fatty Liver Disease.

Chronic alcohol intake leads to alcoholic fatty liver. The pathogenesis of alcoholic fatty liver is related to abnormal lipid accumulation, oxidative stress, endotoxins, and cytokines. Solanum muricatum Ait. (Pepino) is a plant food commonly cultivated in the Penghu island, Taiwan. Previous studies indicated that the aqueous extract of pepino was able to attenuate diabetic progression via its antioxidative and anti-inflammatory effects. However, the mechanisms of the antioxidative and anti-inflammatory effects of pepino leaf in preventing alcoholic fatty liver remain unknown. In this study, Lieber⁻DeCarli ethanol-containing liquid diet was used to induce alcoholic hepatic injury in C57BL/6 mice. The hepatoprotective effects and the related mechanisms of aqueous extract of pepino leaf (AEPL) were examined. Our results showed that 2% AEPL treatments protected the liver from ethanol-induced injury through reducing serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC) and triglyceride (TG) (all p < 0.05). AEPL had the effects in improving the ethanol-induced lipid accumulation in mice under histological examination. Molecular data indicated that the anti-lipid accumulation effect of AEPL might be mediated via inducing hepatic levels of phospho-adenosine monophosphate-activated kinase (p-AMPK) and peroxisome proliferator-activated receptor (PPAR)-α, and reducing the expressions of hepatic lipogenic enzymes, including sterol regulatory element-binding protein (SREBP)-1c, acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) (all p < 0.05). AEPL also decreased hepatic levels of thiobarbituric acid relative substances (TBARS), tumor necrosis factor (TNF)-α, and interleukin (IL)-6, as well as the expression of nuclear factor kappa B (NF-κB) (all p < 0.05). Moreover, AEPL significantly elevated the activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx), and glutathione (GSH) content compared to the ethanol-fed group (all p < 0.05). Our present study suggests that AEPL could protect the liver against ethanol-induced oxidative injury and lipid accumulation.

Taiwanese and Japanese yam (Dioscorea spp.) extracts attenuate doxorubicin-induced cardiotoxicity in mice.

The present study was designed to explore whether yam could protect the heart from doxorubicin (DOX)-induced oxidative stress leading to cardiotoxicity in vivo. In this study, the protective effects of water and ethanol extracts of three varieties of yam, including water extracts of Dioscorea japonica Thunb., ethanol extracts of D. japonica Thunb., water extracts of Dioscorea alata, ethanol extracts of D. alata, water extracts of Dioscorea purpurea, and ethanol extracts of D. purpurea, against DOX-induced cardiotoxicity in experimental mice were evaluated. DOX treatment led to significant decreases in the ratio of heart weight to body weight and heart rate, and increases in blood pressure and the serum level of lactate dehydrogenase, a marker of cardiotoxicity, were recovered by yam extracts, especially in water extracts of D. alata. Yam extracts also decreased the cardiac levels of thiobarbituric acid relative substances, reactive oxygen species, and inflammatory factors, as well as the expression of nuclear factor kappa B, while ethanol extracts of D. japonica Thunb. and D. purpurea were shown to be more potent. Moreover, yam extracts had a role in increasing the activities of glutathione peroxidase and superoxide dismutase, thus improving the DOX-induced alterations in oxidative status in the heart tissue of DOX-treated mice. All ethanol extracts of yam exhibited their antiapoptotic abilities on caspase-3 activation and mitochondrial dysfunction, and ethanol extracts of D. alata still exerted a superior effect. Based on these findings, it can be concluded that yam has significant cardioprotective properties against DOX-induced damage via its multiple effects on antioxidant, anti-inflammatory, or antiapoptotic activities.

Pepino polyphenolic extract improved oxidative, inflammatory and glycative stress in the sciatic nerves of diabetic mice.

The effect of pepino polyphenolic extract (PPE) on diabetic neuropathy was examined. Using HPLC/ESI-MS-MS analysis, PPE was demonstrated to contain coumaroyl and caffeoyl derivatives among polyphenols. PPE at 0.5 or 1% was supplied to diabetic mice for 12 weeks. The PPE intake at two doses significantly improved glycaemic control. These treatments reserved the glutathione (GSH) level, and decreased the thiobarbituric acid reactive substances (TBARS) level, reactive oxygen species (ROS), interleukin (IL)-6, tumour necrosis factor (TNF)-alpha, fructose, and glycation intermediates and precursors of advanced glycation end products (AGEs), such as methylglyoxal (MG) and N-(carboxymethyl)lysine (CML), in the sciatic nerves of diabetic mice. In a histological study of sciatic nerves, PPE had the effects in improving the nerves of diabetic mice, showing disorganization of the fascicle with numerous small myelinated fibers. The PPE intake at two doses retained the activity, and the protein and mRNA levels of glutathione peroxidase (GPX), and decreased protein expressions of aldose reductase (AR) and the receptor for the advanced glycation end product (RAGE) in sciatic nerves. These findings support that pepino polyphenolic extract could attenuate oxidative, inflammatory and glycative stress in diabetic peripheral nerves.

In Vivo Protective Effects of Diosgenin against Doxorubicin-Induced Cardiotoxicity.

Doxorubicin (DOX) induces oxidative stress leading to cardiotoxicity. Diosgenin, a steroidal saponin of Dioscorea opposita, has been reported to have antioxidant activity. Our study was aimed to find out the protective effect of diosgenin against DOX-induced cardiotoxicity in mice. DOX treatment led to a significant decrease in the ratio of heart weight to body weight, and increases in the blood pressure and the serum levels of lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and creatine kinase myocardial bound (CK-MB), markers of cardiotoxicity. In the heart tissue of the DOX-treated mice, DOX reduced activities of antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GPx), were recovered by diosgenin. Diosgenin also decreased the serum levels of cardiotoxicity markers, cardiac levels of thiobarbituric acid relative substances (TBARS) and reactive oxygen species (ROS), caspase-3 activation, and mitochondrial dysfunction, as well as the expression of nuclear factor kappa B (NF-κB), an inflammatory factor. Moreover, diosgenin had the effects of increasing the cardiac levels of cGMP via modulation of phosphodiesterase-5 (PDE5) activity, and in improving myocardial fibrosis in the DOX-treated mice. Molecular data showed that the protective effects of diosgenin might be mediated via regulation of protein kinase A (PKA) and p38. Our data imply that diosgenin possesses antioxidant and anti-apoptotic activities, and cGMP modulation effect, which in turn protect the heart from the DOX-induced cardiotoxicity.

Hibiscus sabdariffa Leaf Extract Inhibits Human Prostate Cancer Cell Invasion via Down-Regulation of Akt/NF-kB/MMP-9 Pathway.

Hibiscus sabdariffa leaf has been previously shown to possess hypoglycemic, hypolipidemic, and antioxidant effects, and induce tumor cell apoptosis. However, the molecular mechanisms involved in the anticancer activity of H. sabdariffa leaf extract (HLE) are poorly understood. The object of the study was to examine the anti-invasive potential of HLE. First, HLE was demonstrated to be rich in polyphenols. The results of wound-healing assay and in vitro transwell assay revealed that HLE dose-dependently inhibited the migration and invasion of human prostate cancer LNCaP (lymph node carcinoma of the prostate) cells under non-cytotoxic concentrations. Our results further showed that HLE exerted an inhibitory effect on the activity and expressions of matrix metalloproteinase-9 (MMP-9). The HLE-inhibited MMP-9 expression appeared to be a consequence of nuclear factor-kappaB (NF-κB) inactivation because its DNA-binding activity was suppressed by HLE. Molecular data showed all these influences of HLE might be mediated via inhibition of protein kinase B (PKB, also known as Akt)/NF-kB/MMP-9 cascade pathway, as demonstrated by the transfection of Akt1 overexpression vector. Finally, the inhibitory effect of HLE was proven by its inhibition on the growth of LNCaP cells and the expressions of metastasis-related molecular proteins in vivo. These findings suggested that the inhibition of MMP-9 expression by HLE may act through the suppression of the Akt/NF-kB signaling pathway, which in turn led to the reduced invasiveness of the cancer cells.

Hibiscus sabdariffa leaf polyphenolic extract induces human melanoma cell death, apoptosis, and autophagy.

Melanoma is the least common but most fatal form of skin cancer. Previous studies have indicated that an aqueous extract of Hibiscus sabdariffa leaves possess hypoglycemic, hypolipidemic, and antioxidant effects. In this study, we want to investigate the anticancer activity of Hibiscus leaf polyphenolic (HLP) extract in melanoma cells. First, HLP was exhibited to be rich in epicatechin gallate (ECG) and other polyphenols. Apoptotic and autophagic activities of HLP and ECG were further evaluated by DAPI stain, cell-cycle analysis, and acidic vascular organelle (AVO) stain. Our results revealed that both HLP and ECG induced the caspases cleavages, Bcl-2 family proteins regulation, and Fas/FasL activation in A375 cells. In addition, we also revealed that the cells presented AVO-positive after HLP treatments. HLP could increase the expressions of autophagy-related proteins autophagy-related gene 5 (ATG5), Beclin1, and light chain 3-II (LC3-II), and induce autophagic cell death in A375 cells. These data indicated that the anticancer effect of HLP, partly contributed by ECG, in A375 cells. HLP potentially could be developed as an antimelanoma agent.

Antidiabetic Effects of Carassius auratus Complex Formula in High Fat Diet Combined Streptozotocin-Induced Diabetic Mice.

Carassius auratus complex formula, including Carassius auratus, Rhizoma dioscoreae, Lycium chinense, and Rehmannia glutinosa Libosch, is a combination prescription of traditional Chinese medicine, which has always been used to treat diabetes mellitus in ancient China. In this study, we provided experimental evidence for the use of Carassius auratus complex formula in the treatment of high fat diet combined streptozotocin- (STZ-) induced type 2 diabetes. Carassius auratus complex formula aqueous extract was prepared and the effects of it on blood glucose, serum insulin, adipose tissue weight, oral glucose tolerance test (OGTT), total cholesterol, and triglyceride (TG) levels in mice were measured. Moreover, adiponectin, TG synthesis related gene expressions, and the inhibitory effect of aldose reductase (AR) were performed to evaluate its antidiabetic effects. After the 8-week treatment, blood glucose, insulin levels, and adipose tissue weight were significantly decreased. OGTT and HOMA-IR index showed improved glucose tolerance. It could also lower plasma TG, TC, and liver TG levels. Furthermore, Carassius auratus complex formula could inhibit the activity of AR and restore adiponectin expression in serum. Based on these findings, it is suggested that Carassius auratus complex formula possesses potent anti-diabetic effects on high fat diet combined STZ-induced diabetic mice.

Andrographolide sensitizes the cytotoxicity of human colorectal carcinoma cells toward cisplatin via enhancing apoptosis pathways in vitro and in vivo.

Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, has been shown to suppress the growth and invasion of human colorectal carcinoma (CRC) Lovo cells, and trigger apoptosis in vitro. The potential of Andro as a chemotherapeutic agent in CRC was evaluated by investigating its cytotoxic effects as a single agent or in coadministration with cisplatin (CDDP). Andro potentiated the cytotoxic effect of CDDP in Lovo cells through apoptosis. The molecular mechanism for these favorable cellular response was further investigated by analyzing the apoptotic profiles, protein levels, and mRNA expression patterns of several key genes after treatments of Andro or/and CDDP. Molecular results indicated that the effect of Andro alone might be mediated via both intrinsic and extrinsic apoptotic pathways in Lovo cells. The addition of Andro to CDDP induced synergistic apoptosis, which could be corroborated to the changes in protein and mRNA levels of Bax and Bcl-2, and the increased Fas/FasL association in these cells, resulting in increased release of cytochrome c, and activation of caspases. Pretreatment of Nok-1 monoclonal antibody, a Fas signaling inhibitor, or Bax inhibitor peptide V5 repressed the Andro-induced cleavage of procaspase and the sensitization to CDDP-induced apoptosis. Finally, the combination therapy of Andro with CDDP was evidenced by its synergistic inhibition on the growth of Lovo cells in xenograft tumor studies. The results indicate that Andro, in combination with chemotherapeutics, is likely to represent a potential therapeutic strategy for CRC.

Hibiscus sabdariffa leaf polyphenolic extract inhibits LDL oxidation and foam cell formation involving up-regulation of LXRα/ABCA1 pathway.

The oxidative modification of low-density lipoprotein (LDL) is involved in the pathogenesis of atherosclerotic lesions through the formation of macrophage-derived foam cells. In the present study, we aimed to investigate the anti-atherosclerotic effect of Hibiscus sabdariffa leaf polyphenolic extract (HLP), which is rich in flavonoid. The inhibitory effect of HLP on oxidation and lipid peroxidation of LDL was defined in vitro. HLP showed potential in reducing foam cell formation and intracellular lipid accumulation in oxidised-LDL (ox-LDL)-induced macrophage J774A.1 cells under non-cytotoxic concentrations. Molecular data showed these influences of HLP might be mediated via liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) pathway, as demonstrated by the transfection of LXRα siRNA. Our data implied that HLP up-regulated the LXRα/ABCA1 pathway, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that HLP potentially could be developed as an anti-atherosclerotic agent.

Carnosic acid, a rosemary phenolic compound, induces apoptosis through reactive oxygen species-mediated p38 activation in human neuroblastoma IMR-32 cells.

Carnosic acid (CA), a rosemary phenolic compound, has been shown to display anti-cancer activity. We examined the apoptotic effect of CA in human neuroblastoma IMR-32 cells and elucidated the role of the reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK) associated with carcinogenesis. The result indicated that CA decreased the cell viability in a dose-dependent manner. Further investigation in IMR-32 cells revealed that cell apoptosis following CA treatment is the mechanism as confirmed by flow cytometry, hoechst 33258, and caspase-3/-9 and poly(ADP-ribose) polymerase (PARP) activation. Immunoblotting suggested a down-regulation of anti-apoptotic Bcl-2 protein in the CA-treated cells. In flow cytometric analysis, CA caused the generation of reactive oxygen species (ROS); however, pretreatment with the antioxidant N-acetylcysteine (NAC) attenuated the CA-induced generation of ROS and apoptosis. This effect was accompanied by increased activation of p38 and by decreased activation of extracellular signal-regulated kinase (ERK) as well as activation of c-Jun NH(2)-terminal kinase (JNK). Moreover, NAC attenuated the CA-induced phosphorylation of p38. Silencing of p38 by siRNA gene knockdown reduced the CA-induced activation of caspase-3. In conclusion, ROS-mediated p38 MAPK activation plays a critical role in CA-induced apoptosis in IMR-32 cells.

Chemopreventive properties and molecular mechanisms of the bioactive compounds in Hibiscus sabdariffa Linne.

Hibiscus sabdariffa Linne is a traditional Chinese rose tea and has been effectively used in folk medicines for treatment of hypertension, inflammatory conditions. H. sabdariffa aqueous extracts (HSE) were prepared from the dried flowers of H. sabdariffa L., which are rich in phenolic acids, flavonoids and anthocyanins. In this review, we discuss the chemopreventive properties and possible mechanisms of various H. sabdariffa extracts. It has been demonstrated that HSE, H. sabdariffa polyphenol-rich extracts (HPE), H. sabdariffa anthocyanins (HAs), and H. sabdariffa protocatechuic acid (PCA) exert many biologic effects. PCA and HAs protected against oxidative damage induced by tert-butyl droperoxide (t-BHP) in rat primary hepatocytes. In rabbits fed cholesterol and human experimental studies, these studies imply HSE could be pursued as atherosclerosis chemopreventive agents as they inhibit LDL oxidation, foam cell formation, as well as smooth muscle cell migration and proliferation. The extracts also offer hepatoprotection by influencing the levels of lipid peroxidation products and liver marker enzymes in experimental hyperammonemia. PCA has also been shown to inhibit the carcinogenic action of various chemicals in different tissues of the rat. HAs and HPE were demonstrated to cause cancer cell apoptosis, especially in leukemia and gastric cancer. More recent studies investigated the protective effect of HSE and HPE in streptozotocin induced diabetic nephropathy. From all these studies, it is clear that various H. sabdariffa extracts exhibit activities against atherosclerosis, liver disease, cancer, diabetes and other metabolic syndromes. These results indicate that naturally occurring agents such as the bioactive compounds in H. sabdariffa could be developed as potent chemopreventive agents and natural healthy foods.

Andrographolide down-regulates hypoxia-inducible factor-1α in human non-small cell lung cancer A549 cells.

Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess multiple pharmacological activities. In our previous study, Andro had been shown to inhibit non-small cell lung cancer (NSCLC) A549 cell migration and invasion via down-regulation of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Here we demonstrated that Andro inhibited the expression of hypoxia-inducible factor-1α (HIF-1α) in A549 cells. HIF-1α plays an important role in tumor growth, angiogenesis and lymph node metastasis of NSCLC. The Andro-induced decrease of cellular protein level of HIF-1α was correlated with a rapid ubiquitin-dependent degradation of HIF-1α, and was accompanied by increased expressions of hydroxyl-HIF-1α and prolyl hydroxylase (PHD2), and a later decrease of vascular endothelial growth factor (VEGF) upon the treatment of Andro. The Andro-inhibited VEGF expression appeared to be a consequence of HIF-1α inactivation, because its DNA binding activity was suppressed by Andro. Molecular data showed that all these effects of Andro might be mediated via TGFß1/PHD2/HIF-1α pathway, as demonstrated by the transfection of TGFß1 overexpression vector and PHD2 siRNA, and the usage of a pharmacological MG132 inhibitor. Furthermore, we elucidated the involvement of Andro in HIF-1α transduced VEGF expression in A549 cells and other NSCLC cell lines. In conclusion, these results highlighted the potential effects of Andro, which may be developed as a chemotherapeutic or an anti-angiogenesis agent for NSCLC in the future.

Inhibitory effects of andrographolide on migration and invasion in human non-small cell lung cancer A549 cells via down-regulation of PI3K/Akt signaling pathway.

Lung cancer is the leading cause of death among cancers worldwide and non-small cell lung cancer (NSCLC) comprises more than 80% of lung cancer cases. Treatment options for patients with advanced NSCLC have evolved in the last decade with the advent of novel biological agents. Andrographolide, a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to have the potential to be developed as a chemotherapeutic agent. In order to understand the anti-cancer properties of andrographolide, we examined its effect on migration and invasion in human NSCLC A549 cells. The results of wound-healing assay and in vitro transwell assay revealed that andrographolide inhibited dose-dependently the migration and invasion of A549 cells under non-cytotoxic concentrations. Molecular data showed that the effect of andrographolide in A549 cells might be mediated via sustained inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt signal involved in the up-regulation of matrix metalloproteinases (MMPs). Our results showed that andrographolide exerted an inhibitory effect on the activity and the mRNA and protein levels of MMP-7, but not MMP-2 or MMP-9. The andrographolide-inhibited MMP-7 expression or activity appeared to occur via activator protein-1 (AP-1) because of its DNA binding activity was suppressed by andrographolide. Additionally, the transfection of Akt over-expression vector (Akt1 cDNA) to A549 cells could result in an increase expression of MMP-7 concomitantly with a marked induction on cell invasion. These findings suggested that the inhibition on MMP-7 expression by andrographolide may be through suppression on PI3K/Akt/AP-1 signaling pathway, which in turn led to the reduced invasiveness of the cancer cells.