Modulatory effects of diallyl sulfide against testosteroneinduced oxidative stress in Swiss albino mice

Aim： To investigate the protective effect of diallyl sulfide （DAS）, a constituent of garlic, against testosterone-induced oxidative stress in male Swiss albino mice. Methods： The animals were given low （250 mg/animal） and high dose （500 mg/animal） of DAS in corn oil for 7 days along with testosterone （5 mg/kg body weight, i.p.）. At the end of the study period, the prostate and the liver were dissected to determine various antioxidant enzyme levels （catalase, superoxide dismutase, glutathione reductase, glutathione-s-transferase） and lipid peroxidation. Results： In testosterone treated mice, depleted antioxidant enzyme level was accompanied with enhancement in lipid peroxidation in prostate and liver. DAS significantly restored the testosterone-induced antioxidant enzymes and lipid peroxidation in the both organs. These changes appear to be mediated by the antioxidant-enhancing effects of DAS. Conclusion： The results of the present study suggest that DAS is effective in exerting antioxidant effects by inhibiting testosterone-induced oxidative stress and might be helpful in preventing prostate cancer.

Experimental Study on Inhibitory Effects of Diallyl Sulfide on Growth and Invasion of Human Osteosarcoma MG-63 Cells

The inhibitory effects of diallyl sulfide(DAS) derived from allicin on in vitro and in vivo proliferation of human osteosarcoma MG-63 cells and the action mechanism,and the influence of DAS on invasive capability of MG-63 cells were investigated in order to search for the novel medicines for osteosarcoma.In the in vitro experiment,MG-63 cells were treated with different concentrations of DSA,and the morphological changes of MG-63 cells were observed under an inverted phase microscope.MTT method was used to assay the proliferation of MG-63 cells.Semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) was used to detect the VEGF mRNA expression level in MG-63 cells.By using Transwell invasion assay,the influence of DAS on invasive ability of MG-63 cells was tested.In the in vivo experiment,the nude mice MG-63 cells tumor-bearing model was established,and different concentrations of DAS were injected beside the tumor.Twenty-one days after treatment,the mice were killed,the tumor size and tumor inhibition rate were calculated.The microvessel density(MVD) was determined by using immunohistochemistry.In the in vitro experiment,different concentrations of DAS could obviously inhibit proliferation of MG-63 cells in a time-and concentration-dependent manner.RT-PCR revealed that the expression levels of VEGF mRNA in DSA groups(different concentrations) were significant reduced as compared with those in control group(all P<0.05).Transwell invasion assay indicated that in 20 and 40 μg/mL DAS groups,the number of migratory cells was 91.4±8.3 and 81.8±7.4 respectively,which was significantly declined as compared with that in control group(150.4±14.7,both P<0.05).In the in vivo experiment,DAS could significantly suppress the growth of MG-63 tumor-bearing tissue.Immunohistochemistry demonstrated that different concentrations(20 and 40 μg/mL) of DAS could significantly decrease MVD of MG-63 tumor-bearing tissue(all P<0.05).It was suggested that DAS could inhibit the growth of MG-63 cells probably by suppressing the expression of VEGF mRNA.

Antitumor Activity of Diallyl Sulfide in Two-StageMouse Skin Model of Carcinogenesis

It has been reported that diallyl sulfide (DAS), a sulfur-containing volatile compound in garlic (Allium sativum ), exerts anticarcinogenic activity in various rodent tumor models. In the present study, the antitumor property of DAS was tested in Swiss albino mice in the two steqe initiation-promotion mouse skin carcinogenesis. Skin cancers were initiated topically with a single subcarcinOgenic dose (52μg) of 7, 12-dimethyl benz (a) anthracene (DMBA). Promotion was performed by twice weekly applications of 12-O-tetradecanoyl phorbol-13-acetate (TPA) at a dose of 5μg/animal for 32 weeks. DAS was applied topically (250μg/animal) thrice weekly for 3 weeks for anti-initiating and 1 h prior to each promotion treatment for anti-promoting studies. The results showed that the treatment schedule of DAS can effectively delay the onset of tumorigenesis and reduce the cumulative number of tumors and the average number of tumors per mouse. In groups in which DAS applied prior to initiation or promotion, a significant population of the aniinals remained tumor-free till the termination of experiment. These findings suggest that DAS can effectively inhibit chemically induced mouse skincarcinogenesis.