Hepatoprotective and Metabolic Effects of Dietary Soy Phytoestrogens against Hyper Caloric Diet in Cyclic Female Wistar Rats is Mediated through Estradiol Receptors

Boswellic acid protects against Bisphenol-A and gamma radiation induced hepatic steatosis and cardiac remodelling in rats: role of hepatic PPAR-α/P38 and cardiac Calcineurin-A/NFATc1/P38 pathways

Bisphenol-A (BPA) and gamma-radiation are two risky environmental pollutants that human beings are exposed to in everyday life and consequently they threaten human health via inducing oxidative stress, inflammation, and eventually tissue damage. This study aims at appraising the protective effect of Boswellic Acid (BA) (250 mg/kg/day, orally) administration on BPA (150 mg/kg/day, i.p) and γ-irradiation (IR) (3 Gy/week for 4 weeks up to cumulative dose of 12 Gy/experimental course) for 4 weeks-induced damage to liver and heart tissues of rats. The present results indicated a significant improvement against damage induced by BPA and IR revealed in biochemical investigations (hepatic PPAR-α/P38 and cardiac ET-1/Calcineurin-A/NFATc1/P38) and histopathological examination of liver and heart. It could be concluded that BA possesses a protective effect against these two deleterious environmental pollutants which attracted major global concerns due to their serious toxicological impact on human health.

Melatonin enhances antioxidant defenses but could not ameliorate the reproductive disorders in induced hyperthyroidism model in male rats

The present study was carried out to clarify the effect of different doses of melatonin on some reproductive hormones, serum total antioxidant, histopathological examination, lipid peroxidation, and antioxidant parameters in liver, kidney, heart, and testis tissues in induced-hyperthyroidism (HT) male rat model. A total of 75 mature male Wistar rats were equally allocated into five groups; control groups were daily I/P injected with distilled water containing 4 M ammonium hydroxide in methanol and 1% absolute ethanol; on hyperthyroidism model group, rats received daily I/P injection of L-thyroxine (0.2 mg/kg body weight). In melatonin-treated groups, rats were injected with the same dose of L-thyroxine followed by I/P injection of melatonin (1, 5, or 10 mg/kg, respectively) for 21 days. The hyperthyroidism group showed significant increase in serum thyroxine (T4), triiodothyronine (T3), and testosterone levels and a significant decrease in the levels of thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and serum total antioxidants capacity, with a significant decrease in superoxide dismutase (SOD) activity and glutathione reductase (GSH) content with a significant increase in malondialdehyde (MDA) concentration in all examined tissues. While, melatonin co-treatment to HT groups partially counteracted the effect of hyperthyroidism by decreasing serum T4 and T3 levels and increasing serum TSH. In addition, melatonin could decrease serum levels of FSH, LH, and testosterone, as well as it could increase serum total antioxidants capacity, SOD activity, and GSH content and decreased MDA concentration in all examined tissues. Additionally, melatonin could amend the histopathological alterations in the examined tissues of hyperthyroid rats but not the testicular tissue. It is concluded that melatonin has a protective role against the hyperthyroidism-induced oxidative damage but cannot ameliorate the reproductive disorders in male rat model.

Sub-chronic exposure to Tris(1,3-dichloro-2-propyl) phosphate induces sex-dependent hepatotoxicity in rats

As the application and environmental release of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) are being increased rapidly, serious concerns have been raised regarding its adverse effects on human health. Exposure to TDCIPP has been implicated in hepatotoxicity, but the molecular mechanisms remain unclear. Here, both male and female Sprague Dawley rats were administered TDCIPP with 125, 250, or 500 mg/kg/day for 12 weeks. Then the ultrastructure of liver, biochemical indicators in serum and liver, and hepatic gene expression were analyzed to reveal molecular mechanisms of hepatotoxicity induced by TDCIPP. Continuous TDCIPP exposure decreased body weight, particularly in 500 mg/kg/day TDCIPP-exposed males, and dose dependently increased the ratio of liver to body weight in both genders. The decreased levels of triglyceride, cholesterol, and transaminase in the serum and livers were observed in both genders after TDCIPP exposure, which indicated dysfunction in the hepatic metabolism. Liver histopathology revealed hepatocellular damages in males and females after TDCIPP exposure. The transcriptomic analysis indicated that TDCIPP exposure significantly changed pathways of bile acid metabolism, inflammatory response, oxidative phosphorylation and carcinogenicity in 250 and 500 mg/kg/day TDCIPP-exposed males and 500 mg/kg/day TDCIPP-exposed females, and there was no statistical significance in any other TDCIPP-exposed groups. The transcriptional analysis showed that TDCIPP exposure led to oxidative stress in the livers of rats, thereby increasing the inflammatory response and promoting mechanisms of carcinogenesis in both genders. Finally, TDCIPP led to more severe adverse phenotypic effects in male than female rats.

Mercury induces nuclear estrogen receptors to act as vasoconstrictors promoting endothelial denudation via the PI3K/Akt signaling pathway

Cardiovascular diseases (CVD) are more frequent among postmenopausal women due to the decline of estrogen concentration in plasma. However, the role of the vascular modulator effect of estrogen is controversial, since it occurs both in physiological and pathological conditions, increasing or reducing vascular reactivity. As mercury is widely associated with the development of CVD, we investigated putative hazardous effects on the mechanisms that modulate vascular reactivity in aortic rings of female Wistar rats promoted by acute mercury exposure. Mercury increased vascular reactivity and oxidative stress possibly due to NADPH oxidase participation, increased production of cyclooxygenase-2 (COX-2) and thromboxane A₂ (TXA₂) formation. The metal also induced endothelial denudation in the aorta by reducing the bioavailability of nitric oxide (NO) and enhancing the activity of the PI3K/Akt signaling pathway. Mercury exposure also induced nuclear estrogen receptors (ERα, ERβ) to act as vasoconstrictors. Our findings suggest that mercury might increase the chances of developing cardiovascular diseases in females and should be considered an important environmental risk factor.

Soy Isoflavones Ameliorate Metabolic and Immunological Alterations of Ovariectomy in Female Wistar Rats: Antioxidant and Estrogen Sparing Potential

Hormone replacement therapy (HRT) can alleviate estrogen deficiency symptoms especially during menopause. The present study aimed at investigating the effect of soy isoflavones as HRT on immunological and bone health-related parameters with a special focus on the interactions between immunological status and metabolism. Thirty healthy cyclic female Wistar rats were used in this experiment. Ten females were sham-operated, and 20 females were subjected to ovariectomy. Overiectomized (OVX) female rats were randomly divided into 2 groups: the control group (G1, OVX/casein) was fed a casein-based diet, and the second group (G2, OVX/soy) was fed a high soy isoflavone diet. Both groups were compared to a sham-operated group (G3, sham/casein). Treatments continued for 7 weeks. Feed intake, weight gain, and lymphoid organ relative weights were recorded. Some metabolic, immunological, and bone health-related parameters were measured. Moreover, nitric oxide (NO), malondialdehyde (MDA), and total antioxidant capacity (TAC) were determined. Bone histopathology and immunohistochemistry to estrogen receptor alpha (ERα) were done. Feeding soy to OVX females reduced feed intake, weight gain, relative lymphoid organ weight, and T-lymphocytes transformation. Soy isoflavone administration normalized nearly all metabolic and immunological parameters to a level comparable to the sham group via oxidative stress amelioration and bone ERα promotion. Soy isoflavones seemed to be good HRT in estrogen deprivation which modulated the appetite, weight gain, lipid profile, proinflammation, and bone turnover.

Hepatoprotective activity of Uncaria tomentosa extract against sub-chronic exposure to fipronil in male rats

The effects of fipronil (FPN) on the liver of rats were studied. Rats (n = 6) were treated with 9.7 mg/kg (1/10 of FPN LD₅₀), and other rats (n = 6) received 120 mg/kg of 10% Uncaria tomentosa extract, while a mixture of 9.7 mg/kg FPN and 120 mg/kg of 10% Uncaria tomentosa extract were administered orally to the rats (n = 6) daily for 6 weeks. Body, hepatic weights, liver enzymes, and lipid profile were determined. Hepatic activities of MDA, TNO, TAC, TNF-α, and IL-6 in liver homogenate were measured. Immunohistochemistry of NF-kB and liver histopathology were performed. Fipronil-treated rats had a significant (P = 0.02) lower weight gain. Moreover, relative liver weight was significantly (P = 0.003) increased in FPN-treated rats. Rats administrated with FPN exhibited a significantly (P = 0.02) higher liver enzymes and promoted levels of MDA, TNO, TNF-α, and IL-6 (P < 0.0001) than that in the other groups. Immunostaining of NF-κB was increased (P < 0.0001) in FPN-treated rats. Interestingly, Uncaria tomentosa alone or with FPN decreased the liver immunostaining of NF-κB. In conclusion, FPN produced liver injury through lipid peroxidation and stimulation of NF-κB. However, Uncaria tomentosa combated the oxidative stress and liver damage induced by FPN via inhibition of NF-κB.

Lycopene: Hepatoprotective and Antioxidant Effects toward Bisphenol A-Induced Toxicity in Female Wistar Rats

Bisphenol A (BPA)—an endocrine disruptor xenoestrogen—is widely spread in the environment. Lycopene (LYC) is an antioxidant phytochemical carotenoid. The hereby study was designed to verify the deleterious effect of BPA on cyclic female rats' hepatic tissue as well as evaluation of the effect of LYC toward BPA hepatic perturbation. Twenty-eight female Wistar rats were allocated equally into four groups: control group, LYC group (10 mg/kg B.wt), BPA group (10 mg/kg B.wt), and BPA + LYC group (the same doses as former groups). The treatments were given daily via gavage to the rats for 30 days. The rats in BPA displayed high activities of serum liver enzymes with low levels of total proteins (TP) and albumin. Moreover, BPA induced hepatic oxidative stress via depletion of antioxidant enzymes concomitant with augmentation of lipid peroxidation, increased comet tail DNA %, and overexpression of caspase-3. Meanwhile, LYC administration reduced the cytotoxic effects of BPA on hepatic tissue, through improving the liver function biomarkers and oxidant-antioxidant state as well as DNA damage around the control values. These findings were confirmed by hepatic histopathological examination. Finally, LYC credited to have a noticeable protective effect versus BPA provoked oxidative injury and apoptosis of the liver tissue.

Methylmercury promotes breast cancer cell proliferation

CONTEXT

Metalloestrogens are small ionic metals that activate the estrogen receptor (ER). Studies have shown that when metalloestrogens bind to the ER, there is an increase in transcription and expression of estrogen-regulated genes, which induces proliferation of estrogen-dependent breast cancer. Methylmercury (MeHg), a metalloestrogen, is present in the environment and is toxic at moderate to high concentrations. However, at lower concentrations MeHg may promote the proliferation of ER-positive breast cancers and protect cells against pro-apoptotic signals.

OBJECTIVE

To investigate the effects of MeHg treatment on breast cancer cells in vitro.

MATERIALS AND METHODS

MCF7 breast cancer cells were treated with concentrations of MeHg ranging from 1 nM to 100 mM. Hg analysis was used to quantify intracellular mercury concentrations. Cell proliferation and apoptosis were determined by cell counting and Annexin-V staining, respectively.

RESULTS

We defined a protocol that maximizes cellular exposure to mercury. Treatment of human ER-positive breast cancer cells with 1 nM MeHg promoted proliferation, while treatment with a concentration of 100 nM induced apoptosis.

DISCUSSION AND CONCLUSIONS

Clarifying the effects of MeHg on breast cancer will improve our understanding of how environmental toxins affect tumor progression and may lead to the development of future therapeutic strategies.

Black Seed Thymoquinone Improved Insulin Secretion, Hepatic Glycogen Storage, and Oxidative Stress in Streptozotocin-Induced Diabetic Male Wistar Rats

Diabetes mellitus is one of the metabolic diseases having several complications. Nigella sativa oil (NSO) might have beneficial effects in the treatment of diabetic complications. Thirty-two mature male Wistar rats were equally divided into four experimental groups: control, control NSO 2 mL/kg, streptozotocin- (STZ-) induced diabetic, and diabetic (STZ-induced) treated with oral NSO 2 mg/kg for 30 days. Fasting blood glucose (FBG), insulin, and lipid profile levels were determined. Pancreatic and hepatic tissues were used for catalase and GSH. Histopathology, hepatic glycogen contents, insulin immunohistochemistry, and pancreatic islet morphometry were performed. NSO 2 mL/kg was noticed to decrease (P < 0.05) FBG and increase (P < 0.05) insulin levels in diabetic rats than in diabetic nontreated animals. Lipid profile showed significant (P < 0.5) improvement in diabetic rats that received NSO 2 mL/kg than in the diabetic group. Both pancreatic and hepatic catalase and GSH activities revealed a significant (P < 0.05) increment in the diabetic group treated with NSO than in the diabetic animals. NSO improved the histopathological picture and hepatic glycogen contents of the diabetic group as well as increased (P < 0.05) insulin immunoreactive parts % and mean pancreatic islet diameter. NSO exerts ameliorative and therapeutic effects on the STZ-induced diabetic male Wistar rats.

Dietary soy isoflavones during pregnancy suppressed the immune function in male offspring albino rats

•

Less attention has been paid to the immune effects of phytoestrogens during pregnancy on the first generation.

•

Soy isoflavones fed to pregnant rats could modulate the immune response of the male offspring.

•

Isoflavones reduced spleen and thymus weights in rats born to dams fed dietary soy.

•

Soy isoflavones possibly mediated its effect through reduction of IFN-γ that interacts with the IL-12 production pathway.

Phytoestrogens have an impact on both animals and humans due to use of legumes in animal diets as well as the increase of vegetarian diets in some human populations. Phytoestrogens thought to have varieties of adverse effects, among which immune system was involved. The present study aimed to investigate the effect of prenatal exposure to dietary soy isoflavones on some immunological parameters in male albino rat offspring. The pregnant rats were divided to three groups (12/group). Control group (free soy isoflavones), low soy isoflavones group (6.5%) and high soy isoflavones group (26%). The male offspring cell-mediated immune response was determined using phytohemagglutinin (PHA) injection and the intumesce index which was calculated on postnatal day 50 (PND 50). At PND 50, blood samples were collected for interleukin 12 (IL-12), interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α) determination. Spleen, thymus, and PHA injected footpads were fixed for histopathology. Intumesce index, IL-12, IFN-γ, spleen and thymus relative weights were significantly (P < 0.05) decreased in offspring born to dams fed low and high dietary soy isoflavones. In contrary, TNF-α was significantly (P < 0.05) increased in offspring born to dams fed high dietary soy isoflavones. Spleen of rats born to dams fed high dose of dietary soy isoflavones showed coagulative necrosis in white pulp. In conclusion, male offspring born to dams fed different levels of soy isoflavones showed marked immunosuppression after PHA stimulation. This effect was mediated through the reduced IFN-γ that interacts with the IL-12 production pathway.