Volume 28, Issue 4

Both obesity and breast cancer are already recognized worldwide as the most common syndromes in our modern society. Currently, there is accumulating evidence from epidemiological and experimental studies suggesting that these syndromes are closely associated with circadian disruption. It has been suggested that melatonin (MLT) and the circadian clock genes both play an important role in the development of these syndromes. However, we still poorly understand the molecular mechanism underlying the association between circadian disruption and the modern health syndromes. One promising candidate is epigenetic modifications of various genes, including clock genes, circadian-related genes, oncogenes, and metabolic genes. DNA methylation is the most prominent epigenetic signaling tool for gene expression regulation induced by environmental exposures, such as artificial light-at-night (ALAN). In this review, we first provide an overview on the molecular feedback loops that generate the circadian regulation and how circadian disruption by ALAN can impose adverse impacts on public health, particularly metabolic disorders and breast cancer development. We then focus on the relation between ALAN-induced circadian disruption and both global DNA methylation and specific loci methylation in relation to obesity and breast cancer morbidities. DNA hypo-methylation and DNA hyper-methylation, are suggested as the most studied epigenetic tools for the activation and silencing of genes that regulate metabolic and monostatic responses. Finally, we discuss the potential clinical and therapeutic roles of MLT suppression and DNA methylation patterns as novel biomarkers for the early detection of metabolic disorders and breast cancer development.

Background: The present study was designed to explore the anti-stress role of AR-A014418, a selective glycogen synthase kinase-3β inhibitor (GSK-3β), on changes provoked by immobilization stress of varying duration. Methods: Acute stress of varying degree was induced by subjecting mice to immobilization stress of short duration (30 min) or long duration (120 min). Thereafter, these animals were exposed to the same stressor for 5 days to induce stress adaptation. The behavioral alterations were assessed using an actophotometer, a hole-board, and the open field and social interaction tests. The serum corticosterone levels were assessed as markers of the hypothalamic-pituitary-adrenal (HPA) axis activity. The levels of total GSK-3β and p-GSK-3β-S9 were determined in the prefrontal cortex. Results: A single exposure to short or long immobilization stress produced behavioral and biochemical changes and the levels of p-GSK-3β-S9 decreased without affecting the total GSK-3β levels in the brain. However, repeated exposure to both short and long stress reversed the behavioral and biochemical changes along with the normalization of p-GSK-3β-S9 levels. The administration of AR-A014418, a selective GSK-3β inhibitor, diminished acute stress-induced behavioral and biochemical changes. Furthermore, AR-A014418 normalized acute stress-induced alterations in p-GSK-3β-S9 levels without changing total GSK-3β levels. Conclusions: Our study suggests that acute stress-induced decrease in p-GSK-3β-S9 levels in the brain contributes to the development of behavioral and biochemical alterations and the normalization of GSK-3β signaling may contribute to stress adaptive behavior in mice which have been subjected to repeated immobilization stress.

Background: Statins represent a group of drugs that are currently indicated in the primary and secondary prevention of cardiovascular events. Their administration can be associated with side effects and the insufficient reduction of triacylglyceride (TAG) levels. This study aimed to assess the effect of the triple combination of statins with omega-3 fatty acids and coenzyme Q10 (CoQ10) on parameters associated with atherogenesis and statin side effects. Methods: In this pilot randomized double-blind trial, 105 subjects who met the criteria of combined dislipidemia and elevated TAG levels were randomly divided into three groups. In the control group, unaltered statin therapy was indicated. In the second and third groups, omega-3 PUFA 2.52 g/day ( Zennix fa Pleuran ) and omega-3 PUFA 2.52 g+CoQ10 200 mg/day (Pharma Nord ApS) were added, res//. At the end of the 3-month period (±1 week), all patients were evaluated. Results: Significant reduction of hepatic enzymes activity, systolic blood preasure, inflammatory markers and TAG levels were detected in both groups in comparison to the control group. Activity of SOD and GPx increased significantly after additive therapy. Coenzyme Q10 addition significantly reduced most of the abovementioned parameters (systolic blood preasure, total cholesterol, LDL, hsCRP, IL-6, SOD) in comparison with the statin+omega-3 PUFA group. The intensity of statin adverse effects were significantly reduced in the group with the addition of CoQ10. Conclusions: The results of this pilot study suggest the possible beneficial effects of triple combination on the lipid and non-lipid parameters related to atherogenesis and side effects of statin treatment.

Abstract: Background: Various parts of the Moringa oleifera (M. oleifera) tree are widely accepted to have ameliorative effects against metal toxicity. In the present study, M. oleifeira oil (MO) was tested against HgCl 2 -induced tissue pathologies and oxidative stress. Methods: Male Wistar rats were administered MO (1.798 mg/kg p.o.) or HgCl 2 (5 mg/kg body wt) alone or in combination (5 mg/kg HgCl 2 +1.798 mg/kg MO p.o.) three times per week for 21 days. After exposure and treatment periods, rats were sacrificed; blood collected and the oxidative status of the liver and kidney homogenates were evaluated. Results: In the liver, malondialdehyde (MDA) level, glutathione (GSH), and superoxide dismutase (SOD) activities were higher whereas catalase (CAT) activity was lower in the HgCl 2 group than in the control group. In the kidney, MDA level, SOD, and CAT activities were higher whereas GSH activity was unchanged in the HgCl 2 group compared to the control group. In the liver, MDA level, SOD, and CAT activities were lower in the HgCl 2 +MO group than in the HgCl 2 group. In the kidney, MDA level, SOD and CAT activities were lower in the HgCl 2 +MO than in the HgCl 2 group. Furthermore, Hg-induced increases in creatinine and bilirubin levels as well as the increase in γ-glutamyl transferase, lactate dehydrogenase, and alkaline phosphatase activities were attenuated in the combine exposure group and the animals showed improvement in the histology of the liver and kidney. Conclusions: MO decreased the negative effects of Hg-induced oxidative stress in rats.

Background: Renovascular hypertension (RVH) is a result of renal artery stenosis, which is commonly due to astherosclerosis. In this study, we aimed to clarify the central and peripheral effects of ghrelin on the renin-angiotensin system (RAS) in a rat model of RVH. Methods: RVH was induced in rats by partial subdiaphragmatic aortic constriction. Experiment A was designed to assess the central effect of ghrelin via the intracerebroventricular (ICV) injection of ghrelin (5 μg/kg) or losartan (0.01 mg/kg) in RVH rats. Experiment B was designed to assess the peripheral effect of ghrelin via the subcutaneous (SC) injection of ghrelin (150 μg/kg) or losartan (10 mg/kg) for 7 consecutive days. Mean arterial blood pressure (MAP), heart rate, plasma renin activity (PRA), and oxidative stress markers were measured in all rats. In addition, angiotensin II receptor type 1 (AT1R) concentration was measured in the hypothalamus of rats in Experiment B. Results: RVH significantly increased brain AT1R, PRA, as well as the brain and plasma oxidative stress. Either SC or ICV ghrelin or losartan caused a significant decrease in MAP with no change in the heart rate. Central ghrelin or losartan caused a significant decrease in brain AT1R with significant alleviation of the brain oxidative stress. Central ghrelin caused a significant decrease in PRA, whereas central losartan caused a significant increase in PRA. SC ghrelin significantly decreased PRA and plasma oxidative stress, whereas SC losartan significantly increased PRA and decreased plasma oxidative stress. Conclusions: The hypotensive effect of ghrelin is mediated through the amelioration of oxidative stress, which is induced by RAS centrally and peripherally.

Background: We have investigated the effects of α-lipoic acid (LA), a powerful antioxidant, on the fatty acid (FA) profiles, aluminum accumulation, antioxidant activity and some minerals such as zinc, copper and iron against aluminum chloride (AlCl 3 )-induced oxidative stress in rat liver. Methods: Twenty-eight male Wistar rats were divided into four groups as control, LA, AlCl 3 and LA+AlCl 3 . For 30 days, LA was intraperitoneally administrated (50 mg/kg) and AlCl 3 was given via orogastric gavage (1600 ppm) every other day. Results: AlCl 3 -treated animals exhibited higher hepatic malondialdehyde concentration and lower glutathione peroxidase and catalase activity, whereas these alterations were restored by the LA supplementation. Total saturated FA of the AlCl 3 -treated group was higher than the LA supplementation groups. Moreover, total unsaturated FA level of the LA+AlCl 3 group was higher than the AlCl 3 -treated group. Hepatic zinc level of the AlCl 3 -treated group was lower than the control group, whereas it was higher in the LA and the LA+AlCl 3 groups. Hepatic copper levels did not significantly change in the experimental groups. Iron level was lower in the LA and LA+AlCl 3 groups compared with the AlCl 3 -treated group. Moreover, the liver Al concentration was found to be lower in the LA and LA+AlCl 3 groups compared to the AlCl 3 group. Conclusions: These results indicate that AlCl 3 treatment can induce oxidative stress in the liver. LA supplementation has a beneficial effect on the AlCl 3 -induced alterations such as high lipid peroxidation, Al accumulation, FA profile ratios and mineral concentrations.

Background: Most cycling studies involve professional cyclists. Because training may affect riding style, it is of interest to determine the physiological basis for the personal choice of cycling cadence in nonprofessional cyclists. Methods: Eleven nonprofessional (5.2±1.7-year-riding experience) male road cyclists, aged 35.0±11.0 years, underwent four separate laboratory test sessions. The first two sessions included habituation, anthropometry, V˙O2max,$\dot V{{\text{O}}_{\text{2}}}{\text{max}},$ and lactate threshold (LaTH) measurements. Freely preferred cadence at LaTH was determined during the second session (mean±SD=94.7±2.9 rev·min −1 ). During the third and fourth sessions participants performed LaTH tests at 60 and 95 rev·min −1 in a randomized order, with power output (PO) increments of 25 W every 4 min, up to ~90% of V˙O2max.$\dot V{{\text{O}}_{\text{2}}}{\text{max}}{\text{.}}$ Results: V˙O2,$\dot V{{\text{O}}_{\text{2}}},$ expired ventilation (V˙E),$({\dot V_E}),$ blood lactate (La), and calculated net mechanical efficiency (MEnet) rose with increased PO. At 95 rev·min −1 , V˙O2, V˙E,$\dot V{{\text{O}}_2},{\text{ }}{\dot V_{\text{E}}},$ and La were significantly higher than at 60 rev·min −1 at all POs. MEnet at 95 rev·min −1 was lower than at 60 rev·min −1 . Mean PO attained at LaTh did not differ significantly between 60 and 95 rev·min −1 (220.9±29.0 and 214.5±9.2 W, respectively). La values at LaTH were higher at 95 rev·min −1 than at 60 rev·min −1 (3.01±0.17 vs. 2.10±0.13 mM, p<0.05, respectively). Conclusions: Our findings indicate that mechanical and physiological efficiencies may not determine the choice of cycling cadence by nonprofessional cyclists. This choice may reflect the need to maintain endurance at the expense of riding at a lower than optimal riding efficiency.

Background: Ascorbic acid (AA) is known to modulate lymphocyte function, but the mechanism of action is not clearly understood. As voltage-gated potassium currents play an important role in lymphocyte function, the effect of AA on voltage-gated potassium currents was studied. Methods: Peripheral blood mononuclear cells were cultured in the presence of increasing concentrations of AA (0, 0.125, 0.25, 0.5, and 1 mM). Potassium currents in resting lymphocytes were studied by whole cell patch clamp technique using a depolarizing protocol. Lymphocyte function was assessed by measuring interleukin-2 (IL-2) secretion after mitogenic stimulation by ELISA. Results: The mean current density of potassium currents recorded from cells cultured for 48 h in the presence of 0.125 mM AA was not significantly different from that of cells cultured in the absence of AA. There was about 50% inhibition of IL-2 secretion in cell cultures with 0.125 mM AA when compared to controls without AA. At higher concentrations of AA, the IL-2 secretion decreased further. Conclusions: The results of the study indicate that the inhibition of lymphocyte function by AA in vitro may not be due to inhibition of potassium currents in the concentration tested.

Background: The Elaeagnus angustifolia fruit has been traditionally used in Iranian herbal medicine to treat diarrhea and rheumatoid arthritis. In the present study, the effects of E. angustifolia fruit extract on the acute and chronic phases of formalin-induced rat paw edema were examined. Methods: The acute and chronic anti-inflammatory effects of E. angustifolia fruit extract were investigated through the subcutaneous injection of 100 μL of formalin (2.5%) into a rat’s hind paw. Thirty minutes before the procedure, the experimental groups were treated intraperitoneally with hydroalcoholic fruit extracts of E. angustifolia (concentrations of 100, 300, 700, and 1000 mg/kg); sodium salicylate (SS, 400 mg/kg) and distilled water were used as positive and negative control groups, respectively. Treatment with SS and the fruit extracts were performed daily for 8 days, and the degree of edema was measured by using mercury plethysmometer and digital caliper. Results: In the acute anti-inflammatory study, the extract showed a significant anti-inflammatory effect in a dose-dependent manner. The results of 1000 mg/kg of the extract was significantly different compared with the negative control group (p<0.05) and was comparable to sodium salicylate (p<0.05). Results from the chronic study suggested that E. angustifolia extract significantly reduced paw edema and inflammation in a dose-dependent manner. The results also showed that the measurement by digital caliper and mercury plethysmometer were both reliable and might be applied interchangeably (p<0.01). Phytochemical tests indicated that the hydroalcoholic fruit extract of E. angustifolia was positive for cardiac glycosides, flavonoids, terpenoids, and saponins. Conclusions: Based on our findings, the E. angustifolia fruit extract probably has acute and chronic anti-inflammatory activities to support its applications in folk medicine.

Background: In continuation of our study of the biological activity of the aqueous extract of Costus afer stem used in tradomedicare in Nigeria, this work has investigated the biochemical, nephroprotective, hepatoprotective and protective effects of aqueous extract of C. afer stem on alloxan-induced hyperglycaemic albino Wistar rats. Methods: Thirty male albino Wistar rats (150−200 g) were weight-matched into six groups of five rats each. Groups 1 and 2 were the normal (non-induced) and toxic (alloxan-induced) controls, respectively. Groups 3−6 were induced and treated with 1, 2 and 3 g/kg of the aqueous extract of C. afer stem and glibenclamide (5 mg/kg), respectively. Food and fluid intake, body weight, absolute and relative weight of organs (liver, pancreas, and kidneys) and biochemical parameters were measured. Results: There was a significant reduction in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin triglyceride, creatinine, urea and electrolyte when compared with toxic control group. The liver marker enzymes were restored in all the treated groups. The aqueous stem extract possessed hypoglycaemic effect and reversed the histopathological damage in alloxan-induced diabetic rats. Conclusions: This study suggests that aqueous stem extract of C. afer possesses both hypoglycaemic and organ protective properties.

Background: Anogeissus leiocarpus and Hunteria umbellata have been reportedly used in traditional medicine for the management of erectile dysfunction (ED). However, the scientific basis for their use has not been well established. Therefore, this study was designed to investigate the inhibitory effects of water extractable phytochemicals of H. umbellata and A. leiocarpus on phosphodiesterase-5 (PDE-5) and arginase as well as pro-oxidants induced lipid peroxidation in rat penile tissue. Methods: The effects of the extracts on important enzymes (PDE-5 and arginase) linked with ED and pro-oxidants (Fe 2+ and sodium nitroprusside) induced lipid peroxidation were investigated. Also, radicals scavenging and metal chelating abilities were determined. In addition, phenolic contents were determined and characterized using HPLC. Results: The results showed that both extracts inhibited PDE-5 and arginase activities in a dose-dependent manner. Inhibitory property of A. leiocarpus (IC 50 – 174.19 μg/mL) was significantly better (p<0.05) than that of H. umbellata (IC 50 – 537.72 μg/mL) in PDE-5 assay. The extracts were potent inhibitors of arginase than PDE-5, and these extracts were equally potent in inhibiting arginase. Furthermore, Fe 2+ and sodium nitroprusside caused a significant increase in malondialdehyde content; however, both extracts reduced malondialdehyde level in concentration-dependent manner. It is noteworthy that both extracts scavenged radicals (OH* and ABTS*) and chelated Fe 2+ . HPLC analysis revealed abundance of rutin, chlorogenic acid, gallic acid, caffeic acid, and quercetin, among others. Conclusions: The ability of the extracts to inhibit PDE-5, arginase and pro-oxidant induced lipid peroxidation, and chelate metal might suggest their folkloric use for the management of ED.

Background: Our previous studies showed that fruit methanol extract from Xylopia aethiopica (MEXA) exhibited antiproliferative activity in human cervical cancer cells via the induction of apoptosis. The present study was designed to assess the antiproliferative, antiangiogenic and antioxidant effects of MEXA on prostate cancer (PCa) cells (PC-3 and LNCaP). Methods: PC-3 and LNCaP cells were cultured and treated with MEXA (10, 50 and 100 μg/mL). The sodium 3′-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis (4-methoxy-6-nitro) benzene sulfonic acid hydrate (XTT) and lactate dehydrogenase (LDH) assays were used to evaluate cell viability and cytotoxicity, respectively. DNA fragmentation was determined by cell death detection ELISA plus, and angiogenesis was assessed by chicken chorioallantoic membrane (CAM) assay. The antioxidant activities of MEXA were determined by DPPH and hydroxyl (OH) radicals’ scavenging methods as well as through the inhibition of lipid peroxidation (LPO) in rats’ liver homogenate. Results: MEXA at 100, 250 and 500 μg/mL scavenged DPPH by 48%, 62%, 70% and OH radical by 39%, 58%, 67%, respectively. MEXA significantly (p<0.05) inhibited LPO in a concentration-dependent manner. In addition, MEXA had antiproliferative effects on PC-3 and LNCaP with IC 50 of 62.1 and 73.6 μg/mL, respectively, at 96 h. The LDH assay showed that MEXA had low toxicity in vitro at its IC 50 values. The extent of DNA fragmentation by MEXA showed higher values in PC-3 and LNCaP, suggesting the possible induction of apoptosis. In contrast, MEXA did not affect the network of vessels in CAM, thus lacking anti-angiogenic property. Conclusions: These findings suggest that MEXA induces antiproliferative activity in PCa cells through a mechanism that involves apoptosis. Therefore, MEXA may be a potential therapeutic agent for PCa.