Ethanol extract of Ilex hainanensis Merr. exhibits anti-melanoma activity by induction of G1/S cell-cycle arrest and apoptosis.

OBJECTIVE: To evaluate anti-melanoma effect of ethanol extract of Ilex hainanensis Merr. (IME) and elucidate its underlying mechanism. METHODS: 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. RESULTS: IME significantly inhibited the proliferation of B16-F10 cells (P<0.01). Flow cytometric analysis showed that IME induced G1/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. CONCLUSION: 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.

[Interaction Between Occupational Vanadium Exposure and hsp70-hom on Neurobehavioral Function].

OBJECTIVE: In determine the effect of heat shock protein 70-hom gene (hsp70-hom) polymorphism on the neurobehavioral function of workers exposed to vanadium. METHODS: Workers from the vanadium products and chemical industry were recruited by cluster sampling. Demographic data and exposure information were collected using a questionnaire. Neurobehavioral function was assessed by Neurobehavioral Core Test Battery. The hsp70-hom genotype was detected by restricted fragment length polymorphism-polymerase chain reaction (RFLP-PCR). A neurobehavioral index (NBI) was formulated through principal component analysis. RESULTS: Workers with a T/C genotype had worse performance in average reaction time, visual retention, digital span (backward), Santa Ana aiming (non-habitual hand), pursuit aiming (right points, total points), digit symbol and NBI score than others (P < 0.05). The relative risk of abnormal NBI score of the workers with a T/C genotype was 1.748 fold of those with a T/T genotype. The relative risk of abnormal.NBI score of the workers exposed to vanadium was 3.048 fold of controls (P < 0.05). But after adjustment with age and education, only vanadium exposure appeared with a significant effect on NBI score. When gene polymorphism and vanadium exposure coexisted, the effect of vanadium on neurobehavioral function was attenuated, but the influence of T/C genotype increased Codds ratio (OR = 4.577, P < 0.05). After adjustment with age and education, the OR of T/C genotype further increased to 7.777 (P < 0.05). Vanadium exposure and T/C genotype had.a bio-interaction effect on NBI score Crelative excess risk due to interaction (RERI) = 4.12, attributable proportion (AP) = 0.7, synergy index (S) = 6.45]. After adjustment with age and education, the RERI became 2.49 and the AP became 0.75, but no coefficient of interaction was produced. CONCLUSION: Priorities of occupational protection should be given to vanadium-exposed workers with a hsp70-hom T/C genotype and low education level.

[Oxidative Stress Level of Vanadium-exposed Workers].

OBJECTIVE: To determine the oxidative stress level in peripheral blood of vanadium-exposed workers, as an indication of population health effect of vanadium on human neurobehavioral system. METHODS: 86 vanadium-exposed workers and 65 non-exposed workers were recruited by cluster sampling. A questionnaire was administered to collect demographic and occupational exposure information. Serum activity of superoxide dismutase (SOD), inducible nitric oxide synthase (iNOS) and malonaldehyde (MDA) contents were detected by kit assay. The differences in oxidative stress level between vanadium-exposed and non-exposed workers were compared. RESULTS: Vanadium-exposed workers had higher levels of MDA contents than the controls. The total superoxide dismutase(T-SOD) activity in vanadium-exposed workers was significantly lower than that in the controls, which was associated with lowered levels of manganese superoxide dismutase (Mn-SOD) activity. No changes in serum levels of cupro-zinc superoxide dismutase (CuZn-SOD) was found in vanadium-exposed workers. No difference in iNOS activity was found between vanadium-exposed workers and controls. CONCLUSION: Vanadium exposure increases free radical production in serum and reduces antioxidant capacity. But the relationship between vanadium exposure and iNOS damage remains uncertain.