Chemopreventive effect of garlic powder diet in diethylnitrosamine-induced rat hepatocarcinogenesis

Antioxidant and Antiproliferative Activities of Several Garlic Forms

It is hypothesized that garlic, Allium sativum, might protect against oxidative stress that causes damage to cells and tissues leading to the development of various health conditions including cancer. However, it is not known whether garlic's potential anticancer benefits differ by form of garlic consumed. This study aimed to quantify and compare the in vitro antioxidant and antiproliferative activity of several garlic forms in water and alcohol extracts including fresh garlic, fresh garlic set aside, heated garlic, heated garlic set aside, garlic powder, black garlic, two commercially available garlic supplements. Antioxidant activity of different garlic forms were measured using three assays: DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay, superoxide assay, and hydroxyl assay. In vitro effects of garlic extracts were investigated against the most common lung cancer subtypes: H520, H1975, and A549 cell lines using the sulforhodamine B (SRB) assay. Among free radical scavenging assays, Garlicin®, a commercially available supplement, displayed high antioxidant activity in water and alcohol extracts (DPPH assay: 2.02 mg AAE (mg ascorbic acid equivalent)/g garlic and 3.53 mg AAE/g garlic, respectively; superoxide assay: 6.73 mg AAE/g garlic and 7.13 mg AAE/g garlic, respectively). In the hydroxyl assay, water extract of fresh garlic crushed and set aside for 10 min showed the highest antioxidant activity. Garlicin® alcohol extract and fresh garlic water extracts strongly inhibited the proliferation of H1975, A549 and H520 cells. Other forms of garlic including garlic powder and black garlic exhibited low antioxidant and antiproliferative activity. Our results demonstrate that the preparation and processing methods of garlic may lead to different antioxidant benefits.

The efficacy of applying some plants and herbs in cancer therapy for humans and animals – a comperhensive review

Cancer is a challenging ailment and represents the main reason for death worldwide for humans and animals. Although great developments have hindered cancer progression, several adverse effects are associated with modern chemotherapy. Natural remedies, such as the usage of medicinal plant or their products in cancer treatment, may decrease prejudicial side properties. Recently, the modern research scheme and innovative screening practices for herbs or plants have enabled phytochemical discovery for the prevention and treatment of cancer. This criticism highlights herbs such as acacia, basil, black seeds, cedar, castus, ficus, garlic, ginger, indigo, onion, pomegranate, quince, and thyme, promising anticancer effects. The present review also revealed the mode of action of each herb as anticancer effects at level in vitro and in vivo studies. The item also totalizes the vital mechanisms and signaling molecules involved in preventing cancer diseases. This will fill the investigate gap in the exploration of using natural molecules and encourage researchers in clinical trials of anticancer agents from herbs for humans and animals.

Microencapsulation of Plant Phenolic Extracts Using Complex Coacervation Incorporated in Ultrafiltered Cheese Against AlCl3-Induced Neuroinflammation in Rats

Plant-derived phenolic compounds have numerous biological effects, including antioxidant, anti-inflammatory, and neuroprotective effects. However, their application is limited because they are degraded under environmental conditions. The aim of this study was to microencapsulate plant phenolic extracts using a complex coacervation method to mitigate this problem. Red beet (RB), broccoli (BR), and spinach leaf (SL) phenolic extracts were encapsulated by complex coacervation. The characteristics of complex coacervates [zeta potential, encapsulation efficiency (EE), FTIR, and morphology] were evaluated. The RB, BR, and SL complex coacervates were incorporated into an ultrafiltered (UF) cheese system. The chemical properties, pH, texture profile, microstructure, and sensory properties of UF cheese with coacervates were determined. In total, 54 male Sprague–Dawley rats were used, among which 48 rats were administered an oral dose of AlCl₃ (100 mg/kg body weight/d). Nutritional and biochemical parameters, including malondialdehyde, superoxide dismutase, catalase, reduced glutathione, nitric oxide, acetylcholinesterase, butyrylcholinesterase, dopamine, 5-hydroxytryptamine, brain-derived neurotrophic factor, and glial fibrillary acidic protein, were assessed. The RB, BR, and SL phenolic extracts were successfully encapsulated. The RB, BR, and SL complex coacervates had no impact on the chemical composition of UF cheese. The structure of the RB, BR, and SL complex coacervates in UF cheese was the most stable. The hardness of UF cheese was progressively enhanced by using the RB, BR, and SL complex coacervates. The sensory characteristics of the UF cheese samples achieved good scores and were viable for inclusion in food systems. Additionally, these microcapsules improved metabolic strategies and neurobehavioral systems and enhanced the protein biosynthesis of rat brains. Both forms failed to induce any severe side effects in any experimental group. It can be concluded that the microencapsulation of plant phenolic extracts using a complex coacervation technique protected rats against AlCl3-induced neuroinflammation. This finding might be of interest to food producers and researchers aiming to deliver natural bioactive compounds in the most acceptable manner (i.e., food).

Preclinical Evaluation of Dimethyl Itaconate Against Hepatocellular Carcinoma via Activation of the e/iNOS-Mediated NF-κB-Dependent Apoptotic Pathway

Hepatocellular carcinoma (HCC) is one of the most common tumors affecting a large population worldwide, with the fifth and seventh greatest mortality rates among men and women, respectively, and the third prime cause of mortality among cancer victims. Dimethyl itaconate (DI) has been reported to be efficacious in colorectal cancer by decreasing IL-1β release from intestinal epithelial cells. In this study, diethylnitrosamine (DEN)-induced HCC in male albino Wistar rats was treated with DI as an anticancer drug. The function and molecular mechanism of DI against HCC in vivo were assessed using histopathology, enzyme-linked immunosorbent assay (ELISA), and Western blot studies. Metabolomics using ¹H-NMR was used to investigate metabolic profiles. As per molecular insights, DI has the ability to trigger mitochondrial apoptosis through iNOS- and eNOS-induced activation of the NF-κB/Bcl-2 family of proteins, CytC, caspase-3, and caspase-9 signaling cascade. Serum metabolomics investigations using ¹H-NMR revealed that aberrant metabolites in DEN-induced HCC rats were restored to normal following DI therapy. Furthermore, our data revealed that the DI worked as an anti-HCC agent. The anticancer activity of DI was shown to be equivalent to that of the commercial chemotherapeutic drug 5-fluorouracil.

Ameliorative effect of fluvoxamine against colon carcinogenesis via COX-2 blockade with oxidative and metabolic stress reduction at the cellular, molecular and metabolic levels

Fluvoxamine's (FLX's) anticancer potential was investigated in pre-clinical research utilizing a DMH-induced colorectal cancer (CRC) rat model. qRT-PCR and immunoblotting validated the mechanistic investigation. The CRC condition was induced in response to COX-2 and IL-6, however, following FLX therapy, the condition returned to normal. FLX's anti-CRC potential may be attributable to COX-2 inhibition since this molecular activity was more apparent for COX-2 than IL-6. FLX repaired the altered metabolites linked to CRC rats, according to ¹H-NMR analysis. FLX was shown to be similar to 5-FU in terms of tumor protection, which may be useful in future medication development.

Antibacterial properties of Allium sativum L. against the most emerging multidrug-resistant bacteria and its synergy with antibiotics

Garlic has long been known as the most effective plant species in treatment of bacterial infections. Considering the vast potential of garlic as a source of antimicrobial drugs, this study is aimed to evaluate the antibacterial activity of Allium sativum extracts and their interactions with selected antibiotics against drug-sensitive and multidrug-resistant isolates of emerging bacterial pathogens that are frequently found in healthcare settings. As shown by the in vitro data obtained in this study, the whole Allium sativum extract inhibited the growth of a broad range of bacteria, including multidrug-resistant strains with bactericidal or bacteriostatic effects. Depending on the organism, the susceptibility to fresh garlic extract was comparable to the conventional antibiotic gentamycin. Since the combinations of fresh garlic extract with gentamycin and ciprofloxacin inhibited both the drug sensitive and MDR bacteria, in most cases showing a synergistic or insignificant relationship, the potential use of such combinations may be beneficial, especially in inhibiting drug-resistant pathogens. The study results indicate the possibility of using garlic as e.g. a supplement used during antibiotic therapy, which may increase the effectiveness of gentamicin and ciprofloxacin.

Antileukemic activity of sulfoxide nutraceutical allicin against THP-1 cells is associated with premature phosphatidylserine exposure in human erythrocytes

Background

Allicin (ACN), a sulfoxide in freshly crushed garlic, is known for its diverse bioactive properties. Among the most notable effects of ACN is its antitumor activity against a wide array of cancer types. Thus, ACN may be a promising anticancer therapeutic. Nevertheless, chemotherapy-induced anemia is a major obstacle in cancer management with a prevalence of up to 70%. Although the pathophysiology behind it remains elusive, a number of medications known to cause anemia in patients have been shown to induce premature programmed cell death in red blood cells (RBCs) known as eryptosis. This study, thus, investigates the anticancer potential of ACN against THP-1 monocytic leukemia cells, its toxic effects on human RBCs, and delineate the underlying biochemical mechanisms.

Methods

Cytotoxicity was detected using the MTT assay, while hemoglobin leakage was used as a surrogate for hemolysis which was photometrically measured. Major eryptotic events were examined using flow cytometry with fluorescent probes. Phosphatidylserine (PS) exposure was detected by Annexin-V-FITC, cytosolic calcium with Fluo4/AM, and reactive oxygen species with H₂DCFDA.

Results

Our results show that ACN induces hemolysis in a dose-dependent fashion, which is significantly abrogated in absence of extracellular calcium. Moreover, ACN stimulates PS exposure, intracellular calcium overload, and oxidative stress. Using small-molecule inhibitors, we demonstrate that the pro-eryptotic activity of ACN is ameliorated in presence of zVAD(OMe)-FMK, SB203580, and D4476.

Conclusion

ACN possesses both hemolytic and eryptotic properties mediated through elevated intracellular calcium levels, oxidative stress, caspase, p38 MAPK, and CK1α.

Benefits of aged garlic extract in modulating toxicity biomarkers against p-dimethylaminoazobenzene and phenobarbital induced liver damage in Rattus norvegicus

Garlic (Allium sativum L.), a popular spice, has been used for decades in treating several medical conditions. Although Allicin, an active ingredient of garlic has been extensively studied on carcinogen-induced hepatotoxicity and oxidative stress in rats (Rattus norvegicus), no systematic study on the beneficial effects of generic aged garlic and specific aged garlic extract-Kyolic has been done. The present study involves rats fed chronically with two liver carcinogens, p-dimethylaminoazobenzene and phenobarbital, to produce hepatotoxicity. The aged garlic extract was characterized by UV-spectra, FTIR, HPLC and GC-MS. Biochemical and pathophysiological tests were performed by keeping suitable controls at four fixation intervals, namely, 30, 60, 90, and 120 days, utilizing several widely accepted toxicity biomarkers. Compared to the controls, remarkable elevation in the activities of lactate dehydrogenase, gamma glutamyl transferase and decline in catalase and glucose-6-phosphate dehydrogenase were observed in the carcinogen fed rats. Daily administration of aged garlic extract, could favorably modulate the elevated levels of various toxicity biomarkers including serum triglyceride, creatinine, urea, bilirubin, blood urea nitrogen except total cholesterol. It also altered the levels of blood glucose, HDL-cholesterol, albumin, AST, ALT, and hemoglobin contents in carcinogen intoxicated rats, indicating its protective potential against hepatotoxicity and oxidative stress in the experimental rats. Down-regulation of Bcl-2 and p53 proteins caused cell cycle arrest and apoptosis in garlic fed group. Kyolic exhibited additional benefits by arresting cell viability of cancer cells. This study would thus validate the use of aged garlic extract in the treatment of diseases causing liver toxicity including hepatocarcinoma.

Antioxidant and Hepatoprotective Effect of Cajanus cajan in N-Nitrosodiethylamine-Induced Liver Damage

N-Nitrosodiethylamine (NDEA) is a nitrosamine derivative with carcinogenic and mutagenic properties which can be found in tobacco smoke, meat and various food products. This study examined the antioxidant and hepatoprotective potential of Cajanus cajan (C. cajan) with respect to hepatotoxicity in male Wistar rats. Administration of NDEA induced hepatotoxicity at 200 mg/kg while C. cajan was administered (200, 400 and 800 mg/kg) for 28 days. NDEA-induced hepatotoxicity significantly (p ≤ 0.05) increased alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malondialdehyde (MDA) and significantly (p ≤ 0.05) decreased reduced glutathione (GSH), albumin (ALB), glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD). C. cajan-treated groups were seen to have significantly (p ≤ 0.05) decreased ALT and AST and significantly (p < 0.05) increased ALB, GST, GSH, SOD and CAT. The NDEA-treated group also showed a marginal increase in body weight and a significant (p ≤ 0.05) increase in liver weight. The C. cajan treated groups showed a significant (p ≤ 0.05) increase and decrease respectively in body and liver weights. Histopathological changes also substantiated NDEA-induced hepatotoxicity and the hepatoprotective effect of C. cajan on the liver. The results indicate that C. cajan has the potential to ameliorate NDEA-induced hepatotoxicity.

Diethylnitrosamine Increases Proliferation in Early Stages of Hepatic Carcinogenesis in Insulin-Treated Type 1 Diabetic Mice

Diethylnitrosamine (DEN) induces hepatocarcinogenesis, increasing mitotic hepatocytes and leading to chronic inflammation. In addition, type 1 diabetes mellitus (T1DM) is also characterized by a proinflammatory state and by requiring insulin exogenous treatment. Given the association of diabetes, insulin treatment, and cell proliferation, our specific goal was to determine whether the liver in the diabetic state presents a greater response to DEN-induced cell cycle alteration, which is essential for the malignant transformation. Male C57BL/6 mice (four-week-old) were divided into 4 groups: C, C + DEN, T1DM, and T1DM + DEN. Mice were euthanized ten weeks after DEN injection. DEN per se produced an increase in liver lipid peroxidation levels. Besides, in T1DM + DEN, we found a greater increase in the proliferation index, in comparison with C + DEN. These results are in agreement with the increased expression observed in cell cycle progression markers: cyclin D1 and E1. In addition, a proapoptotic factor, such as activated caspase-3, evidenced a decrease in T1DM + DEN, while the Vascular Endothelial Growth Factor (VEGF) and the protooncogene p53 showed a higher increase with respect to C + DEN. Overall, the results allow us to highlight a major DEN response in T1DM, which may explain in part the greater predisposition to the development of hepatocarcinoma (HCC) during the diabetic state.

Novel Indole-fused benzo-oxazepines (IFBOs) inhibit invasion of hepatocellular carcinoma by targeting IL-6 mediated JAK2/STAT3 oncogenic signals

Inspired by the well-documented tumor protecting ability of paullones, recently, we synthesized novel paullone-like scaffolds, indole-fused benzo-oxazepines (IFBOs), and screened them against hepatocellular carcinoma (HCC) specific Hep-G2 cells. Three of the synthesized compounds significantly attenuated the progression of HCC in vitro. By computational studies, we further discovered that IFBOs exhibited a stable binding complex with the IL-6 receptor. In this context, we investigated in vivo study using the nitrosodiethyl amine (NDEA)-induced HCC model, which strengthened our previous findings by showing the blockade of the IL-6 mediated JAK2/STAT3 oncogenic signaling pathway. Treatment with IFBOs showed remarkable attenuation of cellular proliferation, as evidenced through a decrease in the number of nodules, restoration of body weight, oxidative stress parameters, liver marker enzymes and histological architecture. Interestingly, using a metabolomic approach we further discovered that IFBOs can restore the perturbed metabolic profile associated with the HCC condition to normalcy. Particularly, the efficacy of compound 6a for an anti-HCC response was significantly better than the marketed chemotherapeutic drug, 5-fluorouracil. Altogether, these remarkable findings open up possibilities of developing IFBOs as novel future candidate molecules for plausible alternatives for HCC treatment.

5H-benzo[h]thiazolo[2,3-b]quinazolines ameliorate NDEA-induced hepatocellular carcinogenesis in rats through IL-6 downregulation along with oxidative and metabolic stress reduction

5H-benzo[h]thiazolo[2,3-b]quinazoline scaffold is known to have an antitumor effect on certain types of malignancies; however, its effect on hepatocellular carcinoma (HCC) remains unclear. Previously, we reported p-toluenesulfonic acid-promoted syntheses, molecular modeling and in vitro antitumor activity of 5H-benzo[h]thiazolo[2,3-b]quinazoline against human hepatoma (Hep-G2) cells where compounds 4A and 6A were found to be potent inhibitors among the series. In continuation to our previous effort to develop novel therapeutic strategies for HCC treatment, here we investigated the in vivo antitumor activity and the mechanism underlying the effects of 4A and 6A in N-nitrosodiethylamine (NDEA)-induced HCC using male Wistar rats. NDEA was administered weekly intraperitoneally at a dose of 100 mg/kg for 6 weeks. Various physiological and morphological changes, oxidative parameters, liver marker enzymes and cytokines were assessed to evaluate the antitumor effect of 4A and 6A. In addition, proton nuclear magnetic resonance-based serum metabolomics were performed to analyze the effects of 4A and 6A against HCC-induced metabolic alterations. Significant tumor incidences with an imbalance in carcinogen metabolizing enzymes and cellular redox status were observed in carcinogenic rats. Tumor inhibitory effects of 4A and 6A were noted by histopathology and biochemical profiles in NDEA-induced hepatic cancer. Compounds 4A and 6A had a potential role in normalizing the elevated levels of inflammatory mediators such as interleukin-1β (IL-1β), IL-2, IL-6 and IL-10. At molecular level, the real-time quantitative reverse-transcribed polymerase chain reaction analysis revealed that 4A and 6A attenuated the IL-6 gene overexpression in hepatic cancer. Further, orthogonal partial least squares discriminant analysis scores plot demonstrated a significant separation of 4A and 6A-treated groups from carcinogen control group. Both the compounds have potential to restore the imbalanced metabolites due to HCC, signifying promising hepatoprotective activities. All these findings suggested that 4A and 6A could be potential drug candidates to treat HCC.

E-Cadherin/β-Catenin Complex: A Target for Anticancer and Antimetastasis Plants/Plant-derived Compounds

Plants reputed to have cancer-inhibiting potential and putative active components derived from those plants have emerged as an exciting new field in cancer study. Some of these compounds have cancer-inhibiting potential in different clinical staging levels, especially metastasis. A few of them which stabilize cell-cell adhesions are controversial topics. This review article introduces some effective herbal compounds that target E-cadherin/β-catenin protein complex. In this article, at first, we briefly review the structure and function of E-cadherin and β-catenin proteins, Wnt signaling pathway, and its target genes. Then, effective compounds of the Teucrium persicum, Teucrium polium, Allium sativum (garlic), Glycine max (soy), and Brassica oleracea (broccoli) plants, which influence stability and cellular localization of E-cadherin/β-catenin complex, were studied. Based on literature review, there are some compounds in these plants, including genistein of soy, sulforaphane of broccoli, organosulfur compounds of garlic, and the total extract of Teucrium genus that change the expression of variety of Wnt target genes such as MMPs, E-cadherin, p21, p53, c-myc, and cyclin D1. So they may induce cell-cycle arrest, apoptosis and/or inhibition of Epithelial-Mesenchymal Transition (EMT) and metastasis.

Exacerbation of N-nitrosodiethylamine Induced Hepatotoxicity and DNA Damage in Mice Exposed to Chronic Unpredictable Stress

Psychological stress contributes to increased susceptibility to a number of diseases including cancer. The present study was designed to assess the effect of chronic unpredictable stress on N-nitrosodiethylamine induced liver toxicity in terms of in vivo antioxidant status and DNA damage in Swiss albino mice. The animals used in this study were randomized into different groups based on the treatment with N-nitrosodiethylamine or chronic unpredictable stress alone and post-stress administration of N-nitrosodiethylamine. The mice were sacrificed after 12 weeks of treatment, and the status of major enzymatic and non-enzymatic antioxidants, liver function markers, lipid peroxidation and the extent of DNA damage were determined in circulation and liver tissues of all the groups. The N-nitrosodiethylamine treated group showed significantly compromised levels of the antioxidant enzymes, lipid peroxidation, and the liver function markers with enhanced DNA damage as compared to chronic unpredictable stress or control groups. A similar but less typical pattern observed in the chronic unpredictable stress treated mice. All the measured biochemical parameters were significantly altered in the group treated with the combination of chronic unpredictable stress and N-nitrosodiethylamine when compared to controls, or chronic unpredictable stress alone and/or N-nitrosodiethylamine alone treated groups. Thus, exposure to continuous, unpredictable stress conditions even in general life may significantly enhance the hepatotoxic potential of N-nitrosodiethylamine through an increase in the oxidative stress and DNA damage.

Thymoquinone attenuates diethylnitrosamine induction of hepatic carcinogenesis through antioxidant signaling

Hepatocellular carcinoma accounts for about 80–90% of all liver cancer and is the fourth most common cause of cancer mortality. Although there are many strategies for the treatment of liver cancer, chemoprevention seems to be the best strategy for lowering the incidence of this disease. Therefore, this study has been initiated to investigate whether thymoquinone (TQ), Nigella sativa derived-compound with strong antioxidant properties, supplementation could prevent initiation of hepatocarcinogenesis-induced by diethylnitrosamine (DENA), a potent initiator and hepatocarcinogen, in rats. Male Wistar albino rats were divided into four groups. Rats of Group 1 received a single intraperitoneal (I.P.) injection of normal saline. Animals in Group 2 were given TQ (4 mg/kg/day) in drinking water for 7 consecutive days. Rats of Group 3 were injected with a single dose of DENA (200 mg/kg, I.P.). Animals in Group 4 were received TQ and DENA. DENA significantly increased alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin, thiobarbituric acid reactive substances (TBARS) and total nitrate/nitrite (NOx) and decreased reduced glutathione (GSH), glutathione peroxidase (GSHPx), glutathione-s-transferase (GST) and catalase (CAT) activity in liver tissues. Moreover, DENA decreased gene expression of GSHPx, GST and CAT and caused severe histopathological lesions in liver tissue. Interestingly, TQ supplementation completely reversed the biochemical and histopathological changes induced by DENA to the control values. In conclusion, data from this study suggest that: (1) decreased mRNA expression of GSHPx, CAT and GST during DENA-induced initiation of hepatic carcinogenesis, (2) TQ supplementation prevents the development of DENA-induced initiation of liver cancer by decreasing oxidative stress and preserving both the activity and mRNA expression of antioxidant enzymes.

Modulation of N-nitrosodiethylamine (NDEA) induced oxidative stress by vitamin E in rat erythrocytes

Nitrosamines, such as N-nitrosodiethylamine (NDEA), induced oxidative stress due to the generation of reactive oxygen species, which are capable of initiating peroxidative damage to the cell. The present study was designed to establish whether pre-treatment with vitamin E (40 mg/kg body wt, intraperitoneally (ip), twice a week for 4 weeks) to NDEA induced rats provides protection against oxidative stress caused by NDEA. A single necrogenic dose of NDEA (200 mg/kg body wt) was administered intraperitoneally (ip) to the rats with or without vitamin E pre-treatment and the animals were sacrificed on Day 7, 14 or 21 after NDEA administration. Lipid peroxidation (LPO) and the activities of antioxidant enzymes were determined in erythrocytes as indices of oxidative damage. The result showed elevated levels of LPO in erythrocytes with NDEA treatment, however, vitamin E pre-treated rats administered NDEA showed decreased LPO (Day 14 and 21). Superoxide dismutase (SOD) enzyme activity and the glutathione (GSH) content increased with NDEA treatment and remained high in vitamin E pre-treated group. Catalase (CAT), glutathione reductase (GSH-R) and glutathione-S-transferase (GST) enzyme activities declined with NDEA treatment; however, vitamin E pre-treated rats administered NDEA, showed elevation in the enzyme activities. Glutathione peroxidase (GSH-Px) activity increased in erythrocytes in vitamin E pre-treated rats administered NDEA, while SeGSH-Px activity was not affected significantly. This study demonstrates that the pre-treatment with vitamin E prior to the administration of NDEA was effective in counteracting and modulating oxidative stress in rat erythrocytes in a time-dependent manner.

Chemoprevention of Diethylnitrosamine-Initiated and Phenobarbital-Promoted Hepatocarcinogenesis in Rats by Sulfated Polysaccharides and Aqueous Extract of Ulva lactuca

Hepatocellular carcinoma (HCC) is one of the common cancers and lethal diseases worldwide. Both oxidative stress and chronic inflammation contribute to the pathogenesis of HCC. Because of limited treatment options and a grave prognosis of HCC, preventive management has been emphasized. The marine macroalgae Ulva lactuca (Ulvaceae) is consumed by humans and livestock because of its nutritional value. Recent studies showed that various extracts of U. lactuca possess antiviral, antiplasmodial, antinephrotoxic, antioxidant, and anti-inflammatory properties. However, very limited information is available on anticancer potential of U. lactuca with no reports on liver cancer chemopreventive efficacy of this marine algae. Accordingly, the present study was initiated to evaluate the possible antihepatocarcinogenic effects and antioxidant mechanisms of action of various U. lactuca extracts against a clinically relevant rodent model of HCC. Initiation of hepatocarcinogenesis was performed in Sprague-Dawley rats by a single injection of dietary carcinogen diethylnitrosamine (DENA, 200 mg/kg, intraperitoneally), followed by promotion with phenobarbital (0.05%) in drinking water. The rats were fed with daily oral dose (50 mg/kg) of polysaccharide sulfate or aqueous extract of U. lactuca for 2, 12, and 24 weeks. At these timepoints, blood samples were taken to measure hepatic injury markers, including alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transferase, and bilirubin. The liver tissue was harvested for measurement of hepatic oxidative indices, including lipid peroxidation, reduced glutathione, nitric oxide, catalase, superoxide dismutase, glutathione reductase, and glutathione S-transferase. Hepatic histopathology, immunohistochemical analysis of cell proliferation and apoptosis by DNA fragmentation assay were performed. Our results clearly indicate that sulfated polysaccharides of U. lactuca exert a marked chemoprevention of DENA-initiated hepatocarcinogenesis through inhibition of abnormal cell proliferation and induction of apoptosis. A modest inhibition rat liver carcinogenesis was observed with the aqueous extract. The sulfated polysaccharides altered serum parameters of hepatic damage and modulated various components of the hepatic enzymatic and nonenzymatic antioxidant defense systems. The sulfated polysaccharides from U. lactuca may have unique properties of providing protection against DENA-induced oxidative stress which could contribute to chemoprevention of experimental hepatocarcinogenesis. U. lactuca sulfated polysaccharides could be developed as chemopreventive and therapeutic drug against human HCC.

Prophylactic Role of Averrhoa carambola (Star Fruit) Extract against Chemically Induced Hepatocellular Carcinoma in Swiss Albino Mice

Liver cancer remains one of the severe lethal malignancies worldwide and hepatocellular carcinoma (HCC) is the most common form. The current study was designed to evaluate the prophylactic role of the fruit of Averrhoa carambola (star fruit or Kamrak) on diethylnitrosamine- (DENA-) induced (15 mg/kg b.wt.; single i.p. injection) and CCl4-promoted (1.6 g/kg b.wt. in corn oil thrice a week for 24 weeks) liver cancer in Swiss albino mice. Administration of ACE was made orally at a dose of 25 mg/kg b.wt/day for 5 consecutive days and it was withdrawn 48 hrs before the first administration of DENA (preinitiational stage). CCl4 was given after 2 weeks of DENA administration. A cent percent tumor incidence was noted in carcinogen treated animals while ACE administration resulted in a considerable reduction in tumor incidence, tumor yield, and tumor burden. Further, ACE treatment brings out a significant reduction in lipid peroxidation (P < 0.001) along with an elevation in the activities of enzymatic antioxidants (superoxide dismutase, P < 0.001, and catalase, P < 0.001), nonenzymatic antioxidant (reduced glutathione, P < 0.001), and total proteins (P < 0.001) when compared to the carcinogen treated control. These results demonstrate that ACE prevents the DENA/CCl4 induced adverse physical and biochemical alterations during hepatic carcinogenesis in mice. This study suggests the prophylactic role of Averrhoa carambola against hepatocellular carcinoma in mice; therefore, it could be employed for the further screening as a good chemopreventive natural supplement against cancer.

Biochemical and molecular studies on the possible influence of the Brassica oleracea and Beta vulgaris extracts to mitigate the effect of food preservatives and food chemical colorants on albino rats

This study aimed to investigate the biochemical influence of broccoli and beet extracts on selected individual additives NaNO2 or sunset yellow treated rats, in addition to the gene expression of some antioxidant enzymes. Forty-two male rats were assigned to seven groups of six rats in each group. The control group was fed a diet without an additive for four weeks. Group (2) received NaNO2, groups (3) received NaNO2 co-administered with broccoli extract (4) NaNO2 co-administered with beet extracts, Group (5) received sunset yellow, Group (6) received sunset yellow co-administered with broccoli extract, and Group (7) received sunset yellow co-administered with beet extract, for four weeks. At the end of the experiment, blood, liver, kidney, and brain samples were taken for biochemical and/or molecular analysis. The mRNA expression of antioxidant enzymes was determined by reversing transcriptase-polymerase chain reaction (RT-PCR). The obtained results revealed that rats co-administered with beet or broccoli extracts had a significant decrease in serum levels of AST, ALT, ALP, urea, total lipids, and triglycerides, as well as a significant increase in reduced glutathione (GSH), glutathione peroxidase (GSH-px), and superoxide dismutase (SOD) enzyme activities, compared to the normal control group. Oral administration of NaNO2 or sunset yellow caused a significant increase in serum levels of AST, ALT, ALP, urea, total lipids, and triglycerides, as well as a significant decrease in GSH, GSH-px, and SOD compared to the positive group. In conclusion, this study showed that broccoli and beet extracts have a protective effect against NaNO2 or sunset yellow in rat treated groups.

Effect of two selenium sources on hepatocarcinogenesis and several angiogenic cytokines in diethylnitrosamine-induced hepatocarcinoma rats

This experiment was designed to compare the effect of two selenium sources at the dosage of therapeutic level on hepatocarcinogenesis and angiogenic cytokines in DEN-induced hepatocarcinoma rats to further approach their possible anticancer's mechanism. One hundred and seventy-eight Sprague-Dawley (SD) rats (average weight being 100-120g) were randomly divided into 5 groups (I-V). Animals in group I, group II and group III served as the negative control, sodium selenite control (SS) and positive controls respectively, and received 0.1, 3.0, and 0.1mg/kg selenium from sodium selenite supplemented diets during the whole experimental time. Rats in group IV and group V were fed with selenium from selenium-enriched malt (SEM) and sodium selenite (SS) supplemented diets (3mg/kg respectively). To balance the nutritional content among each group, normal malt which was not treated with selenium was added into the diets of the challenge groups. The nutrition contents, except the selenium of the diet in each group, were similar and in accordance with NRC standards. Rats in groups III-V were treated by aqueous diethylnitrosamine solution (100mg/L) at the dosage of 10mg/kg body weight every day for 16 weeks to induce hepatocarcinoma, and drank sterilized water for an additional two weeks. Rats in group I and group II drank sterilized water throughout the experiment. At 4th, 8th, 12th, 16th week, five rats in each group were then sacrificed by cervical decapitation. At the termination of the study, at 18th week, the surplus rats were sacrificed by cervical decapitation. Feed was withheld from the rats for 12h before sampling. The number of hepatoma nodules in liver and mortality of rats were calculated. The values of the following items, including α-fetoprotein (AFP), gamma-glutamyltranspeptidase (GGT), tumor necrosis factor-α (TNF-α), insulin-like growth factors-II (IGF-II), nitric oxide (NO) and total nitric oxide synthase (T-NOS) in plasma were determined. At the same time, the positive numbers of vascular endothelial growth factor (VEGF) and protein kinase C-α (PKCα) staining cells in tumor tissue were analyzed by immunohistochemistry using the Envision two step methods with a kit. The results indicated that SEM could significantly decrease the mortality of rats and the number of hepatoma nodules, values of GGT and AFP, and the levels of IGF-II, NO and NOS and lessen the positive numbers of VEGF and PKCα staining cells in tumor tissue. Moreover, SEM could increase the levels of TNF-α in the initiated time of hepatocarcinogenesis, whereas, decrease the levels of TNF-α in the progressive time of hepatocarcinogenesis. SS could only significantly inhibit the positive numbers of PKCα staining cells in tumor tissue, decrease the levels of GGT, AFP and TNF-α at minority sampling times, and increase the levels of NO. In conclusion, SEM could reduce the mortality. It might be related to deaden significantly the lesion of liver, delay the cause of hepatocarcinogenesis, and inhibit the progress of angiogenesis to increase the livability of DEN-induced hepatocarcinoma rats. SS at the same therapeutic dosage had less effect on the hepatocarcinogenesis by inhibiting angiogenesis and relative cytokines to some extent.

6-shogaol-rich extract from ginger up-regulates the antioxidant defense systems in cells and mice

The rhizome of ginger (Zingiber officinale Roscoe) is known to have several bioactive compounds including gingerols and shogaols which possess beneficial health properties such as anti-inflammatory and chemopreventive effects. Based on recent observations that 6-shogaol may have more potent bioactivity than 6-gingerol, we obtained a 6-shogaol-rich extract from ginger and examined its effects on the nuclear factor E2-related factor2 (Nrf2)/antioxidant response element (ARE) pathway in vitro and in vivo. 6-Shogaol-rich extract was produced by extracting ginger powder with 95% ethanol at 80 °C after drying at 80 °C (GEE8080). GEE8080 contained over 6-fold more 6-shogaol compared to the room temperature extract (GEE80RT). In HepG2 cells, GEE8080 displayed much stronger inductions of ARE-reporter gene activity and Nrf2 expression than GEE80RT. GEE8080 stimulated phosphorylations of mitogen-activated protein kinases (MAPKs) such as ERK, JNK, and p38. Moreover, the GEE8080-induced expressions of Nrf2 and HO-1 were attenuated by treatments of SB202190 (a p38 specific inhibitor) and LY294002 (an Akt specific inhibitor). In a mouse model, the GEE8080 decreased the diethylnitrosamine (DEN)-mediated elevations of serum aspartate transaminase and alanine transaminase as well as the DEN-induced hepatic lipid peroxidation. Inductions of Nrf2 and HO-1 by GEE8080 were also confirmed in the mice. In addition, the administration of GEE8080 to the mice also restored the DEN-reduced activity and protein expression of hepatic antioxidant enzymes such as superoxide dismutase, glutathione peroxidase and catalase. In conclusion, GEE8080, a 6-shogaol-rich ginger extract, may enhance antioxidant defense mechanism through the induction of Nrf2 and HO-1 regulated by p38 MAPK and PI3k/Akt pathway in vitro and in vivo.

Ginger ingredients inhibit the development of diethylnitrosoamine induced premalignant phenotype in rat chemical hepatocarcinogenesis model

To investigate the possible antitumor activity of ginger extract against hepatic carcinogenesis initiated by diethylnitrosoamines (DEN) and promoted by carbon tetrachloride (CCl(4) ). A total of 60 male Wistar albino rats were divided into four groups with 15 animals in each group. Rats in group 1 (control group) received a single intraperitoneal (i.p.) injection of normal saline. Animals in group 2 were given ginger (50 mg/kg/day) in drinking water for 8 weeks. Rats in group 3 (DEN group) were injected with a single dose of DEN (200 mg/kg, i.p.), 2 weeks later received a single dose of CCl(4) (2 mL/kg i.g) by gavage as 1:1 dilution in corn oil. Animals in group 4 (DEN-ginger group) received the same carcinogenesis induction protocol as in group 3 plus ginger (50 mg/kg/day) in drinking water for 2 weeks before induction of hepatocarcinogenesis and continued throughout the experimental period. DEN-initiated and CCl(4) -promoted hepatocarcinogenesis in male Wistar rats was manifested biochemically by elevation of serum hepatic tumor markers tested; α-fetoprotein and carcinoembryonic antigen. In addition, hepatocarcinogenesis was further confirmed by a significant increase in hepatic tissue growth factors; vascular endothelial growth factor, basic fibroblast growth factor, and hydroxyproline content. A marked decrease in endostatin and metallothonein were also observed. Long-term ginger extract administration 2 weeks before induction of hepatocarcinogenesis and throughout the experimental period prevented the decrease of the hepatic content of metallothionein and endostatin and the increase in the growth factors induced by the carcinogen. Moreover, ginger extract normalize serum hepatic tumor markers. Histopathological examination of liver tissue also correlated with the biochemical observations. These findings suggest a protective effect of ginger extract against premalignant stages of liver cancer in the DEN-initiated and CCl(4) -promoted hepatocarcinogenesis model in rats.

Protective effects of garlic and silymarin on NDEA-induced rats hepatotoxicity

Background ­— The present study was conducted to investigate the chemopreventive effects of garlic extract and silymarin on N-nitrosodiethylamine (NDEA) and carbon tetrachloride (CCl₄)-induced hepatotoxicity in male albino rats. Methods and Results — Animals were pretreated with garlic, silymarin or both for one week prior to the injection of NDEA. Then animals received a single injection of NDEA followed by weekly subcutaneous injections of CCl₄ for 6 weeks. Oral administration was then continued along with the injection of CCl₄ for the duration of the experiment. Serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), hepatic lipid peroxidation (LPO), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione-S-transferase (GST) and glutathione reductase (GSR) were measured. Injection of NDEA induced a significant elevation in serum AST, ALT and ALP. In the liver, NDEA increased oxidative stress through the increase in LPO and decrease in SOD, and GSH-dependent enzymes. Although administration of garlic or silymarin significantly reduced the liver toxicity, combined administration was more effective in preventing the development of hepatotoxicity. Conclusion — These novel findings suggest that silymarin and garlic have a synergistic effect, and could be used as hepatoprotective agents against hepatotoxicity.

Garlic: nature's protection against physiological threats

Currently reliance on natural products is gaining popularity to combat various physiological threats including oxidative stress, cardiovascular complexities, cancer insurgence, and immune dysfunction. The use of traditional remedies may encounter more frequently due to an array of scientific evidence in their favor. Garlic (Allium sativum) holds a unique position in history and was recognized for its therapeutic potential. Recent advancements in the field of immunonutrition, physiology, and pharmacology further explored its importance as a functional food against various pathologies. Extensive research work has been carried out on the health promoting properties of garlic, often referred to its sulfur containing metabolites i.e. allicin and its derivatives. Garlic in its preparations are effective against health risks and even used as dietary supplements such as age garlic extract (AGE) and garlic oil etc. Its components/formulations can scavenge free radicals and protect membranes from damage and maintains cell integrity. It also provides cardiovascular protection mediated by lowering of cholesterol, blood pressure, anti-platelet activities, and thromboxane formation thus providing protection against atherosclerosis and associated disorders. Besides this, it possesses antimutagenic and antiproliferative properties that are interesting in chemopreventive interventions. Several mechanisms have been reviewed in this context like activation of detoxification phase-I and II enzymes, reactive oxygen species (ROS) generation, and reducing DNA damage etc. Garlic could be useful in preventing the suppression of immune response associated with increased risk of malignancy as it stimulates the proliferation of lymphocytes, macrophage phagocytosis, stimulates the release of interleukin-2, tumor necrosis factor-alpha and interferon-gamma, and enhances natural killer cells. In this paper much emphasis has been placed on garlic's ability to ameliorate oxidative stress, core role in cardiovascular cure, chemopreventive strategies, and indeed its prospective as immune booster.

Apoptosis induction in human lung adenocarcinoma cells by oil-soluble allyl sulfides: triggers, pathways, and modulators

DAS (diallyl sulfide), DADS (diallyl disulfide), and DATS (diallyl trisulfide) are major oil-soluble allyl sulfides (OAS) that represent major garlic constituents. The anticarcinogenic and antimutagenic effects of these substances have been extensively studied during the last decades. Previous reports suggest that induction of apoptosis by OASs might contribute to their chemopreventive effects. In this study, we report that OASs DADS and DATS induce significant apoptosis in human lung adenocarcinoma A549 cells, whereas DAS does not. Differential modulation of reactive oxygen intermediates (ROI) and mitochondria membrane potential (MMP) may account for the apoptotic effects of DADS and DATS. The underlying molecular mechanisms of apoptosis induction by both compounds include activation of C-Jun N-terminal kinase (JNK), up-regulation of p53, and down-regulation of bcl-2 expression. In our test series, up-regulation of extracellular signal-regulated protein kinase (ERK) was dispensable for apoptosis induction; DAS, DADS, or DATS did not modify expression of MAPK p38, bax, and bcl-xL. Further investigation revealed that the specific JNK inhibitor SP600125 and the antioxidant NAC blocked DADS and DATS-induced apoptosis, whereas ERK inhibitors did not. Additionally, our data provide the first evidence that Fas-mediated cell death pathway is partly involved in DADS but not DATS-mediated cell death. Taken together, our work has elucidated the triggers, important modulators, and signal transduction pathways in DADS and DATS-mediated apoptosis.

Progression of diethylnitrosamine-induced hepatic carcinogenesis in carnitine-depleted rats

AIM: To investigate whether carnitine deficiency is a risk factor during the development of diethylnitrosamine (DENA)-induced hepatic carcinogenesis.

METHODS: A total of 60 male Wistar albino rats were divided into six groups with 10 animals in each group. Rats in group 1 (control group) received a single intraperitoneal (i.p.) injection of normal saline. Animals in group 2 (carnitine-supplemented group) were given L-carnitine (200 mg/kg per day) in drinking water for 8 wk. Animals in group 3 (carnitine-depleted group) were given D-carnitine (200 mg/kg per day) and mildronate (200 mg/kg per day) in drinking water for 8 wk. Rats in group 4 (DENA group) were injected with a single dose of DENA (200 mg/kg, i.p.) and 2 wk later received a single dose of carbon tetrachloride (2 mL/kg) by gavage as 1:1 dilution in corn oil. Animals in group 5 (DENA-carnitine depleted group) received the same treatment as group 3 and group 4. Rats in group 6 (DENA-carnitine supplemented group) received the same treatment as group 2 and group 4.

RESULTS: Administration of DENA resulted in a significant increase in alanine transaminase (ALT), gamma-glutamyl transferase (G-GT), alkaline phosphatase (ALP), total bilirubin, thiobarbituric acid reactive substances (TBARS) and total nitrate/nitrite (NOx) and a significant decrease in reduced glutathione (GSH), glutathione peroxidase (GSHPx), catalase (CAT) and total carnitine content in liver tissues. In the carnitine-depleted rat model, DENA induced a dramatic increase in serum ALT, G-GT, ALP and total bilirubin, as well as a progressive reduction in total carnitine content in liver tissues. Interestingly, L-carnitine supplementation resulted in a complete reversal of the increase in liver enzymes, TBARS and NOx, and a decrease in total carnitine, GSH, GSHPx, and CAT induced by DENA, compared with the control values. Histopathological examination of liver tissues confirmed the biochemical data, where L-carnitine prevented DENA-induced hepatic carcinogenesis while D-carnitine-mildronate aggravated DENA-induced hepatic damage.

CONCLUSION: Data from this study suggest for the first time that: (1) carnitine deficiency is a risk factor and should be viewed as a mechanism in DENA-induced hepatic carcinogenesis; (2) oxidative stress plays an important role but is not the only cause of DENA-induced hepatic carcinogenesis; and (3) long-term L-carnitine supplementation prevents the development of DENA-induced liver cancer.

Phytochemicals as potential chemopreventive and chemotherapeutic agents in hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the fifth commonest malignancy worldwide and the incidence is rising. Surgery, including transplantation resection, is currently the most effective treatment for HCC; however, recurrence rates are high and long-term survival is poor. Identifying novel chemopreventive and chemotherapeutic agents and targeting them to patients at high risk of developing HCC or following curative treatment may go some way towards improving prognosis. This review examines current knowledge regarding the chemopreventive and chemotherapeutic potential of phytochemicals in heptocarcinogenesis. Both in-vitro and animal studies demonstrate that several phytochemicals, including curcumin, resveratrol, green tea catechins, oltipraz and silibinin, possess promising chemopreventive and chemotherapeutic properties. Despite this, very few clinical trials have been performed. Problems regarding validation of biomarkers, agent delivery, side effects and patient selection are barriers that need to be overcome to determine the potential of such agents in clinical practice.

Garlic oil ameliorates ferric nitrilotriacetate (Fe-NTA)-induced damage and tumor promotion: Implications for cancer prevention

Intraperitoneal injection of ferric nitrilotriacetate (Fe-NTA) to rats and mice results in iron-induced free radical injury and cancer in kidneys. This study was designed to investigate the effects of garlic oil on Fe-NTA-induced damage and tumor promotion. Pretreatment of rats with garlic oil at a dose regimen of 50-100 mg/kg body weight for a week significantly and dose dependently protected against Fe-NTA induced damage as well as tumor promotion. Garlic oil afforded protection against hepatic lipid peroxidation, generation of hydrogen peroxide, preserved glutathione levels and activities of antioxidant enzymes. A protection against Fe-NTA induced hepatic tumor promotion was also apparent as inhibition in the modulation of hepatic tumor markers viz., ornithine decarboxylase activity and DNA synthesis. These results clearly demonstrate the role of oxidative stress and its relation to tumor promotion and suggest protective effects of garlic oil against Fe-NTA induced hepatic toxicity and it can serve as potent chemopreventive agent to suppress oxidant-induced tissue injury and carcinogenesis.

Chemo-preventive effect of Star anise in N-nitrosodiethylamine initiated and phenobarbital promoted hepato-carcinogenesis

The generation of free radicals is a cause of many pathological conditions like diabetes mellitus, cancer, stroke, etc. Free radicals cause damage to cellular DNA and initiate carcinogenesis. Free radicals also bring about proliferation of cells via cell signaling. An inverse relationship between the consumption of vegetable diets and the risk of cancer has been established. In the present study, Star anise (Illicium verum), which is a commonly used condiment in Indian cuisine, was assessed for its anti-carcinogenic potential in N-nitrosodiethylamine (NDEA) initiated and phenobarbital (PB) promoted hepato-carcinogenesis. Rats were randomly selected for eight experimental groups. The carcinogenesis was induced by injecting the rats, with a single dose of NDEA (200mg/kg body weight) intraperitoneally as initiator, followed by promotion with PB (0.05%) in drinking water for 14 consecutive weeks. The treatment with NDEA increased liver weight, while Star anise (Star) treatment reduced the liver weight of rats. The treatment with Star throughout for 20 weeks or during the promotion stage (6-20 weeks) significantly reduced the nodule incidence and nodule multiplicity in the rats, while the treatment with Star at the initiation phase (first 4 weeks) only could not reduce these parameters. The treatment with Star for 20 consecutive weeks significantly reduced the nodule size and nodule volume. The treatment with Star throughout as well as at the promotion stage lowered the lipid peroxidation (LPO) in liver and erythrocytes, while the LPO was not lowered, when Star was administered during initiation stage only. The treatment with Star restored the liver and erythrocyte super-oxide dismutase (SOD) activities to normal in the carcinogenesis-induced rats. The liver catalase (CAT) activity increased in all the treated groups. The erythrocyte CAT activity increased in the rats treated with Star during initiation and promotion stage only. The liver glutathione (GSH) level increased significantly in the groups treated with Star. The erythrocyte GSH level was lowered in the rats treated with NDEA and PB, however, Star treatment helped in increasing the erythrocyte GSH level to some extent. The liver and erythrocyte glutathione-S-transferase (GST) activity increased in all the groups treated with NDEA and PB. The treatment with Star decreased GST level significantly. These results indicate that the treatment with Star reduces the tumor burden, lowers oxidative stress and increases the level of phase II enzymes, which may contribute to its anti-carcinogenic potential.

Silymarin modulates the oxidant-antioxidant imbalance during diethylnitrosamine induced oxidative stress in rats

Oxidative stress is a common mechanism contributing to initiation and progression of hepatic damage in a variety of liver disorders. Hence, there is a great demand for the development of agents with potent antioxidant effect. The aim of the present investigation is to evaluate the efficacy of silymarin as a hepatoprotective and an antioxidant against diethylnitrosamine induced hepatocellular damage. Single intraperitoneal administration of diethylnitrosamine (200 mg/kg) to rats resulted in significantly elevated levels of serum aspartate transaminase (AST) and alanine transaminase (ALT), which is indicative of hepatocellular damage. Diethylnitrosamine induced oxidative stress was confirmed by elevated levels of lipid peroxidation and decreased levels of superoxide dismutase (SOD), catalase, glutathione peroxidase, glutathione reductase (GR) and glutathione-S-transferase (GST) in the liver tissue. The status of non-enzymic antioxidants like, vitamin-C, vitamin-E and reduced glutathione (GSH) were also found to be decreased in diethylnitrosamine administered rats. Further, the status of membrane bound ATPases was also altered indicating hepatocellular membrane damage. Posttreatment with the silymarin (50 mg/kg) orally for 30 days significantly reversed the diethylnitrosamine induced alterations in the liver tissue and offered almost complete protection. The results from the present study indicate that silymarin exhibits good hepatoprotective and antioxidant potential against diethylnitrosamine induced hepatocellular damage in rats.

Effect of selenium-enriched malt on hepatocarcinogenesis, paraneoplastic syndrome and the hormones regulating blood glucose in rats treated by diethylnitrosamine

233 SD rats weighing 100 approximately 120 g were divided randomly into 6 groups. The animals in group I and group II received 0.1 mg/kg selenium in the form of sodium selenite only and served as the negative control and positive control, respectively. Animals in groups III, IV and V were fed with selenium as Se-enriched malt supplemented diets (0.3, 1 and 3 mg/kg), and group VI with selenium by using sodium selenite supplemented diets (3 mg/kg). Animals of groups II approximately VI were induced hepatoma by diethylnitrosamine (100 mg/l) for 16 weeks, then drunk with sterilized water for 2 more weeks. Subsequently, the effects of Se-enriched malt and sodium selenite on hepatoma nodules, relative liver weight, the liver function indices including alanine aminotransferase (ALT), alkaline phosphatase (ALP), albumin (ALB), total bilirubin (TBIL), and the tumor markers, named as gamma-glutamyltranspeptidase (GGT), alpha-fetoprotein (AFP), insulin-like growth factor-II (IGF-II) were recorded. The calcium concentration, glucose content in plasma and values of the hormones regulating blood glucose, such as insulin, glucagons and thyroid hormones (3,5,3'-tetraiodothyronine, T(3); 3,5,3'5'-tetraiodothyronine, T(4)) were observed as well. At the same time, the correlations between the concentration of plasma glucose and related hormones were also analyzed. The results indicated that Se-enriched malt showed a better chemopreventive efficiency in decreasing the number of hepatoma nodules, relative liver weight and the contents of AFP, GGT, IGF-II, ALT, ALP and TBIL in the plasma, and delaying the descent of hormones in the serum, names as insulin, glucagons, T(3) and T(4) than those feeding with sodium selenite. Effect of Se-enriched malt excelled sodium selenite in the aspects of deadening the descent of glucose concentration in the plasma and the rise of calcium concentration in the serum of the rats with hepatoma induced by diethylnitrosamine. The values of glucose and calcium were significantly related to those items fore-named. In conclusion, the function of Se-enriched malt in deadening the lesion and delaying the development of hepatoma of rats induced by diethylnitrosamine was better than that of sodium selenite. Hypoglycemia and hypercalcemia were significantly correlated with the multifactors mentioned above.

Protective role of Vitamin E pre-treatment on N-nitrosodiethylamine induced oxidative stress in rat liver

Nitrosamine compounds are known hepatic carcinogens. In the metabolism of nitrosamines, such as N-nitrosodiethylamine (NDEA), there is evidence of the formation of reactive oxygen species (ROS) resulting in oxidative stress, which may be one of the factors in the etiology of cancer. The formation of ROS may alter the antioxidant system, while the presence of Vitamin E may counteract NDEA induced oxidative stress. This study was planned to determine whether pre-treatment with Vitamin E (40 mg/kg body weight, i.p., twice a week for 4 weeks) to NDEA induced rats provides protection against oxidative stress in liver caused by the carcinogen. A single necrogenic dose of NDEA (200mg/kg body weight) was administered i.p. to the male albino rats with or without Vitamin E pre-treatment and the animals were sacrificed on Days 7, 14 or 21 after the administration of NDEA. The result showed enhanced levels of hepatic lipid peroxidation (LPO) and conjugated dienes of NDEA treated rats as the indices of oxidative stress, however, Vitamin E pre-treated rats administered NDEA showed decreased LPO and conjugated dienes (Day 21). Superoxide dismutase (SOD) activity in liver was not altered significantly in NDEA treated rats with or without Vitamin E pre-treatment. Catalase (CAT) activity was inhibited with NDEA treatment, however, Vitamin E pre-treatment showed recovery in hepatic CAT activity (Days 14 and 21). Total and Se-glutathione peroxidase (GSH-Px) activities and glutathione-S-transferase (GST) activity in liver increased in NDEA treated rats irrespective of Vitamin E pre-treatment. Glutathione reductase (GSH-R) activity as well as total glutathione (GSH) content in liver decreased in NDEA treated animals, both of which were recovered in Vitamin E pre-treated rats administered NDEA. Activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) were increased significantly following NDEA treatment to rats with or without Vitamin E pre-treatment. The activities of AST and ALT enzymes were significantly reduced on Days 14 and 21 and ALP activity was reduced on Day 21 in NDEA+Vitamin E treated animals when compared to NDEA treated alone. LDH enzyme activity was normalized on Day 14 in Vitamin E pre-treated animals administered NDEA. However, the AST, ALT and ALP enzyme activities remained high in all treatment groups as compared to control group. Normal control and Vitamin E treated alone rats revealed normal histology of liver. On the other hand, NDEA treated animals showed alterations in normal hepatic histoarchitecture, which comprised of necrosis and vacuolization of the cells. However, the rats treated with Vitamin E+NDEA showed that the liver cells were normal, with very little necrosis (Day 21). This study concludes that the pre-treatment with Vitamin E prior to the administration of NDEA, reduced the degree of oxidative stress, although this vitamin produced only slight changes in the hepatic injury, in a time-dependent manner.

Chemopreventive Effect of Indole-3-Carbinol on Induction of Preneoplastic Altered Hepatic Foci

Indole-3-carbinol (I3C) is a cleavage product of glucobrassicanin, a natural compound present in a wide variety of plant food substances including members of the family Cruciferae. I3C is known to possess cancer-chemopreventive potential in various animal models. The present study reveals the protective effect of I3C on the development of diethylnitrosamine (DEN)-initiated and 2-acetylaminofluorene (AAF)-promoted preneoplastic, altered hepatic foci (AHF) in Wistar rats. I3C was given at dose levels of 0.5 and 1 mg/kg body weight for five consecutive days along with DEN and AAF. AHF were scored and analyzed by quantitative stereology using the Image Analysis System from frozen liver sections stained for positive and negative biological markers of AHF, that is, glutathione S-transferase (GST-P), gamma-glutamyl transpeptidase (GGT), glucose-6-phosphatase (G6Pase), adenosine triphosphatase (ATPase), and alkaline phosphatase (AlkPase). Results revealed the chemopreventive effect of I3C on the DEN-initiated AHF in Wistar rats. The expression of G6Pase, ATPase, and AlkPase was restored in the I3C-supplemented animal. Similarly the induced expression GST-P and GGT also decreased in the animals with I3C administration. The recovery of altered levels of these biomarkers was of comparatively higher magnitude in the animals given a higher dose of I3C (1 mg/kg body weight) in comparison with the animals given 0.5 mg/kg body weight dose of I3C, although no dose-dependence pattern was recorded in I3C-supplemented groups. These results thus suggest the chemopreventive effect of I3C in rat hepatocarcinogenesis by suppressing DEN- and AAF-induced AHF development.

Modulation of altered hepatic foci induction by diallyl sulphide in Wistar rats

Diallyl sulphide (DAS) is a sulphur-containing volatile compound present in garlic (Allium sativum). It has been shown to inhibit a number of chemically induced forms of cancer in experimental animals. The present study demonstrates the inhibitory effect of DAS on the development of diethylnitrosamine (DEN) initiated and 2-acetyl-aminofluorene (2-AAF) promoted preneoplastic altered hepatic foci (AHF) in Wistar rats. AHF were scored and analysed by quantitative stereology using the Image Analysis system from frozen liver sections stained for biological markers, namely glutathione S-transferase, placental form (GST-P), gamma-glutamyl transpeptidase (GGT), adenosine triphosphatase (ATPase), glucose-6-phosphatase (G6 Pase) and alkaline phosphatase (AlkPase). DAS-supplemented rats were found to restore the near-normal levels of enzymes GST-P and GGT when exposed to DEN and 2-AAF. DAS administration following DEN and 2-AAF exposure led to the restoration of enzymic activity of ATPase, G6 Pase and AlkPase, as evident by number and area of the foci. These findings suggest the protective role of DAS in rat hepatocarcinogenesis, by suppressing DEN- and 2-AAF-induced AHF development.