Wea-Lung Lin

Protective effect of Hibiscus anthocyanins against tert-butyl hydroperoxide-induced hepatic toxicity in rats.

Hibiscus anthocyanins (HAs), a group of natural pigments occurring in the dried flowers of Hibiscus sabdariffa L., which is a local soft drink material and medical herb, were studied for antioxidant bioactivity. The preliminary study showed that HAs were able to quench the free radicals of 1,1-diphenyl-2-picrylhydrazyl. This antioxidant bioactivitiy was further evaluated using the model of tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity in rat primary hepatocytes and hepatotoxicity in rats. The results demonstrated that HAs, at the concentrations of 0.10 and 0.20 mg/ml, significantly decreased the leakage of lactate dehydrogenase and the formation of malondialdehyde induced by a 30-min treatment of t-BHP (1.5 mM). The in vivo investigation showed that the oral pretreatment of HAs (100 and 200 mg/kg) for 5 days before a single dose of t-BHP (0.2 mmol/kg, ip) significantly lowered the serum levels of hepatic enzyme markers (alanine and aspartate aminotransferase) and reduced oxidative liver damage. The histopathological evaluation of the liver revealed that Hibiscus pigments reduced the incidence of liver lesions including inflammatory, leucocyte infiltration, and necrosis induced by t-BHP in rats. Based on the results described above, we speculate that Hibiscus pigments may play a role in the prevention of oxidative damage in living systems.

Antitumor progression potential of caffeic acid phenethyl ester involving p75NTR in C6 glioma cells

The previous data showed that caffeic acid phenethyl ester (CAPE), a component of propolis, possesses inducing cell cycle arrest and antiproliferation effect on C6 glioma cells in vitro and in vivo. In the present study, C6 glioma cells treated with CAPE resulted in morphological changes to an astrocytic phenotype and increased the expression of glial differentiation marker proteins including glial fibrillary acidic protein (GFAP) and S-100β. In addition, with scratch assay and Boyden chamber assay, CAPE exhibited inhibitory effects on the motility and invasion of C6 glioma cells. Furthermore, CAPE induced the expression of nerve growth factor (NGF) and p75 neurotrophin receptor (p75(NTR)), which were involved in neural cell differentiation. CAPE could also inhibit the activity of matrix metalloproteinases (MMPs) and induce the expression of RhoB, a tumor suppressor. To examine the involvement of p75(NTR) in the anti-invasive property of CAPE, Western blotting and Boyden Chamber assay were performed by addition of an anti-p75(NTR) antibody in C6 cells. The results showed that blocking p75(NTR) could decrease the CAPE-induced expression of RhoB and the inactivation of MMP-2, -9 as well as the anti-invasion effect in C6 glioma cells. Furthermore, CAPE suppressed IκB-α phosphorylation which was down stream of p75(NTR). Finally, the effect of CAPE on metastasis by lung colonization of the tumor cell in nude mice was also evaluated. It was found that the groups of nude mice injected with CAPE-pretreated cells could decrease both lung size and weight as compared to the positive control group which did not receive CAPE treatment. In addition, histological examination of the mouse lung sections showed that the CAPE-treated group inhibited the metastasis of C6 glioma cells. These data suggest CAPE possesses antitumor progression potential.

Preventive effect of Ganoderma amboinense on acetaminophen-induced acute liver injury

In vivo preventive effects of Ganoderma amboinense against acetaminophen-induced hepatotoxicity in Balb/cA mice were studied. G. amboinense powder at 1% and 2% was mixed with standard diet and supplied to mice for 6 weeks, and followed by acetaminophen (350 mg/kg body weight) intraperitoneal injection. In normal mice (without acetaminophen treatment), the consumption of G. amboinense significantly increased hepatic glutathione (GSH) level. Acetaminophen treatment significantly elevated both alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities; however, the pre-intake of G. amboinense significantly and dose-dependently protected liver against the subsequent acetaminophen-induced elevation of ALT and AST activities. Acetaminophen treatment also caused significant GSH depletion, malondialdehyde (MDA) and reactive oxygen species (ROS) increase, and activity reduction of glutathione peroxidase (GPX) and catalase. However, the pre-intake of G. amboinense significantly diminished the subsequent acetaminophen-induced GSH depletion, MDA and ROS increase, and retarded the loss of catalase and GPX activities, in which the effect of G. amboinense on GPX activity, and formation of MDA and ROS was dose-dependent. These results support that G. amboinense may be considered as a preventive agent for acute liver injury.

Demethylwedelolactone derivatives inhibit invasive growth in vitro and lung metastasis of MDA-MB-231 breast cancer cells in nude mice.

The anticancer properties of demethylwedelolactone (DWEL) and wedelolactone (WEL), which are naturally occurring coumestans, have not been well characterized. In this study, we investigated the anti-invasive effects of synthetic WEL and DWEL on human MDA-MB-231 breast cancer cells. We found that WEL and DWEL inhibited the anchorage-independent growth and also suppressed cell motility and cell invasion of MDA-MB-231 cells. In addition, WEL and DWEL reduced the activity and expression of matrix metalloproteinases (MMPs) involved in blocking the IκB-α/NFκB and MEK/ERK signaling pathways in MDA-MB-231 cells. Furthermore, DWEL suppressed the metastasis and lung colonization of the tumor cells in the nude mice. Altogether, these data suggest that DWEL derivatives exert anti-invasive growth effect on breast cancer cells.

Antitumor progression potential of morusin suppressing STAT3 and NFκB in human hepatoma SK-Hep1 cells

Morusin is a prenylated flavonoid that has been isolated from the root bark of the mulberry tree (Morus species, Moraceae), a Chinese traditional medicine. It has been synthesized by our laboratory from commercially available phloroglucinol, and has demonstrated to possess antitumor effects of cell lines including A549, MCF-7, and MDA-MB-231. In this study, at non-cytotoxic concentrations, morusin altered invasive morphology and suppressed cell-matrix adhesion, cell motility and cell invasion in SK-Hep1 cells. Morusin also increased the expression of E-cadherin, an epithelial cell junction protein, decreased the expression of vimentin, a mesecnchymal marker, and α2-, α6-, β1- integrin, which regulated cancer attachment and migration. In addition, morusin reduced the activity of matrix metalloproteinase-2 and 9 (MMP-2 and MMP-9), which were involved in extracellular matrix (ECM) degradation and promoting cancer cell invasion. Furthermore, morusin suppressed the signal transducer and activator of transcription 3 (STAT3) and nuclear factor-κB (NFκB) signaling pathways, which modulate the protein expression involved in the invasion process. Finally, morusin decreased the lung colonization of the SK-Hep1 cells in the nude mice. These results indicate morusin possesses antitumor progression potential through suppressing STAT3 and NFκB.

Inhibitory effect of 12-O-tetradecanoylphorbol-13-acetate-caused tumor promotion in benzo[a]pyrene-initiated CD-1 mouse skin by baicalein.

The effects of topical application of baicalein on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced promotion of skin tumors, hyperplasia, ornithine decarboxylase activity, and inflammation were evaluated in female CD-1 mice. Topical application of baicalein (0.08, 0.16, or 0.2 mumol) with TPA (5 nmol) twice weekly for 24 weeks to mice previously initiated with benzo[a]pyrene inhibited the number of TPA-induced tumors per mouse significantly. Preapplication of the same amount of baicalein also afforded significant protection against TPA-induced hyperplasia in the ear skin. Topical application of baicalein inhibited tumor promoter-caused induction of epidermal ornithine decarboxylase activity by TPA (5 nmol). The topical application of baicalein (0.008, 0.016, or 0.02 mumol) inhibited TPA-induced edema of mouse ears by 88%, 96%, or 97%, respectively. Pretreatment of mouse skin with various amounts of baicalein caused inhibition of H2O2 and myeloperoxidase formation by TPA. These results indicate that baicalein can be a potential cancer-chemopreventive agent against tumor promotion.

Inhibition of cell survival, cell cycle progression, tumor growth and cyclooxygenase-2 activity in MDA-MB-231 breast cancer cells by camphorataimide B

Both mycelium and fruiting body of Antrodia camphorate, a traditional medicinal fungus of the family Polyporaceae in Taiwan, have been suggested to possess multiple biological functions. However, there is little information on the anticancer components and actions of mycelium of Antrodia camphorate. In the present study, the anticancer potential of synthesized maleimide derivatives, which have been isolated from mycelium of Antrodia camphorate, is examined. Comparing the cytotoxicity of two synthesized maleimide derivatives in four human cancer cell lines, camphorataimide B displayed potent efficacy. Then we investigated the impact of camphorataimide B on cell survival and cell cycle progression in vitro, and tumor growth in vivo in MDA-MB-231 breast cancer cells. Camphorataimide B decreased the cell viability and foci formation of MDA-MB-231 breast cancer cells. Further, camphorataimide B triggered apoptosis and blocked cell cycle progression of MDA-MB-231 breast cancer cells. Using immunoblotting analysis, camphorataimide B decrease the expression of cyclin-A and cyclin-B1. Moreover, we demonstrated for the first time that camphorataimide B inhibited cyclooxygenase-2 (COX-2) activity and protein expression in MDA-MB-231 cells. In nude mice study, camphorataimide B administration retarded the xenograft tumor growth of MDA-MB-231 cells. By immunohistochemical analysis, camphorataimide B decreased the expression of Ki-67 in xenograft tumor in vivo. It implied that camphorataimide B blocked cell cycle progression. Consistent with the cell culture investigation, camphorataimide B also reduced the expression of cyclin-A, cyclin-B1 and COX-2 in xenograft tumor. Thus, camphorataimide B may play a crucial role in prevention and therapy of malignant breast cancer.

High incidence of acute promyelocytic leukemia specifically induced by N -nitroso- N -methylurea (NMU) in Sprague–Dawley rats

Carcinogenic agents such as N-methyl-N-nitrosourea can cause tumors. The aims of the present study were to evaluate and classify a subtype of AML (acute myeloid leukemia) that was induced by NMU. According to previous publications, NMU induces not only mammary cancer but also leukemia in Sprague–Dawley (S-D) rats. However, the subtype of leukemia involved in NMU-treated rats is unknown. We found that both organ weight and relative organ weights were significantly higher in NMU-exposed rats than in controls. Morphological changes of rat livers and spleens were assessed by histological evaluation (H&E staining), which found that these tissues were abnormal in appearance. Also, cytological examination of the blood showed immature white blood cells in a smear using Liu’s and Papanicolaou stains, indicating that gross abnormalities and histopathological changes were pathologically observed. NMU leukemia incidence was 97.1%. In this study, immunohistochemical (IHC) analysis was valuable in classifying the leukemia of poorly differentiated blasts induced by NMU. Paraffin blocks were stained for MPO, CD3, CD15, CD20, and CD34 markers. The NMU-induced group was positive for MPO, but negative for CD3, CD15, CD20, and CD34. These CD markers suggest that they are useful in helping diagnose APL (M3) leukemia. The model of NMU-induced leukemogenesis in an S-D rat suggests a more definite way to classify APL. This APL will provide an important tool for chemical carcinogenesis and leukemia studies.

Assessing the HER2 status in mucinous epithelial ovarian cancer on the basis of the 2013 ASCO/CAP guideline update.

Her2 gene amplification and protein overexpression are important factors in predicting clinical sensitivity to anti-HER2 monoclonal antibody therapy in breast, gastric, or gastro-esophageal junction cancer patients. The purpose of this study was to evaluate the HER2 status in the mucinous epithelial ovarian cancer (EOC). Adopting the 2013 American Society for Clinical Oncology and the College of American Pathologists guideline update for HER2 testing, 49 tissue microarray samples of mucinous EOC were analyzed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) tests. The prevalence of HER2 positivity in Asian mucinous EOC was 9 of 49 Asian women (18.37%). The overall concordance was 100% between IHC and FISH results. Her2 gene copies before chromosome-17 correction increased significantly in a stepwise order through the negative, equivocal, and positive IHC result categories (P<0.001), as did the Her2 gene copies after chromosome-17 correction (P<0.001). Of the Taiwanese cohort (n=21), HER2 heterogeneity was 4.76% (1/21) in all but 14.26% (1/7) in HER2-positive cancer. In conclusion, we demonstrated that the prevalence of HER2 positivity in both Asian and white women was comparable; complete HER2 concordance existed between IHC and FISH tests for the Her2 gene copies per tumor cell either before or after correction of chromosome-17, and this can be applied as a potentially valuable tool to analyze the HER2 status. Polysomy-17 was absent under the CEP17 cutoff ≥3. The existence of HER2 heterogeneity can be discerned in certain HER2-expressed primary mucinous EOC in Taiwanese women.

Prostaglandin E2 Is Involved in the Increase of Cytochrome P-450 2B1 Expression by α-Tocopheryl Succinate in Primary Rat Hepatocytes in the Presence of Phenobarbital

The modulation of cytochrome P-450 2B1 expression by α-tocopheryl succinate and whether prostaglandin E2 is involved in this modulation in primary rat hepatocytes in the presence of phenobarbital were investigated. A primary rat hepatocyte culture model that faithfully reproduces the phenobarbital response observed in vivo was used. Intracellular α-tocopherol content was dose dependently increased by α-tocopheryl succinate incubation. Hepatocytes were demonstrated to have prostaglandin E2-synthesizing capability. α-Tocopheryl succinate inhibited prostaglandin E2 synthesis by hepatocytes and increased cytochrome P-450 2B1 expression in the presence of phenobarbital; however, it had little effect on intracellular cAMP level. To mimic the exogenous source of prostaglandin E2 from nonparenchymal cells, various concentrations of prostaglandin E2 were added to the cell culture. High doses of exogenous prostaglandin E2 (100 and 1,000 nM) inhibited the cytochrome P-450 2B1 expression in the presence of phenobarbital compared with low doses (1 and 10 nM); however, the presence of high doses of prostaglandin E2 had no effect on intracellular cAMP level. Forskolin significantly increased intracellular cAMP level and inhibited cytochrome P-450 2B1 expression in the presence of phenobarbital. The results of this study indicate that α-tocopheryl succinate increases cytochrome P-450 2B1 expression via its inhibition of prostaglandin E2 synthesis in the presence of phenobarbital; however, changes in intracellular cAMP level are not related to cytochrome P-450 2B1 expression.