Enhancement of phagocytic activity of macrophage-like cells by pyrogallol-type green tea polyphenols through caspase signaling pathways

Structural Activity and HAD Inhibition Efficiency of Pelargonidin and Its Glucoside-A Theoretical Approach

Anthocyanins are an important pharmaceutical ingredient possessing diet regulatory, antioxidant, anticancer, antidiabetic, anti-obesity, antimicrobial, and anti-inflammatory properties. Pelargonidin is an important anthocyanin-based orange-red flavonoid compound used in drugs for treating hypoglycemia, retinopathy, skeletal myopathy, etc. The main sources of pelargonidin are strawberries and food products with red pigmentation. There is a lack of evidence for supporting its use as an independent supplement. In the present study, pelargonidin and pelargonidin-3-O-glucoside are studied for their structural properties using quantum chemical calculations based on density functional theory. The results confirmed that the parent compound and its glycosylated derivative acted as good electron donors. Electrostatic potential, frontier molecular orbitals, and molecular descriptor analyses also substantiated their electron donating properties. Furthermore, based on the probability, a target prediction was performed for pelargonidin and pelargonidin-3-O-glucoside. Hydroxyacyl-coenzyme A dehydrogenase was chosen as an enzymatic target of interest, since the presence work focuses on glucuronidated compounds and their efficacy over diabetes. Possible interactions between these compounds and a target with nominable binding energies were also evaluated. Further, the structural stability of these two compounds were also analyzed using a molecular dynamics simulation.

Medicinal Importance, Pharmacological Activities, and Analytical Aspects of Strictinin: A Mini-Review

BACKGROUND

Plants and their derived products have been used in history as food and medicine. Plant materials are rich sources of fiber, minerals, vitamins, and bioactive phytochemicals, which are useful for human beings. Strictinin is an important phytoconstituent of green tea.

METHODS

Present work mainly focuses on the biological importance, therapeutic potential, and pharmacological activities of strictinin in medicine. Numerous scientific data have been collected from various literature databases such as Google Scholar, Science Direct, PubMed, and Scopus database in order to realize the health beneficial potential of strictinin. Pharmacological data has been collected and analyzed in the present work to find the effectiveness of strictinin against human disorders and complications. Analytical data of strictinin has been also collected and analyzed in the present work.

RESULTS

Scientific data analysis revealed the biological importance of strictinin in medicine. Scientific data analysis signified the therapeutic benefit of strictinin mainly due to its anticancer, antimicrobial, antibacterial, antiviral, and antioxidant activity. However, enzymatic activities, cytotoxicity, effectiveness on skin disorders, and osteogenic potential of strictinin have also been discussed. Analytical data revealed the importance of modern analytical techniques in medicine for the separation, identification, and isolation of strictinin.

CONCLUSION

Present work signified the biological importance and therapeutic benefits of strictinin in medicine and other allied health sectors.

Targeting the tumor immune microenvironment with "nutraceuticals": From bench to clinical trials

The occurrence of immune effector cells in the tissue microenvironment during neoplastic progression is critical in determining tumor growth outcomes. On the other hand, tumors may also avoid immune system-mediated elimination by recruiting immunosuppressive leukocytes and soluble factors, which coordinate a tumor microenvironment that counteracts the efficiency of the antitumor immune response. Checkpoint inhibitor therapy results have indicated a way forward via activation of the immune system against cancer. Widespread evidence has shown that different compounds in foods, when administered as purified substances, can act as immunomodulators in humans and animals. Although there is no universally accepted definition of nutraceuticals, the term identifies a wide category of natural compounds that may impact health and disease statuses and includes purified substances from natural sources, plant extracts, dietary supplements, vitamins, phytonutrients, and various products with combinations of functional ingredients. In this review, we summarize the current knowledge on the immunomodulatory effects of nutraceuticals with a special focus on the cancer microenvironment, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of nutraceuticals for envisioning future therapies employing nutraceuticals as chemoadjuvants.

The enhancing effect of Acanthopanax sessiliflorus fruit extract on the antibacterial activity of porcine alveolar 3D4/31 macrophages via NF-κB1 and lipid metabolism regulation

Objective

The demands for measures to improve disease resistance and productivity of livestock are increasing, as most countries prohibit the addition of antibiotics to feed. This study therefore aimed to uncover functional feed additives to help enhance livestock immunity and disease resistance, using Acanthopanax sessiliflorus fruit extract (ASF).

Methods

ASF was extracted with 70% EtOH, and total polyphenolic and catechin contents were measured by the Folin-Ciocalteu and vanillin assay, respectively. The 3D4/31 porcine macrophage cells (MΦ) were activated by phorbol 12-myristate 13-acetate (PMA), and cell survival and growth rate were measured with or without ASF treatment. Flow-cytometric analysis determined the lysosomal activity, reactive oxygen species levels (ROS), and cell cycle distribution. Nuclear factor kappa B (NF-κB) and superoxide dismutase (SOD) protein expression levels were quantified by western blotting and densitometry analysis. Quantitative polymerase chain reaction was applied to measure the lipid metabolism-related genes expression level. Lastly, the antibacterial activity of 3D4/31 MΦ cells was evaluated by the colony forming unit assay.

Results

ASF upregulated the cell viability and growth rate of 3D4/31 MΦ, with or without PMA activation. Moreover, lysosomal activity and intracellular ROS levels were increased after ASF exposure. In addition, the antioxidant enzyme SOD2 expression levels were proportionately increased with ROS levels. Both ASF and PMA treatment resulted in upregulation of NF-κB protein, tumor necrosis factor (TNF)α mRNA expression levels, lipid synthesis, and fatty acid oxidation metabolism. Interestingly, co-treatment of ASF with PMA resulted in recovery of NF-κB, TNFα, and lipid metabolism levels. Finally, ASF pretreatment enhanced the in vitro bactericidal activity of 3D4/31 MΦ against Escherichia coli.

Conclusion

This study provides a novel insight into the regulation of NF-κB activity and lipid metabolism in MΦ, and we anticipate that ASF has the potential to be effective as a feed additive to enhance livestock immunity.

Tea polyphenols induce S phase arrest and apoptosis in gallbladder cancer cells

Gallbladder cancer (GBC) is the most common malignancy in the biliary tract. Without effective treatment, its prognosis is notoriously poor. Tea polyphenols (TPs) have many pharmacological and health benefits, including antioxidant, anti-inflammatory, anti-tumor, anti-thrombotic, antibacterial, and vasodilatory properties. However, the anti-cancer effect of TPs in human gallbladder cancer has not yet been determined. Cell viability and colony formation assay were used to investigate the cell growth. Cell cycle and apoptosis were evaluated by flow cytometry analysis. Western blot assay was used to detect the expression of proteins related to cell cycle and apoptosis. Human tumor xenografts were used to examine the effect of TPs on gallbladder cancer cells in vivo. TPs significantly inhibited cell growth of gallbladder cancer cell lines in a dose- and time-dependent manner. Cell cycle progression in GBC cells was blocked at the S phase by TPs. TPs also induced mitochondrial-related apoptosis in GBC cells by upregulating Bax, cleaved caspase-3, and cleaved PARP expressions and downregulating Bcl-2, cyclin A, and Cdk2 expressions. The effects of TPs on GBC were further proven in vivo in a mouse xenograft model. Our study is the first to report that TPs inhibit GBC cell growth and these compounds may have potential as novel therapeutic agents for treating gallbladder cancer.

Pelargonidin-3-O-glucoside and its metabolites have modest anti-inflammatory effects in human whole blood cultures

This study hypothesized that the predominant strawberry anthocyanin, pelargonidin-3-O-glucoside (Pg-3-glc), and 3 of its plasma metabolites (4-hydroxybenzoic acid, protocatechuic acid, and phloroglucinaldehyde [PGA]) would affect phagocytosis, oxidative burst, and the production of selected pro- and anti-inflammatory cytokines in a whole blood culture model. For the assessment of phagocytosis and oxidative burst activity of monocytes and neutrophils, whole blood was preincubated in the presence or absence of the test compounds at concentrations up to 5 μmol/L, followed by analysis of phagocytic and oxidative burst activity using commercially available test kits. For the cytokine analysis, diluted whole blood was stimulated with lipopolysaccharide in the presence or absence of the test compounds at concentrations up to 5 μmol/L. Concentrations of selected cytokines (tumor necrosis factor-α, interleukin [IL]-1β, IL-6, IL-8, and IL-10) were determined using a cytometric bead array kit. There were no effects of any of the test compounds on phagocytosis of opsonized or nonopsonized Escherichia coli or on oxidative burst activity. Pg-3-glc and PGA at 0.08 μmol/L increased the concentration of IL-10 (P < .01 and P < .001, respectively), but there was no effect on tumor necrosis factor-α, IL-1β, IL-6, and IL-8, and there were no effects of the other compounds. In conclusion, this study demonstrated a lack of effect of these compounds on the opsonization, engulfment, and subsequent destruction of bacteria. Pg-3-glc and PGA, at physiologically relevant concentrations, had anti-inflammatory properties; however, effects were modest, only observed at the lowest dose tested and limited to IL-10.

Tea polyphenol decreased growth and invasion in human ovarian cancer cells

Tea polyphenols (TP) are functional substances present in tea, which is one of the most promising preventive agents for cancer. This study was carried out to analyze the effects of TP on the ovarian cancer cells and possible mechanisms involved. TP led to inhibition of cell growth in a time- and dose-dependent manner, and promoted entry into the apoptosis-phase of the cell cycle. TP also decreased the invasion of ovarian cancer cells in vitro. In addition, TP treatment upregulated the mRNA expressions rate of Bax/Bcl-2 and downregulated Cyclin D and MMP2 mRNA expressions. Taken together, our data highlight that TP could be a potential therapeutic strategy for ovarian cancer. These findings also suggested that oncogens are involved in the anti-cancer effects of TP.

Modulation of BV-2 microglia functions by novel quercetin pivaloyl ester

Chronic inflammation in brain plays a critical role in major neurodegenerative diseases such as Alzheimer's, Parkinson's disease, stroke or multiple sclerosis. Microglia, resident macrophages and intristinc components of CNS, appear to be main effectors in this pathological process. Quercetin, a naturally occurring flavonoid, was proven to downregulate inflammatory genes in microglia. Synthetically modified quercetin, 3'-O-(3-chloropivaloyl) quercetin (CPQ), is assumed to possess better biological availability and enhanced antioxidant properties. In the present study, antineuroinflammatory capability of the novel compound CPQ was assessed in BV-2 microglial cells. Our data show that treatment with CPQ attenuated the production of the inflammatory mediators, nitric oxide (NO) and tumour necrosis factor-α (TNF-α), in LPS-stimulated microglia somewhat more efficiently than did quercetin (p > 0.05 for CPQ vs. quercetin-treated group). Also, protein level of inducible NO synthase (iNOS) in LPS-activated BV-2 microglia was to some extent more effectively supressed by CPQ than by unmodified flavonoid. In consistence with the extent of their effects on pro-inflammatory markers, CPQ and quercetin showed down-regulation of NFκB activation. This quercetin analogue caused also a decline in BV-2 microglia proliferation with interfering with cell cycle progression (p < 0.001 for CPQ vs. quercetin-treated group). However, CPQ did not remarkably affect cell viability. In addition, CPQ showed a minor better suppression of PMA-induced generation of superoxide than did quercetin. Neither CPQ nor quercetin influenced phagocytosis of BV-2 cells. These results point to the therapeutic potential of 3'-O-(3-chloropivaloyl)quercetin (CPQ) as a novel antiinflammatory drug in neurodegenerative diseases, mediating favourable modulation of pro-inflammatory functions of microglia.

Tea polyphenols induced apoptosis of breast cancer cells by suppressing the expression of Survivin

To study the mechanism of tea polyphenols (TP)-induced apoptosis of breast cancer cells. Proliferation of MCF-7 and SK-BR-3 cells was evaluated by MTT assays. Cellular ultrastructure was examined by electron microscopy. Apoptosis was detected by TUNEL. PCNA、 Cyclin D1、 Cyclin E and Survivin expression was measured by Western blot. Cell proliferation was significantly inhibited by TP. Spindle and round cells were loosely distributed with increased particles after TP treatment. Increased cell size, frequent nuclear atypia and a collapse of apoptosis were observed. The nucleus was pushed towards one side, while the cytoplasm was rich in free ribosome. The membrane of mitochondria was thickening, and the cell apoptotic body was observed. TP treated cells experienced significantly enhanced apoptosis compared with 5-Fu treated or control groups. The expression of survivin was downregulated by TP. To conclude, TP can inhibit cell growth and induce apoptosis through downregulating the expression of survivin in breast cancer.

Green tea catechin induced phagocytosis can be blocked by catalase and an inhibitor of transient receptor potential melastatin 2 (TRPM2)

The major polyphenols in green tea, (-)-epigallocatechin and (-)-epigallocatechin gallate, have been shown to enhance the phagocytic activity of macrophage-like cells; however, the mechanism involved was not clarified. In this study, we have identified that the catechins induced phagocytosis can be blocked by catalase and an inhibitor of transient receptor potential melastatin 2.

Regulation of nodularin-induced apoptosis by epigallocatechin-3-gallate on fish lymphocytes in vitro

Nodularin is one of the most conspicuous and widespread pollutants that elicit water ecological hazards to fish, causing serious damage on the immune system and physiological functions. Nodularin can cause oxidative stress-induced apoptosis on fish lymphocytes. The regulatory effects of epigallocatechin-3-gallate (EGCG) at 10, 100, and 1000 μg/L levels on the antioxidant defense system and apoptosis of Carassius auratus lymphocytes exposed to a high dose of nodularin (100 μg/L) were quantified in vitro. EGCG reduced nodularin-induced oxidative damage on fish immune cells. This compound significantly increased the activities of superoxide dismutase and catalase and the level of glutathione but decreased the levels of intracellular reactive oxygen species and malondialdehyde. Flow cytometry results showed that the percentages of apoptotic cells after treatment with 10, 100, and 1000 μg/L EGCG for 12 h reached 27.9%, 19.1%, and 13.7%, respectively. By contrast, the nodularin alone-induced group showed a high percentage of apoptosis (44.2%). Western blot analysis showed the increased expression of bcl-2 and the decreased expression of bax and caspase-3 in EGCG-treated fish lymphocytes. EGCG also inhibited the potential collapse of the mitochondrial membrane. Overall, EGCG can inhibit nodularin-induced apoptosis and protect the normal immunity of fish by regulating bax/bcl-2 and blocking the downstream of mitochondrial apoptosis pathway with increased intracellular antioxidant enzyme activity.