Comparison of phytochemical profiles,antioxidant and cellular antioxidant activities of seven cultivars of Aloe

A comparative assessment of the phytochemical profiles and antioxidant activities of seven cultivars of Aloe was conducted to evaluate the potential health benefits of Aloe. Aloe arborescens contained the highest levels of phenolic content, total antioxidant capacity by the oxygen radical scavenging capacity assay and cellular antioxidant activity assay. Aloe vera showed the highest levels of flavonoid content and antioxidant capacity by the peroxyl radical scavenging capacity assay. Aloe greenii had the highest CAA value with a PBS wash before adding ABAP. There were no significant differences observed between Aloe arborescens and Aloe greenii. Aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside, catechin, epicatechin, sinapic acid and chlorogenic acid were identified in Aloe samples by the HPLC analysis. Aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside and catechin showed strong relationships with antioxidant activity. Significant levels of aloin, aloe‐emodin‐8‐O‐beta‐D‐glucopyranoside and catechin were determined in Aloe greenii, Aloe vera and Aloe saponaria, respectively.     

芦荟多糖对D-半乳糖致HepG2细胞氧化损伤的保护作用

目的:探讨芦荟多糖对HepG2细胞氧化损伤的保护作用,分析其体外抗氧化能力。方法:以HepG2细胞为研究对象,建立D-半乳糖诱导细胞氧化损伤模型,以不同浓度芦荟多糖进行预保护处理。采用细胞增殖与毒性检测试剂盒测定HepG2细胞存活率,生物化学法检测细胞超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶活力,酶联免疫吸附法测定细胞总抗氧化能力及丙二醛（malondialdehyde,MDA）含量,实时荧光定量PCR检测细胞Keap1、Nrf2、NQO1和HO-1基因表达水平。结果:与D-半乳糖模型组比较,25、50、100 μg/mL的芦荟多糖预保护处理能不同程度地提高HepG2细胞存活率;芦荟多糖能显著增强细胞中抗氧化酶的活性,降低细胞MDA的生成量（P<0.05）,且作用效果与芦荟多糖浓度成正比;细胞中Keap1基因表达显著降低,Nrf2、NQO1、HO-1 mRNA表达显著提高（P<0.05）。结论:芦荟多糖可以减轻HepG2细胞的氧化应激损伤,激活Nrf2表达并抑制其泛素化降解,提高下游NQO1、HO-1的转录水平,增强细胞抗氧化酶系活性并调控细胞氧化还原系统,以达到减轻细胞氧化损伤程度、提高细胞抗氧化应激损伤的效果。     

Antioxidant activity and hepatoprotective effect of Schizandra chinensis Baill. Extracts containing active components in alcohol-induced HepG2 cells

The antioxidant activities and hepatoprotective effects of Schizandra chinensis Baill. extracts (SCE) were evaluated. The contents of the active components schisandrin, schisandrin C, gomisin A, and gomisin N in SCE were 8.802±1.390, 1.011±0.203, 0.954±0.191, and 3.351±0.829 mg/g, respectively. The antioxidant activity of SCE was measured based on the DPPH free radical scavenging activity and the superoxide dismutase (SOD)-like activity. The IC₅₀ values for the DPPH radical scavenging activity and SOD-like activity were 18.1 and 44.2mg/mL, respectively. The protective effect of SCE against alcohol-induced oxidative injury in HepG2 cells was investigated. Cells pretreated with SCE (100–400 μg/mL) showed an increased resistance to oxidative stress in a dose-dependent manner. Expressions of Bcl-2 and pro-caspase-3 proteins were induced by SCE in HepG2 cells. SCE can be useful for management of antioxidant and hepatoprotective effects.     

Isolation and identification of compound from dropwort (Oenanthe javanica) with protective potential against oxidative stress in HepG2 cells

The protective effect of dropwort (Oenanthe javanica) was investigated in HepG2 cells under oxidative stress, and its active compound was identified. Compared to H₂O₂-alone treated cells, a drastic increase (35%) in protective activity was observed in the cells pretreated with 80% ethanol extract (OJE) of dropwort, suggesting that OJE possessed a potent hepatoprotectant. After a sequential procedure consisting of solvent-partitioning chromatography, TLC, and HPLC was conducted, the compound with proven hepatoprotective activity from OJE was isolated and identified as caffeic acid. Results indicated that caffeic acid in dropwort contributed to this herb’s protective profile against oxidative stress-induced liver damage.     

Emodin,a natural inhibitor of protein kinase CK2, suppresses growth,hyphal development,and biofilm formation of Candida albicans

Emodin (1,3,8‐trihydroxy‐6‐methyl‐anthraquinone) is a natural secondary plant product, originally isolated from the rhizomes of Rheum palmatum. Many reports show its diuretic, vasorelaxant, antibacterial, antiviral, anti‐ulcerogenic, immunosuppressive, hepatoprotective, anti‐inflammatory and anticancer potential. Emodin is a pleiotropic molecule capable of interacting with several major molecular targets, e.g. NF‐κB, AKT/mTOR and STAT3. The compound can also act as an inhibitor of some protein kinases, with special affinity to protein kinase CK2. The aim of the presented report was to evaluate antifungal properties of emodin and its activity towards CK2 isolated from Candida cells. Our studies revealed that the compound suppressed growth of the cells of reference strains as well as clinical Candida strains, with minimal inhibitory concentration and minimal fungicidal concentration values between 12.5 and 200 μg/mL. Moreover, at a low concentration, the compound was able to effectively stop hyphal formation, thus showing a distinct antivirulent potential. Interestingly, we showed that emodin added to Candida culture inhibited the phosphorylation of many cellular proteins, presumably owing to the inhibition of protein kinase CK2. Notably, the enzyme isolated from the Candida cells was susceptible to emodin with IC₅₀ of 2.8 μg/mL. Indeed, our computational modelling revealed that emodin was able to occupy the ATP‐binding pocket of CK2. Copyright © 2017 John Wiley & Sons, Ltd.     

Yogurt and Streptococcus thermophilus metabolites ameliorated telomere attrition in D-galactose-induced ageing mice and t-BHP-challenged HepG2 cells

Antioxidant-rich diets affect telomere length, an integrative marker associated with age-related diseases. Yogurt exerts antioxidative capacity and is speculated to support healthy ageing. However, direct experimental evidence is missing. Here, the effects of yogurt and dairy-fermenting bacteria on D-galactose-induced ageing mice and chemically challenged HepG2 cells were evaluated. Relative telomere length (RTL) in leucocyte and liver were significantly longer in yogurt (1.21 ± 0.07; 1.23 ± 0.11) and Streptococcus thermophilus group (1.18 ± 0.15; 1.13 ± 0.12). When t-BHP-challenged HepG2 cells were treated with digested yogurt and S. thermophilus, the senescence index (13.67 ± 3.30; 19.67 ± 2.87) were lower and RTL (1.25 ± 0.11; 1.18 ± 0.10) were longer than the model. Antioxidative effects were observed for yogurt and S. thermophilus metabolites, whereas milk and Lactobacillus rhamnosus metabolites showed minimal influence on RTL and oxidative stress. In conclusion, this study showed that yogurt and S. thermophilus metabolites ameliorated telomere attrition in ageing mice and t-BHP-challenged HepG2 cells, possibly by reducing oxidative stress.     

Dihydrocaffeic acid,a major microbial metabolite of chlorogenic acids,shows similar protective effect than a yerba mate phenolic extract against oxidative stress in HepG2 cells

The hepatoprotective effect of a yerba mate phenolic extract (YMPE), rich in chlorogenic acids, and its main circulating metabolites dihydrocaffeic (DHCA) and dihydroferulic (DHFA) acids were assessed in human hepatoma HepG2 cells subjected to oxidative damage induced by tert-butylhydroperoxide (t-BOOH). Direct treatment of HepG2 cells with realistic concentrations of YMPE (1, 10 and 50 μg/mL), DHCA or DHFA (0.2, 1, 10 μM) for 20 h was not cytotoxic and significantly decreased ROS generation. Pre-treatment with YMPE and DHCA prevented the cytotoxicity and macromolecular damage induced by t-BOOH. Moreover, decreased levels of reduced glutathione (GSH), and increased ROS levels and antioxidant enzyme activity induced by t-BOOH were dose-dependently recovered. DHFA only showed a slight protection against cell cytotoxicity, lipid oxidation and GSH depletion. In conclusion, YMPE and one of its major microbial metabolites, DHCA, confer significant protection against oxidative damage, adding evidences to the beneficial health effects associated with mate intake.     

Suppressive effect of ethyl acetate extract of Teucrium polium on cellular oxidative damages and apoptosis induced by 2-deoxy-d-ribose: Role of de novo synthesis of glutathione

The effect of ethyl acetate (EtOAc) extract of Teucrium polium on 2-deoxy-d-ribose (dRib)-induced oxidative stress and apoptosis in erythroleukemic K562 cells was investigated. K562 cells exposed to dRib (50 mM) exhibited abnormal properties such as overproduction of reactive oxygen species, lipid peroxidation, glutathione (GSH) depletion and biochemical features of apoptosis. Treatment with EtOAc extract (25 and 50 μg/ml) reduced oxidative stress and apoptosis among the dRib-treated K562 cells. To disclose the mode of action, the effect of the extract on the cellular GSH and its synthesis by γ-glutamylcysteine synthetase (γ-GCS), a key rate-limiting enzyme of the GSH synthetic pathway, were evaluated. The results demonstrated that the antioxidant property of EtOAc extract mainly results from increasing the level of cellular GSH by inducing the activity of γ-GCS. It can be concluded that the EtOAc extract of T. polium prevents dRib-induced oxidative stress and apoptosis mostly through antioxidative mechanisms.     

Protective effects of sweet orange (Citrus sinensis) peel and their bioactive compounds on oxidative stress

Protective effects of sweet orange (Citrus sinensis) peel and their bioactive compounds on oxidative stress were investigated. According to HPLC-DAD and HPLC-MS/MS analysis, hesperidin (HD), hesperetin (HT), nobiletin (NT), and tangeretin (TT) were present in water extracts of sweet orange peel (WESP). The cytotoxic effect in 0.2 mM t-BHP-induced HepG2 cells was inhibited by WESP and their bioactive compounds. The protective effect of WESP and their bioactive compounds in 0.2 mM t-BHP-induced HepG2 cells may be associated with positive regulation of GSH levels and antioxidant enzymes, decrease in ROS formation and TBARS generation, increase in the mitochondria membrane potential and Bcl-2/Bax ratio, as well as decrease in caspase-3 activation. Overall, WESP displayed a significant cytoprotective effect against oxidative stress, which may be most likely because of the phenolics-related bioactive compounds in WESP, leading to maintenance of the normal redox status of cells.     

Antioxidant Potential and Type II Diabetes-Related Enzyme Inhibition of Cassia obtusifolia L.: Effect of Indigenous Processing Methods

The methanolic extract of Cassia obtusifolia L. (Sicklepod) seed, an underutilized food legume from India, was analyzed for antioxidant and health relevant functionality. The total free phenolic content of the raw seeds was 13.33?±?1.73?g catechin equivalent/100?g extract. The extract exhibited 1,292?mmol Fe[II] per milligram extract of ferric reducing/antioxidant power, 49.92% inhibition of ?-carotene degradation, 65.79% of scavenging activity against DPPH, and 50.78% of superoxide radicals. The in vitro starch digestion bioassay of the extract showed 79.80% of ??-amylase and 81.04% of ??-glucosidase enzyme inhibition characteristics. Sprouting?+?oil frying caused an apparent increase on the total free phenolic content with significant improvement on the antioxidant and free radical scavenging capacity of C. obtusifolia seeds, while soaking?+?cooking as well as open-pan roasting treatments show diminishing effects. Inhibition of ??-amylase and ??-glucosidase enzyme activity was 23.81% and 42.36%, respectively, following sprouting?+?oil-frying treatment. These enzyme inhibition values were similar to that of synthetic antidiabetic agent acarbose.     

Composition,characteristics, and in-vitro physiological effects of the water-soluble polysaccharides from Cassia seed

The popular beverage ingredients Cassia obtusifolia and Cassia tora were found to have considerable amounts of water-soluble polysaccharides (WSPs) (58.5 and 55.9/100 g of dried extract). The composition, characteristics, and in-vitro physiological effects of these polysaccharides and their possible health benefits were investigated. The major polysaccharide components in the WSP of C. obtusifolia were possibly pectic polysaccharides and hemicellulose, while C. tora WSP was mainly composed of arabinoglucan and pectic polysaccharides. These WSPs had inhibitory effects on the activities of α-amylase and pancreatic lipase, while they rendered an increase in protease activity. These WSPs also had the ability to bind bile acids and reduce the amount of cholesterol available for absorption. This suggested that these WSPs had potential application as herbal ingredients in beverages. Further investigations on their in-vivo hypocholesterolaemic effects and intestinal functions using animal-feeding experiments are under way.     

Hepatoprotective peptides purified from Corbicula fluminea and its effect against ethanol-induced LO2 cells injury

This study was focused on the purification, identification and mechanism of hepatoprotective peptides from Corbicula fluminea by using Sephadex G-15 chromatography, UPLC–MS/MS, oxygen radical absorbance capacity (ORAC) assay, cell experiment and molecular docking. Six identified peptides were synthesised chemically and subjected to evaluate hepatoprotective effect. ORAC value and hepaprotective effect against ethanol-induced LO2 cell injury in vitro were determined. The results showed that Tyr-Phe-Leu-Pro (YP-4) and Leu-Val-Tyr-Pro (LP-4) exhibited the strongest antioxidant activity and significantly increased the viability of ethanol-injured LO2 cells. These two peptides significantly reduced ROS levels and efficiently inhibited the decrease of mitochondrial membrane potential in ethanol-injured LO2 cells. Molecular docking revealed that YP-4 and LP-4 possess potential inhibitory activity on CYP2E1 and thus reduce ethanol-induced oxidative stress. It is suggested that YP-4 and LP-4 have good hepatoprotective effect against alcoholic liver injury.     

Chemical characterization and chemo-protective activity of cranberry phenolic powders in a model cell culture. Response of the antioxidant defenses and regulation of signaling pathways

Oxidative stress and reactive oxygen species (ROS)-mediated cell damage are implicated in various chronic pathologies. Emerging studies show that polyphenols may act by increasing endogenous antioxidant defense potential. Cranberry has one of the highest polyphenol content among commonly consumed fruits. In this study, the hepato-protective activity of a cranberry juice (CJ) and cranberry extract (CE) powders against oxidative stress was screened using HepG2 cells, looking at ROS production, intracellular non-enzymatic and enzymatic antioxidant defenses by reduced glutathione concentration (GSH), glutathione peroxidase (GPx) and glutathione reductase (GR) activity and lipid peroxidation biomarker malondialdehyde (MDA). Involvement of major protein kinase signaling pathways was also evaluated. Both powders in basal conditions did not affect cell viability but decreased ROS production and increased GPx activity, conditions that may place the cells in favorable conditions against oxidative stress. Powder pre-treatment of HepG2 cells for 20 h significantly reduced cell damage induced by 400 μM tert-butylhydroperoxide (t-BOOH) for 2 h. Both powders (5–50 μg/ml) reduced t-BOOH-induced increase of MDA by 20% (CJ) and 25% (CE), and significantly reduced over-activated GPx and GR. CE, with a significantly higher amount of polyphenols than CJ, prevented a reduction in GSH and significantly reduced ROS production. CJ reversed the t-BOOH-induced increase in phospho-c-Jun N-terminal kinase. This study demonstrates that cranberry polyphenols may help protect liver cells against oxidative insult by modulating GSH concentration, ROS and MDA generation, antioxidant enzyme activity and cell signaling pathways.     

Effects of Graptopetalumparaguayense extract on tert‐ butylhydroperoxide‐induced oxidative stress

BACKGROUND: Graptopetalum paraguayense E. Walther is used in folk medicine to lower blood pressure, protect liver function and relieve pain and infection. The effect and mechanism of its 50% ethanolic extract (GE50) were investigated in tert‐butylhydroperoxide (t‐BHP)‐induced Wistar rats. The serum was analysed for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities while the tissue cytosols were analysed for lipid peroxidation, antioxidant level and enzyme activities. RESULTS: The liver was the primary target organ while the heart appeared to be the least responsive organ for t‐BHP treatment among the three tissues investigated. t‐BHP treatment increased serum AST and ALT activities, which are indicators of liver toxicity, while GE50 pretreatment reduced t‐BHP‐induced liver damage. t‐BHP treatment induced lipid peroxidation in the liver and brain but not in the heart. GE50 pretreatment prevented t‐BHP‐induced lipid peroxidation by maintaining superoxide dismutase (SOD) activity as well as glutathione (GSH) and vitamin C levels in the liver and vitamin E level in the brain. Although t‐BHP treatment did not induce lipid peroxidation in the heart, it caused a decrease in antioxidant level. GE50 pretreatment prevented the t‐BHP‐induced decrease in vitamin C level in the heart. CONCLUSION: GE50 pretreatment in rats protects the liver and brain from possible damage by t‐BHP‐induced lipid peroxidation. Copyright © 2007 Society of Chemical Industry     

Choleretic Activity of Turmeric and its Active Ingredients

Turmeric, a rhizome of Curcumin longa L. is widely used as both a spice and an herbal medicine. The traditional use of turmeric in gastroenterology is mainly based on its choleretic activity. The aim of this study is to determine the effects of turmeric on bile flow (BF) and total bile acids (TBAs) excretion in a bile fistula rat model after acute duodenal administration. A significant dose‐dependent enhancement in both BF and TBAs was detected after treatment with the turmeric decoctions which suggested the choleretic activity was bile acid‐dependent secretion. In order to direct the active group of compounds, aqueous (AE), ethyl acetate (EtOAc), and petroleum ether (PE) extracts were investigated. The EtOAc and PE extracts showing high effects were purified to locate the active ingredients. Three curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) and 2 sesquiterpenes (bisacurone B and ar‐turmerone) were isolated. It was found Bisacurone B was the most potent choleretic ingredient followed by ar‐turmerone, bisdemethoxycurcumin demethoxycurcumin, and then curcumin. The amounts of the active ingredients were quantitatively analyzed by high‐performance liquid chromatography. The EtOAc and PE extracts had high sesquiterpenes and curcuminoids content, while the AE extract had poor content of sesquiterpenes and curcuminoids which affected neither BF nor TBAs. Based on the results of multiple linear regression analysis, the content of BIS and TUR were dominant factors (P < 0.01) of controlling BL and TBAs in EtOAC and PE extracts.     

The 4‐acetylantroquinonol B isolated from mycelium of Antrodia cinnamomea inhibits proliferation of hepatoma cells

BACKGROUND: Antrodia cinnamomea is known for its antihepatoma activity, yet the identity of its active compound was unclear. In this study, a 5‐ton fermenter was used to prepare sufficient mycelium of A. cinnamomea for active compound isolation and identification. RESULTS: Using antiproliferative activity toward HepG2 cells as guidance in the isolation process, 4‐acetylantroquinonol B was purified and identified to be the major bioactive compound of A. cinnamomea cultivated by submerged fermentation. The median effective doses (EC₅₀) of 4‐acetylantroquinonol B for HepG2 cells were 0.10 ± 0.00 and 0.08 ± 0.00 µg mL^?1 for 72 and 96 h treatments, respectively. The selective indices of 4‐acetylantroquinonol B were 100 and 125 for 72 and 96 h treatments, respectively, indicating that this compound had high selective activity for hepatoma cells. CONCLUSION: 4‐Acetylantroquinonol B is the major antihepatoma constituent of Antrodia cinnamomea mycelium produced by submerged fermentation. Copyright © 2010 Society of Chemical Industry     

决明子提取物潜在风险因子分析

本文主要综述了决明子的功效及近些年服用决明子后的不良反应,并对决明子的主要成分及含量进行分析,筛查出其中的潜在风险因子,主要有蒽醌类物质,植物甾醇及其氧化物和生物碱等。重点对这些潜在风险因子进行分析,包括它们的性质、结构和安全性分析。大黄素等蒽醌类物质具有平面刚性结构,能显著抑制L-02细胞的活性;植物甾醇与胆固醇的结构类似,易被氧化而产生与胆甾醇氧化物(COPs)类似危害的植物甾醇氧化物(POPs),谷甾醇氧化物能显著抑制HepG2的细胞活性;腺嘌呤对大鼠口服也具有明显的急性毒性。最后对决明子提取物的毒理性研究进行展望,指出应建立体外毒理学评价模型、剂量-反应模型和结构-毒性模型,形成基础毒理数据库,构建保健食品安全性评价预警体系,提出安全限值建议。