Gunasekaran Krishnamoorthy

Quercetin downregulates matrix metalloproteinases 2 and 9 proteins expression in prostate cancer cells (PC-3)

Background: Cancer metastasis, involving multiple processes and various cytophysiological changes, is a primary cause of cancer death and may complicate the clinical management, even lead to death. Quercetin is a flavonoid and widely used as an antioxidant and recent studies have revealed its pleiotropic anticancer and antiproliferative capabilities. Gelatinases A and B (matrixmetalloproteinases 2 and 9) are enzymes known to involve in tumor invasion and metastases. In this study, we observed the precise involvement of quercetin role on these proteinases expression and activity. Design and methods: PC-3 cells were treated with quercetin at various concentrations (50 and 100 μM), for 24 h period and then subjected to western blot analysis to investigate the impact of quercetin on matrix metalloproteinase-2 (MMP-2) and 9 (MMP-9) expressions. Conditioned medium and cell lysate of quercetin-treated PC-3 cells were subjected to western blot analysis for proteins expression of MMP-2 and MMP-9. Gelatin zymography was also performed in quercetin treated PC-3 cells. Results: The results showed that quercetin treatment decreased the expressions of MMP-2 and MMP-9 in dose-dependent manner. The level of pro-MMP-9 was found to be high in the 100 μM quercetin-treated cell lysate of PC-3 cells, suggesting inhibitory role of quercetin on pro-MMP-9 activation. Gelatin zymography study also showed the decreased activities of MMP-2 and MMP-9 in quercetin treated cells. Conclusion: Hence, we speculated that inhibition of metastasis-specific MMPs in cancer cells may be one of the targets for anticancer function of quercetin, and thus provides the molecular basis for the development of quercetin as a novel chemopreventive agent for metastatic prostate cancer.

Protective role of melatonin on PCB (Aroclor 1254) induced oxidative stress and changes in acetylcholine esterase and membrane bound ATPases in cerebellum, cerebral cortex and hippocampus of adult rat brain

Polychlorinated biphenyls (PCBs) are one of the environmental toxicants and neurotoxic compounds which induce the production of free radicals leading to oxidative stress. Membrane proteins that control ion gradients across organellar and plasma membranes appear to be particularly susceptible to oxidation induced changes. Melatonin plays an important role in neurodegenerative diseases as an antioxidant and neuroprotector. The aim of this study was to determine the protective role of melatonin on PCB (Aroclor 1254) induced changes in activities of membrane bound ATPases and acetylcholine esterase in selected brain regions of adult rats. Group I: rats intraperitoneally (i.p.) administered corn oil (vehicle) for 30 days. Group II: rats injected i.p. with Aroclor 1254 (PCB) at 2 mg/kg bw/day for 30 days. Groups III and IV: rats intraperitoneally received melatonin (5 or 10 mg/kg bw/day) simultaneously with Aroclor 1254 for 30 days. Groups V and VI: rats intraperitoneally received melatonin (5 or 10 mg/kg bw/day) alone for 30 days. After 30 days, rats were sacrificed and the brain regions were dissected to cerebral cortex (Cc), cerebellum (C) and hippocampus (H). Lipid peroxidation (LPO), hydrogen peroxide (H2O2), hydroxyl radical (*OH) and the activities of Na+K+ ATPase, Ca2+ ATPase, Mg2+ ATPase and acetyl cholinesterase were determined. Reduced glutathione (GSH) level was also determined. Melatonin levels in serum was measured by enzyme labeled immunosorbent assay (ELISA). Activities of all the enzymes and GSH level were decreased while an increase in H2O2, *OH and LPO were observed in brain regions of PCB treated animals. Melatonin levels in serum was decreased in PCB exposed animals. Exogenous melatonin supplementation retrieved all the parameters, significantly. These results suggest that PCB alters membrane bound ATPases and cholinergic function by inducing oxidative stress in brain regions, which can be protected by melatonin.

Effect of melatonin on PCB (Aroclor 1254) induced neuronal damage and changes in Cu/Zn superoxide dismutase and glutathione peroxidase-4 mRNA expression in cerebral cortex, cerebellum and hippocampus of adult rats

Polychlorinated biphenyls (PCBs) are one of the environmental toxicants and neurotoxic compounds which induce the production of free radicals leading to oxidative stress. Free radicals represent a class of biologically generated species that pose a potential threat to neuronal survival. Cu/Zn superoxide dismutase (SOD) and glutathione peroxidase-4 (GPx-4) are the key cellular antioxidant enzymes by which neurons and other cells detoxify free radicals and protect themselves from damage. Melatonin, an indoleamine plays an important role in neurodegenerative diseases as an antioxidant and neuroprotector. The aim was to carry out to investigate the effect of melatonin on PCB (Aroclor 1254) induced changes in histomorphology and Cu/Zn SOD, GPx-4 mRNA expression in selected brain regions of adult rats. Group I: rats intraperitoneally (i.p.) administered with corn oil (vehicle) for 30 days. Group II: rats injected (i.p.) with Aroclor 1254 (PCB) at 2mg/kgbw/day for 30 days. Groups III and IV: rats (i.p.) received melatonin (5 or 10mg/kgbw/day) simultaneously with PCB for 30 days. Groups V and VI: rats (i.p.) received melatonin (5 or 10mg/kgbw/day) alone for 30 days. After 30 days, rats were sacrificed and the brain regions were dissected to cerebral cortex, cerebellum and hippocampus. Activities of enzymatic antioxidants such as total SOD, Cu/Zn SOD, Mn SOD, glutathione peroxidase (GPx) were estimated. mRNA expressions of Cu/Zn SOD and GPx-4 were quantified by reverse transcriptase polymerase chain reaction (RT-PCR) method. Histological study was also observed. Specific activities of all antioxidant enzymes and mRNA expression of Cu/Zn SOD and GPx-4 were decreased in brain regions of PCB exposed animals. Neuronal damages were observed in all the brain regions. Exogenous melatonin supplementation retrieved all the parameters. These results suggest that melatonin protects PCB-induced oxidative stress and prevents neuronal damage in brain regions.

Studies on the protective role of lycopene against polychlorinated biphenyls (Aroclor 1254)-induced changes in StAR protein and cytochrome P450 scc enzyme expression on Leydig cells of adult rats

Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environmental contaminants that disturb normal endocrine functions, including gonadal functions in humans and mammals. PCBs (Aroclor 1254) - induced toxic manifestations are associated with the production of free radicals. Lycopene belongs to the group of natural carotenoids, which are found in many fruits, vegetables and other green plants. Lycopene, the most potent antioxidant protects against oxidative damage. The present study was conducted to elucidate the protective role of lycopene against Aroclor 1254-induced changes in Leydig cellular steroidogenic acute regulatory (StAR) protein, cytochrome P450 side chain cleavage (P450 scc) enzyme expression and 3beta-hydroxy steroid dehydrogenase (3beta-HSD) activity. The rats were divided into four groups. Each group consists of six animals. Group I rats were administered with corn oil intraperitoneally (i.p.) for 30 days. Group II rats were treated with Aroclor 1254 (i.p.) 2mgkg(-1)body weight (bwt)day(-1) for 30 days. Group III rats were treated with Aroclor 1254 (i.p.) 2mgkg(-1)bwtday(-1) along with simultaneous supplementation of lycopene 4mgkg(-1)bwtday(-1) (gavage) for 30 days. Group IV rats administered with lycopene alone at the dose of 4mgkg(-1)bwt day(-1) (gavage) for 30 days. After 24h of the last treatment, animals were decapitated, blood was collected and serum testosterone level was estimated by radioimmunoassay (RIA). Testes were removed and Leydig cells were isolated in aseptic condition. StAR protein, cytochrome P450 scc enzyme expression were studied by Western blot analysis and 3beta-HSD activity was estimated spectrophotometrically. Aroclor 1254 treatment significantly reduced the serum testosterone level. Simultaneous supplementation of lycopene maintained the serum testosterone to near normal. Aroclor 1254 exposure decreased Leydig cellular StAR protein, cytochrome P450 scc enzyme expression and activity of 3beta-HSD. However, simultaneous supplementation of lycopene improved Leydig cellular StAR protein, cytochrome P450 scc expression and activity of 3beta-HSD. These results suggested that lycopene have ameliorative role against Aroclor 1254 induced Leydig cell dysfunction.

Oxidative stress alters creatine kinase system in serum and brain regions of polychlorinated biphenyl (Aroclor 1254)-exposed rats: protective role of melatonin.

Polychlorinated biphenyls are one of the environmental toxicants and neurotoxic compounds which induce the production of free radicals. Creatine kinase plays a key role in energy metabolism of nervous tissue and might be one of the targets for reactive oxygen species. Melatonin, an indoleamine, plays an important role in neurodegenerative diseases as an antioxidant and neuroprotector. The objective of the present study was to investigate the protective role of melatonin on polychlorinated biphenyl (Aroclor 1254)-induced oxidative stress and the changes in creatine kinase activity in brain regions of adult rats. Group I: rats were intraperitoneally (i.p.) administered with corn oil (vehicle) for 30 days. Group II: rats injected i.p. with Aroclor 1254 at 2 mg/kg body weight (bw)/day for 30 days. Groups III and IV: rats i.p. received melatonin (5 or 10 mg/kg bw/day) simultaneously with Aroclor 1254 for 30 days. After 30 days, rats were killed and the brain regions were dissected to cerebral cortex, cerebellum and hippocampus. Lipid peroxidation, hydroxyl radical and hydrogen peroxide (H2O2) levels were determined. The activity of creatine kinase was assayed in serum and brain regions, and its isoenzymes in serum were separated electrophoretically. Activity of creatine kinase was decreased while an increase in H2O2, hydroxyl radical and lipid peroxidation was observed in brain regions of polychlorinated biphenyl-treated rats. Also polychlorinated biphenyl exposure showed a significant increase in serum creatine kinase level and its isoforms such as BB-creatine kinase, MB-creatine kinase, and MM-creatine kinase. Administration of melatonin prevented these alterations induced by polychlorinated biphenyl by its free radical scavenging mechanism. Thus, polychlorinated biphenyl alters creatine kinase activity by inducing oxidative stress in brain regions, which can be protected by melatonin.

Lycopene supplementation prevents reactive oxygen species mediated apoptosis in Sertoli cells of adult albino rats exposed to polychlorinated biphenyls

Abstract Sertoli cell proliferation is attenuated before attaining puberty and the number is fixed in adult testes. Sertoli cells determine both testis size and daily sperm production by providing physical and metabolic support to spermatogenic cells. Polychlorinated biphenyls (PCBs) exposure disrupts functions of Sertoli cells causing infertility with decreased sperm count. On the other hand, lycopene is improving sperm count and motility by reducing oxidative stress in humans and animals. Hence we hypothesized that PCBs-induced infertility might be due to Sertoli cell apoptosis mediated by oxidative stress and lycopene might prevent PCBs-induced apoptosis by acting against oxidative stress. To test this hypothesis, animals were treated with vehicle control, lycopene, PCBs and PCBs + lycopene for 30 days. After the experimental period, the testes and cauda epididymidis were removed for isolation of Sertoli cells and sperm, respectively. We observed increased levels of oxidative stress markers (H2O2 and LPO) levels, increased expression of apoptotic molecules (caspase-8, Bad, Bid, Bax, cytochrome C and caspase-3), decreased anti-apoptotic (Bcl2) molecule and elevated apoptotic marker activity (caspase-3) in Sertoli cells of PCBs-exposed animals. These results were associated with decreased sperm count and motility in PCBs exposed animals. On the other hand, lycopene prevented the elevation of Sertoli cellular apoptotic parameters and prevented the reduction of sperm parameters (count and motility). The data confirmed that lycopene as an antioxidant scavenged reactive oxygen substances, prevented apoptosis, maintained normal function in Sertoli cells and helped to provide physical and metabolic support for sperm production, thereby treating infertility in men.

Polychlorinated biphenyls-induced oxidative stress on rat hippocampus: a neuroprotective role of quercetin.

Present study is aimed to evaluate the ameliorative role of quercetin on PCBs-induced oxidative stress in hippocampus of Wistar rats. Group I rats received vehicle (corn oil) intraperitoneally (i.p); Group II received quercetin 50 mg/kg bwt/day (gavage); Group III received PCB 2 mg/kg bwt/day (i.p); Group IV received PCB (i.p) and simultaneously quercetin through gavage. After 30 days, rats were euthanized and hippocampus was dissected from each rat brain. Oxidative stress was assessed by determining the levels of H2O2, LPO, Pcc, and alteration in the functional markers such as CK, AchE, and ATPases activities in the hippocampus of control and experimental animals. A significant increase in the levels of stress markers and decrease in level of functional markers were observed in PCBs-treated rats. Moreover DNA fragmentation and histological studies were ascertained to confirm PCBs toxicity. In conclusion, quercetin shows a protective role against PCBs-induced oxidative damage in rat hippocampus.

Effect of Quercetin on Haematobiochemical and Histological Changes in the Liver of Polychlorined Biphenyls-Induced Adult Male Wistar Rats

Polychlorinated biphenyls exposure damages the rat liver cells. Hematological parameters such as hemoglobin, packed cell volume, red-blood cells, white-blood cells, neutrophils, platelet counts, and RBC indices were significantly decreased. Polymorphs, eosinophil counts, and erythrocyte sedimentation rate were significantly increased. Serum liver enzymes such as aspartate transaminase, alanine transaminase, alkaline phosphatase, and gamma-glutamyl transferase were increased by PCBs treatment. Serum lipid profiles such as cholesterol, triglycerides, low-density lipoproteins and very-low-density lipoproteins were increased in PCBs-treated rats. High-density lipoprotein, total protein, albumin, globulin levels, and albumin/globulin ratio were also decreased after PCB exposure. Then levels of sodium, potassium, chloride, and bicarbonate were also altered. Serum glucose levels were increased along with total bilirubin after PCBs exposure. Simultaneous quercetin supplementation significantly protected the PCBs-induced changes of hematobiochemical parameters. Thus, quercetin shows a protective role against PCBs-induced alterations in the hematological and biochemical parameters.

Impact of Lycopene on Epididymal Androgen and Estrogen Receptors’ Expression in Polychlorinated Biphenyls–Exposed Rat

The aim of the study was to evaluate the androgen (AR) and estrogen receptors’ (ER) expression in epididymis of polychlorinated biphenyls (PCBs)-exposed rats. The rats were assigned to groups. Group I controls were treated with corn oil 80 µL/d intraperitoneally (ip), group II were treated with 2 mg/kg/d of A1254 ip; and group III were treated with 2 mg/kg/d of A1254 ip along with simultaneous oral supplementation of 4 mg/kg/d lycopene . The treatment was given daily for 30 days. After 24 hours of treatment, the rats were killed, and the epididymal regions (caput, corpus, and cauda) were dissected out, weighed, and prepared to estimate the levels of sialic acid, glyceryl phosphoryl choline (GPC), hydrogen peroxide (H2O2), and lipid peroxidation (LPO). The messenger RNA (mRNA) expressions of AR, ERα, and ERβ were analyzed by reverse transcriptase–polymerase chain reaction, and ERα and ERβ protein expressions were analyzed by immunoblotting. The toxicity of PCBs was also confirmed by histology. There was a marked decrease in epididymal weight, sialic acid, and GPC levels, while oxidative stress markers H2O2 and LPO were increased in PCBs-treated rats. The mRNA and protein expression of AR, ERα, and ERβ were decreased in PCBs-treated groups, and the histology confirms the cytoplasmic damage in the regions of caput, corpus, and cauda in PCBs-treated rats. Simultaneous supplementation of lycopene to PCBs-exposed rats resulted in significant decrease in the oxidative stress markers as that of control, while the AR, ERα, and ERβ gene expressions were near to control. The results suggest that lycopene has ameliorative effect against PCBs-induced toxicity in epididymis.