Mingqing Huang

Anti-cancer natural products isolated from chinese medicinal herbs.

In recent years, a number of natural products isolated from Chinese herbs have been found to inhibit proliferation, induce apoptosis, suppress angiogenesis, retard metastasis and enhance chemotherapy, exhibiting anti-cancer potential both in vitro and in vivo. This article summarizes recent advances in in vitro and invivo research on the anti-cancer effects and related mechanisms of some promising natural products. These natural products are also reviewed for their therapeutic potentials, including flavonoids (gambogic acid, curcumin, wogonin and silibinin), alkaloids (berberine), terpenes (artemisinin, β-elemene, oridonin, triptolide, and ursolic acid), quinones (shikonin and emodin) and saponins (ginsenoside Rg3), which are isolated from Chinese medicinal herbs. In particular, the discovery of the new use of artemisinin derivatives as excellent anti-cancer drugs is also reviewed.

Terpenoids: natural products for cancer therapy

Introduction: Terpenoids constitute the largest class of natural products and are a rich reservoir of candidate compounds for drug discovery. Recent efforts into the research and development of anti-cancer drugs derived from natural products have led to the identification of a variety of terpenoids that inhibit cancer cell proliferation and metastasis via various mechanisms. Despite the increasing number of research reports, there lacks a comprehensive review of anti-cancer activity of terpenoids. Areas covered: The present article provides an overview of the recent progress in the anti-cancer studies on terpenoids. Over a dozen naturally originated terpenoid compounds, in particular those derived from traditional Chinese medicine, were classified into five categories according to the structures, namely monoterpenoids, sesquiterpenoids, diterpenoids, triterpenoids and tetraterpenoids. The anti-cancer activities and relevant mechanistic insights of these compounds are discussed in this review. Expert opinion: The anti-cancer activity of terpenoids appears promising and will potentially open more opportunities for cancer therapy. However, current studies are restricted to descriptive findings and lack mechanistic insights and systematic structure–activity relationship (SAR) studies. Future efforts into the systematic identification of the targets of terpenoids are believed to increase chances of gaining breakthrough insights in the field.

Biological activities and potential molecular targets of cucurbitacins: a focus on cancer.

Cucurbitacin and its derivatives (cucurbitacins) are a class of highly oxidized tetracyclic triterpenoids. They are widely distributed in the plant kingdom, where they act as heterologous chemical pheromones that protect plants from external biological insults. Their bioactivities first attracted attention in the 1960s. Documented data demonstrate that cucurbitacins possess strong pharmacological properties, such as antitumor, anti-inflammatory, and hepatoprotective effects, etc. Several molecular targets for cucurbitacins have been discovered, such as fibrous-actin, signal transducer and activator of transcription 3, cyclooxygenase-2, etc. The present study summarizes the achievements of the 50 years of research on cucurbitacins. The aim was to systematically analyze their bioactivities with an emphasis on their anticancer effects. Research and development has shed new insight into the beneficial properties of these compounds.

Synergistic anti-cancer activity of the combination of dihydroartemisinin and doxorubicin in breast cancer cells.

BACKGROUND Dihydroartemisinin (DHA) exhibits potent anti-malarial and anti-cancer activities. This study aimed to investigate the anti-proliferative effects of a combination of DHA and doxorubicin (DOX) on human breast cancer cells. METHODS MTT assay and the combination index (CI) were used to show the anti-proliferative effects and calculate the synergism potential, respectively. Flow cytometry assay was used to detect apoptosis and the intracellular accumulation of DOX. JC-1 staining was used to determine the mitochondrial membrane potential. Western blot analysis was used to detect the protein expression of some apoptosis-related molecules. RESULTS Asynergistic anti-proliferative effect was found, and the enhanced anti-cancer activity was observed to be accompanied by the prompt onset of apoptosis in MCF-7 cells. The combinative treatment remarkably decreased the mitochondrial membrane potential and activated caspase cascades more than the mono-treatment. Pretreatment with DHA also did not influence the accumulation of DOX in MCF-7 cells. CONCLUSION This study presented a new opportunity to enhance the effectiveness of future treatment regimens of breast cancer using DOX.

Salvianolic Acid B Inhibited PPARγ Expression and Attenuated Weight Gain in Mice with High-Fat Diet-Induced Obesity

Background/Aims: Obesity contributes to the development of cardiometabolic disorders such as type 2 diabetes, fatty liver disease and cardiovascular disease. Salvianolic acid B (Sal B) is a molecule derived from the root of Salvia miltiorrhiza (Danshen), which is a traditional Chinese medicine that is widely used to treat cardiovascular diseases. However, the role of Sal B in obesity and obesity-related metabolic disorders is unknown. In this study, we aimed to investigate the effects of Sal B on high-fat diet-induced obesity and determine the possible mechanisms involved. Methods: Male C57BL/6J mice fed a high-fat diet for 12 weeks received a supplement of Sal B (100 mg/kg/day) by gavage for a further 8 weeks. These mice were compared to control mice fed an un-supplemented high-fat diet. 3T3-L1 preadipocytes were used in vitro studies. Results: Sal B administration significantly decreased body weight, white adipose tissue weight, adipocyte size and lipid (triglyceride and total cholesterol) levels in obese mice. Eight weeks of Sal B administration also improved the intraperitoneal glucose tolerance test (IPGTT) and intraperitoneal insulin tolerance test (IPITT) scores in high-fat diet-induced obese mice. In 3T3-L1 preadipocytes that were cultured in vitro and induced to differentiate, Sal B reduced the accumulation of lipid droplets and lipid content in a dose-dependent manner. Immunoblotting indicated that Sal B decreased peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα) expression but increased the expression of GATA binding protein 2 and 3 (GATA 2, GATA 3) both in vivo and in vitro. Conclusion: Our data suggest that Sal B may reduce obesity and obesity-related metabolic disorders by suppressing adipogenesis. The effects of Sal B in adipose tissue may be related to its action on PPARγ, C/EBPα, GATA-2 and GATA-3.

Biological activities of salvianolic acid B from Salvia miltiorrhiza on type 2 diabetes induced by high-fat diet and streptozotocin

Abstract Context: Salvia miltiorrhiza Bge. (Labiatae) has been widely used for treating diabetes for centuries. Salvianolic acid B (SalB) is the main bioactive component in Salvia miltiorrhiza; however, its antidiabetic activity and possible mechanism are not yet clear. Objective: To investigate the effects of SalB on glycometabolism, lipid metabolism, insulin resistance, oxidative stress, and glycogen synthesis in type 2 diabetic rat model. Materials and methods: High-fat diet (HFD) and streptozotocin-induced diabetic rats were randomly divided into model group, SalB subgroups (50, 100, and 200 mg/kg), and rosiglitazone group. Results: Compared with the model group, SalB (100 and 200 mg/kg) significantly decreased blood glucose (by 23.8 and 21.7%; p < 0.05 and p < 0.01) and insulin (by 31.3 and 26.6%; p < 0.05), and increased insulin sensitivity index (by 10.9 and 9.3%; p < 0.05). They also significantly decreased total cholesterol (by 24.9 and 27.9%; p < 0.01), low-density lipoprotein cholesterol (by 56.2 and 64.6%; p < 0.01), non-esterified fatty acids (by 32.1 and 37.9%; p < 0.01), hepatic glycogen (by 41.3 and 60.5%; p < 0.01), and muscle glycogen (by 33.2 and 38.6%; p < 0.05), and increased high-density lipoprotein cholesterol (by 50.0 and 61.4%; p < 0.05 and p < 0.01), which were originally altered by HFD and streptozotocin. In addition, SalB (200 mg/kg) markedly decreased triglyceride and malondialdehyde (by 31.5 and 29.0%; p < 0.05 and p < 0.01), and increased superoxide dismutase (by 56.6%; p < 0.01), which were originally altered by HFD and streptozotocin. Discussion and conclusion: The results indicate that SalB can inhibit symptoms of diabetes mellitus in rats and these effects may partially be correlated with its insulin sensitivity, glycogen synthesis and antioxidant activities.

Antidiabetic effect of the total polyphenolic acids fraction from Salvia miltiorrhiza Bunge in diabetic rats.

An investigation was made to evaluate the therapeutic potential of the total polyphenolic acids fraction (PAF) from Salvia miltiorrhiza Bunge in the type 2 diabetes mellitus rats model with an oral dose of 187 mg/kg for 28 days. The results showed that PAF induced a significant decrease in fasting blood glucose (FBG), fasting blood insulin (FINS), total cholesterol (TC), triglyceride (TG) and blood urea nitrogen (BUN), and an obvious increase in insulin sensitivity index (ISI) in diabetic rats induced by a high fat diet and a low dose of streptozocin (STZ). These results suggested that PAF has antidiabetic potential in vivo. Copyright

Dehydrocorydaline inhibits breast cancer cells proliferation by inducing apoptosis in MCF-7 cells.

Dehydrocorydaline is an alkaloid isolated from traditional Chinese herb Corydalis yanhusuo W.T. Wang. We discovered that it possessed anti-tumor potential during screening of anti-tumor natural products from Chinese medicine. In this study, its anti-tumor potential was investigated with breast cancer line cells MCF-7 in vitro. The anti-proliferative effect of dehydrocorydaline was determined by MTT assay and the mitochondrial membrane potential (Δ Ψ m) was monitored by JC-1 staining. DNA fragments were visualized by Hoechst 33342 staining and DNA ladder assay. Apoptotic related protein expressions were measured by Western blotting. Dehydrocorydaline significantly inhibited MCF-7 cell proliferation in a dose- dependent manner, which could be reversed by a caspase-8 inhibitor, Z-IETD-FMK. Dehydrocorydaline increased DNA fragments without affecting ΔΨm. Western blotting assay showed that dehydrocorydaline dose-dependently increased Bax protein expression and decreased Bcl-2 protein expression. Furthermore, dehydrocorydaline induced activation of caspase-7,-8 and the cleavage of PARP without affecting caspase-9. These results showed that dehydrocorydaline inhibits MCF-7 cell proliferation by inducing apoptosis mediated by regulating Bax/Bcl-2, activating caspases as well as cleaving PARP.

Salvianolic Acid B Ameliorates Hyperglycemia and Dyslipidemia in db/db Mice through the AMPK Pathway.

Background/Aims: Salvianolic acid B (Sal B), a major polyphenolic compound of Salvia miltiorrhiza Bunge, has been shown to possess potential antidiabetic activities. However, the action mechanism of SalB in type 2 diabetes has not been investigated extensively. The present study was designed to investigate the effects of Sal B on diabetes-related metabolic changes in a spontaneous model of type 2 diabetes, as well as its potential molecular mechanism. Methods: Male C57BL/KsJ-db/db mice were orally treated with Sal B (50 and 100 mg/kg) or metformin (positive drug, 300 mg/kg) for 6 weeks. Results: Both doses of Sal B significantly decreased fasting blood glucose, serum insulin, triglyceride and free fatty acid levels, reduced hepatic gluconeogenic gene expression and improved insulin intolerance in db/db mice. High dose Sal B also significantly improved glucose intolerance, increased hepatic glycolytic gene expression and muscle glycogen content, and ameliorated histopathological alterations of pancreas, similar to metformin. Sal B treatment resulted in increased phosphorylated AMP-activated protein kinase (p-AMPK) protein expression in skeletal muscle and liver, increased glucose transporter 4 (GLUT4) and glycogen synthase protein expressions in skeletal muscle, and increased peroxisome proliferator-activated receptor alpha (PPARα) and phosphorylated acetyl CoA carboxylase (p-ACC) protein expressions in liver. Conclusion: Our data suggest that Sal B displays beneficial effects in the prevention and treatment of type 2 diabetes at least in part via modulation of the AMPK pathway.

Effects of alisol B 23-acetate on ovarian cancer cells: G1 phase cell cycle arrest, apoptosis, migration and invasion inhibition

BACKGROUND Ovarian cancer is the first leading cause of death among gynecologic malignancies worldwide. Discovery of new chemotherapeutic drugs is still imperative for the improvement of the survival rate. PURPOSE This study aims to investigate the anti-cancer potential of alisol B 23-acetate (AB23), a protostane-type triterpene isolated from the Alismatis Rhizoma, in the parental and paclitaxel-resistant ovarian cancer cells. METHODS MTT assay was performed to evaluate cell viability after treatment with AB23, along with flow cytometry for apoptosis and cell cycle analysis. Western blotting was conducted to determine the relative protein level. Wound healing and transwell assays were performed to investigate the effect of AB23 on cell migration and invasion. RESULTS AB23 obviously inhibited proliferation of the three ovarian cancer cell lines, down-regulated the protein levels of CDK4, CDK6, and cyclin D1, and blocked the cell cycle progressions in G1 phase. Meanwhile, AB23 induced accumulation of the sub-G1 phase in the three cell lines in a concentration dependent manner. The protein levels of cleaved poly ADP-ribose polymerase (PARP) and the ratio of Bax/Bcl-2 were up-regulated after treatment with AB23. Further study showed that AB23 induced endoplasmic reticulum stress through IRE1 signaling pathway and silencing of IRE1α partially enhanced AB23-induced apoptosis. Wound healing and transwell assays showed that AB23 could also suppress the migration and invasion of HEY cells. Moreover, it down-regulated the protein levels of matrix metalloproteinases MMP-2 and MMP-9. CONCLUSION AB23 possessed anti-proliferation, anti-migration and anti-invasion activities as a single agent on ovarian cancer cells.