Synthesis and thermomechanical properties of bioplastics and biocomposites: a systematic review.

Materials research relating to bio-based polymers and composites has become the order of the day and several types of research are being undertaken on these materials. This is mainly due to the belief in the ability of these polymers and composites to serve as potential alternatives for synthetic polymers and fiber-reinforced composites and to mitigate problems pertaining to environmental pollution. A majority of synthetic fibers and polymers in the market today are developed from nonrenewable petroleum-based materials. These have the potential to harm the natural biodiversity of the environment. On the other hand, the use of bioplastics and biocomposites is supported by a few facts such as low cost, lesser energy consumption during production, and notable mechanical and thermal characteristics. The usage of bio-based fibers and polymers in the manufacture of biocomposites in numerous applications greatly enhance the sustainability by eradicating the problem of waste generation. Considering all the above points, the current review focuses on the synthesis and characterization of bioplastics and biocomposites. An elaborate discussion on the mechanical and thermal properties of these materials has also been made. In addition, this review comprehensively discusses the applications, challenges, and prospects of bioplastics and biocomposites.

A Critical Review on Hygrothermal and Sound Absorption Behavior of Natural-Fiber-Reinforced Polymer Composites.

Increasing global environmental problems and awareness towards the utilization of eco-friendly resources enhanced the progress of research towards the development of next-generation biodegradable and environmentally friendly material. The development of natural-based composite material has led to various advantages such as a reduction in greenhouse gases and carbon footprints. In spite of the various advantages obtained from green materials, there are also a few disadvantages, such as poor interfacial compatibility between the polymer matrix and natural reinforcements and the high hydrophilicity of composites due to the reinforcement of hydrophilic natural fibers. This review focuses on various moisture-absorbing and sound-absorbing natural fiber polymer composites along with the synopsis of preparation methods of natural fiber polymer composites. It was stated in various studies that natural fibers are durable with a long life but their moisture absorption behavior depends on various factors. Such natural fibers possess different moisture absorption behavior rates and different moisture absorption behavior. The conversion of hydrophilic fibers into hydrophobic is deemed very important in improving the mechanical, thermal, and physical properties of the natural-fiber-reinforced polymer composites. One more physical property that requires the involvement of natural fibers in place of synthetic fibers is the sound absorption behavior. Various researchers have made experiments using natural-fiber-reinforced polymer composites as sound-absorbing materials. It was found from various studies that composites with higher thickness, porosity, and density behaved as better sound-absorbing materials.

Post-operative pain and analgesic requirements after paravertebral block for mastectomy: A randomized controlled trial of different concentrations of bupivacaine and fentanyl.

BACKGROUND: Paravertebral block (PVB) is useful for post-operative analgesia after breast surgery. Bupivacaine is used for PVB at higher concentrations (0.5%), which may lead to systemic toxicity after absorption. Therefore, we proposed to evaluate the efficacy of lower concentrations of bupivacaine with and without fentanyl for thoracic PVB in patients undergoing surgery for carcinoma breast. METHODS: Forty-eight patients scheduled for surgery for breast cancer were enrolled in this prospective, randomized, double-blinded, placebo-controlled trial and were allocated to one of four groups: 0.25% bupivacaine with epinephrine 5 mcg/ ml, 0.25% bupivacaine + epinephrine 5 mcg/ ml with 2 mcg/ml fentanyl, 0.5% bupivacaine + epinephrine 5 mcg/ml or isotonic saline. PVB was performed and 0.3 ml/kg of the test drug was administered before induction of general anaesthesia. The primary outcome assessed was post-operative analgesic requirement for a period of 24 h. Secondary outcome measures were post-operative pain scores at rest and on movement of the arm, latency to first opioid, post-operative nausea and vomiting, quality of sleep, ability to move arm and patient satisfaction. RESULTS: The patient characteristics and anaesthetic technique were comparable among the groups. The rescue analgesic consumption as well as cumulative pain scores at rest and on movement were significantly less in 0.25% bupivacaine+epinephrine with fentanyl and 0.5% bupivacaine+epinephrine groups (P<0.05). The average duration of analgesia was found to be 18 h after either 0.25% bupivacaine with epinephrine+fentanyl or 0.5% bupivacaine with epinephrine. CONCLUSIONS: Lower concentrations of bupivacaine can be combined with fentanyl to achieve analgesic efficacy similar to bupivacaine at higher concentrations, decreasing the risk of toxicity in PVB.

Comprehensive decongestive therapy in postmastectomy lymphedema: an Indian perspective.

BACKGROUND: Lymphedema following breast cancer treatment is one of the most morbid conditions affecting breast cancer survivors. Currently, no therapy completely cures this condition. Comprehensive Decongestive Therapy (CDT), a novel physiotherapeutic method offers promising results in managing this condition. This therapy is being widely used in the West. Till date, there are no studies evaluating the effectiveness and feasibility of this therapy in the east. MATERIALS AND METHODS: The therapeutic responses of 25 patients with postmastectomy lymphedema were analyzed prospectively in this study. Each patient received an intensive phase of therapy for eight days from trained physiotherapists, which included manual lymphatic drainage, multi layered compression bandaging, exercises, and skin care. Instruction in self management techniques were given to the patients on completion of intensive therapy. The patients were followed up for three months. Changes in the volume of the edematous limb were assessed with a geometric approximation derived from serial circumference measurements of the limb and by water displacement volumetry. Changes in skin and sub cutis thickness were assessed using high frequency ultrasound. RESULTS: The reduction in limb volume observed after therapy was 32.3% and 42% of the excess, by measurement and volumetry, respectively. The maximum reduction was obtained after the intensive phase. The reduction in skin and subcutis thickness of the edematous limb followed the same pattern as volume reduction. Patients could maintain the reduction obtained by strictly following the protocols of the maintenance phase. CONCLUSIONS: CDT combined with long-term self management is effective in treating post mastectomy lymphedema. The tropical climate is a major factor limiting the regular use of bandages by the patients.

Persistent pneumonia: Underlying cause and outcome.

OBJECTIVE: To identify the causes and contributing factors of persistent pneumonia in children. METHODS: 41 cases with persistent pneumonia were investigated (biochemical, microbiological, histopathological, immunological and radiological tests) to find out the underlying cause. RESULTS: Out of 41 cases, 8 had pulmonary tuberculosis and 12 had Gram negative bacterial infections, 12 had aspiration due to gastroesophageal reflux disease or oil instillation, 3 had immunodeficiency due to HIV infection, 2 had congenital lung malformation, 2 had cardiac disorders and one had foreign body aspiration as causes of persistent pneumonia. The etiology could not be established in one case. CONCLUSION: The most common underlying cause of persistent pneumonia were persistent infection followed by aspiration and acquired immunodeficiency.

Tamoxifen use and gallstone formation in postmenopausal breast cancer patients in south Indian population.

BACKGROUND: Tamoxifen is being used in patients with estrogen receptor positive breast cancer as an adjuvant or palliative hormonal therapy. w0 estern studies have found a 30% incidence of gallstones in patients who are taking Tamoxifen and they have proved a significant association between the two. OBJECTIVES: The objective of the study was to find out the association of Tamoxifen use and gallstone formation in postmenopausal breast cancer patients in a South Indian population. METHODS: Ninety patients who had undergone surgery for invasive breast cancer in our institute, and were receiving adjuvant Tamoxifen, were recruited for the study. An equal number of age-matched postmenopausal women were taken as controls. All of them underwent an abdominal ultrasound screening test for gallstones. Presence or absence of gallstones was noted down from their ultrasound scan reports. Pretreatment status of the gall bladder was assessed from the preoperative scan reports. RESULTS: An odds ratio of 1 was derived when the case group was compared with the control group. CONCLUSIONS: In our study we could not establish that an association existed between Tamoxifen use and gallstone formation in postmenopausal South Indian women.

Lycopene: a review of its potential as an anticancer agent.

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.

Ethanolic neem (Azadirachta indica) leaf extract induces apoptosis in the hamster buccal pouch carcinogenesis model by modulation of Bcl-2, Bim, caspase 8 and caspase 3.

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.

Ethanolic leaf extract of neem (Azadirachta indica) inhibits buccal pouch carcinogenesis in hamsters.

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.

Altered expression of anti and proapoptotic proteins during chemoprevention of hamster buccal pouch carcinogenesis by tomato and garlic combination.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: The induction of apoptosis may be one of the mechanisms through which functional foods such as tomato and garlic exert their anticancer properties.

Dose-response effect of tomato paste on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis.

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.

Effects of aqueous extracts of garlic (Allium sativum) and neem (Azadirachta indica) leaf on hepatic and blood oxidant-antioxidant status during experimental gastric carcinogenesis.

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.

Cranial computed tomography in partial motor seizures.

OBJECTIVE: To identify the pattern of intracranial structural lesions in developmentally normal children with partial motor seizures by computed tomography and to monitor the behavior of single ring enhancing lesion (SREL) after a period of time with or without treatment. METHODS: Consecutive developmentally normal children between one year and twelve years with partial motor seizures in a tertiary care referral Hospital. After clinical examination and appropriate investigation for tuberculosis and cysticercosis, CT scan was performed. In addition to anticonvulsants, children received antituberculous or anticysticercal therapy if indicated. Repeat CT was performed on children with SREL after 6 months. RESULTS: Computed tomography was abnormal in 102 (68%) children. Majority of the children (75) had SREL. The lesions were located in decreasing order of frequency in the parietal lobe (65), frontal lobe (7), occipital lobe (1), temporal lobe (1) and cerebellum (1). Repeat CT scan was performed on 50 of the 75 children with SREL. Among these, in 41 children who were only on antiepileptic therapy, the SREL had decreased in size in thirty-two whereas in the rest (9), there was no change in the size. CONCLUSION: Awareness of the existence of disappearing SREL lesions is essential to avoid unnecessary treatment with antituberculous or anticysticercal therapy and provides ample justification in treating with anticonvulsant drugs only.

Tomato and garlic by gavage modulate 7,12-dimethylbenz[a]anthracene-induced genotoxicity and oxidative stress in mice.

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.

Tomato and garlic by gavage modulate 7, 12-dimethylbenz[a]anthracene-induced genotoxicity and oxidative stress in mice

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.

Dose-dependent protection by tomato against 7,12-dimethylbenz[a]anthracene-induced genotoxicity and oxidative stress in mice.

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.

Sequential Changes in the Cellular Redox State During 7,12-Dimethylbenz[a]anthracene-Induced Carcinogenesis in the Hamster Buccal Pouch.

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.

Antiperoxidative effects of lycopene during N-methyl-N'-nitro-N-nitrosoguanidine-induced gastric carcinogenesis.

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.

Induction of glutathione-dependent hepatic biotransformation enzymes by lycopene in the hamster cheek pouch carcinogenesis model.

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.