Attenuation of hyperplasia in lung parenchymal and colonic epithelial cells in DMBA-induced cancer by administering Andrographis paniculata Nees extract using animal model.

OBJECTIVES: This study was designed to evaluate the potential of Andrographis paniculata ethanolic extract to inhibit the increase in proliferation and induction of abnormal cell death. METHODS: The hyperplasia stage as an early stage of cancer development was induced by oral administration of 20 mg/Kg BW DMBA to SD rats twice a week for 5 weeks. There were five groups in this study include negative control, positive control, and treatment groups of DMBA induction followed by administration of A. paniculata ethanolic extract in doses equivalent to 10, 30 or 100 mg/Kg BW andrographolide once per day for 6 consecutive weeks. On the last day, rats were sacrificed, lung and colon tissues were collected. Histological examination by HE staining and immunohistochemistry using p53, telomerase, and caspase-3 antibodies were aimed at observing hyperplasia state in these tissues. RESULTS: DMBA induction to SD rats was able to produce hyperplasia in lung parenchymal and colon epithelial tissue. This can be showed by the increasing number of proliferated cells and as indicated by the number of brown-colored nuclei with sharper intensity. As well telomerase appears to be overexpressed strongly, while p53 and caspase-3 show low intensity. The administration of A. paniculata extract for 6 weeks showed a decrease in the number of cells that actively proliferate, a decrease in telomerase activity, and an increase in caspase-3 levels which indicate cellular death activity. CONCLUSIONS: A. paniculata ethanolic extract can inhibit the development of cancer at the hyperplasia stage by reducing telomerase activity and increasing apoptosis, marked by an increase of caspase-3 expressions.

The Association of Myo-Inositol and Selenium Contrasts Cadmium-Induced Thyroid C Cell Hyperplasia and Hypertrophy in Mice.

Previous studies have demonstrated that, in addition to inducing structural changes in thyroid follicles, cadmium (Cd) increased the number of C cells. We examined the effects of myo-inositol (MI), seleno-L-methionine (Se), MI + Se, and resveratrol on C cells of mice exposed to cadmium chloride (Cd Cl2), as no data are currently available on the possible protective effects of these molecules. In contrast, we have previously shown this protective effect against CdCl2 on the thyroid follicles of mice. Ninety-eight C57 BL/6J adult male mice were divided into 14 groups of seven mice each: (i) 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); (ii) Se (0.2 mg/kg/day per os); (iii) Se (0.4 mg/kg/day per os); (iv) MI (360 mg/kg/day per os); (v) Se (0.2 mg/kg/day) + MI; (vi) Se (0.4 mg/kg/day) + MI; (vii) resveratrol (20 mg/kg); (viii) CdCl2 (2 mg/kg/day i.p.) + vehicle; (ix) CdCl2 + Se (0.2 mg/kg/day); (x) CdCl2 + Se (0.4 mg/kg/day); (xi) CdCl2 + MI; (xii) CdCl2 + Se (0.2 mg/kg/day) + MI; (xiii) CdCl2 + Se (0.4 mg/kg/day) + MI; (xiv) CdCl2 + resveratrol (20 mg/kg). After 14 days, thyroids were processed for histological, immunohistochemical, and morphometric evaluation. Compared to vehicle, Cd significantly decreased follicle mean diameter, increased CT-positive cells number, area and cytoplasmic density, and caused the disappearance of TUNEL-positive C cells, namely, the disappearance of C cells undergoing apoptosis. Se at either 0.2 or 0.4 mg/kg/day failed to significantly increase follicular mean diameter, mildly decreased CT-positive cells number, area and cytoplasmic density, and was ineffective on TUNEL-positive C cells. Instead, MI alone increased significantly follicular mean diameter and TUNEL-positive cells number, and decreased significantly CT-positive cells number, area and cytoplasmic density. MI + Se 0.2 mg/kg/day or MI + Se 0.4 mg/kg/day administration improved all five indices more markedly. Indeed, follicular mean diameter and TUNEL-positive cells number increased significantly, while CT-positive cells number, area and cytoplasmic density decreased significantly. Thus, all five indices overlapped those observed in vehicle-treated mice. Resveratrol improved significantly all the considered parameters, with a magnitude comparable to that of MI alone. In conclusion, the association Myo + Se is effective in protecting the mouse thyroid from the Cd-induced hyperplasia and hypertrophy of C cells. This benefit adds to that exerted by Myo + Se on thyrocytes and testis.

Prediction of the therapeutic mechanism responsible for the effects of Sophora japonica flower buds on contact dermatitis by network-based pharmacological analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: The flower buds of Sophora japonica L. are a major traditional medicine in China, Japan, and Korea and are used to stop bleeding and 'cool the blood'. Accordingly, they are used to treat bleeding haemorrhoids, hypertension, and pyoderma. In addition, it was recently found that the flower buds of S. japonica (SJ) have cosmetic whitening properties. MATERIALS AND METHODS: Compounds in SJ and their targets and related diseases were investigated using the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and analysis platform. Target gene information was obtained from the UniProt database. Network construction was carried out using Cytoscape 3.72. Contact dermatitis (CD)-related gene searching was performed using the Cytoscape string App. Docking analysis was conducted using AutoDock Vina. Six-week-old Balb/c male mice with DNFB (1-fluoro-2,4-dinitrofluorobenzene)-induced CD were treated with a methanol extract of the flower buds of S. japonica (MESJ), and its effects on skin colour, lesions, and immune cell infiltration, and on histopathological abnormalities such as epidermal hyperplasia were investigated. RESULTS: Eleven compounds targeted 13 CD-related genes, that is, serum albumin (ALB), prostaglandin G/H synthase (COX) 2, C-X-C motif chemokine (CXCL) 2, CXCL10, ICAM1, IFN-γ, IL-10, IL-1α, IL-1ß, IL-2, IL-6, E-selectin, and TNF. In the murine DNFB model, MESJ significantly suppressed scaling, erythema, and skin thickening as compared with DNFB controls and epithelial hyperplasia and immune cell infiltrations induced by repeated DNFB application. CONCLUSIONS: Our animal study showed that the mode of action of MESJ was closely related to the prevention of epithelial hyperplasia and immune cell infiltration. The results obtained demonstrated that the flower buds of S. japonica offer a potential means of treating CD, and suggest that the therapeutic mechanism of CD is explained by relations between 11 major components of SJ, including kaempferol and quercetin, and 13 CD-related genes.

Efficacy of Lubeikangru formulation in mice with hyperplasia of the mammary glands induced by estrogen and progesterone.

OBJECTIVE: To evaluate the protective effects of Lubeikangru formula (LF) on hyperplasia of the mammary glands (HMG) induced by estrogen and progesterone in mice. METHODS: Female mice were divided randomly into five groups: normal, model, tamoxifen (3 mg/kg), Rupixiao (900 mg/kg) and LF (900 mg/kg). All mice except those in the normal group were treated sequentially with estradiol and progesterone to induce HMG. From the tenth day of induction, mice in normal and model groups received distilled water and mice in the other groups were given the corresponding drugs by gavage, once a day, for 30 d. At the end of treatment, the mammary glands, ovaries, hypothalamus, and serum was collected for whole-mount and hematoxylin and eosin (HE) staining, enzyme-linked immunosorbent assays (ELISAs), or western blotting. RESULTS: Whole-mount and HE staining of mammary glands showed that LF rescued (at least in part) the hyperplasic morphology of the mammary glands, and the number of branch points decreased after LF treatment (P < 0.05). ELISAs revealed that levels of estrogen and progesterone were decreased following LF treatment, whereas levels of gonadotropin-releasing hormone, follicle-stimulating hormone, and luteinizing hormone were increased in serum and tissues. Western blotting confirmed that LF treatment led to a reduction in expression of phosphorylated (p)-Erk, p-p38 and p-c-Jun N-terminal kinase. LF was also confirmed to be safe by acute-toxicity tests. CONCLUSION: LF can protect the mammary glands of mice from estrogen- and progesterone-induced hyperplasia by adjusting hormone levels and regulating the mitogen-activated protein kinase pathway.

Mild electrical stimulation with heat shock reduces inflammatory symptoms in the imiquimod-induced psoriasis mouse model.

Psoriasis is a chronic skin disease caused by immune disorder. The chronic skin inflammation involves inflammatory molecules that are released from T lymphocytes and keratinocytes. Therefore, developing an anti-inflammatory therapy that is suitable for long-term treatment is needed. Electrical stimulation induces biological responses by modulating intracellular signaling pathways. Our previous studies showed that the optimized combination treatment of mild electrical stimulation (MES, 0.1-millisecond; ms, 55-pulses per second; pps) and heat shock (HS, 42°C) modulates inflammatory symptoms of metabolic disorders and chronic kidney disease in mice models and clinical trials. Here, we investigated the effect of MES+HS treatment on imiquimod-induced psoriasis mouse model. Topical application of imiquimod cream (15 mg) to mice ear induced keratinocyte hyperproliferation and psoriasis-like inflammation. In MES+HS-treated mice, imiquimod-induced skin hyperplasia was significantly decreased. MES+HS treatment reduced the protein expression of IL-17A and the infiltration of CD3-positive cells in lesioned skin. In addition, MES+HS-treated mice had decreased mRNA expression level of antimicrobial molecules (S100A8 and Reg3γ) which aggravate psoriasis. In IL-17A-stimulated HaCaT cells, MES+HS treatment significantly lowered the mRNA expression of aggravation markers (S100A8, S100A9 and ß-defensin2). Taken together, our study suggested that MES+HS treatment improves the pathology of psoriasis via decreasing the expression of inflammatory molecules.

Sub-chronic toxicity of Gyejibokryeong-hwan in Sprague-Dawley rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional herbal formula Gyejibokryeong-hwan (GJBRH; Guizhifuling-wan, Keishibukuryo-gan) consisting five medicinal herbs has been used to treat uterine disorders, gynecological diseases and blood stasis syndrome in Asia. AIM OF THE STUDY: We evaluated the safety of GJBRH in Crl:CD Sprague-Dawley (SD) rats over a period of 13 weeks. MATERIALS AND METHODS: To confirm the stability of the components of GJBRH, we analyzed the component contents in GJBRH at different storage periods, using high-performance liquid chromatography. Male and female SD rats were orally administered with GJBRH at doses of 0, 1000, 2000 and 5000 mg/kg/day for 13 weeks and assessed after a 4-week recovery period. Mortality, changes in body weight and food consumption, organ weights, hematology and serum biochemistry were monitored during the experimental period, along with clinical observations, ophthalmological examinations, urinalysis and histopathology. RESULTS: There were no significant differences among the eight marker compounds in GJBRH according to storage period. No significant GJBRH-treatment-related toxicological changes were observed in mortality or ophthalmological examinations in either sex. However, soft feces were observed in the male 5000 mg/kg/day group. In addition, there were significant changes in body weight and food consumption in both male and female rats treated with GJBRH at a dose of 5000 mg/kg/day. In the hematological examinations, we found a significant increase in white blood cells, neutrophils and fibrinogen in the 5000 mg/kg/day groups. In the urinalysis, a decrease in the total protein and albumin and an increase in the ovalbumin/globulin ratio were observed in both male and female rats treated with GJBRH at a dose of 5000 mg/kg/day. Histopathological examinations revealed erosion/ulcers and dilated glands in the stomachs of males from the 5000 mg/kg/day group, and squamous cell hyperplasia and epithelial atrophy was observed in the stomachs of both male and female rats treated with GJBRH at a dose of 5000 mg/kg/day. CONCLUSION: The no-observed-adverse-effect level (NOAEL) was 2000 mg/kg/day for both sexes.

Cryptotanshinone reduces psoriatic epidermal hyperplasia via inhibiting the activation of STAT3.

The discovery of new therapeutic drugs with the efficacious and safe ability to prevent epidermal hyperplasia is extremely urgent for psoriasis. Cryptotanshinone (CTS), an active component isolated from the root of Salvia miltiorrhiza Bunge, has been reported to have antibacterial and antitumor effects. However, its effects on psoriasis have not been reported. Here, we investigated the therapeutic effects of CTS on imiquimod (IMQ)-induced psoriatic-like skin model and explored the underlying mechanisms. Our results revealed that CTS effectively alleviates IMQ-induced epidermal hyperplasia. In vitro studies also indicated that CTS potently inhibits the growth of keratinocytes. We further found that STAT3, a transcription factor for the cell growth, is the key mediator of CTS on the proliferation of keratinocytes. Taken together, our findings indicated that the curative effects of CTS on psoriasis are accomplished mainly through modulating STAT3, which providing evidences to develop CTS as a potential therapeutic agent for patients with psoriasis.

A MOUSE MODEL OF MAMMARY HYPERPLASIA INDUCED BY ORAL HORMONE ADMINISTRATION.

BACKGROUND: Mammary hyperplasia is one of the most common benign breast disorders. Although traditional Chinese medicine has a vast experience in the treatment of mammary hyperplasia, it is not accepted widely due to its unclear mechanism. METHODS AND MATERIALS: To address the mechanism, we developed a mouse model of mammary hyperplasia. We gave mice estradiol valerate tablets and progesterone capsules sequentially for one month by intragastric administration. RESULTS: Mice treated by this method had a series of pathological changes which are similar to those detected in women with mammary hyperplasia, including ectopic level of estradiol and progesterone in serum, hyperplasia of mammary glands and increased expression of ERα and PR. CONCLUSION: This model will facilitate the mechanical study of traditional medicine on mammary hyperplasia.

The anti-hyperplasia of mammary gland effect of protein extract HSS from Tegillarca granosa.

Tegillarca granosa Linnaeus, possesses various biological functions and has been used a Chinese traditional medicine more than one century, but there is no report about anti-hyperplasia of mammary gland (HMG) activity of drugs from T. granosa. In this study, we investigated the anti-HMG effect of protein extract named HSS from T. granosa. The HMG model of virgin female Sprague Dawley rats was prepared by injecting estrogen in the thigh muscle of the rats and progestogen consecutively. HMG rats were treated with either HSS or positive control drug by i.g. for 35 consecutive days. In order to evaluate anti-HMG activity of HSS, Changes of nipple height and diameter, serum sex hormones levels, organ indexes and pathologic changes of mammary gland were performed. Body weight, food intake, pathomorphology examination of organs (heart, liver, spleen, lung, kidney), hematological and biochemical analysis were performed to evaluate the toxicity of HSS. HSS could significantly reduce nipples height and diameter, increase P concentration of HMG rat serum, spleen and thymus index, decrease uterus index, and has therapeutic effect on rat HMG and no toxicity at 500mg/kg/day. The anti-HMG mechanism of HSS may be related to AP-2α and P53. HSS has protective and therapeutic effects on HMG rats, and may be a promising agent for treating hyperplasia of mammary glands.

Modulatory Effect of Fermented Papaya Extracts on Mammary Gland Hyperplasia Induced by Estrogen and Progestin in Female Rats.

Fermented papaya extracts (FPEs) are obtained by fermentation of papaya by Aspergillus oryzae and yeasts. In this study, we investigated the protective effects of FPEs on mammary gland hyperplasia induced by estrogen and progestogen. Rats were randomly divided into 6 groups, including a control group, an FPE-alone group, a model group, and three FPE treatment groups (each receiving 30, 15, or 5 ml/kg FPEs). Severe mammary gland hyperplasia was induced upon estradiol benzoate and progestin administration. FPEs could improve the pathological features of the animal model and reduce estrogen levels in the serum. Analysis of oxidant indices revealed that FPEs could increase superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, decrease malondialdehyde (MDA) level in the mammary glands and serum of the animal models, and decrease the proportion of cells positive for the oxidative DNA damage marker 8-oxo-dG in the mammary glands. Additionally, estradiol benzoate and progestin altered the levels of serum biochemical compounds such as aspartate transaminase (AST), total bilirubin (TBIL), and alanine transaminase (ALT), as well as hepatic oxidant indices such as SOD, GSH-Px, MDA, and 8-oxo-2'-deoxyguanosine (8-oxo-dG). These indices reverted to normal levels upon oral administration of a high dose of FPEs. Taken together, our results indicate that FPEs can protect the mammary glands and other visceral organs from oxidative damage.

Effects of hyperbaric oxygen therapy on rat facial skin.

INTRODUCTION: We used immunohistochemistry to investigate the histopathologic effects of hyperbaric oxygen (HBO) on the facial skin of rats. MATERIAL AND METHODS: Rats in the HBO group (n = 6) were placed in a 20 L HBO chamber at 2.5 atmospheres absolute at 25-26°C with 100% oxygen for 90 min/day for 7 days. Following euthanasia, sections of facial skin were removed for examination. RESULTS: Epidermal hyperplasia and degeneration, basal-cell hypertrophy, subepithelial fibrosis, and increased connective tissue were observed in the HBO group. E-cadherin expression was reduced in the epidermis, hair follicles, and sebaceous glands in HBO-treated rats relative to control animals. HBO treatment was associated with vimentin immunoreactivity in fibroblasts, endothelial cells, and the bulbus pilorum of a subset of hair follicles. It also resulted in increased type IV collagen expression within the connective tissue in the hair follicles and sebaceous glands. CONCLUSION: The HBO group demonstrated epidermal hyperplasia and degeneration, basal-cell hypertrophy, and subepithelial fibrosis. In addition, HBO decreased E-cadherin expression, which suggests that HBO may impair intracellular adhesion. Expression of vimentin and type IV collagen was also observed in the dermis. Increased connective tissue, hemorrhage, and mononuclear cell infiltration were observed in the dermis of HBO-treated animals. Thus, HBO has effects on the structures of the epidermis and dermis.

Thyroid follicular lesions induced by thiazole-Zn feed treatment for one year in Sprague-Dawley rats.

Thiazole-Zn is a newly created Chinese systemic fungicide that is a thiadiazole compound. The toxicity of thiazole-Zn was examined in Sprague-Dawley rats fed diets containing 0, 4, 20 and 100mg/kg thiazole-Zn for one year. Lower body weight gains were noted in both males and females of the 100mg/kg diet group. Moreover, we show that the toxicity of thiazole-Zn was low, as evidenced by the absence of toxicologically significant changes in the general condition and appearance, hematology and clinical chemistry parameters, organ weights and necropsy findings of the rats. Thyroid follicular cell hyperplasia was the only finding of potential significance. The incidence of thyroid follicular cell hyperplasia significantly increased in high-dose males (4/10) and females (3/10) at the 26-week interim examination; one follicular adenoma in the thyroid was observed in high-dose males. At 52 weeks, the incidence of thyroid follicular cell hyperplasia was significantly higher in high-dose males (4/10) and females (4/10) than in the controls. Two thyroid follicular adenomas were observed in high-dose males. Other treatment-related effects and tumors at other sites were not observed. This study suggests that thiazole-Zn is a thyroid disrupter and likely a rat thyroid carcinogen.

Tocopherols inhibit oxidative and nitrosative stress in estrogen-induced early mammary hyperplasia in ACI rats.

Oxidative stress is known to play a key role in estrogen-induced breast cancer. This study assessed the chemopreventive activity of the naturally occurring γ-tocopherol-rich mixture of tocopherols (γ-TmT) in early stages of estrogen-induced mammary hyperplasia in ACI rats. ACI rats provide an established model of rodent mammary carcinogenesis due to their high sensitivity to estrogen. Female rats were implanted with 9 mg of 17ß-estradiol (E2) in silastic tubings and fed with control or 0.3% γ-TmT diet for 1, 3, 7, and 14 d. γ-TmT increased the levels of tocopherols and their metabolites in the serum and mammary glands of the rats. Histological analysis revealed mammary hyperplasia in the E2 treated rats fed with control or γ-TmT diet. γ-TmT decreased the levels of E2-induced nitrosative and oxidative stress markers, nitrotyrosine, and 8-oxo-dG, respectively, in the hyperplastic mammary tissues. 8-Isoprostane, a marker of oxidative stress in the serum, was also reduced by γ-TmT. Noticeably, γ-TmT stimulated Nrf2-dependent antioxidant response in the mammary glands of E2 treated rats, evident from the induced mRNA levels of Nrf2 and its downstream antioxidant enzymes, superoxide dismutase, catalase, and glutathione peroxidase. Therefore, inhibition of nitrosative/oxidative stress through induction of antioxidant response is the primary effect of γ-TmT in early stages of E2-induced mammary hyperplasia. Due to its cytoprotective activity, γ-TmT could be a potential natural agent for the chemoprevention of estrogen-induced breast cancer.

Evaluation of endometrial thickness and bone mineral density based on CYP2D6 polymorphisms in Turkish breast cancer patients receiving tamoxifen treatment.

BACKGROUND: Several previous studies have examined the effect of CYP2D6 gene polymorphism on the efficacy and metabolism of tamoxifen (Tamoxifen Teva, Nolvadex) in the treatment of breast cancer. In the present study, the metabolic profiles associated with various CYP2D6 genotypes were evaluated. METHOD: In the present study 92 Turkish breast cancer patients with early-stage hormone receptor-positive tumors treated with adjuvant tamoxifen (20 mg) were evaluated for CYP2D6 genotype and metabolic profiles. Known side effects of tamoxifen treatment, including endometrial thickening, changes in serum lipid levels and bone density, and hepatosteatosis, were evaluated according to the CYP2D6 polymorphism. RESULT: The distribution of metabolic characteristics in the Turkish population was as follows: 77.1% normal metabolism, 11.5% intermediate metabolism, 5.2% ultrarapid metabolism, and 2.1% poor metabolism. The CYP2D6 genotypes associated with rapid metabolism were CYP2D6 3X*1/*1 duplication (DUP) and CYP2D6 2X*1/*2, while poor metabolism was associated with the genotypes CYP2D6 *3/*4 and CYP2D6 *6/*6. There was no statistically significant relationship between metabolic characteristics and bone density or hepatosteatosis. A statistically significant difference in total cholesterol and triglycerides was detected in lipid profile analysis (p = 0.003, p = 0.02). Assessment of endometrial thickness revealed a significant association of hyperplasia and poor metabolism, and an association between atrophy and ultrarapid metabolism (p = 0.01). CONCLUSION: Significant development of endometrial hyperplasia was identified among individuals with poor tamoxifen metabolism. As a result, tamoxifen may be a significant predictor of endometrial thickening among individuals with poor metabolic characteristics.

Saffron reduction of 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis.

Our aim was to investigate the chemopreventive potential of saffron in DMBA-induced hamster buccal pouch carcinogenesis. Assessment was by monitoring the percentage of tumor bearing hamsters, tumor size as well as the status of detoxification agents, lipid peroxidation and antioxidants. Oral squamous cell carcinomas were induced in the buccal pouch of Syrian golden hamsters by painting them with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. We observed 100% oral tumor formation with severe histopathological abnormalities in all the hamsters treated with DMBA alone, activities of phase I and phase II detoxification enzymes, lipid peroxidation and antioxidants being significantly altered. Though oral administration of saffron completely prevented the formation of tumors, we noticed severe hyperplasia and dysplasia in hamsters treated with DMBA, suggesting that tumors might eventually develop. Oral administration of saffron return detoxification enzymes, lipid peroxidation and antioxidants to normal ranges. The chemopreventive potential of saffron thus is likely due to antioxidant properties and modulating effects on detoxification in favour of the excretion of carcinogenic metabolites during DMBA-induced hamster buccal pouch carcinogenesis.

Mechanistic insights from the NTP studies of chromium.

Hexavalent chromium (Cr(VI)) is a contaminant of water and soil and is a human lung carcinogen. Trivalent chromium (Cr(III)), a proposed essential element, is ingested by humans in the diet and in dietary supplements such as chromium picolinate (CP). The National Toxicology Program (NTP) demonstrated that Cr(VI) is also carcinogenic in rodents when administered in drinking water as sodium dichromate dihydrate (SDD), inducing neoplasms of the oral cavity and small intestine in rats and mice, respectively. In contrast, there was no definitive evidence of toxicity or carcinogenicity following exposure to Cr(III) administered in feed as CP monohydrate (CPM). Cr(VI) readily enters cells via nonspecific anion channels, in contrast to Cr(III), which cannot easily pass through the cell membrane. Extracellular reduction of Cr(VI) to Cr(III), which occurs primarily in the stomach, is considered a mechanism of detoxification, while intracellular reduction is thought to be a mechanism of genotoxicity and carcinogenicity. Tissue distribution studies in additional groups of male rats and female mice demonstrated higher Cr concentrations in tissues following exposure to Cr(VI) compared to controls and Cr(III) exposure at a similar external dose, indicating that some of the Cr(VI) escaped gastric reduction and was distributed systemically. The multiple potential pathways of Cr-induced genotoxicity will be discussed.

Catechin induced modulation in the activities of thyroid hormone synthesizing enzymes leading to hypothyroidism.

Catechins, the flavonoids found in abundance in green tea, have many beneficial health effects such as antioxidative, anticarcinogenic, anti-inflammatory, antiallergic, and hypotensive properties. However, flavonoids have antithyroid/goitrogenic effect, although less information is available about the effect of pure catechin on thyroid physiology. The present investigation has been undertaken to explore the effect of catechin administration on thyroid physiology in rat model. For the in vivo experiment catechin was injected intraperitoneally (i.p.) at doses of 10, 20 and 30 mg/kg body to male albino rats for 15 and 30 days, respectively, and thyroid activities were evaluated with respect to determination of serum levels of thyroid hormones, thyroid peroxidase, 5'-deiodinase I (5'-DI), and Na(+), K(+)-ATPase activities that are involved in the synthesis of thyroid hormone. Catechin decreased the activities of thyroid peroxidase and thyroidal 5'-deiodinase I, while Na(+), K(+)-ATPase activity significantly increased in dose-dependent manner; substantial decrease in serum T3 and T4 levels coupled with significant elevation of serum TSH were also noted. Histological examinations of the thyroid gland revealed marked hypertrophy and/or hyperplasia of the thyroid follicles with depleted colloid content. In in vitro study, short-term exposure of rat thyroid tissue to catechin at the concentrations of 0.10, 0.20, and 0.30 mg/ml leads to decrease in the activities of thyroid peroxidase and 5'-deiodinase I, while the activity of thyroidal Na(+), K(+)-ATPase remains unaltered even at high concentration of catechin treatment. The present study reinforces the concept that catechin, tea flavonoids possess potent antithyroid activity as evidenced from in vivo and in vitro studies.

Indirubin, a purple 3,2- bisindole, inhibited allergic contact dermatitis via regulating T helper (Th)-mediated immune system in DNCB-induced model.

ETHNOPHARMACOLOGICAL RELEVANCE: Indirubin, isolated from Indigo naturalis (Apiaceae) is a purple 3,2- bisindole and a stable isomer of indigo. Although it is known to have anti-inflammatory activities, its mechanism of action has not been elucidated. MATERIALS AND METHODS: Seven-week-old female BALB/c mice were sensitized with 1-chloro-2,4-dinitrobenzene (DNCB) to induce skin inflammation. Hematoxylin and eosin staining was performed to assess epidermal and dermal hyperplasia, which were determined by measuring the thicknesses of the epidermis and dermis, respectively. We also evaluated serum immunoglobulin E (IgE) levels and cytokines production, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-4, 6 and Interferon (IFN)-gamma. In addition, we investigated nuclear factor (NF)-κB, IκB-α and mitogen-activated protein (MAP) kinase activities for verifying the molecular mechanism of inflammation. RESULTS: Indirubin treatment suppressed skin inflammation in DNCB-exposed mice. The skin lesions were significantly thinner in the Indirubin-treated group than in untreated controls, and the hyperkeratosis disappeared. Indirubin reduced the total serum IgE level and cytokines production. In addition, it normalized NF-κB, IκB-α and MAP kinase expression. CONCLUSIONS: Indirubin might be a useful treatment for allergic contact dermatitis via regulating the co-expression of T helper (Th) 1 and 2 cell-mediated immune responses.

Baicalein inhibits DMBA/TPA-induced skin tumorigenesis in mice by modulating proliferation, apoptosis, and inflammation.

Baicalein, one of the four major flavanoids extracted from the root of Scutellaria baicalensis, has been shown to exert chemopreventive effect against several cancers, including skin cancer. However, the precise mechanisms remain to be elucidated. In the present study, we investigated the chemopreventive activity of baicalein against 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-mediated skin tumorigenesis in C57BL/6 mice. We found that topical treatment with baicalein resulted in a significant inhibitory effect on DMBA/TPA-mediated tumor promotion. Furthermore, we observed that baicalein suppressed cell proliferation and promoted apoptosis in DMBA/TPA-mediated group. Additionally, pretreatment with baicalein inhibited the production of inflammatory cells in DMBA/TPA-induced skin/tumors. Further experiments showed that baicalein reduced TPA-induced skin hyperplasia as well as infiltration of polymorphonuclear leukocytes in the dermis. In conclusion, our data suggest that baicalein inhibits DMBA/TPA-induced skin tumorigenesis by suppressing proliferation and inflammation and promoting apoptosis.

Mushroom Ganoderma lucidum prevents colitis-associated carcinogenesis in mice.

BACKGROUND: Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT). The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice. METHODS/PRINCIPAL FINDINGS: Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP]) and inflammation (dextran sodium sulfate [DSS]) in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF) formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue. CONCLUSIONS: Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer.