Antiproliferative activity of fucoidan was associated with the induction of apoptosis and autophagy in AGS human gastric cancer cells

Fucoidan, a sulfated polysaccharide purified from brown algae, possesses a variety of pharmacologic effects, including antiinflammatory, antioxidant, and anticancer properties; however, the underlying action mechanisms are not completely understood. This study investigated the possible mechanisms through which fucoidan exerts its antiproliferative action in cultured AGS human gastric adenocarcinoma cells. We found that fucoidan effectively inhibits the growth of AGS cells by inducing autophagy, as well as apoptosis. Apoptosis by fucoidan treatment was associated with the downregulation of antiapoptotic Bcl-2 and Bcl-xL expression, loss of mitochondrial membrane potential, activation of caspases, and concomitant degradation of poly-(ADP-ribose) polymerase protein. In addition, the morphological study indicated a characteristic finding of autophagy, such as the formation of autophagosomes in fucoidan-treated AGS cells. Furthermore, markers of autophagy, namely, the conversion of microtubule-associated protein light chain 3 (LC3)-I to LC3-II and increased beclin-1 accumulation, were observed. Overall, the present data suggest that fucoidan induces apoptotic and autophagic cell death, and both apoptotic and autophagic mechanisms contribute to the fucoidan-induced AGS cell death.     

Antimicrobial and human cancer cell cytotoxic effect of synthetic angiotensin-converting enzyme (ACE) inhibitory peptides

Four peptides with high angiotensin-converting enzyme (ACE) inhibitory effect were separated from beef sarcoplasmic protein hydrolysates using commercial enzymes. They were identified as GFHI, DFHING, FHG, and GLSDGEWQ and their 50% inhibition concentration (IC₅₀) values against ACE were 117, 64.3, 52.9, and 50.5 μg/ml, respectively. These peptides were synthesised and further biological activities of these four peptides were measured, including antimicrobial, cytotoxic effect against cancer cells, and macrophage-stimulating effect. Peptide GLSDGEWQ showed growth inhibition on Salmonella Typhimurium, Bacillus cereus, Escherichia coli, and Listeria monocytogenes at a 100 ppm level but not on Staphylococcus aureus and Pseudomonas aeruginosa. Peptide GFHI showed higher inhibition activity on the growth of E. coli and P. aeruginosa at concentrations of 200 and 400 μg/ml. However, peptide FHG inhibited only P. aeruginosa at 200 and 400 μg/ml. The effect of separated peptides on breast cancer (MCF-7), lung cancer (A549), and stomach cancer (AGS) cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Peptide GFHI showed a slight decrease of MCF-7 cell viability in a dose dependent manner. When 400 μg/ml of peptide GFHI was applied to the AGS cell, its viability was decreased by 75%. However, peptide DFHINQ seemed to act as a nutrient to AGS cell because it increased its viability. None of the four peptides had a cytotoxic effect on A549 cells. Nitric oxide (NO) production of peptide GFHI by stimulation of macrophage was investigated at 100, 300, and 1000 μg/ml concentration. NO was not produced in all treatments. From these results it is expected that the ACE inhibitory peptides identified from beef sarcoplasmic protein hydrolysates have both antimicrobial and cancer cell cytotoxic effects.     

Vitamin C induces apoptosis in AGS cells by down-regulation of 14-3-3σ via a mitochondrial dependent pathway

Ascorbic acid (vitamin C) is an essential component of most living cells. Apart from antioxidant activity, it has been reported to inhibit cancer cell growth in vitro in human cancer cells. However, the cellular mechanism underlying anticancer activity has not been fully elucidated. In this study, vitamin C showed a cytotoxic effect on human gastric cancer cell line AGS (LD50 300μg/ml). Further, flow cytometry analysis showed that vitamin C increased the sub-G1 (apoptosis) population and apoptosis confirmed by fluorescein isothiocyanate-Annexin V double staining in AGS cells. Moreover, specific immuno-blotting revealed the expression of the phosphorylated form of Bad (S136), 14-3-3σ, pro-caspases-3, -6, -8, and-9 protein levels were significantly decreased and Bax/Bcl-xL ratio was increased in a dose-dependent manner. Also, wound healing assay results showed that vitamin C inhibited AGS cell proliferation. These findings suggest that vitamin C induces apoptosis and might be a potential therapeutic agent for gastric cancer.     

盐酸哈尔酚骆驼蓬碱对人肝癌细胞生长的影响与自噬诱导作用的研究

目的探讨低剂量盐酸哈尔酚骆驼蓬碱(harmol hydrochloride dihydrate,HHD)对肝癌细胞株HepG2生长的影响及其自噬诱导作用。方法用不同浓度的HHD作用于肝癌细胞株HepG2 24 h后四甲基偶氮唑盐(methyl thiazolyl tetrazolium, MTT)法检测细胞活力,用流式细胞仪检测细胞凋亡,用Hoechst和PI双重染色方法观察细胞凋亡,用蛋白质印迹(western blotting, WB)的方法检测LC-3Ⅱ表达水平。结果 MTT检测结果显示不同浓度的HHD作用于HepG2细胞24h后,细胞活力随HHD浓度升高而降低,差异均有统计学意义(P0.05)。0、0.005、0.01 mg/mL HHD作用于HepG2细胞24 h后,细胞凋亡率均明显高于空白对照组(P0.05)。0.01 mg/mL的HHD处理HepG2细胞24 h后,凋亡小体的形成明显增多(P0.05)。Western blotting法检测发现0.01 mg/mL HHD作用细胞24 h后自噬标记蛋白LC-3Ⅱ表达显著升高。结论 HHD抑制肝癌细胞株HepG2在体外生长,其诱导细胞自噬可能是抑制作用机制之一。     

君迁子叶杨梅苷诱导HepG2细胞凋亡及其作用机制

目的：探究君迁子叶杨梅苷诱导人肝癌细胞HepG2细胞凋亡及其作用机制。方法：噻唑蓝法测定杨梅苷对细胞存活率的影响；激光共聚焦显微镜结合Hoechst 33342染色观察杨梅苷对细胞形态的影响；流式细胞分析仪检测杨梅苷对细胞凋亡、周期阻滞、胞内活性氧（reactive oxygen species，ROS）水平和单丹璜酰戊二胺（monodansylcadaverine，MDC）荧光强度的影响；Western blot检测杨梅苷对细胞凋亡和自噬相关蛋白表达量的影响。结果：浓度为10～200 μmol/L的杨梅苷对人正常肝细胞L-02细胞无显著影响（P＞0.05），但可显著降低HepG2细胞的存活率（P＜0.05），促进其凋亡，提升ROS水平，增加MDC和细胞核荧光强度，将细胞阻滞在G2/M期；此外，可显著上调HepG2细胞中Bax、细胞色素c、Apaf-1、Caspase-9、Caspase-3、Beclin 1、Atg5和LC3-II的相对表达量（P＜0.05），下调Bcl-2和LC3-I的相对表达量（P＜0.05）。结论：杨梅苷具有抗肝癌作用，其机制与激活线粒体介导的凋亡通路、阻滞细胞周期、提升ROS水平和促进细胞自噬有关。实验可为杨梅苷作为天然抗肝癌药物的研究及应用提供参考。     

Neferine from Nelumbo nucifera induces autophagy through the inhibition of PI3K/Akt/mTOR pathway and ROS hyper generation in A549 cells

Previously we have reported that neferine from the medicinal plant Nelumbo nucifera, inhibited cancer cell proliferation by inducing apoptosis. The present study was focused on the action mechanism of neferine in inducing autophagy in lung cancer cells. Neferine markedly inhibited A549 cell proliferation in a dose dependent manner. Acidic vesicular accumulation was observed in neferine treated cells as an indication of autophagy. Neferine could induce the conversion of LC3B-I to LC3B-II without affecting the expression levels of PI3KCIII and Beclin1. It has been observed that neferine mediated autophagy is dependent on inhibition of PI3K/Akt/mTOR signaling by neferine. Neferine treatment could also lead to the ROS hypergeneration and depletion of cellular antioxidant, GSH. The results demonstrate that neferine-induced autophagy is mediated through ROS hypergeneration and mTOR inhibition. Taken together, the present study unveils a novel mechanism of action of neferine on lung cancer cells in the induction of autophagy.     

Purification and identification of antihypertensive peptides from seaweed pipefish (Syngnathus schlegeli) muscle protein hydrolysate

Angiotensin-I-converting enzyme (ACE-I) inhibitory peptides were purified from the seaweed pipefish muscle protein using papain, alcalase, neutrase, pronase, pepsin and trypsin. Among them, the alcalase hydrolysate exhibited the highest ACE-I inhibitory activity. The alcalase hydrolysate was separated into four fractions (Fr1, Fr2, Fr3, and Fr4) by fast protein liquid chromatography (FPLC) on a Hiprep 16/10 DEAE FF anion exchange column. Among four fractions, Fr3 has shown the highest ACE-I inhibitory activity and it was further purified into three fractions (Fr3-I, Fr3-II, and Fr3-III) using reverse-phase high performance liquid chromatography (RP-HPLC) on a Primesphere 10 C18 (20 × 250 mm) column. The Fr3-II has exhibited the highest ACE-I inhibition (IC₅₀, 0.62 mg/ml) than the Fr3-III (IC₅₀, 1.44 mg/ml). The amino acid sequences of the obtained peptides from Fr3-II and Fr3-III were identified as Thr-Phe-Pro-His-Gly-Pro (MW, 744 Da) and His-Trp-Thr-Thr-Gln-Arg (MW, 917 Da) respectively. Furthermore, cell viability assay showed that no cytotoxicity of alcalase hydrolysate on human lung fibroblasts cell line (MRC-5). These results suggest that peptides derived from seaweed pipefish can be developed as antihypertensive ingredients in functional foods.     

Purification and anti-tumour activity of cyanidin-3-O-glucoside from Chinese bayberry fruit

Chinese bayberry (Myrica rubra Sieb. & Zucc.) is a rich source of cyanidin-3-O-glucoside (C3G). Purification of C3G was established by using high-speed counter-current chromatography (HSCCC) at 520 nm. The optimised flow rate was 2 ml/min and rotational speed was 850 rpm, and n-butanol-methyl tertiary butyl ether-acetonitrile-trifluoroacetic acid-water (30:20:40:1:100, v/v/v/v/v) solvent showed the highest partition coefficient (K = 1.50) to purify C3G. Different HSCCC fractions showed significant different anti-tumour effect on SGC7901, AGS, and BGC823 gastric cells, which were correlated with their C3G concentrations and DPPH^• scavenging activities. Cells treated with C3G resulted in reduced cell proliferation, decreased cell adherence, and abnormal morphological changes characteristics of apoptosis, all in dose-dependent manners. In addition, increased concentrations of C3G treatment resulted in increased inhibition of matrix metalloproteinase 2 (MMP-2) in SGC7901 cells, which may provide important information for the possible mechanism of C3G-induced anti-tumour activity against gastric adenocarcinoma cells.     

Anti‐inflammatory and anticancer activities of water‐soluble peptide extracts of buffalo and cow milk Cheddar cheeses

This article aimed to assess the anti‐inflammatory and anticancer potential of water‐soluble peptide (WSP) extracts from buffalo and cow milk Cheddar cheeses. Anti‐inflammatory activity was evaluated on the basis of nitric oxide (NO) production in lipopolysaccharide‐stimulated macrophage (RAW‐264.7) cells. A cell viability assay, cell cycle arrest and apoptosis were performed to explore anticancer activity in a colon cancer model (HT‐29). The WSP extracts of both Cheddar cheeses effectively inhibited NO production in activated macrophages. Maximum growth inhibition was observed in the HT‐29 cells at concentrations of 400 and 500 μg/mL. A significant increase in cell population at G₀/G₁ phase of the cell cycle was observed. Moreover, the WSP extracts also induced extensive apoptosis in colon cancer cells.     

Combination of low dose of genistein and daidzein has synergistic preventive effects on isogenic human prostate cancer cells when compared with individual soy isoflavone

The reduced incidence of prostate cancer (PCa) in Asia countries has been attributed to high soy diets, and major soy isoflavones, in particular daidzein and genistein, are thought to be the source of the beneficial and anti-cancer effects of soy foods. However, attention has been drawn to the safety of using high levels of soy isoflavones in humans, which is especially the concern for consumers taking regular soy isoflavone dietary supplements. The main objective of this study is thus to identify a soy isoflavone combination with lower levels of daidzein and genistein to be a more efficacious and safer chemo-preventive agent for PCa. The anticancer effects of daidzein and genistein, and their combinations on early-stage androgen-dependent PCa cells (LNCaP) and bone metastatic LNCaP-derivative PCa cells (C4-2B) were compared. Cells were treated with varying concentrations of daidzein, genistein (25–200 μM) or their combinations (25 or 50 μM) and cell proliferation, apoptosis, cell cycles and cellular uptakes of the isoflavones were measured after 48 h. Daidzein and genistein showed a synergistic effect on inhibiting cell proliferation and inducing apoptosis of both PCa cells. Twenty-five μM daidzein/50 μM genistein and 50 μM daidzein/50 μM genistein significantly increased the apoptotic effects on C4-2B cells although they did not show any effect when used individually. Except 50 μM daidzein/50 μM genistein, all other combinations had no impacts on cell cycles. For treatment with soy isoflavone combination, genistein was always better taken up than daidzein by both LNCaP and C4-2B cells.     

Cytoprotective and pro-apoptotic activities of native Australian herbs polyphenolic-rich extracts

Three commercially grown native herbs unique to Australia, Tasmannia pepper leaf (Tasmannia lanceolata R. Br., Winteracea; TPL), anise myrtle (Syzygium anisatum Vickery, Craven & Biffen, Myrtaceae; AM) and lemon myrtle (Backhousia citriodora F. Muell, Myrtaceae; LM) as well as a reference sample bay leaf (Laurus nobilis L., Lauraceae; BL) were examined for potential cytoprotective properties. All native herbs exhibited greater cellular antioxidant activity as measured by the cellular antioxidant activity (CAA) assay than bay leaf and reduced the hydrogen peroxide (H₂O₂) induced death of hepatocellular carcinoma (HepG2) cells by 25–50%. All herb extracts reduced the proliferation of colon (HT-29; IC₅₀ = 0.75–1.39 mg/ml), stomach (AGS; IC₅₀ = 0.59–1.88 mg/ml), bladder (BL13; IC₅₀ = 0.56–1.12 mg/ml) and liver (HepG2; IC₅₀ = 0.38–1.36 mg/ml) cancer cells. No significant reduction of cell viability of non-transformed colon (CCD-18Co; IC₅₀ > 2.0 mg/ml) and mixed stomach and intestine (Hs 738.St/Int; IC₅₀ > 2.0 mg/ml) cells was observed. Flow cytometry analysis and the results of the cytokinesis block micronucleus cytome (CBMNCyt) assay conducted with respectively, promyelocytic leukaemia (HL-60) and colon adenocarcinoma (HT-29) cells suggest an increase in apoptosis following treatment with the herb extracts. The occurrence of apoptotic cells coincided with an increase in caspase-3 enzyme activity. The results of the CBMNCyt assay suggested no direct DNA damage in colon adenocarcinoma (HT-29) cells as a result of treatment with all extracts, applied at final concentrations of 0.5 and 1.0 mg/ml.     

Differential effects of polyphenols-enriched extracts from hawthorn fruit peels and fleshes on cell cycle and apoptosis in human MCF-7 breast carcinoma cells

This study was to investigate the anticancer effects of the peel polyphenolic extract (HPP) and flesh polyphenolic extract (HFP) from hawthorn fruit in human MCF-7 breast cancer cells. It was found that the polyphenol and flavonoid contents of HPP were significant higher than that of HFP. Both HPP and HFP inhibited cell growth in a dose-dependent manner with the IC₅₀ of 88.6 μg/mL and 175.5 μg/mL, respectively, suggesting that HPP was more effective against MCF-7 cells than HFP. Flow cytometric analysis revealed that both HPP and HFP mediated the cell-cycle arrest at the S-phase, and also dose-dependently led to apoptosis of MCF-7 cells via the mitochondrial pathway, as evidenced by the activation of caspase-3 and caspase-9 and the elevation of intracellular ROS production. All these findings indicate that hawthorn fruit, especially its peel, is an excellent source of natural chemopreventive agents in the treatment of breast cancer.     

Anthocyanin-rich Mulberry extract inhibit the gastric cancer cell growth in vitro and xenograft mice by inducing signals of p38/p53 and c-jun

Anthocyanins have been well characterized by various bioactive properties. In previous studies, Mulberry anthocyanins (MACs) have proven to prevent atherosclerosis and inhibit melanoma metastasis. Here, AGS cells demonstrated an increase in the distribution of hypodiploid phase (apoptotic peak) after treatment with MACs. Further investigation revealed that MACs exerted their influence by inducing intrinsic and extrinsic apoptosis through p38/p53 and p38/c-jun signaling pathways. In addition, the caspase-related protein, such as caspase-3, was activated from pro-caspase to cleaved-caspase by treating MACs to AGS cells. We also used the experimental AGS gastric cancer xenograft model to verify the inhibitory effect of MACs. These findings suggest that, by targeting p38/p53 and the c-jun pathways, MACs suppressed cell survival and tumorigenesis, but induced apoptotic death in AGS cells. MACs can potentially prevent the growth of AGS cells for ineffective conventional chemotherapy of gastric carcinoma.     

Impaired autophagy aggravates oxidative stress in mammary gland of dairy cows with clinical ketosis

When ketosis occurs, supraphysiological levels of free fatty acids (FFA) can cause oxidative injury to the mammary gland and autophagy can regulate the cellular oxidative status. The aim of this study was to investigate the autophagy status of mammary tissue and its associations with oxidative stress in healthy and clinically ketotic dairy cows. Mammary tissue and blood samples were collected from healthy cows [n = 15, β-hydroxybutyrate (BHB) <0.6 mM] and clinically ketotic cows (n = 15, BHB >3.0 mM) at 3 to 15 (average = 7) days in milk. For in vitro study, bovine mammary epithelial cells (BMEC) isolated from healthy cows were treated with 0, 0.3, 0.6, or 1.2 mM FFA for 24 h. Furthermore, BMEC were pretreated with 100 nM rapamycin, an autophagy activator, for 4 h or 50 mM 3-methyladenine (3-MA), an autophagy inhibitor, for 1 h, followed by treatment with or without FFA (1.2 mM) for another 24 h. Oxidation indicators and autophagy-related protein abundance were measured. Compared with healthy cows, serum concentrations of FFA, BHB, and malondialdehyde were greater in clinically ketotic cows, but milk production (kg/d), milk protein (kg/d), activities of superoxide dismutase, catalase, and glutathione peroxidase were lower. Abundances of mRNA and protein of autophagy-related gene 5 (ATG5) and 7 (ATG7) were lower, but sequestosome-1 (SQSTM1, also called p62) greater in mammary tissue of clinically ketotic cows. The mRNA abundance of microtubule-associated protein 1 light chain 3 (MAP1LC3, also called LC3) and protein abundance of LC3-II were lower in mammary tissue of clinically ketotic cows. In vitro, exogenous FFA increased the content of malondialdehyde and reactive oxygen species, but decreased the activities of superoxide dismutase, catalase, and plasma glutathione peroxidase. Compared with the 0 mM FFA group, abundance of ATG5, ATG7, LC3-II was greater, but p62 was lower in the 0.6 mM FFA-treated cells. Similarly, abundance of ATG5, ATG7, and LC3-II was lower, but p62 greater in the 1.2 mM FFA-treated cells relative to 0 mM FFA group. Culture with rapamycin alleviated oxidative stress induced by 1.2 mM FFA, whereas 3-MA aggravated it. Overall, results indicated that a low concentration (0.6 mM) of FFA can induce oxidative stress and activate autophagy in BMEC. At higher concentrations of FFA (1.2 mM), autophagy is impaired and oxidative stress is aggravated. Autophagy is a mechanism for BMEC to counteract FFA-induced stress. As such, it could serve as a potential target for further development of novel strategies against oxidative stress.     

Free fatty acids impair autophagic activity and activate nuclear factor kappa B signaling and NLR family pyrin domain containing 3 inflammasome in calf hepatocytes

Free fatty acids (FFA)-induced hepatic inflammation agravates liver injury and metabolic dysfunction in dairy cows with ketosis or fatty liver. Under stressful conditions, autophagy is generally considered as a cell protection mechanism, but whether the FFA-induced inflammatory and stress effect on hepatocytes involves an autophagy response is not well known. Thus, the objective of this study was to investigate the effects of FFA on autophagy and the role of autophagy in the activation of NF-κB (nuclear factor kappa B) signaling and NLRP3 (NLR family pyrin domain containing 3) inflammasome in calf hepatocytes. Calf hepatocytes were isolated from 3 healthy Holstein female new-born calves (1 d of age, 30–40 kg) and exposed to various concentrations of FFA (0, 0.3, 0.6, or 1.2 mM) after treatment with or without the autophagy inhibitor chloroquine (CQ) or the autophagy activator rapamycin. Expression of autophagy markers, LC3 (microtubule-associated protein 1 light chain 3) and p62 (sequestosome 1), NF-κB signaling, and NLRP3 inflammasome-related molecules were analyzed via western blot and quantitative real-time PCR. Results revealed that 0.6 and 1.2 mM FFA activated NF-κB signaling and NLRP3 inflammasome as indicated by an elevated ratio of p-NF-κB/NF-κB, protein abundance of NLRP3 and CASP1 (caspase 1), activity of CASP1, and mRNA abundance of IL1B and IL18. In addition, hepatocyte treated with 0.6 and 1.2 mM FFA or autophagy inhibitor CQ displayed increased protein abundance of p62 and LC3-II. Moreover, there was no difference in protein abundance of p62 and LC3-II between calf hepatocytes treated with 1.2 mM FFA and 1.2 mM FFA plus CQ, indicating that FFA inhibits autophagic activity in calf hepatocytes. Treatment with CQ led to overactivation of NF-κB signaling and NLRP3 inflammasome. Furthermore, CQ plus 1.2 mM FFA aggravated FFA-induced inflammation. In contrast, induction of autophagy by rapamycin ameliorated the FFA-activated NF-κB signaling and NLRP3 inflammasome as demonstrated by a lower ratio of p-NF-κB/NF-κB, protein abundance of NLRP3 and CASP1, activity of CASP1, and mRNA abundance of IL1B and IL18. Overall, inhibition of autophagy exacerbated, whereas induction of autophagy alleviated, FFA-induced inflammatory processes in calf hepatocytes, suggesting that impairment of autophagy might be partly responsible for hepatic inflammation and subsequent liver injury in dairy cows with ketosis or fatty liver. As such, regulation of autophagy may be an effective therapeutic strategy for controlling overt inflammatory responses in vivo.     

Clitocybe alexandri extract induces cell cycle arrest and apoptosis in a lung cancer cell line: Identification of phenolic acids with cytotoxic potential

Mushrooms are a possible rich source of biologically active compounds with the potential for drug discovery. The aim of this work was to gain further insight into the cytotoxicity mechanism of action of Clitocybe alexandri ethanolic extract against a lung cancer cell line (NCI-H460 cells). The effects on cell cycle profile and levels of apoptosis were evaluated by flow cytometry, and the effect on the expression levels of proteins related to cellular apoptosis was also investigated by Western blot. The extract was characterised regarding its phenolic composition by HPLC-DAD, and the identified compounds were studied regarding their growth inhibitory activity, by sulforhodamine B (SRB) assay. The effect of individual or combined compounds on viable cell number was also evaluated using the Trypan blue exclusion assay. It was observed that the C. alexandri extract induced an S-phase cell cycle arrest and increased the percentage of apoptotic cells. In addition, treatment with the GI₅₀ concentration (concentration that was able to cause 50% of cell growth inhibition; 24.8 μg/ml) for 48 h caused an increase in the levels of wt. p53, cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP). The main components identified in this extract were protocatechuic, p-hydroxybenzoic and cinnamic acids. Cinnamic acid was found to be the most potent compound regarding cell growth inhibition. Nevertheless, it was verified that the concomitant use of the individual compounds provided the strongest decrease in viable cell number. Overall, evidence was found for alterations in cell cycle and apoptosis, involving p53 and caspase-3. Furthermore, our data suggests that the phenolic acids identified in the extract are at least partially responsible for the cytotoxicity induced by this mushroom extract.     

Structural characterization and immunostimulatory activity of a novel protein-bound polysaccharide produced by Hirsutella sinensis Liu,Guo, Yu & Zeng

HS002-II, a novel protein-bound polysaccharide with 44 kDa molecular weight, was fractionated from submerged cultures of Hirsutella sinensis Liu, Guo, Yu & Zeng by DEAE-Sepharose and Sephacryl S200 chromatography. Based on the results of infrared spectroscopy, high performance liquid chromatography, methylation, amino acid analysis, NMR spectroscopy and atomic force microscopy, the polysaccharide moieties of HS002-II mainly contained a long backbone of (1 → 3)-linked α-d-ribofuranosyl units (1 → 4)-linked α-d-xylopyranosyl units and (1 → 4)-linked β-d-glucopyranosyl units, which was substituted at C-6. The two branches were β-d-mannopyranosyl residues and β-d-galactopyranosyl residues terminated with α-l-arabinopyranosyl residues, respectively. HS002-II consisted of 57.9% polysaccharide and 42.1% protein with the existence of N-type carbohydrate–protein linkage. In terms of the pro-inflammatory cytokines assay (NO, TNF-α, IL-1β and NF-κB) using murine macrophages cell line (RAW264.7), HS002-II exhibited significant immunomodulatory activity by stimulating the IκB-NF-κB pathway.     

Valorisation of phenolic composition,antioxidant and cell growth activities of tomato waste

Tomato waste, a by-product in juice processing, obtained from different tomato genotypes, was subjected to evaluation as potential source of phenolic antioxidants and anticancer agents. Some individual phenolic compounds, including phenolic acids and flavonoids, were identified and quantified by HPLC. The antioxidant activity of tomato waste extracts was tested by measuring their ability to scavenge hydroxyl and superoxide anion radicals by ESR spectroscopy. The highest hydroxyl radical scavenging activity (IC₅₀ = 0.03 mg/ml) was obtained in the case of Novosadski niski waste extract. The Rutgers waste extract showed the best performance in scavenging superoxide anion radicals (IC₅₀ = 0.45 mg/ml). Cell growth effects were determined in HeLa, MCF7 and MRC-5 cell lines by SRB test. In all cell lines antiproliferative effects were observed at higher investigated concentrations (?6.3 mg/ml). The strongest activity against cancer cells was observed by Saint Pierre extract in HeLa cell line (IC₅₀ = 13.7 mg/ml).     

The chloroform fraction of guava (Psidium cattleianum sabine) leaf extract inhibits human gastric cancer cell proliferation via induction of apoptosis

The antiproliferative activities of the chloroform fraction (CF) of guava (Psidium cattleianum Sabine) leaf extract were evaluated using several cancer cell lines. Maximum cytotoxicity was observed in SNU-16, a human gastric carcinoma cell line, at concentrations of 50–100 μg/ml. Flow cytometric analysis demonstrated that CF treatment resulted in a marked accumulation of SNU-16 cells in the sub-G1 phase at concentrations of 100–200 μg/ml. The induction of apoptosis in SNU-16 cells was confirmed by immunoblotting using antibodies against Bcl-2, Bax, poly (ADP-ribose) polymerase (PARP), caspase-8, and caspase-3. The major CF phytochemicals were identified as ferulic acid, genistein, 3′, 4′, 5′ trimethoxy flavone, phlorizin, and oleanolic acid by high performance liquid chromatography coupled with a photo diode array and electrospray ionisation mass spectrometry (HPLC–PDA-ESI-MS). The results suggest that phytochemicals in the CF of guava (P. cattleianum) leaf extract induce apoptosis in SNU-16 cells. These findings may lead to new strategies for treating human gastric cancer.