V Bhuvaneswari

Annamalai University , Chidambaram, State of Tamil Nadu, India

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Publications (20)33.27 Total impact

  • V Bhuvaneswari, S Nagini
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    ABSTRACT: Dietary chemoprevention has emerged as a cost effective approach to control most prevalent chronic diseases including cancer. In particular, tomato and tomato products are recognised to confer a wide range of health benefits. Epidemiological studies have provided evidence that high consumption of tomatoes effectively lowers the risk of reactive oxygen species (ROS)-mediated diseases such as cardiovascular disease and cancer by improving the antioxidant capacity. Tomatoes are rich sources of lycopene, an antioxidant carotenoid reported to be a more stable and potent singlet oxygen quenching agent compared to other carotenoids. In addition to its antioxidant properties, lycopene shows an array of biological effects including cardioprotective, anti-inflammatory, antimutagenic and anticarcinogenic activities. The anticancer activity of lycopene has been demonstrated both in in vitro and in vivo tumour models. The mechanisms underlying the inhibitory effects of lycopene on carcinogenesis could involve ROS scavenging, upregulation of detoxification systems, interference with cell proliferation, induction of gap-junctional communication, inhibition of cell cycle progression and modulation of signal transduction pathways. This review outlines the sources, structure, absorption, metabolism, bioavailability and pharmacological properties of lycopene with special reference to its antioxidant and anticarcinogenic effects.
    Current Medicinal Chemistry - Anti-Cancer Agents 12/2005; 5(6):627-35.
  • Vaidhyanathan Bhuvaneswari, Suresh K Abraham, Siddavaram Nagini
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    ABSTRACT: Combination chemoprevention by dietary agents is a promising approach toward cancer control. Many dietary agents are known to prevent experimental mutagenesis and carcinogenesis by modulating xenobiotic-metabolizing enzymes. The present study evaluated the combinatorial chemopreventive effects of tomato and garlic on hamster buccal pouch carcinogenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA). Hamsters were assigned to one of four groups. The right buccal pouches of animals in group 1 were painted with 0.5% DMBA three times a week. The right buccal pouches of animals in group 2 were painted with DMBA and received intragastric administration of a combined dose of tomato and garlic on days alternate to DMBA application. Animals in group 3 were given chemopreventive agents alone. Animals in group 4 served as controls. Levels of phase I and II enzymes and the frequency of bone marrow micronuclei were used as biomarkers of chemoprevention. All the hamsters painted with DMBA alone developed buccal pouch carcinomas that exhibited increased activities of xenobiotic-metabolizing enzymes associated with increased frequencies of bone marrow micronuclei. In the liver, an increase in phase I enzymes was accompanied by compromised phase II detoxification activities. Combined administration of tomato and garlic effectively suppressed the incidence and mean tumor burden of hamster buccal pouch carcinomas. In addition, tomato and garlic combination significantly decreased phase I enzymes and increased phase II enzyme activities in the pouch and liver with a decreased incidence of bone marrow micronuclei. From these results, we suggest that modulation of xenobiotic-metabolizing enzymes exerted by tomato and garlic combination plays a key role in mitigating the mutagenic and carcinogenic effects of DMBA.
    Nutrition 07/2005; 21(6):726-31. · 2.86 Impact Factor
  • R Subapriya, V Bhuvaneswari, V Ramesh, S Nagini
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    ABSTRACT: We evaluated the chemopreventive effects of ethanolic neem leaf extract in the initiation and post-initiation phases of 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. The frequency of bone marrow micronuclei as well as the concentrations of lipid peroxides, ratio of reduced to oxidized glutathione (GSH/GSSG), and the activities of the GSH-dependent enzymes glutathione peroxidase (GPx) and glutathione-S-transferase (GST) in the buccal pouch, liver and erythrocytes were used as biomarkers of chemoprevention. All the hamsters painted with DMBA alone for 14 weeks developed buccal pouch carcinomas that showed diminished lipid peroxidation and enhanced antioxidant status associated with increased frequencies of bone marrow micronuclei. In the liver and erythrocytes of tumour-bearing animals, enhanced lipid peroxidation was accompanied by compromised antioxidant defences. Administration of ethanolic neem leaf extract effectively suppressed DMBA-induced HBP carcinogenesis as revealed by the absence of tumours in the initiation phase and reduced tumour incidence in the post-initiation phase. In addition, ethanolic neem leaf extract modulated lipid peroxidation and enhanced antioxidant status in the pouch, liver and erythrocytes and reduced the incidence of bone marrow micronuclei. The results of the present study, demonstrate that ethanolic neem leaf extract inhibits the development of DMBA-induced HBP tumours by protecting against oxidative stress.
    Cell Biochemistry and Function 01/2005; 23(4):229-38. · 1.85 Impact Factor
  • V Bhuvaneswari, K S Rao, S Nagini
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    ABSTRACT: Effective combinations of dietary agents are promising candidates for cancer chemoprevention because of their safety and the fact that they are not perceived as medicine. The present study was designed to investigate the apoptosis-inducing effect of combined administration of tomato and garlic during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Hamsters were divided into four groups. The right buccal pouches of animals in group 1 were painted with 0.5% DMBA three times a week. Animals in group 2 painted with DMBA as in group 1, received in addition intragastric administration of a combined dose of tomato and garlic on days alternate to DMBA application. Group 3 animals were given chemopreventive agents alone. Animals in group 4 served as control. All the animals were sacrificed after an experimental period of 14 weeks. DNA fragmentation and the apoptosis-associated proteins-Bcl-2, Bax, Bim, P53 as well as caspases 8 and 3 were used as markers of apoptosis. Topical application of DMBA for 14 weeks resulted in well-developed squamous cell carcinomas (SCCs) associated with increased expression of Bcl-2 and decreased expression of Bax, Bim, P53 and caspases 8 and 3. Combined administration of tomato and garlic significantly inhibited the development of HBP carcinomas and induced apoptosis. This was evidenced by downregulation of Bcl-2 and upregulation of Bax, Bim, P53 and caspases 8 and 3. The induction of apoptosis may be one of the mechanisms through which functional foods such as tomato and garlic exert their anticancer properties.
    Clinica Chimica Acta 01/2005; 350(1-2):65-72. · 2.85 Impact Factor
  • Balaiya Velmurugan, Vaidhyanathan Bhuvaneswari, Suresh K Abraham, Siddavaram Nagini
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    ABSTRACT: Chemoprevention by dietary constituents has emerged as a cost-effective approach to control the incidence of gastric cancer, the second most common malignancy worldwide, and a major cause of mortality in Chennai, India. Identification of dietary agents with chemopreventive potential requires prescreening in animal models. We evaluated the modifying effects of tomato paste against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced genetic damage and oxidative stress in male Swiss mice. Quantitation of bone marrow micronuclei, extent of lipid peroxidation, and the status of the antioxidants reduced glutathione, glutathione peroxidase, and glutathione S-transferase in the stomach and liver of Swiss albino mice were used to monitor the protective effects of tomato. Three different doses of tomato (0.5, 1, and 2 g/kg of body weight) were administered intragastrically for 5 d consecutively followed by intragastric intubation of MNNG 1.5 h after the final administration. Increased frequency of micronuclei and enhanced lipid peroxidation were accompanied by compromised antioxidant defenses in MNNG-treated rats. Pretreatment of tomato paste at the concentration of 1 and 2 g/kg of body weight significantly decreased micronuclei and lipid peroxidation and enhanced reduced glutathione-dependent antioxidant and detoxifying enzymes. Our results demonstrate that tomato protects against the clastogenic effects of MNNG by decreasing micronucleated polychromatic erythrocytes and lipid peroxidation and enhancing antioxidant status.
    Nutrition 10/2004; 20(9):812-6. · 2.86 Impact Factor
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    V Bhuvaneswari, B Velmurugan, S K Abraham, S Nagini
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    ABSTRACT: Chemoprotection by dietary agents is a promising strategy for cancer prevention. The aim of the present study was to evaluate the combined effect of tomato and garlic against 7,12-dimethylbenz-[a]anthracene (DMBA)-induced genetic damage and oxidative stress in 12-14-week-old male Swiss albino mice. The animals were randomized into experimental and control groups and divided into eight groups of five animals each. Group 1 animals were injected intraperitoneally with 35 mg/kg body weight DMBA suspended in peanut oil as a single dose. Groups 2-4 animals received tomato (500 mg/kg body weight), garlic (125 mg/kg body weight) and a combination of tomato and garlic for 5 days by gavage, respectively, followed by DMBA 1.5 h after the final feeding. The doses of tomato and garlic correspond to the average human daily consumption. Animals in groups 5, 6 and 7 received tomato alone, garlic alone and tomato + garlic combination, respectively, for 5 days. Group 8 animals received the same volume of water and served as control. The incidence of bone marrow micronuclei and the extent of lipid peroxidation and the concentrations of antioxidants glutathione, glutathione peroxidase and glutathione-S-transferase were measured in the liver, 48 h after DMBA exposure. Increased frequency of micronuclei and enhanced lipid peroxidation accompanied by compromised antioxidant defenses were observed in DMBA-treated animals. Although pretreatment with tomato or garlic significantly reduced the frequency of DMBA-induced bone marrow micronuclei, the combination of tomato and garlic exhibited more profound effect in inhibiting DMBA-induced genotoxicity and oxidative stress. We suggest that a broad spectrum of antimutagenic and anticlastogenic effects can be achieved through an effective combination of functional foods such as tomato and garlic.
    Brazilian Journal of Medical and Biological Research 08/2004; 37(7):1029-34. · 1.14 Impact Factor
  • V Bhuvaneswari, B Velmurugan, S Nagini
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    ABSTRACT: We evaluated the dose-response effect of tomato paste on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis using lipid peroxidation, reduced glutathione (GSH) and the GSH-dependent enzymes; glutathione peroxidase (GPx), glutathione-S-transferase (GST) and gamma-glutamyltranspeptidase (GGT) as biomarkers of chemoprevention. Hamsters were divided into eight groups of six animals each. The right buccal pouches of animals in group 1 were painted with a 0.5 per cent DMBA in liquid paraffin three times per week. Animals in groups 2 to 4 painted with DMBA as in group 1, received in addition, intragastric administration of tomato paste containing lycopene at concentrations of 2.5, 5 and 10 mgkg(-1)bw, respectively three times per week on days alternate to DMBA application. Groups 5 through 7 were given tomato paste alone. Animals in group 8 served as controls. All animals were killed after an experimental period of 14 weeks. Lipid peroxidation and GSH-dependent antioxidants were measured in the buccal pouch, liver and erythrocytes. Diminished lipid peroxidation in the HBP tumours was associated with enhanced levels of GSH and GSH-dependent enzymes. In contrast to the buccal pouch, the liver and erythrocytes of tumour-bearing hamsters exhibited elevated lipid peroxidation accompanied by compromised antioxidant status. Administration of tomato paste significantly reduced the incidence of HBP tumours, modulated lipid peroxidation and enhanced GSH and GSH-dependent enzymes in the pouch, liver and erythrocytes. Among the three doses used, tomato paste containing 5 mgkg(-1)bw lycopene showed the optimum effect. It is suggested that tomato paste exerts its chemopreventive effects by modulating lipid peroxidation and enhancing antioxidants in the target organ as well as in the liver and erythrocytes.
    Journal of experimental & clinical cancer research: CR 07/2004; 23(2):241-9. · 1.50 Impact Factor
  • S Arivazhagan, B Velmurugan, V Bhuvaneswari, S Nagini
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    ABSTRACT: The modifying effects of aqueous extracts of garlic and neem leaf during the pre-initiation and post-initiation phases of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine were investigated in male Wistar rats. The extent of lipid peroxidation and the status of phase II biotransformation enzymes such as glutathione peroxidase and glutathione-S-transferase that use reduced glutathione (GSH) as substrate were used to biomonitor the chemopreventive potential of these extracts. Enhanced lipid peroxidation in the liver and blood of tumor-bearing animals was accompanied by significant decreases in the activities of GSH-dependent antioxidants in the pre-initiation as well as in the post-initiation phases. Our results suggest that the modulatory effects of garlic and neem leaf on hepatic and blood oxidant-antioxidant status may play a key role in preventing cancer development at extrahepatic sites.
    Journal of Medicinal Food 02/2004; 7(3):334-9. · 1.64 Impact Factor
  • V. Bhuvaneswari, K.V.P. Chandra Mohan, S. Nagini
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    ABSTRACT: Combination chemoprevention by dietary agents is a promising strategy for cancer prevention. We evaluated the combined chemopreventive effect of tomato paste and aqueous garlic extract against 7, 12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Hamsters were divided into eight groups. Animals in group 1 served as control. Groups 2 through 4 were given tomato, garlic and mixture of tomato and garlic respectively. The right buccal pouches of animals in group 5 were painted with 0.5% DMBA three times a week. Animals in groups 6 to 8 painted with DMBA as in group 5, received in addition, intragastric administration of tomato paste, aqueous garlic extract alone and in combination respectively on days alternate to DMBA application. Lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR) and γ-glutamyltranspeptidase (GGT) as well as GSH/GSSG ratio were measured in the buccal pouch, liver and erythrocytes at the end of 14 weeks. Diminished lipid peroxidation in the HBP tumours was associated with enhanced levels of GSH and GSH-dependent enzymes. In contrast to the buccal pouch, the liver and erythrocytes of tumour-bearing hamsters exhibited elevated lipid peroxidation accompanied by compromised antioxidant status. Although administration of tomato paste and garlic alone significantly reduced the tumour incidence and tumour burden, combined administration of tomato and garlic was more effective in inhibiting the development of HBP carcinomas as revealed by modulation of the cellular redox status. From these results, we suggest that broader spectrum of chemoprevention with less adverse effects can be attained through effective combination of functional foods.
    Nutrition Research. 01/2004;
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    Balaiya Velmurugan, Vaidhyanathan Bhuvaneswari, Siddavaram Nagini
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    ABSTRACT: We investigated the chemopreventive effect of S-allylcysteine (SAC), a water-soluble garlic constituent against gastric carcinogenesis induced in male Wistar rats by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and saturated sodium chloride (S-NaCl). The animals were divided into four groups of six animals. Rats in groups 1 and 2 were administered MNNG (200 mg/kg body weight) on days 0 and 14 as well as S-NaCl (1 mL/rat) three days during weeks 0 to 3, and thereafter placed on basal diet until the end of the experiment. Rats in group 2 in addition received SAC (200 mg/kg body weight) three times per week starting on the day following the first exposure to MNNG and continued until the end of the experimental period. Group 3 animals were given SAC alone as in group 2. Group 4 animals received basal diet and tap water throughout the experiment and served as the untreated control. The animals were sacrificed after an experimental period of 21 weeks. Measurement of lipid peroxidation and antioxidants of the glutathione redox cycle in the stomach tissue, liver and venous blood was used to monitor the chemopreventive potential of SAC. All animals that received MNNG and S-NaCl alone, developed tumours, identified histologically as squamous cell carcinomas. In the tumour tissue, diminished lipid peroxidation was accompanied by increase in reduced glutathione (GSH) and GSH-dependent enzymes, whereas in the liver and circulation, enhanced lipid peroxidation was associated with antioxidant depletion. Administration of SAC suppressed the incidence of MNNG+S-NaCl-induced gastric tumours as revealed by the absence of carcinomas. SAC ameliorated MNNG-induced decreased susceptibility of the gastric mucosa to lipid peroxidation, whilst simultaneously increasing the antioxidant status. In the liver and blood, SAC reduced the extent of lipid peroxidation and significantly enhanced antioxidant activities. We suggest that SAC exerts its chemopreventive effects by modulating lipid peroxidation and enhancing GSH-dependent antioxidants in the target organ as well as in the liver and blood.
    Asia Pacific Journal of Clinical Nutrition 02/2003; 12(4):488-94. · 1.06 Impact Factor
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    ABSTRACT: This study was designed to investigate the protective role of pretreatment with graded doses of freshly prepared tomato paste against 7,12-dimethylbenz[a]anthracene (DMBA)-induced genetic damage and oxidative stress in male Swiss mice. The incidence of bone marrow micronuclei and the extent of hepatic lipid peroxidation and the antioxidants glutathione, glutathione peroxidase, and glutathione S-transferase were monitored. Three different concentrations (0.5, 1, and 2 g/kg body weight) of tomato paste were tested for their anticlastogenic effects against DMBA (35 mg/kg body weight). Increased frequency of micronuclei and enhanced lipid peroxidation accompanied by compromised antioxidant defenses were observed in DMBA-treated animals. Pretreatment with all three doses of tomato paste significantly reduced the frequencies of DMBA-induced micronuclei and oxidative stress. These findings demonstrate that administration of tomato paste protects against the clastogenic effects of DMBA by decreasing lipid peroxidation and enhancing the antioxidant status.
    Journal of Medicinal Food 02/2003; 6(3):169-73. · 1.64 Impact Factor
  • B Velmurugan, V Bhuvaneswari, S Nagini
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    ABSTRACT: The effects of lycopene on blood oxidant-antioxidant balance during N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis in the presence of saturated sodium chloride (S-NaCl) as promoting agent were investigated. Enhanced lipid peroxidation in the blood of tumour-bearing animals was accompanied by significant decreases in the levels of reduced glutathione (GSH), ascorbic acid and vitamin E and the activities of glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR). Administration of lycopene significantly lowered the concentrations of lipid peroxides and enhanced antioxidant levels. We suggest that the modulatory effects of lycopene on the blood oxidant-antioxidant balance may be responsible for its chemopreventive potential.
    Fitoterapia 01/2003; 73(7-8):604-11. · 2.23 Impact Factor
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    ABSTRACT: Our objective was to elucidate sequential changes in the oxidant-antioxidant status during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. In designing the study, we divided hamsters into experimental and control groups. The right buccal pouches of the experimental animals were painted three times a week with a 0.5% solution of DMBA in liquid paraffin. The control animals received paraffin alone. The hamsters were killed after 1, 4, 8, 12, and 16 weeks of DMBA treatment, and the buccal pouches were examined for histopathological changes. The extent of lipid peroxidation and the status of glutathione-dependent antioxidants were evaluated in the buccal pouch, liver, and erythrocytes. Our results showed that the experimental animals developed severe hyperplasia and hyperkeratosis after 4 weeks, dysplasia after 8 weeks, and well-developed squamous cell carcinomas after 16 weeks of DMBA application. Topical application of DMBA increased lipid peroxidation in the buccal pouch up to the 8th week; there was a substantial fall after 12 weeks and significantly low levels after 16 weeks. This was accompanied by a sustained increase in reduced glutathione (GSH) and the activities of glutathione peroxidase (GPx), glutathione-S-transferase (GST), and gamma-glutamyltranspeptidase (GGT) throughout the carcinogenic progression. However, in the liver and erythrocytes, the concentrations of lipid peroxides were higher, and GSH- and GSH-dependent enzyme activities were lower than in the controls throughout the experiment. This study has revealed intrinsic differences in the cellular redox state in the target organ and host tissues of tumor-bearing animals. We suggest that measurement of lipid peroxidation and GSH-dependent antioxidants could be valuable in evaluating carcinogenic progression and the effects of putative chemopreventive agents in the hamster buccal pouch model.
    Toxicology mechanisms and methods 01/2003; 13(3):227-34. · 1.37 Impact Factor
  • V Bhuvaneswari, B Velmurugan, S Nagini
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    ABSTRACT: Consumption of carotenoids is recognised to be inversely related with cancer incidence. Lycopene, a major carotenoid in tomatoes is a potent antioxidant with potential anticarcinogenic properties. We undertook the study to investigate the effect of lycopene on hepatic biotransformation enzymes during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis using hepatic lipid peroxidation, reduced glutathione (GSH) and biotransformation enzymes that use GSH as a substrate such as glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR). Enhanced lipid peroxidation in the liver of tumour-bearing animals was accompanied by significant decreases in the activities of GSH and GSH-dependent enzymes. Administration of lycopene significantly decreased the formation of lipid peroxides and enhanced the activities of hepatic biotransformation enzymes. Our results indicate that elevation of hepatic GSH and biotransformation enzymes by lycopene may play a key role in preventing cancer development at extrahepatic sites.
    The Journal of Biochemistry Molecular Biology and Biophysics 09/2002; 6(4):257-60.
  • B Velmurugan, V Bhuvaneswari, Usha K Burra, S Nagini
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    ABSTRACT: We investigated "the "chemopreventive potential of lycopene against gastric carcinogenesis induced in male Wistar rats by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and saturated sodium chloride (S-NaCl). Administration of lycopene inhibited MNNG+S-NaCl-induced gastric carcinogenesis as revealed by the absence of carcinomas. Lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) were used to monitor the chemopreventive potential of lycopene. The extent of lipid peroxidation was significantly lower, whereas GSH, GPx, GST and GR were markedly enhanced in the gastric mucosa of tumour-bearing animals. Our data suggest that lycopene may exert its inhibitory effects by modulating the oxidant and antioxidant status in the gastric mucosa.
    European Journal of Cancer Prevention 03/2002; 11(1):19-26. · 2.97 Impact Factor
  • Velmurugan B, Bhuvaneswari V, Burra UK, Nagini S
    European Journal of Cancer Prevention 02/2002; 11(1):19-26.. · 2.97 Impact Factor
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    ABSTRACT: The chemopreventive efficacy of lycopene on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis was examined using lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) as biomarkers of chemoprevention. Twenty four male Syrian hamsters were divided into four groups of six animals each. The right buccal pouches of the animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin three times a week. The animals in group 2 were painted with DMBA as in group 1 and in addition received 2.5 mg/kg body weight lycopene orally three times a week on days alternate to DMBA application. Group 3 animals received lycopene as in group 2. Animals in group 4 received neither DMBA nor lycopene and served as control. The hamsters were killed after an experimental period of 14 weeks. Biochemical measurements were carried out in tumour and normal tissues. All hamsters painted with DMBA alone for 14 weeks developed well-differentiated squamous cell carcinomas. Diminished lipid peroxidation in the oral tumour tissue was accompanied by a significant increase in the levels of GSH, GPx, GST and GR. Administration of lycopene significantly suppressed DMBA-induced oral carcinogenesis as revealed by the absence of carcinomas. The results of the present study suggest that lycopene may exert its chemopreventive effects by modulating lipid peroxidation and enhancing the activities of the enzymes in the glutathione redox cycle.
    Fitoterapia 01/2002; 72(8):865-74. · 2.23 Impact Factor
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    ABSTRACT: We investigated the effects of lycopene on hepatic oxidant-antioxidant status during N-methyl-N′-nitro-N-nitrosoguanidine and saturated sodium chloride (S-NaCl)-induced gastric carcinogenesis. The extent of lipid peroxidation and the levels of reduced glutathione (GSH) and activities of the GSH-dependent enzymes glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) were used to monitor the peroxidative balance. Enhanced lipid peroxidation in the livers of tumor-bearing animals was accompanied by significant decreases in the activities of GSH, GPx, GST and GR. Administration of lycopene significantly lowered the levels of lipid peroxides and enhanced GSH levels and activities of GSH-dependent enzymes. Our results suggest that lycopene blocks experimental gastric carcinogenesis by upregulating GSH-dependent hepatic detoxification systems thereby protecting against carcinogen-induced oxidative damage.
    Nutrition Research - NUTR RES. 01/2001; 21(8):1117-1124.
  • V. Bhuvaneswari, B. Velmurugan, S. Nagini
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    ABSTRACT: This study was designed to investigate the effect of lycopene, an antioxidant carotenoid on circulatory lipid peroxidation and antioxidant status during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. All the hamsters painted with 0.5 per cent DMBA on the buccal pouches developed oral squamous cell carcinoma. Enhanced lipid peroxidation in circulation of tumour-bearing animals was accompanied by a significant decrease in the levels of ascorbic acid, vitamin E, reduced glutathione (GSH) and the GSH-dependent enzymes glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR). Administration of lycopene (2.5 mg/kg body weight) significantly suppressed DMBA-induced HBP carcinomas, decreased lipid peroxidation and enhanced the levels of antioxidants. Our results suggest that the antioxidant activity of lycopene is an important mechanism through which lycopene exerts its anticarcinogenic effects.
    Nutrition Research 01/2001; 21(11):1447-1453. · 2.59 Impact Factor
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    R Subapriya, V Bhuvaneswari, S Nagini
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    ABSTRACT: Induction of apoptosis is one of the most active strategies in cancer chemoprevention and the ability of medicinal plants in this regard has attracted major research interest. The present study was designed to investigate the apoptosis inducing capacity of an ethanolic neem leaf extract (ENLE) during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis using the apoptosis-associated proteins Bcl-2, Bim, caspase 8 and caspase 3 as markers. Topical application of DMBA to the hamster cheek pouch for 14 weeks resulted in well developed squamous cell carcinomas associated with increased expression of Bcl-2 and decreased expression of Bim, caspase 8 and caspase 3. Administration of ENLE inhibited DMBA-induced hamster buccal pouch (HBP) carcinogenesis, as revealed by the absence of neoplasms, with induction of Bim and caspases 8 and 3 and inhibition of Bcl-2 expression. Our results suggest that the chemopreventive effects of ENLE may be mediated by induction of apoptosis.
    Asian Pacific journal of cancer prevention: APJCP 6(4):515-20. · 1.50 Impact Factor