ABSTRACT
<p><b>OBJECTIVE</b>To evaluate anti-melanoma effect of ethanol extract of Ilex hainanensis Merr. (IME) and elucidate its underlying mechanism.</p><p><b>METHODS</b>Thirty-six tumor-bearing mice were randomized into 6 groups (n=6) as follows: model group, IME 25, 50, 100, and 200 mg/kg groups and dacarbazine (DTIC) 70 mg/kg group. The mice in the IME treatment groups were intragastrically administered with IME 25, 50, 100 or 200 mg/kg per day, respectively. The mice in the DTIC group were intraperitoneally injected with DTIC 70 mg/kg every 2 days. The drug administration was lasting for 14 days. The cell viability was evaluated by 3-(4,5-dime-thylthylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. Flow cytometry was employed to detect cell cycle and apoptosis. The gene and protein expressions of nuclear factor κB-p65 (NF-κB-p65), Bcl-2, B-cell lymphomaextra large (Bcl-xL) and Bax were detected by quantitative real-time polymerase chain reaction and Western blot analyses. Caspases-3, -8, and -9 activities were detected using the colorimetric method. In addition, a B16-F10 melanoma xenograft mouse model was used to evaluate the anti-cancer activity of IME in vivo. Furthermore, a survival experiment of tumor-bearing mice was also performed to evaluate the possible toxicity of IME.</p><p><b>RESULTS</b>IME significantly inhibited the proliferation of B16-F10 cells (P<0.01). Flow cytometric analysis showed that IME induced G/S cell cycle arrest and apoptosis (both P<0.01). IME inhibited activation of NF-κB, decreased the gene and protein expressions of Bcl-2, Bcl-xL, and increased the gene and protein expressions of Bax (all P<0.01). In addition, IME induced the activation of Caspases-3, -8, and -9 in B16-F10 cells. The study in vivo showed that IME significantly reduced tumor volume (P<0.01), and the inhibitory rate came up to 68.62%. IME also induced large areas of necrosis and intra-tumoral apoptosis that correlated with a reduction in tumor volume. Survival experiment showed that treatment with IME for 14 days significantly prolonged survival time and 20% of mice in the IME 200 mg/kg group were still alive until the 50th day. Notably, IME showed no apparent side-effects during the treatment period.</p><p><b>CONCLUSION</b>IME exhibited significant anti-melanoma activity in vitro and in vivo, suggesting that IME might be a promising effective candidate with lower toxic for malignant melanoma therapy.</p>
ABSTRACT
OBJECTIVE: To investigate the interaction of occupational vanadium exposure and heat shock protein 70-hom( HSP70-hom) gene polymorphism on the oxidative stress level of workers. METHODS: By judgment sampling,87 workers from vanadium products plant as vanadium exposure group and 63 workers from chemical industry as control group were enrolled into this investigation. The activities of total superoxide dismutase( T-SOD),manganese-containing superoxide dismutase( Mn-SOD),copper and zinc-containing superoxide dismutase( Cu Zn-SOD) and inducible nitric oxide synthase( iNOS),and the level of malondialdehyde( MDA) in the serum of studied subjects were detected. The HSP70-hom genotype was examined by restricted fragment length polymorphism-polymerase chain reaction. Based on the above data,the comprehensive impact of HSP70-hom gene polymorphism and vanadium exposure on workers' oxidative stress level was analyzed. RESULTS: Compared with the control one,the activities of serum T-SOD and Mn-SOD of vanadium-exposed group were significantly decreased( P < 0. 01),while the level of serum MDA was significantly increased( P < 0. 01).Furthermore,the serum T-SOD activity of T / T genotype was statistically lower than that of T / C + C / C genotype( P <0. 01). Both high serum( T-SOD) activity and high MDA level were significantly influenced by the interaction between vanadium exposure and HSP70-hom polymorphism by univariate Logistic regression analysis( P < 0. 05). Using multiple Logistic regression and crossover analysis,multiplicative and additive interactions on high serum( T-SOD) activity between vanadium exposure and HSP70-hom polymorphism was observed [odds ratio( OR) was 6. 051,95% confidence interval( CI) : 1. 001-36. 572,P = 0. 05]and the attributable proportion due to interaction was 0. 935( 95% CI: 0. 086-1. 783).However,high serum MDA level was significantly associated with vanadium exposure [OR( 95% CI) : 6. 352( 3. 099-13. 021),P < 0. 01] without interaction observed. There was no significant effect of vanadium exposure or HSP70-hom polymorphism on either Cu Zn-SOD or iNOS. CONCLUSION: Vanadium exposure might have an impact on the oxidative stress level of the workers by regulating the activity of serum SOD and the level of serum MDA. Besides,vanadium exposure and HSP70-hom polymorphism could interactively interfere with serum T-SOD activity of workers.