Analysis of Phytochemical Composition of Camellia oleifera Oil and Evaluation of its Anti-Inflammatory Effect in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

In China, Camellia oleifera oil (COO) is not only a common edible oil but also a traditional remedy widely applied to ameliorate a variety of illnesses associated with inflammation, such as mouth ulcers, thrush, eczema, etc. However, there has been a lack of relevant biological research on the anti-inflammatory capacity of COO, and the specific bioactive lipid phytochemicals contributing to the anti-inflammatory effect need further research. In this study, the RAW 264.7 macrophages model was used to investigate the anti-inflammatory capacity of COO. Our data showed that 33–200 μg/mL COO markedly inhibited the lipopolysaccharide lipopolysaccharide (LPS)-stimulated nitric oxide (NO.) secretion via the suppression of Nos2 and Cox-2 expression. The enzyme immunoassay confirmed that COO also exhibited a strong suppressive effect on the expression of proinflammatory cytokines such as Tnf-α and Il-6. To further explore the correlation between the anti-inflammatory effects and the lipid phytochemicals in COO, 10 samples were collected and screened for their chemical compositions. It was interestingly demonstrated that the polyphenol extracts of COO play a vital role in its anti-inflammatory properties. In addition, an oil-in-water (O/W) emulsion-based system was also developed to deliver the liposoluble COO into the cells, and the feasibility of this system was confirmed. Our research confirms the anti-inflammatory potential of COO and highlights that the main functional ingredient is polyphenol extracts. This may provide a scientific basis for the comprehensive utilization and development of COO and related functional foods.     

野生亚侧耳多糖的提取和对巨噬细胞Raw264.7的免疫调节作用研究

本研究从亚侧耳子实体中分离出水溶性亚侧耳多糖(HSP),通过体外实验评估其对Raw264.7巨噬细胞的免疫调节作用。采用WST-1法检测HSP对巨噬细胞增殖作用的影响,Griess试剂检测一氧化氮(NO)浓度,ELISA法检测HSP对淋巴细胞中一肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素-1β(interleukin-1β,IL-1β)和前列腺素E2(prostaglandins E2,PGE₂)等细胞因子分泌量的影响,反转录聚合酶链式反应分析诱导型一氧化氮合酶(iNOS)、环氧化酶-2(COX-2)、白细胞介素-6(IL-6)、TNF-α和IL-1β的转录水平表达量。结果表明,HSP可显著提高Raw264.7细胞内NO的浓度,在HSP浓度为100.00 μg/mL时,NO的分泌量达到最大值(29.94 mmol/L)。与空白组相比,HSP可以显著提高TNF-α、IL-1β、PGE₂等免疫因子(P<0.05)的分泌量,其中IL-1β、PGE₂的25 μg/mL剂量组中各因子分泌量(31.9524 pg/mL,1.8174 ng/mL)均与LPS(脂多糖)阳性对照组相接近。反转录聚合酶链式反应分析结果表明,HSP能够提高iNOS和COX-2的蛋白表达量。HSP具有免疫调节的功能,可以作为免疫调节剂添加到功能性食品和药品中。     

Chrysin,Apigenin and Acacetin Inhibit Tumor Necrosis Factor-Related Apoptosis—Inducing Ligand Receptor-1 (TRAIL-R1) on Activated RAW264.7 Macrophages

Expression level of Tumor Necrosis Factor—related apoptosis—inducing ligand (TRAIL) receptors is one of the most important factors of TRAIL-mediated apoptosis in cancer cells. We here report for the first time data concerning TRAIL-R1 and TRAIL-R2 receptor expression on RAW264.7 macrophages. Three substances belonging to flavones: chrysin, apigenin and acacetin which differ from their substituents at the 4'' position in the phenyl ring were used in assays because of the variety of biological activities (e.g., anticancer activity) of the polyphenol compounds. The expression of TRAIL-R1 and TRAIL-R2 death receptors on non-stimulated and LPS (lipopolysaccharide)-stimulated macrophages was determined using flow cytometry. We demonstrate that RAW264.7 macrophages exhibit TRAIL-R1 surface expression and that the tested compounds: chrysin, apigenin and acacetin can inhibit TRAIL-R1 death receptor expression level on macrophages.     

Photoshop 中两种图像变小方法对比分析

由于存储介质、传输速度等因素的限制,通常需要将大的图像文件变小。Photoshop 中主要有两种图像变小的 方法：一种是在存储文件时选择更低品质的JPEG 压缩格式;一种是在重定图像像素的情况下降低图像的分辨率。多数PS 用 户不清楚这两种方法的区别与联系,以及针对实际应用如何进行选择。国内外也缺少对此方面的研究。本文从原理、对图像 的影响等方面对这两种图像变小方法进行了对比分析,并引用了三个现实中的实例,有针对性地论述了如何选用两种图像变 小方法,对PS 用户有现实的指导意义。     

二十二碳六烯酸免疫调节活性

以小鼠巨噬细胞RAW264.7细胞为研究对象,采用噻唑蓝法、细胞染色法、相关酶活力的测定以及蛋白 免疫印迹等方法,研究二十二碳六烯酸（docosahexaenoic acid,DHA）的免疫调节活性。噻唑蓝实验结果表明, 当DHA质量浓度为800 ng/mL,作用48 h时,RAW264.7细胞增殖率达到最大值,为73.03%。中性红实验结果表 明DHA可以显著增强RAW264.7细胞的吞噬活性。扫描电子显微镜结果显示DHA具有促进RAW264.7细胞活化的 作用;吖啶橙染色结果表明在DHA作用下,细胞核酸代谢旺盛,RAW264.7细胞被激活;糖原染色结果表明DHA 能通过促进RAW264.7细胞内糖原代谢加快细胞的分化。通过对RAW264.7细胞中相关酶活力的测定,结果表明 DHA能够显著提高酸性磷酸酶、溶菌酶和超氧化物歧化酶的活力。丝裂原活化蛋白激酶（mitogen-activated protein kinases,MAPKs） 蛋白通路结果表明：DHA能够引起细胞外信号调节激酶1/2、p38和应激活化蛋白激酶出现一定 程度的磷酸化,说明DHA诱导巨噬细胞激活部分依赖了MAPKs信号转导通路。以上研究结果证明：DHA具有一定 的免疫调节活性,可为DHA的应用提供理论依据。     

Antioxidant and nitric oxide production inhibitory activities of galacturonyl hydroxamic acid

The self-prepared pectin hydroxamic acid has been reported to have antioxidant activities [Yang, S. S., Cheng, K. D., Lin, Y. S., Liu, Y. W., & Hou, W. C. (2004). Pectin hydroxamic acids exhibit antioxidant activities in vitro. Journal of Agricultural and Food Chemistry, 52, 4270–4273]. In this study, the galacturonic acid (GalA), the monomer unit of the pectin polymer, was esterified with acidic methanol (1 N HCl) at 4 °C with gentle stirring for 5 days to get galacturonic acid methyl ester which was further reacted with alkaline hydroxylamine to get galacturonyl hydroxamic acid (GalA–NHOH). The GalA–NHOH was used to test the antioxidant and antiradical activities in the comparison with GalA. The scavenging activities of GalA–NHOH against DPPH radicals (half-inhibition concentration, IC₅₀, was 82 μM), hydroxyl radicals detected by electron spin resonance (IC₅₀ was 0.227 nM in the comparison with Trolox of 0.433 μM), superoxide radicals (IC₅₀ was 830 μM) were determined. The protection activities of GalA–NHOH against hydroxyl radicals-mediated calf thymus DNA damages, linoleic acid peroxidation and peroxynitrite-mediated dihydrorhodamine 123 oxidations were also investigated. It was found that the GalA–NHOH exhibited dose-dependently antioxidant activity and few or none was found in GalA. The GalA–NHOH was used to evaluate the suppressed activity of nitric oxide (NO) productions of RAW264.7 cells in the presence of lipopolysaccharide (LPS, 100 ng/ml) as inducers. It was found that GalA–NHOH (0.02–0.1 mg/ml) could dose-dependently suppress the NO productions (expressed as nitrite concentrations) in RAW264.7 cells without significant cytotoxicity.