Design and synthesis of novel celastrol derivative and its antitumor activity in hepatoma cells and antiangiogenic activity in zebrafish.

Two series of celastrol derivatives were designed and synthesized by modifying carboxylic acid at the 28th position with amino acid, and their intermediates with isobutyrate at the third position. All compounds were evaluated for their antiproliferation activity by four human cancer cell lines (SCG7901, HGC27, HepG2, and Bel7402) and one normal cell LO2. The most promising compound, compound 8, showed superior bioactivity and lower toxicity than others including celastrol. Further underlying tests illustrated that compound 8 induced apoptosis and cell arrest at G2/M and inhibited proliferation and mobility of human hepatoma cells by suppressing the signal transducer and activator of transcription-3 signaling pathway. Besides these, a highly accurate and reproducible high performance liquid chromatography protocol was established to determine celastrol and compound 8 absorption in zebrafish, and results demonstrated that their concentration increased rapidly within 4 hr in a time-dependent manner and the concentration of compound 8 was higher than that of celastrol. In addition, without detection at 12 hr, compound 8 was rapidly metabolized in vivo. These findings are very helpful for the structural modification of celastrol and other bioactive compounds to improve their bioactivity, toxicity, and absorption.

Assessment of Toxicity and Absorption of the Novel AA Derivative AA-Pme in SGC7901 Cancer Cells In Vitro and in Zebrafish In Vivo.

BACKGROUND Asiatic acid (AA; 2α,3ß,23-trihydroxyurs-12-ene-28-oic acid) is an active compound derived from Centella asiatica, a traditional medicinal plant used widely in many Asian countries, particularly for the treatment of cancer. However, the modified AA derivative N-(2α,3ß,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe) has shown markedly better anti-tumor activity than AA. MATERIAL AND METHODS We evaluated the toxicity of AA and AA-PMe on zebrafish morphology, mortality, and hatching rate and determined the effect on SGC7901 cancer cells by acute toxicity assay. AA-PMe absorption in vitro in SGC7901 cells and in vivo in zebrafish was determined by establishing a highly accurate and reproducible HPLC protocol. RESULTS In zebrafish, the toxicity of AA-PMe was lower than AA, with an acute toxic dose of AA-PMe above 25 µM, compared to acute toxicity at doses above 10 µM for AA. However, chronic toxicity of AA-PMe began occurring at doses below 25 µM but became apparent for AA at doses below 10 µM. Although low doses of AA-PMe were tolerated acutely, it became chronically toxic during zebrafish development, resulting in morphological abnormalities, including peripheral and abdominal edema, hemorrhage, abnormal body shape, enlarged yolk sac, and reduced motility. At low concentrations, absorption of AA-PMe by cells and zebrafish embryos occurred in a dose-dependent manner, but this stabilized as the concentration increased. CONCLUSIONS This pharmacokinetic study outlines the cellular and organismal effects of AA-PMe and suggests a theoretical basis that may underlie its mechanism of action.

Comparative cardio and developmental toxicity induced by the popular medicinal extract of Sutherlandia frutescens (L.) R.Br. detected using a zebrafish Tuebingen embryo model.

BACKGROUND: Sutherlandia frutescens is one of the most promising commercialized, indigenous and medicinal plants of South Africa that is used as an immune-booster, and a traditional treatment for cancer. However, few studies report on its toxicology and dosage in vivo. There is still room to better understand its cytotoxicity effects in animal systems. METHODS: We prepared two extracts, one with 80% (v/v) ethanol, and the other, with water. Both were studied to determine the maximum tolerable concentration when extracts were applied at 0 to 200 µg/ml to a Tuebingen zebrafish embryo line. The development of zebrafish embryos after 24 h post fertilization (hpf) was studied. A concentration range of 5 µg/ml to 50 µg/ml was then chosen to monitor the ontological development of cultured embryos. A liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method was used to study the differences of the two experimental extracts. Chemical variation between the extracts was illustrated using chemometrics. RESULTS: Both extracts led to bleeding and pericardial cyst formation when applied at high concentrations to the zebrafish embryo culture. Chronic teratogenic toxicities, leading to pericardial edema, yolk sac swelling, and other abnormal developmental characteristics, were detected. The aqueous extracts of S. frutescens were less toxic to the larvae than the ethanol extracts, validating preference for aqueous preparations when used in traditional medicine. Chemical differences between the water extracts and alcoholic extracts were analysed using LC-MS/MS. A supervised metabolomics approach, targeting the sutherlandiosides and sutherlandins using orthogonal partial least squares-discriminant analysis (OPLS-DA), illustrated that sutherlandiosides were the main chemical features that can be used to distinguish between the two extracts, despite the extracts being highly similar in their chemical constituents. CONCLUSION: The water extract caused less cytotoxic and abnormal developmental effects compared to the ethanolic extract, and, this is likely due to differences in concentrations of extracted chemicals rather than the chemical profile per se. This study provides more evidence of cytotoxicity effects linked to S. frutescens using the zebrafish embryo bioassay as a study tool.

Asiaticoside hinders the invasive growth of keloid fibroblasts through inhibition of the GDF-9/MAPK/Smad pathway.

Higher expression of growth differentiation factor-9 (GDF-9) in keloids compared with hypertrophic scars and normal skin tissues has been reported recently. The present study was performed to investigate the role of GDF-9 in keloid pathogenesis, and to elucidate its implication for asiaticoside in the keloid management. The data showed that GDF-9 could enhance the proliferation, migration, and invasion of keloid fibroblasts (KFs), while it only slightly elevated collagen expression, indicating that the effect of GDF-9 was opposite to that of TGF-ß1. The bioactivity difference between GDF-9 and TGF-ß1 could be explained by the different phosphorylated sites on the downstream Smad2/3. Moreover, asiaticoside could inhibit GDF-9-induced activation of MAPKs and Smad pathway in KFs. In conclusion, GDF-9 enhanced the invasive growth of KFs, which was achieved by phosphorylation of Smad 2/3 at the linker region through activation of MAPKs pathway. Asiaticoside hindered the invasive growth of KFs by inhibiting the GDF-9/MAPK/Smad pathway.

Synthesis, anti-tumor and anti-angiogenic activity evaluations of asiatic Acid amino Acid derivatives.

Fifteen semi-synthetic derivatives of asiatic acid (AA) have been synthesized and evaluated for their biological activities. The successful modification of these compounds at the C-2, C-3, C-23 and C-28 positions was confirmed using NMR, MS and IR spectra. Further, their anti-tumor effects were evaluated in vitro using different cancer cell lines (HeLa, HepG2, B16F10, SGC7901, A549, MCF7 and PC3), while their anti-angiogenic activities were evaluated in vivo using a larval zebrafish model. Among the derivatives, compounds 4-10 showed more potent cytotoxic and anti-angiogenic effects than AA, while compounds 11-17 had significantly less effects. The new derivative 10 was also included in finished formulations to evaluate its stability using HPLC due to its potential topical use. The derivative 10 had markedly better anti-tumor activities than both AA and other derivatives, with similar stability as its parent compound AA.

Growth inhibitory effect of KYKZL-1 on Hep G2 cells via inhibition of AA metabolites and caspase-3 pathway and cell cycle arrest.

KYKZL-1, a newly synthesized compound with COX/5-LOX dual inhibition, was subjected to the inhibitory activity test on Hep G2 growth. We found that KYKZL-1 inhibited the growth of Hep G2 cells via inducing apoptosis. Further studies showed that KYKZL-1 activated caspase-3 through cytochrome c release from mitochondria and down regulation of Bcl-2/Bax ratio and reduced the high level of COX-2 and 5-LOX. As shown in its anti-inflammatory effect, KYKZL-1 also exhibited inhibitory effect on the PGE2 and LTB4 production in Hep G2 cells. Accordingly, exogenous addition of PGE2 or LTB4 reversed the decreases in cell viability. In addition, KYKZL-1 caused cell cycle arrest at the S-G2 checkpoint via the activation of p21(CIP1) protein and down-regulation of cyclin A expression. These data indicate that the growth inhibitory effect of KYKZL-1 is associated with inhibition of AA metabolites and caspase-3 pathway and cell cycle arrest. Combined with our previous findings, KYKZL-1 exhibiting COX/5-LOX inhibition may be a promising potential agent not only for inflammation control but also for cancer prevention/therapy with an enhanced gastric safety profile.

Inhibition of inflammatory mediators contributes to the anti-inflammatory activity of KYKZL-1 via MAPK and NF-κB pathway.

KYKZL-1, a newly synthesized compound with COX/5-LOX dual inhibition, was subjected to the anti-inflammatory activity test focusing on its modulation of inflammatory mediators as well as intracellular MAPK and NF-κB signaling pathways. In acute ear edema model, pretreatment with KYKZL-1 (p.o.) dose-dependently inhibited the xylene-induced ear edema in mice with a higher inhibition than diclofenac. In a three-day TPA-induced inflammation, KYKZL-1 also showed significant anti-inflammatory activity with inhibition ranging between 20% and 64%. In gastric lesion test, KYKZL-1 elicited markedly fewer stomach lesions with a low index of ulcer as compared to diclofenac in rats. In further studies, KYKZL-1 was found to significantly inhibit the production of NO, PGE2, LTB4 in LPS challenged RAW264.7, which is parallel to its attenuation of the expression of iNOS, COX-2, 5-LOX mRNAs or proteins and inhibition of phosphorylation of p38 and ERK MAPKs and activation of NF-κB. Taken together, our data indicate that KYKZL-1 comprises dual inhibition of COX and 5-LOX and exerts an obvious anti-inflammatory activity with an enhanced gastric safety profile via simultaneous inhibition of phosphorylation of p38 and ERK MAPKs and activation of NF-κB.

Madecassoside, a triterpenoid saponin isolated from Centella asiatica herbs, protects endothelial cells against oxidative stress.

This study aimed to investigate the effect of madecassoside against oxidative stress-induced injury of endothelial cells. Hydrogen peroxide (H(2)O(2), 500 µmol/L) was employed as an inducer of oxidative stress in human umbilical vein endothelial cells (HUVECs). Cell apoptosis was detected by Hoechst 33258 staining and flow cytometry. Caspase-3 activity and mitochondria membrane potential were further examined. As a result, madecassoside (10, 30, 100 µmol/L) could reverse morphological changes, elevate cell viability, increase glutathione levels, and decrease lactate dehydrogenase and malondialdehyde levels caused by H(2)O(2) in a concentration-dependent manner. It attenuated apoptosis, preventing the activation of caspase-3 and the loss of mitochondria membrane potential, as well as the phosphorylation of p38 mitogen-activated protein kinase (MAPK) in HUVECs. These data suggested that madecassoside could protect HUVECs from oxidative injury, which was probably achieved by inhibiting cell apoptosis via protection of mitochondria membranes and downregulation of the activation of caspase-3 and p38 MAPK.

Identification of Major Active Ingredients Responsible for Burn Wound Healing of Centella asiatica Herbs.

Centella asiatica herbs have been prescribed as a traditional medicine for wound healing in China and Southeast Asia for a long time. They contain many kinds of triterpenoid compounds, mainly including glycosides (asiaticoside and madecassoside) and corresponding aglycones (asiatic acid and madecassic acid). To identify which is the major active constituent, a comprehensive and comparative study of these compounds was performed. In vitro, primary human skin fibroblasts, originating from healthy human foreskin samples, were treated with various concentrations of asiaticoside, madecassoside, asiatic acid, and madecassic acid, respectively. Cell proliferation, collagen synthesis, MMP-1/TIMP-1 balance, and TGF-ß/Smad signaling pathway were investigated. In vivo, mice were orally administered with the four compounds mentioned above for two weeks after burn injury. The speed and quality of wound healing, as well as TGF-ß(1) levels in skin tissues, were examined. Interestingly, in contrast to prevalent postulations, asiaticoside and madecassoside themselves, rather than their corresponding metabolites asiatic acid and madecassic acid, are recognized as the main active constituents of C. asiatica herbs responsible for burn wound healing. Furthermore, madecassoside is more effective than asiaticoside (P = 0.0446 for procollagen type III synthesis in vitro, P = 0.0057 for wound healing speed, and P = 0.0491 for wound healing pattern in vivo, correspondingly).

Discovery, synthesis, and evaluation of small-molecule signal transducer and activator of transcription 3 inhibitors.

The signal transducer and activator of transcription 3 (STAT3) oncogene is a promising molecular target and its inhibitors have great potential as anticancer drugs. To identify novel and STAT3-selective inhibitors, a virtual screening based on Specs and Maybridge databases was conducted and a 6,6'-bibenzoxazole type small molecule, compound 3a with a inhibition constant K(i) value of 494.32 nM to STAT3 was explored. Further, a novel series of derivatives originally derived from 3a was synthesized and evaluated through cell-based assays using human breast cancer cell lines, MDA-MB-468 and MCF-7 with or without constitutive expression of STAT3, respectively. In the series, 3a, 3c, 3d and 4e showed a better inhibitory activity with a good selectivity. Among them, 3a and 3c significantly inhibited STAT3 protein level and also displayed binding affinity for STAT3 that detected with flow injection analysis-quartz crystal microbalance (FIA-QCM) analysis system. The results provided a new lead for future design and development of potent STAT3 inhibitors.

Electrochemical detection of extracellular hydrogen peroxide released from RAW 264.7 murine macrophage cells based on horseradish peroxidase-hydroxyapatite nanohybrids.

A new method developed for the reliable determination of extracellular and intracellular H(2)O(2) is very useful for gaining a full understanding of the role that H(2)O(2) plays in pathology and physiology, and the relationship between H(2)O(2) and environmental stresses and lipid peroxidation. This work developed and validated an electrochemical approach for the determination of extracellular H(2)O(2) released from RAW 264.7 murine macrophage cells. This approach is based on the electrocatalytic reduction of the released H(2)O(2) at the biosensor of HRP-HAP/GC, which was fabricated by depositing the horseradish peroxidase-hydroxyapatite (HRP-HAP) nanohybrids on a glassy carbon (GC, 3 mm in diameter) electrode. The biosensor exhibited a rapid response (less than 2 s), a low detection limit (0.1±0.02 µM), a wide linear range (5 µM to 0.82 mM), as well as good stability and repeatability. In addition, the common interfering species, such as uric acid (UA), ascorbic acid (AA), glucose, and 3,4-dihydroxyphenylacetic acid (DOPAC), etc., did not cause any interference due to the use of a low operating potential (-400 mV, versus SCE). Therefore, this work has demonstrated a simple and effective sensing platform for the detection of extracellular H(2)O(2) released from cells such as RAW 264.7 cells, which has potential utility to bioelectroanalytical chemistry, cellular biology, and pathophysiology.

[Bioactive constituents from whole herbs of Vernonia cinerea (II)].

OBJECTIVE: To study the constituents of the whole herbs of Vernonia cinerea by bio-activity guided isolation with PC-12 model. METHOD: The constituents were separated by column chromatography and the structures were elucidated by spectroscopic methods. RESULT: Ten compounds were identified to be (-)-clovane-2,9-diol (1), caryolane-1,9beta-diol (2), apigenin (3), chrysoeriol (4), luteolin (5), thermopsoside (6), luteolin-7-O-beta-D-glucoside (7), quercetin(8), apigenin-4'-O-beta-D-glucoside (9), hyperin (10), beta-amyrin aceate (11), lupeol acetate (12). CONCLUSION: Compounds 1, 2, 6 and 10 were isolated from this genus for the first time.

Corosolic acid isolated from Eriobotrya japonica leaves reduces glucose level in human hepatocellular carcinoma cells, zebrafish and rats.

Type 2 diabetes (T2D) with high morbidity and mortality is characterized by abnormal glucose and lipid metabolism due in part to insulin resistance in liver, which lead to elevated hyperglycemia and hyperlipidemia. This study sough to explore the effects of corosolic acid (CA) in different T2D models and explored the underlying mechanism. Separated from Eriobotrya japonica leaves, CA purity was above 95% measured by a HPLC method. Compared with cAMP and DEX induced T2D HepG2 model, CA significantly stimulated glucose consumption and improved glycogen accumulation by inhibiting PEPCK mRNA expression. And in cAMP and DEX induced T2D zebrafish model, CA reduced glycogen degradation and increased glucose consumption by regulating some key enzymes in carbon metabolism including GLUT1, GLUT2, GLUT3, LDHA, LDHB, GP, G6Pase, GYS1, and PFKFB3. In addition, insulin receptor signals were also involved in CA-regulated hypoglycemic action. Furthermore, in STZ-induced T2D rat model, compared with diabetic control groups, CA remarkably downregulated the levels of serum lipid, blood glucose, ICAM-1, malonaldehyde and insulin resistance index, while upregulated SOD activity and impaired glucose tolerance. In a conclusion, CA can regulate glucose and lipid metabolic adaptation in T2D like HepG2, zebrafish and rat models partly through reducing inflammation and oxidative stress and suppressing PEPCK.

Anti-rheumatoid arthritic effect of madecassoside on type II collagen-induced arthritis in mice.

Madecassoside is the highest amount of triterpene constituent in Centella asiatica herbs, a frequently prescribed crude drug in southeastern Asian and China for wound healing and scar management. The present study aimed to investigate the therapeutic potential and underlying mechanisms of madecassoside on collagen II (CII)-induced arthritis (CIA) in mice. Madecassoside (10, 20 and 40mg/kg), orally administered from the day of the antigen challenge for twenty consecutive days, dose-dependently alleviated the severity of the disease based on the reduced clinical scores, and elevated the body weights of mice. Histopathological examination indicated that madecassoside alleviated infiltration of inflammatory cells and synovial hyperplasia as well as protected joint destruction. Moreover, madecassoside reduced the serum level of anti-CII IgG, suppressed the delayed type hypersensitivity against CII in ears, and moderately suppress CII-stimulated proliferation of lymphocytes from popliteal lymph nodes in CIA mice. In vitro, madecassoside was ineffective in the activation of macrophages caused by lipopolysaccharide. It was concluded that madecassoside substantially prevented mouse CIA, and might be the major active constituent of C. asiatica herbs responsible for clinical uses for rheumatoid arthritis. The underlying mechanisms of action may be mainly through regulating the abnormal humoral and cellular immunity as well as protecting joint destruction.

Antiangiogenic effects of AA-PMe on HUVECs in vitro and zebrafish in vivo.

Angiogenesis plays a vital role in many physiological and pathological processes and several diseases are connected with its dysregulation. Asiatic acid (AA) has demonstrated anticancer properties and we suspect this might be attributable to an effect on angio-genesis. A modified derivative of AA, N-(2α,3ß,23-acetoxyurs-12-en-28-oyl)-L-proline methyl ester (AA-PMe), has improved efficacy over its parent compound, but its effect on blood vessel development remains unclear. METHODS: In this study, we investigated the antiangiogenic activity of AA and AA-PMe in zebrafish embryos and human umbilical vein endothelial cells (HUVECs). First of all, we treated HUVECs with increasing concentrations of AA-PMe or AA, with or without vascular endothelial growth factor (VEGF) present, and assessed cell viability, tube formation, and cell migration and invasion. Quantitative real-time polymerase chain reaction and Western blot analysis were later used to determine the role of vascular endothelial growth factor receptor 2 (VEGFR2)-mediated signaling in AA-PMe inhibition of angiogenesis. We extended these studies to follow angiogenesis using Tg(fli:EGFP) transgenic zebrafish embryos. For these experiments, embryos were treated with varying concentrations of AA-PMe or AA from 24 to 72 hours postfertilization prior to morphological observation, angiogenesis assessment, and endogenous alkaline phosphatase assay. VEGFR2 expression in whole embryos following AA-PMe treatment was also determined. RESULTS: We found AA-PMe decreased cell viability and inhibited migration and tube formation in a dose-dependent manner in HUVECs. Similarly, AA-PMe disrupted the formation of intersegmental vessels, the dorsal aorta, and the posterior cardinal vein in zebrafish embryos. Both in vitro and in vivo AA-PMe surpassed AA in its ability to block angiogenesis by suppressing VEGF-induced phosphorylation of VEGFR2 and disrupting downstream extracellular regulated protein kinase and AKT signaling. CONCLUSION: For the first time, this study reveals that AA-PMe acts as a potent VEGFR2 kinase inhibitor and exerts powerful antiangiogenic activity, suggesting it to be a promising therapeutic candidate for further research.

MicroRNA­675­3p promotes esophageal squamous cell cancer cell migration and invasion.

Esophageal cancer ranks fourth in cancer­associated mortality in China and the incidence of esophageal adenocarcinoma has risen dramatically over the past two decades. MicroRNA (miRNA/miR) serves a pivotal role in human cancer cell growth, invasion and migration. MiR­675­3p is highly expressed in esophageal squamous cell cancer (ESCC) tissues, and may have an influence on ESCC cell migration and invasion. ESCC tumor tissue samples from 35 patients were profiled. MiR­675­3p expression was confirmed by reverse transcription­quantitative polymerase chain reaction. Manipulation of miR­675­3p via knockdown was carried out with subsequent evaluation of effects on cell proliferation, invasion, migration, and use of western blotting and ELISA assays. MiR­675­3p was overexpressed in ESCC tissues compared with normal tissues, and had higher expression levels in ESCC cells compared with the healthy esophageal epithelial cell line. The results revealed a predominant upregulation of cell migration and invasion ability. MiR­675­3p inhibitor inhibited ESCC cell proliferation, migration and invasion ability. It was also demonstrated that downregulation of miR­675­3p decreased the levels of matrix metalloproteinase (MMP) 2 and 9 and increased the level of E­cadherin. In addition, the effects of miR­675­3p inhibitor on ESCC cell lines were eliminated by con­transfection with miR­675­3p inhibitor and miR­675­3p mimic. In conclusion, the results indicated that miR­675­3p may be involved in the progression of ESCC through regulating ESCC cell migration and invasion capacity via modulating epithelial mesenchymal transition markers (MMP2, MMP 9 and E­cadherin).

Increased expression ratio of Bcl-2/Bax is associated with crocin-mediated apoptosis in bovine aortic endothelial cells.

Crocin, extracted and purified from Gardenia jasminoids Ellis in our laboratory, has been reported to have antioxidative, hypolipidaemic and anti-atherosclerorotic effects. However, the underlying molecular mechanisms by which crocin acts as a cytoprotective agent remain to be elucidated. In the present study, we examined the mechanisms of crocin, the digentiobiosyl ester of crocetin, on bovine aortic endothelial cell apoptosis induced by hydrogen peroxide (H2O2). The cells were obtained from the thoracic aorta of newborn calves, and apoptosis was induced by 200 microM H2O2. Before addition of H2O2, the cells were pretreated with different concentrations of crocin for 6 hr. After incubation of the cells with H2O2, a comparative reverse transcriptase-polymerase chain reaction-based repeated amplification protocol assay was used to determine the ratio of bcl-2/bax mRNA expression, and cells loaded with fluo-3/AM were subjected to laser scanning confocal microscopy for detection of intracellular calcium ([Ca2+]i) levels. Treatment of the cells with H2O2 alone decreased the ratio of bcl-2/bax expression to almost twice of those of untreated cells (from 0.33+/-0.05 to 0.16+/-0.02). In the presence of 1 and 10 microM crocin, the ratios were enhanced when compared with H2O2 alone respectively (from 0.16+/-0.02 to 0.58+/-0.04, 1.18+/-0.13). The treatment of cells with crocin alone had little effect on the value of this ratio. In the presence or absence of extracellular Ca2+, H2O2 could induce intracellular calcium elevation not only in the elevation presence of extracellular Ca2+ (Hanks), but also without extracellular calcium present (D-Hanks). But the extent of [Ca2+]i under conditions lacking extracellular calcium is less. Crocin concentration dependently inhibited the [Ca2+]i elevation induced by H2O2 under these two conditions. Our data suggest that crocin may exert anti-atherosclerotic effects by increasing the expression ratio of bcl-2/bax, as a result, inhibiting the bovine aortic endothelial cell apoptosis that plays an important role in the initiation and progression of atherosclerosis.

A novel synthetic Asiatic acid derivative induces apoptosis and inhibits proliferation and mobility of gastric cancer cells by suppressing STAT3 signaling pathway.

Activation of the transcription factor, signal transducers and activators of transcription 3 (STAT3), has been linked to the proliferation and migration of a variety of human cancer cells. These actions occur via the upregulation or downregulation of cell survival and tumor suppressor genes, respectively. Importantly, agents that can suppress STAT3 activation have the potential for use in the prevention and treatment of various cancers. In this study, an Asiatic acid (AA) derivative, N-(2α,3ß,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), is reported to dose dependently suppress constitutive STAT3 activation in gastric cancer cells. This inhibition was mediated by blockade of Janus-activated kinase 2. Additionally, AA-PMe regulated the expression of STAT3-modulated gene products, including cyclin D1, Bax, Bcl-2, c-Myc, and matrix metalloproteinase (MMP)-2 and MMP-9. Finally, transfection with both a STAT3 mimic and an inhibitor reversed the AA-PMe-driven modulation of STAT3 downstream gene products. Overall, these results suggest that AA-PMe is a novel blocker of STAT3 activation and has the potential for the prevention and treatment of gastric cancer.

AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells.

Asiatic acid (AA; 2α,3ß,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3ß,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy.

[Effect of epigallocatechingallate on acute lung injury induced by oleic acid in mice].

AIM: To investigate the effect of epigallocatechingallate (EGCG) on acute lung injury induced by oleic acid in mice and the possible mechanism. METHODS: Acute lung injury was induced by oleic acid in mice. Light microscopy and electron microscopy were used to examine histological changes and lung index as well as wet to dry weight ratio was calculated. Serum TNF-a level was measured by enzyme linked immunosorbent assay (ELISA) and the phosphorylation of p38 MAPK was determined by Western blotting. RESULTS: Pretreatment of EGCG significantly alleviated oleic acid induced lung injury accompanied by reduction of lung index and wet to dry weight ratio, decreased of TNF-a level in serum and inhibition of phosphorylation of p38 MAPK. CONCLUSION: EGCG showed beneficial effect on acute lung injury induced by oleic acid in mice. The ultimate reduction of TNF-alpha in serum caused by inhibition of phosphorylated p38 MAPK is involved in the mechanism of action of EGCG.