Chemopreventive Effects of Sarcophine-diol on Ultraviolet B-induced Skin Tumor Development in SKH-1 Hairless Mice

Sarcophine-diol (SD), one of the structural modifications of sarcophine, has shown chemopreventive effects on 12-dimethylbenz(a)anthracene-initiated and 12-O-tetradecanoylphorbol-13-acetate-promoted skin tumor development in female CD-1 mice. The objective of this study was to determine the chemopreventive effects of SD on UVB-induced skin tumor development in hairless SKH-1 mice, a model more relevant to human skin cancer, and to determine the possible mechanisms of action. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into two groups having 27 mice in each group: control and SD treatment. The control group was topically treated with 100 μL acetone and SD treatment group was topically treated with SD (30 μg/100 μL in acetone) 1 hour before each UVB radiation for 32 weeks. Tumor counts were recorded on a weekly basis for 30 weeks. Effects of SD on the expression of caspases were investigated to elucidate the possible mechanism of action. The proteins from epidermal homogenates of experimental mice were used for SDS-PAGE and Western blotting using specific antibodies against caspase-3, caspase-8 and caspase-9 respectively. TUNEL assay was used for determining DNA fragmented apoptotic cells in situ. Results showed that at the end of experiment, tumor multiplicity in control and SD treatment groups was 25.8 and 16.5 tumors per mouse respectively. Furthermore, Topical treatment of SD induced DNA fragmented apoptotic cells by upgrading the expressions of cleaved caspase-3 and caspase-8. This study clearly suggested that SD could be an effective chemopreventive agent for UVB-induced skin cancer by inducing caspase dependent apoptosis.     

Dose-Response on the Chemopreventive Effects of Sarcophine-Diol on UVB-Induced Skin Tumor Development in SKH-1 Hairless Mice

Sarcophine-diol (SD) is a lactone ring-opened analogue of sarcophine. It has shown chemopreventive effects on chemically-induced skin tumor development in female CD-1 mice, as well as in a UVB-induced skin tumor development model in hairless SKH-1 mice at a dose of 30 μg SD applied topically and 180 mJ/cm² UVB. The objective of this study was to determine the dose-response on the chemopreventive effects of SD on SKH-1 hairless mice when exposed to a UVB radiation dose of 30 mJ/cm². This UVB dose better represents chronic human skin exposure to sunlight leading to skin cancer than previous studies applying much higher UVB doses. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into five groups. The control group was topically treated with 200 μL of acetone (vehicle), and the SD treatment groups were topically treated with SD (30 μg, 45 μg, and 60 μg dissolved in 200 μL of acetone) 1 h before UVB radiation (30 mJ/cm²). The last group of animals received 60 μg SD/200 μL acetone without UVB exposure. These treatments were continued for 27 weeks. Tumor multiplicity and tumor volumes were recorded on a weekly basis for 27 weeks. Weight gain and any signs of toxicity were also closely monitored. Histological characteristics and the proliferating cell nuclear antigen (PCNA) were evaluated in the mice skin collected at the end of the experiment. The dose-response study proved a modest increase in chemopreventive effects with the increase in SD dose. SD reduced the number of cells positively stained with PCNA proliferation marker in mice skin. The study also showed that SD application without UVB exposure has no effect on the structure of skin. The results from this study suggest that broader range doses of SD are necessary to improve the chemopreventive effects.     

Chemopreventive effects of sarcotriol on ultraviolet B-induced skin tumor development in SKH-1 hairless mice

Sarcotriol (ST) has been shown to be chemopreventive on 7,12-dimethyl-benz(a)anthracene (DMBA) initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted skin tumor development in CD-1 mice in recent studies from our laboratory. The objective of this study was to determine the chemopreventive effects of ST on ultraviolet B (UVB)-induced skin tumor development in female SKH-1 hairless mice, an experimental model relevant to human skin cancer development, and its possible mechanisms of action. Female SKH-1 mice were divided into two groups: Control and ST treated. Control was topically treated with 100 μL acetone and ST treated group administered with 30 μg ST in 100 μL acetone one hour before UVB exposure. For UVB-induced tumorigenesis, carcinogenesis was initiated and promoted by UVB (180 mJ/cm²). Group weights and tumor counts were taken once every week. After 30 weeks, mice were sacrificed and dorsal skin samples were collected. The proteins from the skin sample were further used for SDS-PAGE and Western blotting using specific antibodies against caspase-3, caspase-8, caspase-9 and p53. Tumor multiplicity was found 19.6, 5.2 in the control and ST treated groups respectively. Caspase-3, -8, -9 and p53 were significantly (P < 0.05) upregulated in ST treated group compared to Control group. Together, this study for the first time identifies the chemopreventive effects of ST in UVB-induced carcinogenesis possibly by inducing apoptosis and upregulating p53.     

Potent Skin Cancer Chemopreventing Activity of Some Novel Semi-synthetic Cembranoids from Marine Sources

In the course of our continuing research in development and evaluation of novel skin cancer chemopreventive agents from marine sources, five semi-synthetic cembranoids derived from the marine natural product sarcophine, isolated from the soft coral Sarcophyton glaucum, were synthesized and shown to exhibit a remarkable chemopreventive activity in the in-vitro Epstein Barr Virus Early Antigen (EBV-EA) activation assay. These compounds were assayed in vivo using the two-stage carcinogenesis test of mouse skin tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator, and 12-O-tetradecanoylphorbol-13-acetate (TPA) as a promoter by topical administration. They showed potent inhibition of both percentage incidence of skin tumor as well as the multiplicity of skin tumors per mouse compared to untreated controls.     

Efficacy and Mechanism of Action of Marine Alkaloid 3,10-Dibromofascaplysin in Drug-Resistant Prostate Cancer Cells

Efficacy and mechanism of action of marine alkaloid 3,10-dibromofascaplysin (DBF) were investigated in human prostate cancer (PCa) cells harboring different levels of drug resistance. Anticancer activity was observed across all cell lines examined without signs of cross-resistance to androgen receptor targeting agents (ARTA) or taxane based chemotherapy. Kinome analysis followed by functional investigation identified JNK1/2 to be one of the molecular targets of DBF in 22Rv1 cells. In contrast, no activation of p38 and ERK1/2 MAPKs was observed. Inhibition of the drug-induced JNK1/2 activation or of the basal p38 activity resulted in increased cytotoxicity of DBF, whereas an active ERK1/2 was identified to be important for anticancer activity of the alkaloid. Synergistic effects of DBF were observed in combination with PARP-inhibitor olaparib most likely due to the induction of ROS production by the marine alkaloid. In addition, DBF intensified effects of platinum-based drugs cisplatin and carboplatin, and taxane derivatives docetaxel and cabazitaxel. Finally, DBF inhibited AR-signaling and resensitized AR-V7-positive 22Rv1 prostate cancer cells to enzalutamide, presumably due to AR-V7 down-regulation. These findings propose DBF to be a promising novel drug candidate for the treatment of human PCa regardless of resistance to standard therapy.     

Activation of the Tumor Suppressor PP2A Emerges as a Potential Therapeutic Strategy for Treating Prostate Cancer

Protein phosphatase 2A (PP2A) is a tumor suppressor complex that has recently been reported as a novel and highly relevant molecular target in prostate cancer (PCa). However, its potential therapeutic value remains to be fully clarified. We treated PC-3 and LNCaP cell lines with the PP2A activators forskolin and FTY720 alone or combined with the PP2A inhibitor okadaic acid. We examined PP2A activity, cell growth, prostasphere formation, levels of PP2A phosphorylation, CIP2A and SET expression, and AKT and ERK activation. Interestingly, both forskolin and FTY720 dephosphorylated and activated PP2A, impairing proliferation and prostasphere formation and inducing changes in AKT and ERK phosphorylation. Moreover, FTY720 led to reduced CIP2A levels. Treatment with okadaic acid impaired PP2A activation thus demonstrating the antitumoral PP2A-dependent mechanism of action of both forskolin and FTY720. Levels of PP2A phosphorylation together with SET and CIP2A protein expression were studied in 24 PCa patients and both were associated with high Gleason scores and presence of metastatic disease. Altogether, our results suggest that PP2A inhibition could be involved in PCa progression, and the use of PP2A-activating drugs might represent a novel alternative therapeutic strategy for treating PCa patients.     

艾纳香油对晒伤小鼠皮肤氧化应激及DNA损伤的影响

观察艾纳香油对UVB照射后Blab/C小鼠晒伤皮肤氧化应激及DNA损伤的影响。通过建立4组小鼠晒伤模型,在5个不同时间相点测定小鼠皮肤晒伤组织厚度和含水量,利用可见光分光光度法测各组皮肤组织中超氧化物岐化酶(SOD)、丙二醛(MDA)、还原型谷胱甘肽(GSH)和8-羟基脱氧鸟苷(8-OHdG)的含量。结果表明：艾纳香油可明显加快晒伤创面处结痂脱落,抑制晒伤皮肤组织增厚(P＜0.05),减少晒伤组织皮肤含水量的丧失(P＜0.05,P＜0.01);在整个治疗过程,能明显提高小鼠血清SOD活性(P＜0.05,P＜0.01),降低皮肤MDA含量(P＜0.05),升高皮肤GSH的水平(P＜0.05),降低皮肤8-OHdG含量(P＜0.01)。艾纳香油可抵抗UVB晒伤后小鼠表皮增厚,减少光产物表达,并通过清除氧自由基,提高抗氧化酶活性而发挥抗氧化作用。     

茯砖茶对小鼠肠道免疫功能调节作用的研究

探讨了茯砖茶水提物对小鼠肠道免疫功能的调整作用。试验以注射用氨苄青霉素灌胃建立小鼠肠道菌群失调及免疫功能紊乱模型。昆明小鼠随机分6组,正常对照组、自然恢复组、模型组和茯砖茶高、中、低剂量组,分别进行肠道菌群检测、小肠黏液sIgA的测定、血清中IL-2的测定、血清白蛋白和总蛋白含量检测以及回肠切片病理检测。结果表明,注射用氨苄青霉素灌胃5 d小鼠,肠道菌群失调,小肠黏液sIgA、血清中IL-2、血清白蛋白和总蛋白均较正常组降低,回肠组织切片明显病变。分别灌服茯砖茶水提物后,肠道菌群得以调整,小肠黏液sIgA、血清中IL-2、血清白蛋白和总蛋白均有所升高,且与自然恢复组比具有显著性差异。各治疗组之间比较,高剂量组疗效优于低剂量组。说明茯砖茶水提物能修复受损黏膜,有调节肠道免疫功能的作用。     

有效微生物群在玉米生产中作用机理研究

有效微生物群(EM)对萌发种子中酶活性有较大影响。除EM原液外,各种浓度的EM稀释液浸种都能不同程度提高a-淀粉酶活性和CAT活性。叶面喷施ＥＭ能显著提高叶片光合作用速率及干旱条件下SOD和CAT活性,具有促生长和抗旱作用。EM还能加速有机质分解,提高土壤养分供应能力。     

Inhibitory Effect of Dihydroaustrasulfone Alcohol on the Migration of Human Non-Small Cell Lung Carcinoma A549 Cells and the Antitumor Effect on a Lewis Lung Carcinoma-Bearing Tumor Model in C57BL/6J Mice

There are many major causes of cancer death, including metastasis of cancer. Dihydroaustrasulfone alcohol, which is isolated from marine coral, has shown antioxidant activity, but has not been reported to have an anti-cancer effect. We first discovered that dihydroaustrasulfone alcohol provided a concentration-dependent inhibitory effect on the migration and motility of human non-small cell lung carcinoma (NSCLC) A549 cells by trans-well and wound healing assays. The results of a zymography assay and Western blot showed that dihydroaustrasulfone alcohol suppressed the activities and protein expression of matrix metalloproteinase (MMP)-2 and MMP-9. Further investigation revealed that dihydroaustrasulfone alcohol suppressed the phosphorylation of ERK1/2, p38, and JNK1/2. Dihydroaustrasulfone alcohol also suppressed the expression of PI3K and the phosphorylation of Akt. Furthermore, dihydroaustrasulfone alcohol markedly inhibited tumor growth in Lewis lung cancer (LLC)-bearing mice. We concluded that dihydroaustrasulfone alcohol is a new pure compound with anti-migration and anti-tumor growth activity in lung cancer and might be applied to clinical treatment in the future.     

The Potential Protective Effect and Possible Mechanism of Peptides from Oyster (Crassostrea hongkongensis) Hydrolysate on Triptolide-Induced Testis Injury in Male Mice

Peptides from oyster hydrolysate (OPs) have a variety of biological activities. However, its protective effect and exact mechanism on testicular injury remain poorly understood. This study aimed to evaluate the protective effect of OPs on triptolide (TP)-induced testis damage and spermatogenesis dysfunction and investigate its underlying mechanism. In this work, the TP-induced testis injury model was created while OPs were gavaged in mice for 4 weeks. The results showed that OPs significantly improved the sperm count and motility of mice, and alleviated the seminiferous tubule injury. Further study showed that OPs decreased malonaldehyde (MDA) level and increased antioxidant enzyme (SOD and GPH-Px) activities, attenuating oxidative stress and thereby reducing the number of apoptotic cells in the testis. In addition, OPs improved the activities of enzymes (LDH, ALP and ACP) related to energy metabolism in the testis and restored the serum hormone level of mice to normal. Furthermore, OPs promoted the expression of Nrf2 protein, and then increased the expression of antioxidant enzyme regulatory protein (HO-1 and NQO1) in the testis. OPs inhibited JNK phosphorylation and Bcl-2/Bax-mediated apoptosis. In conclusion, OPs have a protective effect on testicular injury and spermatogenesis disorders caused by TP, suggesting the potential protection of OPs on male reproduction.     

不同种植密度对玉米果穗发育动态特性的影响分析

2007年采用60 000株/hm2（B1）,90 000株/hm2（B2）2个密度,对豫玉23号等4个杂交种的果穗发育动态特性进行了研究,结果表明：（1）B1和B2从果穗花丝受精后10～45 d,正常发育成籽粒的小花数量随密度的增加而减少。果穗干重和长度的增长随时间变化呈正相关,两者均符合线性回归关系。果穗发育动态B2比B1晚2～3 d。（2）不同种植密度对果穗干重有显著影响,杂交种间、密度间、杂交种×密度互作效应均表现极显著差异。     

CaCl对盐胁迫下小白菜生长和相关生理特性的影响

采用CaCl2根际注射结合叶面喷施的方法,研究了不同浓度（0、5、10、20、30 mmol/L ）CaCl2对盐胁迫下小白菜（Brassica campestris ssp. chinensis L.）幼苗生长及其生理生化特性的影响。结果显示,10 mmol/L CaCl2处理显著提高了幼苗的株高、单株干重、单株鲜重和展开叶片数等,降低了叶片丙二醛（MDA）含量,增强了叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）等保护酶活性,显著提高盐胁迫下小白菜叶片的光合色素含量、净光合速率等。表明适宜浓度的外     

咖啡碱与儿茶素组合对小鼠体重和脂类代谢的影响

采用不同浓度咖啡碱与儿茶素组合粉末饲料喂养小鼠12周,通过称量小鼠体重、脏器及腹腔脂肪（IPAT）等器官重量,测定血清中的生化指标和肝脏中脂类含量的方法,研究不同浓度咖啡碱与儿茶素组合对小鼠体重、脂类代谢的影响。结果表明,所有实验组的小鼠体重增加与对照组相比有下降趋势,其中Ⅳ组（0.06%咖啡碱+0.6%儿茶素）从第4周开始小鼠体重增加显著减少。咖啡碱与儿茶素组合处理的IPAT重量与对照组相比均明显减少。Ⅰ组（0.03%咖啡碱+0.3%儿茶素）、Ⅱ组（0.03%咖啡碱+0.6%儿茶素）可显著降低血清中游离脂肪酸（NEFA）浓度;Ⅲ组（0.06%咖啡碱+0.3%儿茶素）、Ⅳ组（0.06%咖啡碱+0.6%儿茶素）与对照组相比血清总胆固醇（TC）、甘油三酯（TG）与瘦素浓度明显降低;咖啡碱与儿茶素组合能降低肝脏中TC或TG浓度。以上结果表明,绿茶成分咖啡碱与儿茶素组合通过降低血液与肝脏中的脂类含量,可能引起体内脂肪沉积减少,抑制体重增加。     

增产菌对甜菜作用机制的探讨——Ⅲ.增产菌对甜菜矿质营养的吸收及抗旱能力等的影响

研究表明,增产菌能影响甜菜对矿质营养的吸收速率及选择性,能明显地促进甜菜对N、P、Fe的吸收,但不能促进其对K、Na的吸收。在块根糖分增长期,增产菌有效地改善了碳水化合物的分配和利用,促进碳水化合物由叶片向根部运输。在水分胁迫条件下,增产菌能减少干旱对质膜的伤害作用,并能提高块根中脯氨酸浓度,维持较高叶片含水量和干物质累积速率。     

壳聚糖复合β-乳球蛋白负载EGCG纳米粒的制备及其对糖尿病小鼠血糖的影响

表没食子儿茶素没食子酸酯（EGCG）作为茶叶中主要生物活性成分,具有良好的生理功能,但低稳定性使其容易被氧化降解,生物利用率低。利用羧甲基壳聚糖（CMC）、壳聚糖盐酸盐（CHC）、β-乳球蛋白（β-LG）作为壁材,制备壳聚糖复合β-乳球蛋白负载EGCG纳米粒,通过透射电镜、结构表征（粒径、Zeta电位测定）对颗粒微观形态进行观察,利用高效液相色谱仪对颗粒包埋率、模拟胃肠液释放率进行测定,最后建立糖尿病小鼠模型,探究包埋后颗粒的降血糖活性。结果表明,CS-β-LG-EGCG纳米粒结构完整、粒径10~100 nm、粒子分散;包埋率大于50%,且在肠液和胃液中具有缓释作用;CS-β-LG-EGCG纳米粒与胰岛素无拮抗作用,与未包埋的EGCG相比,包埋后颗粒具备的缓释作用可减缓血糖的回升。     

不同温度处理对离体培养玉米子粒发育的影响研究

以玉米杂交种农单5号和农大108为材料,采用玉米子粒离体培养的方法研究了不同温度处理对子粒发育的影响,并对子粒败育率、粒重、可溶性糖和淀粉含量进行了测定。结果表明,2个品种对温度影响表现出相同的趋势:与18℃、38℃相比,28℃下子粒发育最好,子粒败育率低、粒重高。在18℃和38℃下,子粒的可溶性糖含量高而淀粉含量低。28℃条件下较适合子粒的发育。     

Expression of the Antimicrobial Peptide Piscidin 1 and Neuropeptides in Fish Gill and Skin: A Potential Participation in Neuro-Immune Interaction

Antimicrobial peptides (AMPs) are found widespread in nature and possess antimicrobial and immunomodulatory activities. Due to their multifunctional properties, these peptides are a focus of growing body of interest and have been characterized in several fish species. Due to their similarities in amino-acid composition and amphipathic design, it has been suggested that neuropeptides may be directly involved in the innate immune response against pathogen intruders. In this review, we report the molecular characterization of the fish-specific AMP piscidin1, the production of an antibody raised against this peptide and the immunohistochemical identification of this peptide and enkephalins in the neuroepithelial cells (NECs) in the gill of several teleost fish species living in different habitats. In spite of the abundant literature on Piscidin1, the biological role of this peptide in fish visceral organs remains poorly explored, as well as the role of the neuropeptides in neuroimmune interaction in fish. The NECs, by their role as sensors of hypoxia changes in the external environments, in combination with their endocrine nature and secretion of immunomodulatory substances would influence various types of immune cells that contain piscidin, such as mast cells and eosinophils, both showing interaction with the nervous system. The discovery of piscidins in the gill and skin, their diversity and their role in the regulation of immune response will lead to better selection of these immunomodulatory molecules as drug targets to retain antimicrobial barrier function and for aquaculture therapy in the future.     

信息技术对海南热带农业发展的影响

以发展海南热带农业的重要性为出发点,结合热带农业在生产过程中的信息内容,着重分析信息技术在海南农业上的应用动力,海南热带农业发展过程中对信息的需求,阐述海南农业信息技术发展的现状及发展趋势。     

叶片数量调控对雾培马铃薯生长发育的影响

通过去叶和植株下放的处理方式改变雾化栽培马铃薯植株的源强来探讨源器官调控对植株生长的影响。结果表明:去叶和植株下放能显著增加雾化栽培马铃薯植株的高度,但会极显著降低植株的茎粗、分枝数、根系体积、单株匍匐茎数和单株合格薯块数。