不同剂量前列腺素E2对H9c2心肌细胞肥大的影响

目的: 研究前列腺素E2(PGE2)对H9c2心肌细胞的肥大作用,并分析其量效关系,为寻找抗心肌肥大的潜在靶点提供理论依据。方法: 将H9c2心肌细胞分为空白对照组(C组)和PGE2处理组,PGE2处理组又分为小剂量PGE2组(D1组)、中剂量PGE2组(D2组)和大剂量PGE2组(D3组)。各组细胞培养液中PGE2终浓度分别为0、0.1、1及 10 μmol/L。给药孵育 48 h 后,利用荧光显微镜观察大鼠H9c2心肌细胞形态及体积;通过测量细胞直径大小、BCA法测定细胞总蛋白含量来确定心肌细胞是否肥大;RT-PCR技术测量心钠肽(Atrial natriuretic peptide, ANP)、脑钠肽(Brain natriuretic peptide, BNP) mRNA的表达水平,以此判断是否发生病理性肥大。结果: 与C组比较,免疫荧光显示D1组、D2组及D3组细胞形态改变、体积增大;细胞直径及总蛋白含量显著增加(P<0.05),不同剂量PGE2组间亦具有统计学差异(P<0.05);D2组及D3组较C组细胞内ANP、BNP mRNA表达水平显著增高(P<0.05)。结论: PGE2可剂量依赖地诱导H9c2心肌细胞肥大,较大剂量PGE2引发心肌细胞病理性肥大。抑制PGE2合成有望为抑制心肌肥大提供靶点。     

人参多糖对兔肝缺血/再灌注损伤时TXB2／PG1α平衡的调控作用

目的:观察肝缺血/再灌注损伤时血栓素B₂ (Thromboxane B₂, TXB₂ )、前列环素F₁α (Prostaglandin F_1α, PGF_1α) 、TXB₂/PGF₁α比值变化和人参多糖的干预作用。方法: 30只家免,随机均分为对照组(C组)、缺血/再灌注组(IR组)和人参多糖组(GP组)。分别检测三组缺血前 10 min、缺血 45 min 及再灌注 45 min 后血浆中TXB₂、PGF_1α、ALT及TXB₂/PGF_1α比值的变化,电镜下观察肝细胞超微结构的改变。结果: IR组血浆TXB₂ 各对应时间点浓度均较C组明显升高, PGF_1α含量再灌注 45 min 时较缺血前显著下降,TXB₂/PGF_1α比值明显增高,肝细胞超微结构显著异常。使用人参多糖注射液后,血浆TXB₂浓度较IR组同期水平降低,PGF_1α再灌注45 min显著高于IR组同期水平,TXB₂／PGF_1α显著低于IR组,尤以再灌注45 min为著,肝细胞超微结构异常较IR组有所减轻。结论:人参多糖可通过调节TXB₂/PGF_1α之间的平衡,改善肝脏微循环,从而防治肝缺血/再灌注损伤。     

LC-MS／MS法测定前列地尔注射液中前列腺素A1

目的：建立高效液相色谱一四极杆串联质谱联用法（LC-MS／MS法）测定前列地尔注射液中前列腺素A1的含量。方法：前列地尔注射液经稀释后,采用Agilent．poroshell120SB—C18色谱柱（2．1×50mill,2．7μm）进行分析,流动相为乙腈-0．5％甲酸水溶液,流速0．2mL／min;质谱采用电喷雾离子化（ESI）源,负离子-多反应监测（MRM）模式,内标法定量。结果：前列腺素A1的线性范围为0．3—10ng／mL;平均回收率为100．2％,RSD为1．69％。3批样品每1mL中含前列腺素A1均来过3．0μg。结论：该方法准确、简单、快速,可用于前列地尔注射液中前列腺素A1的测定。     

Polymethoxy flavones are responsible for the anti-inflammatory activity of citrus fruit peel

In traditional Chinese medicine, dried citrus fruit peels are widely used as remedies to alleviate some respiratory inflammatory syndromes and are considered as potential sources of anti-inflammatory components. Seven citrus fruits were selected for this study. We determined the inhibitory ability of citrus peel extracts on the production of pro-inflammatory mediators, prostaglandin E₂ (PGE₂) and nitric oxide (NO), in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Among the tested citrus peels, Ponkan (Citrus reticulata Blanco) and Tonkan (Citrus tankan Hayata) deserve special attention due to their outstanding inhibitory effect on PGE₂ and NO secretion. We have also examined the composition, flavanone glycosides and polymethoxy flavones. The polymethoxy flavone content, especially nobiletin, appears to correlate well with the anti-inflammatory activities of certain citrus peel extracts. Thus, our results suggest that polymethoxy flavones contribute crucially to the anti-inflammatory activity of citrus peels.     

Triglycerides constituted of short and medium chain fatty acids and dicarboxylic acids in Momordica charantia, as well as capric acid,inhibit PGE2 production in RAW264.7 macrophages

This study was aimed to identify compounds in bitter gourd (Momordica charantia) ethyl acetate extract (EAE), which inhibit lipopolysaccharide-induced prostaglandin E₂ (PGE₂) production in RAW264.7 cells. Bitter gourd EAE was partitioned between n-hexane and methanol/H₂O (90/10). The hexane fraction was further separated by repeated silica gel chromatographies, and a reverse phase (RP) C18 chromatography. Fraction RP-10 showed the highest inhibition effect on PGE₂ production (Max inhibition = 96%, IC₅₀ = 2.3 μg/ml) and was identified to be triglycerides constituted of short and medium chain fatty acids by ¹H NMR, IR and H–HCOSY, and dicarboxylic acids by GC/MS. Fatty acids with 3–20 carbons were tested for the inhibitory activity, and capric acid exhibited the highest effect (Max inhibition = 99%, IC₅₀ = 6.5 μM). In conclusion, triglycerides composed of short and medium chain fatty acids and dicarboxylic acids in bitter gourd inhibit PGE₂ production, and capric acid is the most potent inhibitor among the fatty acids.     

Industrial applications of crustacean by-products (chitin,chitosan, and chitooligosaccharides): A review

BackgroundFood processing produces large quantities of by-products. Disposal of waste can lead to environmental and human health problems, yet often they can be turned into high value, useful products. For example, crustacean shell wastes from shrimp, crab, lobster, and krill contain large amounts of chitin, a polysaccharide that may be extracted after deproteinisation and demineralization of the exoskeletons.Scope and approachThis review summarizes the current state of knowledge of these crustacean shellfish wastes and the various ways to use chitin. This biopolymer and its derivatives, such as chitosan, have many biological activities (e.g., anti-cancer, antioxidant, and immune-enhancing) and can be used in various applications (e.g., medical, cosmetic, food, and textile).Key findings and conclusionsDue to the huge waste produced each year by the shellfish processing industry and the absence of waste management which represent an environmental hazard, the extraction of chitin from crustaceans’ shells may be a solution to minimize the waste and to produce valuable compound which possess biological properties with application in many fields. As a food waste, it is important to also be aware of the non-food uses of these wastes.     

Pinolenic acid inhibits human breast cancer MDA-MB-231 cell metastasis in vitro

Pinolenic acid (PNA), a naturally-occurring polyunsaturated fatty acid (PUFA), is found mainly in pine seeds. Although many studies have demonstrated beneficial effects of pine seed oil, there are no reports of the biological effects of PNA on cancer metastasis. The objective of this study was to investigate the effect of PNA on human breast cancer MDA-MB-231 cell proliferation and metastasis in vitro. We found that PNA did not affect cell viability and cell-matrix adhesion, but it inhibited cell metastasis by suppressing cell invasiveness and motility. Suppression could in part be associated with the modification of the n−6 PUFA composition of cells by PNA which significantly decreased the percentage of arachidonic acid (AA) in phospholipids from 12.6% to 4.9%. The lower AA content of the cancer cells might result in less synthesis of prostaglandin E₂ (PGE₂), and subsequent down-regulation of inducible cyclooxygenase (COX-2) expression. Thus, PNA represents a potential anti-cancer agent.     

Dietary n-3 and n-6 PUFA Enhance DHA Incorporation in Retinal Phospholipids Without Affecting PGE<Subscript>1</Subscript> and PGE<Subscript>2</Subscript> Levels

The purpose of this study was to determine whether dietary n-3 and n-6 PUFA may affect retinal PUFA composition and PGE₁ and PGE₂ production. Male Wistar rats were fed for 3 months with diets containing: (1) 10% eicosapentaenoic acid (EPA) and 7% docosahexaenoic acid (DHA), or (2) 10% γ-linolenic acid (GLA), or (3) 10% EPA, 7% DHA and 10% GLA, or (4) a balanced diet deprived of EPA, DHA, and GLA. The fatty acid composition of retinal phospholipids was determined by gas chromatography. Prostaglandin production was measured by enzyme immunoassay. When compared to rats fed the control diet, the retinal levels of DHA were increased in rats fed both diets enriched with n-3 PUFA (EPA + DHA and EPA + DHA + GLA diets) and decreased in those supplemented with n-6 PUFA only (GLA diet). The diet enriched with both n-6 and n-3 PUFA resulted in the greatest increase in retinal DHA. The levels of PGE₁ and PGE₂ were significantly increased in retinal homogenates of rats fed with the GLA-rich diet when compared with those of animals fed the control diet. These higher PGE₁ and PGE₂ levels were not observed in animals fed with EPA + DHA + GLA. In summary, GLA added to EPA + DHA resulted in the highest retinal DHA content but without increasing retinal PGE₂ as seen in animals supplemented with GLA only.     

Bioactivity and chemical composition of blackcurrant (Ribes nigrum) cultivars with and without pesticide treatment

Eleven blackcurrant cultivars grown with pesticide (PT) and without pesticide treatment (PF) were evaluated to compare the differences in plant growth and physical condition, total anthocyanin content, ascorbic acid content, total antioxidant capacity, effect on prostaglandin E2 (PGE2) production and anticancer cell proliferation activities. Results showed that the yield and growth of PT blackcurrants were higher. However, PF blackcurrants contained a higher amount of ascorbic acid, and displayed an increased inhibition against cancer cells compared to PT blackcurrants, indicating that PF blackcurrants have an increased potential to deliver health-promoting benefit for consumers. Significant differences were observed between blackcurrant cultivars in relation to plant growth and physical condition, total anthocyanin content and PGE2 assay, highlighting the importance of cultivar selection.