Antimutagenic effect of polysaccharide ginsan extracted from Panax ginseng

Protective effects of Panax Ginseng against 131I-induced genotoxicity in patients with differentiated thyroid cancer

BACKGROUND

Radioiodine (131I) therapy (RAIT) is associated with oxidative stress (OS)-induced DNA damage in patients with differentiated thyroid cancer (DTC). The goal of this study was to evaluate the possible ameliorating effects of Panax Ginseng (PG) on RAIT-induced genotoxicity in patients with DTC.

MATERIALS AND METHODS

Forty DTC patients who had received 131I (100 to 175 mCi) were enrolled in this study. The patients were randomly classified (n = 10) into control, placebo, PG1 groups (receiving 500 mg/day of PG for 2 days before RAIT), and PG2 group (receiving 500 mg/day of PG for 2 days before to 1 day after RAIT). Blood samples were collected before and 2 days after RAIT. Lymphocyte micronuclei (MN) frequency was measured using the MN assay. Serum total antioxidant capacity (TAC) and ischemia-modified albumin (IMA) were measured using colorimetric assays. Serum albumin, blood urea nitrogen (BUN), creatinine, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were measured using commercial kits.

RESULTS

The mean of baseline MN frequency was the same in the four groups. RAIT increased the MN frequencies to at least three times the baseline values in the control (39 ± 5) and placebo groups (38 ± 6) (P < 0.001). PG caused a significant decrease in the MN frequencies in the treated groups compared to the control and placebo groups (P < 0.001). RAIT and PG administration had no significant effects on the serum IMA, TAC, and markers of liver and kidney toxicity.

CONCLUSION

PG could be considered a useful remedy for the protection against RAIT-induced chromosomal damage in DCT patients.

Protective Effect of Some Essential Oils Against Gamma-Radiation Damages in Tetrahymena pyriformis Exposed to Cobalt-60 Source

The main purpose of this study was to investigate the protective effect of Rosmarinus officinalis, Origanum compactum, Lavandula angustifolia, and Eucalyptus globulus essential oils (EOs) against gamma-radiation-induced damages on Tetrahymena pyriformis growing in presence of cobalt-60 source. The chemical composition of the 4 EOs was analyzed by gas chromatography-mass spectrometry. The protective effects of EOs on growth, on morphology, and on some metabolic enzymes and antioxidant markers have been evaluated. Thus, addition of EOs significantly improves the growth parameters (generation number and time) in irradiating conditions. All EOs allowed restoring growth parameters over more than 90% compared to the controls. The morphological analysis indicated that T. pyriformis cells growing in irradiating conditions were able to regain their normal form in presence of the different EOs. Our results indicate that the 4 EOs also have protective effects on some metabolic enzymes. They allowed recovering totally or partially the glyceraldehyde 3-phosphate dehydrogenase and the succinate dehydrogenase activities compared to the controls. Moreover, the addition of EOs reduced the lipid peroxidation level and decreased the activities of catalase and superoxide dismutase induced by the gamma-radiation exposure. A more pronounced protective effect was found for O. compactum and L. angustifolia EOs compared to R. officinalis and E. globulus EOs. These results suggest that the studied EOs are efficient natural antioxidants that could offer protection against gamma-radiation-induced damages and can therefore be useful in clinical medicine.

Recent progress in polysaccharides from Panax ginseng C. A. Meyer

Panax ginseng C. A. Meyer (P. ginseng) has a long history of medicinal use and can treat a variety of diseases. P. ginseng contains a variety of active ingredients, such as saponins, polypeptides, volatile oils, and polysaccharides. Among them, saponins have always been considered as the main components responsible for its pharmacological activities. However, more and more studies have shown that polysaccharides play an indispensable role in the medicinal value of ginseng. Modern biological and medical studies have found that ginseng polysaccharides have complex structural characteristics and diverse biological activities, such as immune regulation, anti-tumor, antioxidant, hypoglycemic, and anti-radiation functions, among others. Additionally, the structural characteristics of ginseng polysaccharides are closely related to their activity. In this review, the research background, extraction, purification, structural characteristics, and biological activities of ginseng polysaccharides from different parts of P. ginseng (roots, flowers stems and leaves, and berries) under different growth conditions (artificially cultivated ginseng, mountain ginseng, and wild ginseng) are summarized. The structural characteristics of purified polysaccharides were reviewed. Meanwhile, their biological activities were introduced, and some possible mechanisms were listed. Furthermore, the structure-activity relationship of polysaccharides was discussed. Some research perspectives for the study of ginseng polysaccharides were also provided.

Wild simulated ginseng activates mouse macrophage, RAW264.7 cells through TRL2/4-dependent activation of MAPK, NF-κB and PI3K/AKT pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng (Panax ginseng Meyer) is a very well-known traditional herbal medicine that has long been used to enhance the body's immunity. Because it is a type of ginseng, it is believed that wild simulated ginseng (WSG) also has immune-enhancing activity. However, study on the immune-enhancing activity of WSG is quite insufficient compared to ginseng.

AIM OF THE STUDY

In this study, we evaluated immune-enhancing activity of WSG through macrophage activation to provide a scientific basis for the immune enhancing activity of WSG.

MATERIALS AND METHODS

The effect of WSG on viability of RAW264.7 cells was evaluated by MTT assay. The NO level was measured by Griess reagent. The expression levels of mRNA or protein in WSG-treated RAW264.7 cells were analyzed by RT-PCR and Western blot, respectively.

RESULTS

WSG increased the production of immunomodulators such as NO, iNOS, COX-2, IL-1β, IL-6 and TNF-α and activated phagocytosis in mouse macrophages RAW264.7 cells. Inhibition of TLR2 and TLR4 reduced the production of immunomodulators induced by WSG. WSG activated MAPK, NF-κB and PI3K/AKT signaling pathways, and inhibition of such signaling activation blocked WSG-mediated production of immunomodulators. In addition, activation of MAPK, NF-κB and PI3K/AKT signaling pathways by WSG was reversed by TLR2 or TLR4 inhibition.

CONCLUSION

Based on the results of this study, WSG is thought to activate macrophages through the production of immunomodulators and phagocytosis activation through TLR2/4-dependent MAPK, NF-κB and PI3K/AKT signaling pathways. Therefore, it is thought that WSG have the potential to be used as an agent for enhancing immunity.

Ginsenoside Rg3 inhibits grass carp reovirus replication in grass carp ovarian epithelial cells

Ginseng exhibits multiple medicinal properties, including the improvement of immune function and enhancing disease resistance. In this study, we investigated the inhibitory effects of ginsenoside Rg3 on grass carp reovirus (GCRV) infection of grass carp ovarian (CO) epithelial cells, in order to provide a baseline framework for future high-efficacy antiviral drug screening investigations. Ginsenoside Rg3 was added to GCRV-infected CO cells, and cells were cultured at 27 °C before cell proliferation was measured by MTT assays. Label-free real-time cellular analysis (RTCA) after 72 h of experimentation demonstrated that 100 μg/mL ginsenoside Rg3 treatment had the highest inhibitory effect on GCRV (among 1,10,100 μg/mL treatments). We then measured the capacity for cellular antioxidant ability. Cells treated with 1,10,100 μg/mL ginsenoside Rg3 exhibited increases in Total Antioxidant Capacity activity relative to controls, respectively. Furthermore, Antioxidant assay and reverse transcript quantitative polymerase chain reaction (RT-qPCR) showed that ginsenoside Rg3 were efficient to restrain the replication of GCRV in CO cells. Expression analysis of immune-related genes via RT-qPCR showed that treatment with ginsenoside Rg3 promoted expression of IRF-3 and IRF-7 increases, respectively. Moreover, expression of IFN-1 was induced, which then inhibition the expression of tumor necrosis factor-alpha (TNF-α). In conclusion, we demonstrated that ginsenoside Rg3 promotes CO cell proliferation, inhibits GCRV activity, promotes CO cell immune activities, and thereby enhances the resistance of CO to GCRV infection.

Carboxymethylated Sulfated Heteroexopolysaccharide from a Haloarchaeal Strain as Potential Biomolecule for Harmless Adjuvant Therapy in Cancer Treatment

This study explored the possible use of a microbial carboxymethylated sulfated heteroexopolysaccharide (CS-hEPS) as a potential anticancer agent. The investigation was carried out through antioxidant, antifatigue, and antiproliferative activities. Antioxidant potential including scavenging DPPH and hydroxyl radical activities and reducing power was evaluated. Antifatigue activity was determined by assessing the endurance of mice using the forced swimming test. Following 30 days of CS-hEPS oral treatment at different doses, biochemical parameters related to fatigue such as lactic dehydrogenase (LDH), serum urea nitrogen (SUN), and hepatic glycogen (HG) contents were measured. Antitumor activities were investigated against human cancer liver and myelogenous leukemia cells. Results showed that CS-hEPS possesses notable antioxidant, antifatigue, and antitumor effects. CS-hEPS significantly inhibited the proliferation of leukemia (86.6 ± 0.32%) and cancer liver (58.6 ± 0.43%) cells. CS-hEPS are promising natural antioxidant, antifatigue, and antitumor harmless adjuvant materials that could be applied in human cancer therapy.

The antimicrobial properties of ginseng and ginseng extracts

Ginseng is commonly used in traditional Chinese medicine as a tonic and an adaptogen to reduce fatigue and boost the immune system. In recent years, ginseng extracts are shown to have both bacteriostatic and bactericidal actions and seem to exert their effects by several mechanisms, including disruption of biofilms, inhibition of quorum-sensing and virulence factors, and altering motility. Also, ginseng extracts are shown to have antifungal properties as demonstrated by their ability to inhibit the growth of several mold and yeast species. Extracts from ginseng root have a strong antiviral activity against the RNA viruses in cell cultures and animal models. In addition to the antimicrobial activities, ginseng extracts are shown to possess immunomodulatory properties involved in the amelioration of infections. The present paper describes the antimicrobial effects of ginseng and its extracts.

Utilization of cytogenetic biomarkers as a tool for assessment of radiation injury and evaluation of radiomodulatory effects of various medicinal plants - a review

Systematic biological measurement of “cytogenetic endpoints” has helped phenomenally in assessment of risks associated with radiation exposure. There has been a surge in recent times for the usage of radioactive materials in health care, agriculture, industrial, and nuclear power sectors. The likelihood of radiation exposure from accidental or occupational means is always higher in an overburdened ecosystem that is continuously challenged to meet the population demands. Risks associated with radiation exposure in this era of modern industrial growth are minimal as international regulations for maintaining the safety standards are stringent and strictly adhered to, however, a recent disaster like “Fukushima” impels us to think beyond. The major objective of radiobiology is the development of an orally effective radio-modifier that provides protection from radiation exposure. Once available for mass usage, these compounds will not only be useful for providing selective protection against accidental and occupational radiation exposure but also help to permit use of higher doses of radiation during treatment of various malignancies curtailing unwarranted adverse effects imposed on normal tissues. Bio-active compounds isolated from natural sources enriched with antioxidants possess unique immune-modulating properties, thus providing a double edged benefit over synthetic radioprotectors. We aim to provide here a comprehensive overview of the various agents originating from plant sources that portrayed promising radioprotection in various experimental models with special emphasis on studies that used cytogenetic biomarkers. The agents will include crude extracts of various medicinal plants, purified fractions, and herbal preparations.

The hypoglycemic effects of American red ginseng (Panax quinquefolius L.) on a diabetic mouse model

American ginseng (Panax quinquefolius L.) root health benefits include treatment of type 2 diabetes and this study evaluated the hypoglycemic effects of American red ginseng (ARG). ARG roots have increased bioactive phenolic contents, such as cinnamic acid and ferulic acid during the steaming process. The antihyperglycemic effects of methanol fraction extract of ARG, ferulic acid, and cinnamic acid were examined using a type 2 diabetic mouse model. The ARG treated group presented relatively lower blood glucose levels than the control group (P < 0.05). In addition, the glycogen and high density lipoprotein (HDL) contents were significantly increased while levels of plasma cholesterol and low density lipoprotein (LDL) concentration were significantly decreased in the ARG treated group. The groups treated with ferulic and cinnamic acids showed similar effects as those found in the ARG treated group. Thus, it is suggested that ARG roots, ferulic acid, and cinnamic acid have hypoglycemic effects in an animal model.

PRACTICAL APPLICATION

This study was conducted to elucidate the hypoglycemic effects of American red ginseng (ARG) using a type 2 diabetic mouse model. ARG showed an enhanced antioxidant capacity and higher antihyperglycemia effect. The glycogen and high density lipoprotein (HDL) contents were significantly increased while levels of plasma cholesterol and low density lipoprotein (LDL) concentration were significantly decreased in the ARG treated group. It is suggested that ARG has a potential to be used for human diabetic treatment.

Anti-oxidation activity of the crude polysaccharides isolated from Polygonum cillinerve (Nakai) Ohwi in immunosuppressed mice

AIM OF THE STUDY

Polygonum cillinerve (Nakai) Ohwi is commonly used in China for over 2000 years. Previous research has shown that the crude polysaccharides extracted from Polygonum cillinerve (Nakai) Ohwi (PCCP) have the scavenging free radicals and anti-tumor activities in vitro. In present study, PCCP were further approached the perspective of their anti-oxidation in immunosuppressed mice.

METHODS AND MATERIALS

ICR mice were treated firstly with cyclophosphamide (CY, 150 mg/kg), 1 day later, treated with different dosages of PCCP or saline solution once daily for 21 days. Twenty-four hours later for the last drug administration, the animals were weighed, and then killed by decapitation. The liver, spleen, and thymus indices were investigated, and the biochemical parameters were evaluated for various tissues (liver, heart, and kidney).

RESULTS

The administration of PCCP with gavage was able to overcome the cyclophosphamide-induced immunosuppression, and significantly to raise the TOC, CAT, SOD, and GSH-Px level. It also raised the liver, spleen, and thymus indices, and decreased the MDA level in mice.

CONCLUSIONS

PCCP possess the pronounced free radical-scavenging and antioxidant activities, and could play an important role in the prevention of oxidative damage in immunological system.

Whole body radioprotective activity of an acetone-water extract from the seedpod of Nelumbo nucifera Gaertn. seedpod

Procyanidins extracted with acetone-water from lotus (Nelumbo nucifera Gaertn.) seedpod (LSPCs) were evaluated for in vivo radioprotective activity against whole body gamma irradiation in Swiss albino mice. Pretreated with LSPCs 200 mg/kg by intragastric (i.g.) for 15 days was found to be the most effective dose in preventing radiation sickness, reducing radiation-induced mortality, increasing mean survival time and elevating radiation median lethal dose (LD(50)) from 8.9 to 10.5 Gy, indicating a dose modifying factor (DMF) of 1.18. Further, administered LSPCs at a dose of 200 mg/kg could effectively maintain spleen index close to normal, stimulate endogenous spleen colony forming units, promote the levels of red blood cells (RBC), white blood cells (WBC), platelets and hemoglobin in peripheral blood, and prevent spleen and skin damage in irradiated mice, reduce the level of radiation-induced micronucleated polychromatic erythrocytes in bone marrow, maintain the polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) ratio (P/N ratio) and significantly decrease bone marrow chromosomal damage. Alternatively, pretreated with LSPCs (200 mg/kg) significantly decreased the lipid peroxidation (LPO) level, and elevated the activities of endogenous antioxidant enzymes in liver after irradiation. Thus LSPCs possess a strong whole body radioprotective activity, and it may be used as a radioprotector.

Ginsan enhances humoral antibody response to orally delivered antigen

Background

There have been several reports describing the capability of ginseng extracts as an adjuvant. In this study, we tested if ginsan, a polysaccharide extracted from Panax ginseng, was effective in enhancing antibody response to orally delivered Salmonella antigen.

Methods

Ginsan was treated before oral salmonella antigen administration. Salmonella specific antibody was determined by ELISA. mRNA expression was determined by RT-PCR. Cell migration was determined by confocal microscopy and flow cytometry. COX expression was detected by western blot.

Results

Ginsan treatment before oral Salmonella antigen delivery significantly increased both secretory and serum antibody production. Ginsan increased the expression of COX in the Peyer's patches. Various genes were screened and we found that CCL3 mRNA expression was increased in the Peyer's patch. Ginsan increased dendritic cells in the Peyer's patch and newly migrated dendritic cells were mostly found in the subepithelial dome region. When COX inhibitors were treated, the expression of CCL3 was reduced. COX inhibitor also antagonized both the migration of dendritic cells and the humoral immune response against oral Salmonella antigen.

Conclusion

Ginsan effectively enhances the humoral immune response to orally delivered antigen, mediated by CCL3 via COX. Ginsan may serve as a potent vaccine suppliment for oral immunization.

Radioprotective effects of fucoidan on bone marrow cells: improvement of the cell survival and immunoreactivity

Fucoidan is a sulfated polysaccharide purified from brown algae including Fucus vesiculosus and has a variety of biological effects including mobilization of hematopoietic progenitor cells. Recently, we demonstrated that fucoidan stimulates the antigen-presenting functions of dendritic cells. In this study, we investigated the radioprotective effects of fucoidan on bone marrow cells (BMCs), which are the main cellular reservoir for the hematopoietic and immune system. To evaluate the effects of fucoidan, we assayed cell viability and immune responses. In a viability assay, fucoidan significantly increased the viability of BMCs. Based on the results of flow cytometric analysis, the increased viability of fucoidan-treated BMCs was attributed to the inhibition of radiation-induced apoptosis. Furthermore, fucoidan altered the production of immune-related cytokines from BMCs and increased the capability of BMCs to induce proliferation of allogeneic splenocytes. Taken together, our study demonstrated that fucoidan has radioprotective effects on BMCs with respect to cell viability and immunoreactivity. These results may provide valuable information, useful in the field of radiotherapy.

American ginseng suppresses inflammation and DNA damage associated with mouse colitis

Ulcerative colitis (UC) is a dynamic, idiopathic, chronic inflammatory condition associated with a high colon cancer risk. American ginseng has antioxidant properties and targets many of the players in inflammation. The aim of this study was to test whether American ginseng extract prevents and treats colitis. Colitis in mice was induced by the presence of 1% dextran sulfate sodium (DSS) in the drinking water or by 1% oxazolone rectally. American ginseng extract was mixed in the chow at levels consistent with that currently consumed by humans as a supplement (75 p.p.m., equivalent to 58 mg daily). To test prevention of colitis, American ginseng extract was given prior to colitis induction. To test treatment of colitis, American ginseng extract was given after the onset of colitis. In vitro studies were performed to examine mechanisms. Results indicate that American ginseng extract not only prevents but it also treats colitis. Inducible nitric oxide synthase and cyclooxygenase-2 (markers of inflammation) and p53 (induced by inflammatory stress) are also downregulated by American ginseng. Mucosal and DNA damage associated with colitis is at least in part a result of an oxidative burst from overactive leukocytes. We therefore tested the hypothesis that American ginseng extract can inhibit leukocyte activation and subsequent epithelial cell DNA damage in vitro and in vivo. Results are consistent with this hypothesis. The use of American ginseng extract represents a novel therapeutic approach for the prevention and treatment of UC.

Preventive effect of 20(S)-ginsenoside Rg3 against lipopolysaccharide-induced hepatic and renal injury in rats

The preventive effect of 20(S)-ginsenoside Rg(3) (20(S)-Rg(3)) on lipopolysaccharide (LPS)-induced oxidative tissue injury in rats was investigated in this study. The elevated serum nitrite/nitrate, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and creatinine levels in LPS-treated control rats were significantly decreased following 15 consecutive days of 20(S)-Rg(3) administration. In addition, thiobarbituric acid-reactive substance levels in the serum, liver and kidney were dose-dependently lower in 20(S)-Rg(3)-treated groups than in the LPS-treated control group. The nuclear factor-kappaB (NF-kappaB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1) protein expressions in the liver and kidney were significantly increased by LPS treatment. However, the 20(S)-Rg(3) administrations significantly decreased these protein expressions except for HO-1 in the liver. On the other hand, in the kidney, oral administration of 20(S)-Rg(3) showed a tendency to reduce NF-kappaB and iNOS protein expressions and also significantly reduced the elevated COX-2 and HO-1 protein expressions at a dose of 10 mg/kg body weight/day. All these results suggest the preventive effect of 20(S)-Rg(3) against LPS-induced acute oxidative damage in the liver and kidney and the preventive effect of 20(S)-Rg(3) administration against LPS toxicity was thought to be more predominant in the liver than kidney.

The inhibitory effects of garlic and Panax ginseng extract standardized with ginsenoside Rg3 on the genotoxicity, biochemical, and histological changes induced by ethylenediaminetetraacetic acid in male rats

Ethylenediaminetetraacetic acid (EDTA) is widely used in food and other industries to sequester metal ions and to prevent their disadvantageous effects. The objective of the current study was to evaluate the protective effect of Panax ginseng extract standardized with ginsenoside Rg3 (ginsenoside Rg3 content was 3.6% w/w, i.e., 36 microg/mg P. ginseng extract) and garlic against EDTA-induced biochemical, genotoxic, and histological changes in rats. Forty male rats were divided into eight treatment groups and treated for 7 days as follows: the control group, the group treated with EDTA (20 mg/kg b.w) and the groups treated with P. ginseng extract (20 mg/kg b.w), garlic (5 mg/kg b.w), P. ginseng plus garlic alone or in combination with EDTA. In vivo bone marrow micronucleus test and random amplified polymorphism DNA-PCR (RAPD-PCR) method were performed to assess the antigenotoxic effect of both protective agents. The results indicated that EDTA administration caused a significant decrease in the serum biochemical parameters and antioxidant enzymes activity. The administration also increased lipid peroxidation and the incidence of micronucleated polychromatic erythrocytes (MnPCEs), caused appearance of some changes in polymorphism band patterns, and induced different histopathological lesions in the livers, kidneys, and testis. Treatment with P. ginseng, garlic alone or plus EDTA significantly improved all the tested parameters. Moreover, P. ginseng extract was found to be more effective than garlic in restoring the parameters that were altered by EDTA.

Radioprotective effects of an acidic polysaccharide of Panax ginseng on bone marrow cells

An acidic polysaccharide of Panax ginseng (APG), so called ginsan is known to have important immunomodulatory activities. It was recently reported that APG has radioprotective effects in mice but the detailed mechanism was not fully elucidated. This study examined the effects of APG on bone marrow cells (BMs). The phenotypical and functional changes in APG-treated BMs after gamma radiation were studied. The benefit of APG on BMs damaged by gamma radiation was determined by measuring the cell viability. Using 2 different assays, a pretreatment with APG significantly increased the viability of BMs against gamma radiation. APG-treated BMs had a significantly higher amount of IL-12, which is a major cytokine for immune responses, compared with the medium-treated BMs. The expression of MHC class II molecules of APG-treated BMs was also increased, and APG-treated BMs showed significantly higher levels of allogeneic CD4⁺ T lymphocyte proliferation. Furthermore, APG-treated mice had a larger number of BMs after gamma radiation than the control mice, and the BMs of APG-treated mice were successfully cultured into dendritic cells, which are the representative antigen-presenting cells. Overall, this study shows that APG alters the phenotype of BMs, increases the viability and alloreactivity of BMs after gamma radiation both in vitro and in vivo. Therefore, APG may be a good candidate radioprotective agent for BMs.

Protective effect of steamed American ginseng (Panax quinquefolius L.) on V79-4 cells induced by oxidative stress

Heat-processed Asian ginseng roots (Panax ginseng C.A. Meyer), also known as "red ginseng" in Asia, are reported to have more bioactivity than the no-processed white ginseng roots. Therefore, American fresh ginseng roots (Panax quinquefolius L.) were processed to the red ginseng and examined changes in bioactivity during heating process. The fresh America ginseng roots were steamed at 100 degrees C for 30, 60, 90 and 120 min, and their bioactivities were examined by analyzing the content of ginsenosides and total phenolics, and measuring DPPH and superoxide radical scavenging acivity and their protective effects on V79-4 cells viability and lipid peroxidation. The heating treatment proportionally increased total ginsenosides (4.97%, w/w) content compared with white ginseng (3.27%) and total phenolics from 444.5 mg GAE/100 g to 489.6-574.2 mg GAE/100 g. The antioxidant activity also increased from 285 mg/100 g (vitamin C equivalent) to 353-487 mg/100 g. Heated ginseng showed high levels of DPPH radical scavenging activity (59.5-88.5%) and the high level of superoxide radical scavenging activity (44.2-90.9%). The heated ginseng protected cell viability against H2O2-induced oxidative damage, and enhanced the activities of superoxide dismutase and catalase by dose dependently in V79-4 cells.