Microglia-mediated drug substance transfer promotes chemoresistance in brain tumors: insights from an in vitro co-culture model using GCV/Tk prodrug system.

BACKGROUND: It is well known that tumor-associated macrophages (TAMs) play essential roles in brain tumor resistance to chemotherapy. However, the detailed mechanisms of how TAMs are involved in brain tumor resistance are still unclear and lack a suitable analysis model. METHODS: A BV2 microglial cells with ALTS1C1 astrocytoma cells in vitro co-culture system was used to mimic the microglia dominating tumor stroma in the tumor invasion microenvironment and explore the interaction between microglia and brain tumor cells. RESULTS: Our result suggested that microglia could form colonies with glioma cells under high-density culturing conditions and protect glioma cells from apoptosis induced by chemotherapeutic drugs. Moreover, this study demonstrates that microglia could hijack drug substances from the glioma cells and reduce the drug intensity of ALTS1C1 via direct contact. Inhibition of gap junction protein prevented microglial-glioma colony formation and microglia-mediated chemoresistance. CONCLUSIONS: This study provides novel insights into how glioma cells acquire chemoresistance via microglia-mediated drug substance transferring, providing a new option for treating chemo-resistant brain tumors.

Protective Effects of Sesamin against UVB-Induced Skin Inflammation and Photodamage In Vitro and In Vivo.

Ultraviolet (UV) exposure has been demonstrated as the most critical factor causing extrinsic skin aging and inflammation. This study explored the protective effects and mechanisms of sesamin against skin photodamage. Sesamin reduced intracellular reactive oxygen species production after UVB irradiation in human dermal fibroblasts. The sesamin treatment attenuated mitogen-activated protein (MAP) kinase phosphorylation and matrix metalloproteinase (MMPs) overexpression induced by UVB exposure, and it significantly enhanced the tissue inhibitor of metalloproteinase-1 protein expression. Sesamin also elevated the total collagen content in human fibroblasts by inhibiting UVB-induced mothers against decapentaplegic homolog 7 (Smad7) protein expression. Sesamin reduced UVB-induced inducible nitric oxide synthase (i-NOS) and cyclooxygenase-2 (COX-2) overexpression and inhibited nuclear factor-kappa B (NF-κB) translocation. Moreover, sesamin may regulate the c-Jun N-terminal kinases (JNK) and p38 MAP kinase pathways, which inhibit COX-2 expression. Sesamin could reduce UVB-induced inflammation, epidermal hyperplasia, collagen degradation, and wrinkle formation in hairless mice. It also reduced MMP-1, interleukin (IL-1), i-NOS, and NF-κB in the mouse skin. These results demonstrate that sesamin had antiphotodamage and anti-inflammatory activities. Sesamin has potential for use as a skin protection agent in antiphotodamage and skin care products.

Antiobesity effect of Lactobacillus reuteri 263 associated with energy metabolism remodeling of white adipose tissue in high-energy-diet-fed rats.

Obesity is a serious and costly issue to the medical welfare worldwide. Probiotics have been suggested as one of the candidates to resolve the obesity-associated problems, but how they combat obesity is not fully understood. Herein, we investigated the effects of Lactobacillus reuteri 263 (L. reuteri 263) on antiobesity using four groups of Sprague-Dawley rats (n=10/group), namely, C (normal diet with vehicle treatment), HE [high-energy diet (HED) with vehicle treatment], 1X (HED with 2.1×109 CFU/kg/day of L. reuteri 263) and 5X (HED with 1.05×1010 CFU/kg/day of L. reuteri 263), for 8 weeks. L. reuteri 263 improved the phenomenon of obesity, serum levels of proinflammatory factors and antioxidant enzymes. More importantly, L. reuteri 263 increased oxygen consumption in white adipose tissue (WAT). The mRNA expressions of thermogenesis genes uncoupling protein-1, uncoupling protein-3, carnitine palmitoyltransferase-1 and cell death-inducing DFFA-like effector-a were up-regulated in WAT of the 5X group. Moreover, L. reuteri 263 might induce browning of WAT due to the higher mRNA levels of browning-related genes peroxisome proliferator-activated receptor-γ, PR domain containing-16, Pparγ coactivator-1α, bone morphogenetic protein-7 and fibroblast growth factor-21 in the 1X and 5X groups compared to the HE group. Finally, L. reuteri 263 altered the expressions of genes involved in glucose and lipid metabolisms in WAT, including increasing the levels of glucose transporter type 4 and carbohydrate-responsive element-binding protein and decreasing the expression of Acetyl-CoA carboxylase-1. The results suggest that L. reuteri 263 may treat obesity through energy metabolism remodeling of WAT in the high-energy-diet-induced obese rats.

Fisetin Regulates Nrf2 Expression and the Inflammation-Related Signaling Pathway to Prevent UVB-Induced Skin Damage in Hairless Mice.

Chronic ultraviolet (UV) exposure may cause skin damage, disrupt skin barrier function, and promote wrinkle formation. UV induces oxidative stress and inflammation, which results in extracellular matrix degradation in the dermis and epidermal hyperplasia. Our previous study demonstrated that fisetin exerts photoprotective activity by inhibiting mitogen-activated protein kinase/activator protein-1/matrix metalloproteinases (MMPs) activation. In this study, fisetin was applied topically to investigate its antiphotodamage effects in hairless mice. The erythema index (a* values) and transepidermal water loss were evaluated to assess skin damage, and immunohistochemical staining was conducted to elucidate the photoprotective mechanism of fisetin. The results revealed that the topical application of fisetin reduced UVB-induced increase in the a* value and wrinkle formation. In addition, fisetin inhibited epidermal hyperplasia and increased the collagen content in the dermis. Fisetin exerted photoprotective activity by inhibiting the expression of MMP-1, MMP-2, and cyclooxygenase-2 and increasing the expression of nuclear factor erythroid 2-related factor. Furthermore, fisetin increased the expression of filaggrin to prevent UVB-induced barrier function disruption. Altogether, the present results provide evidence of the effects and mechanisms of fisetin's antiphotodamage and antiphotoinflammation activities.

Antinociceptive and Anti-Inflammatory Effects of Zerumbone against Mono-Iodoacetate-Induced Arthritis.

The fresh rhizome of Zingiber zerumbet Smith (Zingiberaceae) is used as a food flavoring and also serves as a folk medicine as an antipyretic and for analgesics in Taiwan. Zerumbone, a monocyclic sesquiterpene was isolated from the rhizome of Z. zerumbet and is the major active compound. In this study, the anti-inflammatory and antinociceptive effects of zerumbone on arthritis were explored using in vitro and in vivo models. Results showed that zerumbone inhibited inducible nitric oxide (NO) synthase (iNOS), cyclooxygenase (COX)-2 expressions, and NO and prostaglandin E2 (PGE2) production, but induced heme oxygenase (HO)-1 expression in a dose-dependent manner in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. When zerumbone was co-treated with an HO-1 inhibitor (tin protoporphyrin (SnPP)), the NO inhibitory effects of zerumbone were recovered. The above results suggest that zerumbone inhibited iNOS and COX-2 through induction of the HO-1 pathway. Moreover, matrix metalloproteinase (MMP)-13 and COX-2 expressions of interleukin (IL)-1ß-stimulated primary rat chondrocytes were inhibited by zerumbone. In an in vivo assay, an acetic acid-induced writhing response in mice was significantly reduced by treatment with zerumbone. Furthermore, zerumbone reduced paw edema and the pain response in a mono-iodoacetate (MIA)-induced rat osteoarthritis model. Therefore, we suggest that zerumbone possesses anti-inflammatory and antinociceptive effects which indicate zerumbone could be a potential candidate for osteoarthritis treatment.

Effects of Lu-Do-Huang Extract (LDHE) on Apoptosis Induction in Human Hep3B Cells.

Lu-Do-Huang (Pracparatum mungo) is a fermented mung bean [corrected] (Vigna radiata) and has long been used as a traditional and functional food in Traditional Chinese Medicine, especially for treating a variety of liver disorders. The present study aimed to evaluate the apoptotic effects of Lu-Do-Huang ethanol extract (LDHE) on Hep3B cells, a human hepatoma cell line. A variety of cellular assays, flow cytometry and immunoblotting were used. Our results showed that LDHE significantly inhibited Hep3B cells growth. Additionally, the cell cycle assay showed that LDHE prevented Hep3B cell entry into S phase and led to an arrest of Hep3B cells in the G0/G1 phase. LDHE induced Hep3B cells to undergo apoptosis as determined through Hep3B cell morphology changes, increase of apoptotic bodies, apoptotic cells, DNA fragmentations and caspase activity. We further examined the protein expression of TRADD, FADD, and Bax to verify the possible apoptotic pathways. The results indicated that LDHE-induced apoptosis in Hep3B cells might be mediated [corrected] by an extrinsic signaling pathway leading to an induction of apoptosis in Hep3B cells. In conclusion, LDHE induced apoptosis and cell cycle arrest in Hep3B cells. Our data provide the evidences regarding the anti-hepatoma potential of LDHE in Hep3B cells.

Immunomodulatory effects of Hedysarum polybotrys extract in mice macrophages, splenocytes and leucopenia.

Astragali Radix (Huang-Qi) is a popular herbal medicine commonly used as a constituent in tonic herbal preparations. Hedysarum polybotrys Handel-Mazzetti is one species used of Astragali Radix. In this study, the immunomodulatory properties of H. polybotrys were explored by LPS-activated and SNP-treated RAW 264.7 cells and splenocytes and, daunoblastina-induced leucopenia BALB/c mice. Formononetin was used as the bioactive marker to monitor the quality of the H. polybotrys extracts. H. polybotrys was extracted with hot-water and methanol, and MeOH extract partitioned with H2O (M-H) and ethyl acetate (M-EA) to yield four different fractions. M-EA had the highest formononetin and total proanthocyanidin content and showed stronger inhibitory effects on the production and expression of NO, PGE2, iNOS and COX-2 in LPS-activated RAW 264.7 cells and splenocytes than the other fractions. In addition, M-EA significantly stimulated the proliferation of LPS-activated RAW 264.7 cells and splenocytes, enhanced NO radicals scavenging and attenuated NO-induced cytotoxicity.  Furthermore, M-EA also significantly increased the rate of recovery of white blood cells level in daunoblastina-induced leucopenia mice. These evidences suggest that this traditional Qi-tonifying herb has potential effects in clinical conditions when immune-enhancing and anti-inflammatory effect is desired.

Pleurotus tuber-regium Polysaccharides Attenuate Hyperglycemia and Oxidative Stress in Experimental Diabetic Rats.

Pleurotus tuber-regium contains polysaccharides that are responsible for pharmacological actions, and medicinal effects of these polysaccharides have not yet been studied in diabetic rats. We examined the antidiabetic, antihyperlipidemic, and antioxidant properties of P. tuber-regium polysaccharides in experimental diabetic rats. Forty rats were equally assigned as diabetic high-fat (DHF) diet and polysaccharides treated DHF groups (DHF+1P, DHF+2P, and DHF+3P, 20 mg/kg bodyweight/8-week). Diabetes was induced by chronic low-dose streptozotocin injections and a high-fat diet to mimic type 2 diabetes. Polysaccharides (1P, 2P, and 3P) were extracted from three different strains of P. tuber-regium. Fasting blood glucose and glycosylated hemoglobin (HbA1c) levels substantially decreased, while serum insulin levels were restored by polysaccharides treatment compared to DHF. Furthermore, plasma total cholesterol, triglycerides, and low-density lipoprotein levels were significantly (P < 0.01) lower in polysaccharide groups. High-density lipoprotein levels were attenuated with polysaccharides against diabetes condition. Polysaccharides inhibited (P < 0.01) the lipid peroxidation index (malondialdehyde), and restored superoxide dismutase and glutathione peroxidase activities in the liver of diabetic rats. The antihyperglycemic property of polysaccharides perhaps boosts the antioxidant system that attenuates oxidative stress. We emphasize that P. tuber-regium polysaccharides can be considered as an alternative medicine to treat hyperglycemia and oxidative stress in diabetic rats.

Wu-Chia-Pi solution attenuates carbon tetrachloride-induced hepatic injury through the antioxidative abilities of its components acteoside and quercetin.

Wu-Chia-Pi medicated wine, composed nine Chinese medicines soaked in 35% alcohol, is widely used in Asia for its health-promoting functions. However, long-term consumption of alcohol could result in liver dysfunction. In this study, Wu-Chia-Pi solution (WCPS) and extract (WCPE) were prepared by modification of the principals given by the Committee on Chinese Medicine and Pharmacy in Taiwan. The aim of this study was to explore the protective effect of WCPS against carbon tetrachloride (CCl4)-induced liver injury and to clarify its active component(s). Antioxidative effects of the test samples were evaluated via MDA inhibition, catalase activity and DPPH-scavenging assays. HPLC was used to analysis the active components. Results showed that WCPS (1 and 5 mL/kg) significantly prevented CCl4-induced liver injury without chronic liver toxicity. Referring to the antioxidative activities, WCPE displayed significant MDA inhibitory and DPPH-scavenging activities with IC50 values of 0.91 ± 0.03 and 0.60 ± 0.04 mg/mL, respectively. Catalase activity was also enhanced by treatment of WCPE, acteoside and quercetin. Therefore, we suggest that acteoside and quercetin are the major contributors to the antioxidative and hepatoprotective activities of WCPS, and a possible mechanism could be mediated through reduction of oxidative stress.

Orally administered mycelial culture of Phellinus linteus exhibits antitumor effects in hepatoma cell-bearing mice.

AIM OF THE STUDY: The aim of this study was to evaluate the anticancer effect of a mycelial culture from Phellinus linteus PL-7 (MCPL-7) and to elucidate its potential mechanism in vivo. MATERIALS AND METHODS: SCID CB-17 mice received a transplant of Hep3B cells followed by daily MCPL-7 administrations for 8 weeks. Following tumor implantation, groups C-E were subcutaneously administered 50 mg/kg, 100 mg/kg, or 250 mg/kg MCPL-7 powder per day, respectively, for 8 weeks. Groups A and B received saline solution subcutaneously for 8 weeks. RESULTS: MCPL-7 administration induced a significant reduction in tumor size and was associated with a significant increase in T cell numbers; IL-12, IFN-γ and TNF-α secretion; NK cell activity; and phagocytic ability. Therefore, increased numbers of CD4(+) cells could have been caused by greater numbers of dendritic cells and macrophages in the spleen. Furthermore, the activation of dendritic cells and macrophages resulted in increased IL-12 secretion, which could upregulate NK cell activation. The increased secretion of IL-12, IFN-γ, and TNF-α enhanced the activity and phagocytic ability of NK cells. Thus, MCPL-7 may provide a potential therapeutic approach for both immunomodulatory and antitumor effects.

Hypolipidemic effects of three purgative decoctions.

In traditional Chinese medicine (TCM), purgation is indicated when a person suffers an illness due to the accumulation of evil internal heat. Obese individuals with a large belly, red face, thick and yellow tongue fur, constipation, and avoidance of heat are thought accumulates of evil internal heat, and they are also treated with purgatives such as Ta-Cheng-Chi-Tang (TCCT), Xiao-Chen-Chi-Tang (XCCT), and Tiao-Wei-Chen-Chi-Tang (TWCCT) by TCM doctors. In previous studies, our group found that TCCT has potent anti-inflammatory activity, and that XCCT is an effective antioxidant. Since rhubarb is the principle herb in these three prescriptions, we will first present a thorough review of the literature on the demonstrated effect (or lack of effect) of rhubarb and rhubarb-containing polyherbal preparations on lipid and weight control. We will then continue our research with an investigation of the anti-obesity and lipid-lowering effect of TCCT, XCCT, TWCCT, and rhubarb extracts using two animal models. TWCCT lowered the serum triglyceride concentration as much as fenofibrate in Triton WR-1339-treated mice. Daily supplementation with XCCT and TWCCT significantly attenuated the high-fat-diet-induced hypercholesterolemia in rats. In addition, TWCCT also significantly lowered the high-fat-diet-induced hypertriglycemia. Although feeding high-fat diet rats with these extracts did not cause loose stools or diarrhea or other deleterious effects on renal or hepatic function. None of these extracts lowered the body weight of rats fed on high-fat diet. In conclusion, the results suggest that XCCT and TWCCT might exert beneficial effects in the treatment of hyperlipidemia.

Prevention of hepatic oxidative injury by Xiao-Chen-Chi-Tang in mice.

The three purgative Cheng-Chi-Tang decoctions (CCTDs) including Ta-Cheng-Chi-Tang (TCCT), Xiao-Chen-Chi-Tang (XCCT), and Tiao-Wei-Chen-Chi-Tang (TWCCT) are used for treating gastrointestinal disorders, including liver diseases in traditional Chinese medicine. However, the underlying mechanisms as liver disease remedies are far from fully clarified. The objective of the study is to investigate and compare the antioxidant activity of the three purgative CCTDs in order to delineate their hepatic protective potential and mechanism. Antioxidant activity measured with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test indicated XCCT as the most potent preparation (IC(50) 8.94 microg/ml). In tert-butylhydroperoxide (TBH, 50mM)-induced lipid peroxidation in ICR mice liver homogenates, XCCT also showed stronger and dose-dependent inhibitory activity against TBH-induced malondialdehyde (MDA, a marker of lipid peroxidation) production (IC(50) 53.66 microg/ml). In addition, XCCT showed dose-dependent protective effect against TBH-induced cytotoxicity in normal human Chung liver cells Furthermore, in carbon tetrachloride (CCl(4))-induced acute liver injury model, mice pretreated with 0.2g/kg and 0.4 g/kg of XCCT extracts showed a decrease of 59.8 and 43.1% in serum glutamic oxaloactetic transaminase (GOT) level, 51.4 and 52% in glutamic pyruvate transaminase (GPT) level, along with a reduction of 31 and 15% in MDA level, respectively, similar to the effects exerted by silymarin. XCCT pretreated mice also showed milder necrotic changes in the microscopic picture of the liver. The results suggest that XCCT has significant antioxidant activity and hepatic protection potential.

Antitumor effects of zerumbone from Zingiber zerumbet in P-388D1 cells in vitro and in vivo.

The fresh rhizome of Zingiber zerumbet (L.) Roscoe ex Smith (Zingiberaceae) is widely used as a folk medicine in Taiwan. In this study, the fresh rhizome was extracted with 95 % EtOH and partitioned with diethyl ether. The antitumor effects of the diethyl ether extract were measured in cultured P-388D (1) cells and in an animal model of P-388D (1)-bearing CDF (1) mice. The results indicated that the extract could induce DNA fragmentation in P-388D (1) cells in vitro, and significantly prolong the life of P-388D (1)-bearing CDF (1) mice (ILS% = 127.8) at a dosage of 5 mg/kg body weight. After column chromatography combined with an MTT cytotoxicity bioassay, zerumbone, a cyclic sesquiterpene was isolated from the diethyl ether extract. Zerumbone inhibited the growth of P-388D (1) cells, induced DNA fragmentation in culture, and significantly prolonged the life of P-388D (1)-bearing CDF (1) mice (ILS% = 120.5) at a dosage of 2 mg/kg. Furthermore, zerumbone inhibited the growth of a human leukemia cell line, HL-60 cells, in a time- and concentration-dependent manner, with IC (50) values of 22.29, 9.12, and 2.27 microg/mL for 6, 12, and 18 h, respectively. The cell cycle of HL-60 cells was observed after treatment with zerumbone, which induced G (2)/M cell cycle arrest in HL-60 cells in a time- and concentration-dependent manner, and decreased the cyclin B1/cdk 1 protein level. These results suggest that zerumbone is an active principal of Z. zerumbet and is potentially a lead compound for the development of anticancer drugs.