Mechanistic elucidation of apoptosis and cell cycle arrest induced by 5-hydroxymethylfurfural, the important role of ROS-mediated signaling pathways

Crude extract of Ruellia tuberosa L. flower induces intracellular ROS, promotes DNA damage and apoptosis in triple negative breast cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ruellia tuberosa L. (Acanthaceae) is a weed plant traditionally used in folklore medicine as a diuretic, anti-hypertensive, anti-pyretic, anti-cancerous, anti-diabetic, analgesic, and gastroprotective agent. It has been previously reported that R. tuberosa L. is enriched with various flavonoids, exhibiting significant cytotoxic potential in various cancer models but a detailed study concerning its molecular mechanism is yet to be explored.

AIM OF THE STUDY

Exploring and validating R. tuberosa L. flower methanolic extract (RTME) as an anti-cancerous agent as per traditional usage with special emphasis on multi-drug resistant human triple-negative breast cancer (TNBC) and investigating the possible signaling networks and regulatory pathways involved in it.

MATERIALS AND METHODS

In this study, RTME was prepared using methanol, and phytochemical analysis was performed through GC-MS. Then, the extract was tested for its anti-cancer potential through in-vitro cytotoxicity assay, clonogenic assay, wound healing assay, ROS generation assay, cell cycle arrest, apoptotic nuclear morphology study, cellular apoptosis study, mitochondrial membrane potential (MMP) alteration study, protein, and gene expressions alteration study. In addition, toxicological status was evaluated in female Balb/C mice, and to check the receptor-ligand interactions, in-silico molecular docking was also conducted.

RESULTS

Several phytochemicals were found within RTME through GC-MS, which have been already reported to act as ROS inductive, DNA damaging, cell cycle arresting, and apoptotic agents against cancer cells. Moreover, RTME was found to exhibit significant in-vitro cytotoxicity along with a reduction in colony formation, and inhibition of cell migratory potential. It also induced intracellular ROS, promoted G0/G1 cell cycle arrest, caused mitochondrial membrane potential (MMP) alteration, and promoted cell death. The Western blot and qRT-PCR data revealed that RTME promoted the intrinsic pathway of apoptosis. Furthermore, blood parameters and organ histology on female Balb/C mice disclosed the non-toxic nature of RTME. Finally, an in-silico molecular docking study displayed that the three identified lead phytochemicals in RTME show strong receptor-ligand interactions with the anti-apoptotic Bcl-2 and give a clue to the possible molecular mechanism of the RTME extract.

CONCLUSIONS

RTME is a potential source of several phytochemicals that have promising therapeutic potential against TNBC cells, and thus could further be utilized for anti-cancer drug development.

Experimental and pharmacoinformatic approaches unveil the neuropharmacological and analgesic potential of chloroform fraction of Roktoshirinchi (Achyranthes ferruginea Roxb.)

ETHNOPHARMACOLOGICAL RELEVANCE

Achyranthes ferruginea (A. ferruginea) Roxb. is a common plant used in traditional medicine in Asia and Africa. It has a variety of local names, including "Gulmanci" in Nigeria, "Dangar" in Pakistan, "Thola" in Ethiopia, and "Roktoshirinchi" in Bangladesh. It is edible and has several ethnomedical uses for a wide range of illnesses, including hysteria, dropsy, constipation, piles, boils, asthma, and shigellosis. However, the neuropharmacological and analgesic potential of A. ferruginea remains uninvestigated.

AIM OF THE STUDY

To assess the neuropharmacological and analgesic potential of A. ferruginea through a multifaceted approach encompassing both experimental and computational models.

MATERIALS AND METHODS

Methanol was used to extract the leaves of A. ferruginea. It was then fractionated with low to high polar solvents (n-hexane, chloroform, ethyl acetate, and water) to get different fractions, including chloroform fraction (CLF). The study selected CLF at different doses and conducted advanced chemical element and proximate analyses, as well as phytochemical profiling using GC-MS. Toxicological studies were done at 300 μg per rat per day for 14 days. Cholinesterase inhibitory potential was checked using an in-vitro colorimetric assay. Acetic acid-induced writhing (AAWT) and formalin-induced licking tests (FILT) were used to assess anti-nociceptive effects. The forced swim test (FST), tail suspension test (TST), elevated plus maze (EPM), hole board test (HBT), and light and dark box test (LDB) were among the behavioral tests used to assess depression and anxiolytic activity. Network pharmacology-based analysis was performed on selected compounds using the search tool for interacting chemicals-5 (STITCH 5), Swiss target prediction tool, and search tool for the retrieval of interacting genes and proteins (STRING) database to link their role with genes involved in neurological disorders through gene ontology and reactome analysis.

RESULTS

Qualitative chemical element analysis revealed the presence of 15 elements, including Na, K, Ca, Mg, P, and Zn. The moisture content, ash value, and organic matter were found to be 11.12, 11.03, and 88.97%, respectively. GC-MS data revealed that the CLF possesses 25 phytoconstituents. Toxicological studies suggested the CLF has no effects on normal growth, hematological and biochemical parameters, or cellular organs after 14 days at 300 μg per rat. The CLF markedly reduced the activity of both acetylcholinesterase and butyrylcholinesterase (IC50: 56.22 and 13.22 μg/mL, respectively). Promising dose-dependent analgesic activity (p < 0.05) was observed in chemically-induced pain models. The TST and FST showed a dose-dependent substantial reduction in immobility time due to the CLF. Treatment with CLF notably increased the number of open arm entries and time spent in the EPM test at doses of 200 and 400 mg/kg b.w. The CLF showed significant anxiolytic activity at 200 mg/kg b.w. in the HBT test, whereas a similar activity was observed at 400 mg/kg b.w. in the EPM test. A notable increase in the amount of time spent in the light compartment was observed in the LDB test by mice treated with CLF, suggesting an anxiolytic effect. A network pharmacology study demonstrated the relationship between the phytochemicals and a number of targets, such as PPARA, PPARG, CHRM1, and HTR2, which are connected to the shown bioactivities.

CONCLUSIONS

This study demonstrated the safety of A. ferruginea and its efficacy in attenuating cholinesterase inhibitory activity, central and peripheral pain, anxiety, and depression, warranting further exploration of its therapeutic potential.

Apoptotic Potential of Glucomoringin Isothiocyanate (GMG-ITC) Isolated from Moringa oleifera Lam Seeds on Human Prostate Cancer Cells (PC-3)

Inhibition of several protein pathways involved in cancer cell regulation is a necessary key in the discovery of cancer chemotherapy. Moringa oleifera Lam is often used in traditional medicine for the treatment of various illnesses. The plant contains glucomoringin isothiocyanate (GMG-ITC) with therapeutic potential against various cancer cells. Therefore, GMG-ITC was evaluated for its cytotoxicity against the PC-3 prostate cancer cell line and its potential to induce apoptosis. GMG-ITC inhibited cell proliferation in the PC-3 cell line with IC50 value 3.5 µg/mL. Morphological changes as a result of GMG-ITC-induced apoptosis showed chromatin condensation, nuclear fragmentation, and membrane blebbing. Additionally, Annexin V assay showed proportion of cells in early and late apoptosis upon exposure to GMG-ITC in a time-dependent manner. Moreover, GMG-ITC induced a time-dependent G2/M phase arrest, with reduction of 39.1% in the PC-3 cell line. GMG-ITC also activates apoptotic genes including caspase, tumor suppressor gene (p53), Akt/MAPK, and Bax of the proapoptotic Bcl family. Early apoptosis proteins (JNK, Bad, Bcl2, and p53) were significantly upregulated upon GMG-ITC treatment. It is concluded that apoptosis induction was observed in PC-3 cells treated with GMG-ITC. These phenomena suggest that GMG-ITC from M. oleifera seeds could be useful as a future cytotoxic agent against prostate cancer.

Cell-penetrating peptide-mediated delivery of therapeutic peptides/proteins to manage the diseases involving oxidative stress, inflammatory response and apoptosis

OBJECTIVES

Peptides and proteins represent great potential for modulating various cellular processes including oxidative stress, inflammatory response, apoptosis and consequently the treatment of related diseases. However, their therapeutic effects are limited by their inability to cross cellular barriers. Cell-penetrating peptides (CPPs), which can transport cargoes into the cell, could resolve this issue, as would be discussed in this review.

KEY FINDINGS

CPPs have been successfully exploited in vitro and in vivo for peptide/protein delivery to treat a wide range of diseases involving oxidative stress, inflammatory processes and apoptosis. Their in vivo applications are still limited due to some fundamental issues of CPPs, including nonspecificity, proteolytic instability, potential toxicity and immunogenicity.

SUMMARY

Totally, CPPs could potentially help to manage the diseases involving oxidative stress, inflammatory response and apoptosis by delivering peptides/proteins that could selectively reach proper intracellular targets. More studies to overcome related CPP limitations and confirm the efficacy and safety of this strategy are needed before their clinical usage.

5-Hydroxymethylfurfural Exerts Negative Effects on Gastric Mucosal Epithelial Cells by Inducing Oxidative Stress, Apoptosis, and Tight Junction Disruption

5-Hydroxymethylfurfural (5-HMF) is a processing byproduct present in foods that are consumed daily by humans, and the diet is the principal route for human exposure to it. However, its adverse effects on gastric epithelial cells are not fully understood. Based on the half inhibitory concentration value, concentrations of HMF of 2, 4, 8, and 16 mM were selected for this study. After 5-HMF treatment for 24 h, the number of living cells decreased to 89.61 ± 0.48, 77.30 ± 0.57, 58.75 ± 0.36, and 19.61 ± 0.40% of the control, respectively. Apoptosis activated through both the death receptor and mitochondrial pathways was confirmed to be the primary mode of HMF-induced cell death. Further analysis revealed that the reactive oxygen species (ROS) levels in GES-1 cells increased 1.7-6.5 fold after exposure to 5-HMF. Moreover, the inhibition of ROS by N-acetylcysteine blocked HMF-induced apoptosis and cell proliferation suppression, indicating that oxidative stress was important in HMF-induced apoptosis. Besides, after 5-HMF treatment, the gene expressions of occludin and ZO-1 were reduced by 1.1-3.4 fold and 2.0-9.4 fold, respectively. The cell surface morphology and tight junction-related protein expression analysis also revealed the destructive effect of 5-HMF on tight junction integrity. Our research highlights a potential mechanism of HMF-induced toxicity in GES-1 cells and provides additional information on the health risks of 5-HMF exposure to the human gastric epithelium.

Antioxidant and immune-modulating activities of egg yolk protein extracts

Egg yolk is widely used to extract lecithin, which is utilized in the food and cosmetics industry. After lecithin is removed, the rest of egg yolk is generated as a by-product. Thus, it is necessary to properly utilize it. In this study, egg yolk protein extracts were produced using ethanol (EYE-E) and water (EYE-W). Their antioxidant and immunomodulatory effects were then evaluated. Antioxidant activities of EYE-E and EYE-W were determined using cellular antioxidant capacity (CAC) assay and comet assay. EYE-E and EYE-W showed significant (p<0.05) scavenging effects on intracellular reactive oxygen species (ROS) in a dose dependent manner. At a concentration of 50 μg/mL, EYE-W showed higher (p<0.05) antioxidant activity than EYE-E. EYE-E and EYE-W also exhibited protective effects against DNA damage caused by oxidative stress. After treatment with EYE-E and EYE-W, DNA damage level of 48.7% due to oxidative stress was decreased to 36.2% and 31.8% levels, respectively. In addition, EYE-E and EYE-W showed immunomodulatory effects by regulating Th1 cytokines (TNF-α and IL-2) and Th2 cytokines (IL-10 and IL-4) in Balb/c mouse splenocytes. These data suggest that EYE-E and EYE-W could be used as functional food ingredients with excellent antioxidant and immunomodulatory activities in the food industry.

Alpha-Ketoglutarate and 5-HMF: A Potential Anti-Tumoral Combination against Leukemia Cells

We have recently shown that a combined solution containing alpha-ketoglutarate (aKG) and 5-hydroxymethyl-furfural (5-HMF) might have anti-tumoral potential due to its antioxidative activities. The question arises if these substances have caspase-3- and apoptosis-activating effects on the cell proliferation in Jurkat and HF-SAR cells. Antioxidative capacity of several combined aKG + 5-HMF solution was estimated by cigarette smoke radical oxidized proteins of fetal calf serum (FCS) using the estimation of carbonylated proteins. The usage of 500 µg/mL aKG + 166.7 µg/mL 5-HMF showed the best antioxidative capacity to inhibit protein modification of more than 50% compared to control measurement. A Jurkat cell line and human fibroblasts (HF-SAR) were cultivated in the absence or presence of combined AKG + 5-HMF solutions between 0 µg/mL aKG + 0 µg/mL 5-HMF and different concentrations of 500 µg/mL aKG + 166.7 µg/mL 5-HMF. Aliquots of Jurkat cells were tested for cell proliferation, mitochondrial activity, caspase activity, apoptotic cells and of the carbonylated protein content as marker of oxidized proteins in cell lysates after 24, 48, and 72 h of incubation. The combined solutions of aKG + 5-HMF were shown to cause a reduction in Jurkat cell growth that was dependent on the dose and incubation time, with the greatest reductions using 500 µg/mL aKG + 166.7 µg/mL 5-HMF after 24 h of incubation compared to 24 h with the control (22,832 cells vs. 32,537 cells), as well as after 48 h (21,243 vs. 52,123 cells) and after 72 h (23,224 cells). Cell growth was totally inhibited by the 500 µg/mL AKG + 166.7 µg/mL solution between 0 and 72 h of incubation compared to 0 h of incubation for the control. The mitochondrial activity measurements supported the data on cell growth in Jurkat cells: The highest concentration of 500 µg/mL aKG + 166.7 µg/mL 5-HMF was able to reduce the mitochondrial activity over 24 h (58.9%), 48 h (28.7%), and 72 h (9.9%) of incubation with Jurkat cells compared not only to the control incubation, but also to the concentrations of 500 µg/mL aKG + 166.7 µg/mL 5-HMF or 375 µg/mL aKG 125 µg/mL 5-HMF, which were able to significantly reduce the mitochondrial activity after 48 h (28.7% or 35.1%) and 72 h (9.9% or 18.2%) compared to 24 h with the control (100%). A slight increase in cell proliferation was found in HF-SAR using the highest concentration (500 µg/mL aKG + 166.7 µg/mL 5-HMF) between 0 h and 72 h incubation of 140%, while no significant differences were found in the mitochondrial activity of HF-SAR in the absence or presence of several combined aKG + 5-HMF solutions. The solutions with 500 µg/mL aKG + 166.7 µg/mL 5-HMF or 250 µg/mL aKG + 83.3 µg/mL 5-HMF showed a significantly higher caspase activity (51.6% or 13.5%) compared to the control (2.9%) in addition to a higher apoptosis rate (63.2% or 31.4% vs. control: 14.9%). Cell lysate carbonylated proteins were significantly higher in Jurkat cells compared to HF-SAR cells (11.10 vs. 2.2 nmol/mg). About 72 h incubation of Jurkat cells with 500 µg/mL aKG + 166.7 µg/mL 5-HMF or 250 µg/mL aKG + 83.3 µg/mL 5-HMF reduced significantly the carbonylated protein content down to 5.55 or 7.44 nmol/mg whereas only the 500 µg/mL aKG + 166.7 µg/mL 5-HMF solution showed a significant reduction of carbonylated proteins of HF-SAR (1.73 nmol/mg).

Antioxidant activity of SSeCAHK in HepG2 cells: a selenopeptide identified from selenium-enriched soybean protein hydrolysates

This paper is aimed at purifying and identifying selenium (Se)-containing antioxidative peptides from Se-enriched soybean peptides (SSP). In this work, the SSP was separated into five fractions (F1 to F5). Fraction F4, displaying the highest antioxidative activity, was further separated, and sub-fractions F4-1 to F4-5 were selected for antioxidative activity evaluation using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzo-thiazoline-6-sulphonic acid)diammonium salt (ABTS), and OH⁻ radical scavenging assays. The Se-containing antioxidative peptides with sequence Ser–SeC–Ala–His–Lys (SSeCAHK) were identified in sub-fraction F4-1 and chemically synthesized. This Se-containing pentapeptide showed a preventive effect against hydrogen peroxide (H₂O₂)-induced oxidative stress in HepG2 cells. Pretreating the cells for 2 h with SSeCAHK (0.13–0.50 mg mL⁻¹) induced strong intracellular, reactive oxygen species (ROS) scavenging activity while preventing a decrease in reduced glutathione (GSH) and an increase in malondialdehyde (MDA). Therefore, SSeCAHK treatment improved H₂O₂-induced oxidative stress in HepG2 cells, demonstrating the significant potential of SSeCAHK as a natural antioxidative functional material for dietary supplementation.

Se-containing antioxidative soybean peptides were isolated and identified as SSeCAHK. The SSeCAHK had protective effects against H₂O₂-induced oxidative stress in HepG2 cells and could be used as a natural food-born antioxidant.

Regulation of H2O2-induced cells injury through Nrf2 signaling pathway: An introduction of a novel cysteic acid-modified peptide

A novel peptide (Cya-Phe-Leu-Ala-Pro, SCP) was formulated through non-protein amino acid-cysteic acid (Cya) modification of collagen peptide (Phe-Leu-Ala-Pro, CP) from Acaudina molpadioides. Introduction of this Cya showed remarkable improvement in the scavenging activities of OH·. SCP exhibited stronger effects than CP in preventing H₂O₂-induced oxidative damage due to lower levels of ROS and MDA, and higher activities of antioxidant enzymes, such as SOD, GSH-Px, HO-1, and NQO1. It was speculated that SCP could significantly increase the expression level of Nrf2 compared to CP, thereby activating the expression of downstream ARE genes. The expression levels of p38 in the upstream pathway to regulate Nrf2 content were significantly higher in both the CP and SCP-treated groups, while a higher level of JNK was observed only in the SCP-treated groups. The present study provided insights towards the application of cysteic acid modified peptide in protecting cell from oxidative damage through the JNK/Nrf2 pathway.

Biotransformation of 5-hydroxymethylfurfural into 2,5-dihydroxymethylfuran by Ganoderma sessile and toxicological assessment of both compounds

Biotransformation has the advantages of low cost and environmental protection and is a preferred method for production of compounds. At present, most 2,5-dihydroxymethylfuran (DHMF) is synthesized by chemical methods. In this study, 12.008 μg/mL DHMF was produced from 9.045 μg/mL 5-hydroxymethylfurfural (5-HMF) with a yield of 1.33 g/g using the crude enzymes from fungus Ganoderma sessile. To elucidate the toxic potential for both compounds, cytotoxicity tests and acute toxicity were evaluated respectively. 5-HMF induced weak cytotoxicity in HCT-8, A549 and SGC-7901 cells and DHMF exerted no cytotoxicity on HCT-8 while induced inhibition proliferation of A549 and SGC-7901 cells. The acute toxicity study showed no mortality happened in any group even at the single dose of 2000 mg/kg body weight. These results suggest it is feasible to convert 5-HMF to DHMF via crude enzymes from fungus G. sessile under mild condition, and that DHMF displays a potential effect of antitumor in vitro with little acute toxicity.

Proteomic analysis of the molecular mechanism of curcumin/β-cyclodextrin polymer inclusion complex inhibiting HepG2 cells growth

This research aimed to explore whether curcumin/β-cyclodextrin polymer (CUR/CDP) inclusion complex caused inhibitory effect on HepG2 cells proliferation and its possible molecular mechanisms. We found that CUR/CDP inclusion complex exhibited inhibitory effects on HepG2 cells growth. To understand the underlying mechanism of how CUR/CDP inclusion complex inhibited HepG2 cells growth, we examined the proteome of HepG2 cells treated at 640 μg/ml CUR/CDP inclusion complex using proteomic approach. We found that 15 protein spots identified by MALDI-TOF/TOF MS were changed. Biological progress analysis demonstrated that protein related to cell cycle and apoptosis accounted for 33% of the detected proteins. Among these proteins, nucleophosmin (NPM1) and peroxiredoxin-6 (PRDX6) were involved in the ROS-P53 pathway. PRDX6 and NPM1 were down-regulated, thereby improving the expression level of phosphorylated p53 and ROS content, which regulated cell apoptosis. This findings provide a better understanding of CUR/CDP regulatory anti-tumor mechanisms. PRACTICAL APPLICATIONS: Cyclodextrins polymer was used to prepare the curcumin/cyclodextrins polymer inclusion complex to improve curcumin solubility and stability in our group. And we found that it showed novel anticancer activity. However, the molecular mechanisms is unclear. This research elucidates the underlying molecular mechanisms of the curcumin/cyclodextrins polymer inclusion complex-inhibited HepG2 cells growth. The inclusion complex has the potential to be a novel complex of curcumin to treat human cancers.

Kaempferol Attenuates ROS-Induced Hemolysis and the Molecular Mechanism of Its Induction of Apoptosis on Bladder Cancer

Bladder cancer has become the most common malignant urinary carcinoma. Studies have shown that significant antioxidant and bladder cancer-fighting properties of several plant-based diets like Psidium guajava, ginger and amomum, are associated with their high kaempferol content. In this paper, we evaluated the antioxidant and anticancer activities of kaempferol and its mechanism of induction to apoptosis on bladder cancer cells. Our findings demonstrated that kaempferol showed an obvious radical scavenging activity in erythrocytes damaged by oxygen. Kaempferol promoted antioxidant enzymes, inhibited ROS generation and lipid peroxidation and finally prevented the occurrence of hemolysis. Additionally, kaempferol exhibited a strong inhibitory effect on bladder cancer cells and high safety on normal bladder cells. At the molecular level, kaempferol suppressed EJ bladder cancer cell proliferation by inhibiting the function of phosphorylated AKT (p-AKT), CyclinD1, CDK4, Bid, Mcl-1 and Bcl-xL, and promoting p-BRCA1, p-ATM, p53, p21, p38, Bax and Bid expression, and finally triggering apoptosis and S phase arrest. We found that Kaempferol exhibited strong anti-oxidant activity on erythrocyte and inhibitory effects on the growth of cancerous bladder cells through inducing apoptosis and S phase arrest. These findings suggested that kaempferol might be regarded as a bioactive food ingredient to prevent oxidative damage and treat bladder cancer.

Biotin-Modified Polylactic- co-Glycolic Acid Nanoparticles with Improved Antiproliferative Activity of 15,16-Dihydrotanshinone I in Human Cervical Cancer Cells

15,16-Dihydrotanshinone I (DI), a natural compound isolated from a traditional Asian functional food Salvia Miltiorrhiza Bunge, is known for its anticancer activity. However, poor solubility of DI limits its desirable anticancer application. Herein, polylactic- co-glycolic acid (PLGA) was functionalized with polyethylene glycol (PEG) and biotin to form copolymers PEG-PLGA (PPA) and biotin-PEG-PLGA (BPA). DI was encapsulated in copolymers PPA and BPA to obtain DI-PPA-NPs (NPs = nanoparticles) and DI-BPA-NPs, respectively. The particle size and its distribution, encapsulation efficiency, and in vitro releasing capacity of DI-BPA-NPs were characterized by biophysical methods. MTT assay was used to evaluate the antiproliferative activity of free DI, DI-PPA-NPs, and DI-BPA-NPs in human cervical cancer Hela cells. DI-BPA-NPs showed the highest cytotoxicity on Hela cells with an IC₅₀ value of 4.55 ± 0.631 μM, while it was 8.20 ± 0.849 and 6.14 ± 0.312 μM for DI and DI-PPA-NPs in 72 h, respectively. The superior antiproliferative activity was supported by the fact that DI-BPA-NPs could be preferentially internalized by Hela cells, owing to their specific interaction between biotin and overexpressed biotin receptors. In addition, DI-BPA-NPs effectively inhibited Hela cell proliferation by inducing G2/M phase cycle arrest and decreasing the intracellular reactive oxygen species (ROS) level by 31.50 ± 2.29% in 5 min. In summary, DI-BPA-NPs shows improved antiproliferative activity against human cervical cancer as comparing with free DI, demonstrating its application potential in cancer therapy.

5-Hydroxymethylfurfural (HMF) levels in honey and other food products: effects on bees and human health

An organic compound known as 5-hydroxymethylfurfural (HMF) is formed from reducing sugars in honey and various processed foods in acidic environments when they are heated through the Maillard reaction. In addition to processing, storage conditions affect the formation HMF, and HMF has become a suitable indicator of honey quality. HMF is easily absorbed from food through the gastrointestinal tract and, upon being metabolized into different derivatives, is excreted via urine. In addition to exerting detrimental effects (mutagenic, genotoxic, organotoxic and enzyme inhibitory), HMF, which is converted to a non-excretable, genotoxic compound called 5-sulfoxymethylfurfural, is beneficial to human health by providing antioxidative, anti-allergic, anti-inflammatory, anti-hypoxic, anti-sickling, and anti-hyperuricemic effects. Therefore, HMF is a neo-forming contaminant that draws great attention from scientists. This review compiles updated information regarding HMF formation, detection procedures, mitigation strategies and effects of HMF on honey bees and human health.

Apoptosis triggered by isoquercitrin in bladder cancer cells by activating the AMPK-activated protein kinase pathway

Cancer cells are well known to require a constant supply of protein, lipid, RNA, and DNA via altered metabolism for accelerated cell proliferation. Targeting metabolic pathways is, therefore, a promising therapeutic strategy for cancers. Isoquercitrin (ISO) is widely distributed in dietary and medicinal plants and displays selective cytotoxicity to cancer cells, primarily by inducing apoptosis and cell cycle arrest. The aims of this study were to find out whether ISO could stabilize in a bladder-like acidic environment and inhibit bladder cancer cell proliferation by affecting their metabolism, and to investigate its molecular mechanism. In this study, the exposure of T24 bladder cancer cells to ISO (20-80 μM) decreased cell viability by causing ROS overproduction. This ROS change regulated the AMPK signaling pathway, and caused Caspase-dependent apoptosis as well as metabolism dysfunction. Metabolic alterations elevated metabolic pathway variation, which in turn destabilized lipid synthesis and altered anaerobic glycolysis. This linkage was proved by immunoblotting assay, and metabolomics as identified by UHPLC-QTOF-MS. Our findings provide comprehensive evidence that ISO influenced T24 bladder cancer cell metabolism, and that this process was mainly involved in activating the AMPK pathway. This study could lead to an understanding of how ISO suppresses bladder cancer cell growth, and whether the affected cancer metabolism is a common mechanism by which nutritional compounds suppress cancers.

Structural Characterization of a Tetrapeptide from Sesame Flavor-Type Baijiu and Its Preventive Effects against AAPH-Induced Oxidative Stress in HepG2 Cells

Peptides are rarely reported from Chinese Baijiu (Chinese liquor) because they are often present in very low concentrations in the complex matrix. A tetrapeptide, Ala-Lys-Arg-Ala (AKRA), was recently identified by high-performance liquid chromatography and quadrupole-time-of-flight-mass spectrometry (HPLC-Q-TOF-MS) from sesame flavor-type Baijiu at a concentration of 8.497 ± 0.753 μg/L (P > 0.05), and this tetrapeptide showed preventive effects against 2,2'-azobis(2-methylpropanimidamidine) dihydrochloride (AAPH)-induced oxidative stress in HepG2 cells. The cellular antioxidant activity assay results showed that AKRA protected AAPH-induced oxidative stress in HepG2 cells in a concentration-dependent manner. Pretreatment of the cells for 2 h with AKRA (0.38-1.50 mg/mL) caused strong intracellular reactive oxygen species (ROS) scavenging activities and prevented a decrease in reduced glutathione (GSH) and increases in oxidized glutathione (GSSG) and malondialdehyde (MDA). In addition, AKRA treatment prevented significant decreases in glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) induced by AAPH. Thus, AKRA treatment ameliorated AAPH-induced oxidative stress in HepG2 cells. This study will be important for the design and regulation of functional Baijiu production.

5-HMF attenuates striatum oxidative damage via Nrf2/ARE signaling pathway following transient global cerebral ischemia

Recent studies have shown 5-hydroxymethyl-2-furfural (5-HMF) has favorable biological effects, and its neuroprotection in a variety of neurological diseases has been noted. Our previous study showed that treatment of 5-HMF led to protection against permanent global cerebral ischemia. However, the underlying mechanisms in cerebral ischemic injury are not fully understood. This study was conducted to investigate the neuroprotective effect of 5-HMF and elucidate the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway mechanism in the striatum after transient global cerebral ischemia. C57BL/6 mice were subjected to bilateral common carotid artery occlusion for 20 min and sacrificed 24 h after reperfusion. 5-HMF (12 mg/kg) or an equal volume of vehicle was intraperitoneally injected 30 min before ischemia and 5 min after the onset of reperfusion. At 24 h after reperfusion, neurological function was evaluated by neurological disability status scale, locomotor activity test and inclined beam walking test. Histological injury of the striatum was observed by cresyl violet staining and terminal deoxynucleotidyl transferase (TdT)-mediated dNTP nick end labeling (TUNEL) staining. Oxidative stress was evaluated by the carbonyl groups introduced into proteins, and malondialdehyde (MDA) levels. An enzyme-linked immunosorbent assay (ELISA)-based measurement was used to detect Nrf2 DNA binding activity. Nrf2 and its downstream ARE pathway protein expression such as heme oxygenase-1, NAD (P)H:quinone oxidoreductase 1, glutamate-cysteine ligase catalytic subunit and glutamate-cysteine ligase modulatory subunit were detected by western blot. Our results showed that 5-HMF treatment significantly ameliorated neurological deficits, reduced brain water content, attenuated striatum neuronal damage, decreased the carbonyl groups and MDA levels, and activated Nrf2/ARE signaling pathway. Taken together, these results demonstrated that 5-HMF exerted significant antioxidant and neuroprotective effects following transient cerebral ischemia, possibly through the activation of the Nrf2/ARE signaling pathway.

Horner-Wadsworth-Emmons approach to piperlongumine analogues with potent anti-cancer activity

Natural products with anti-cancer activity play a vital role in lead and target discovery. We report here the synthesis and biological evaluation of the plant-derived alkaloid, piperlongumine and analogues. Using a Horner-Wadsworth-Emmons coupling approach, a selection of piperlongumine-like compounds were prepared in good overall yield from a novel phosphonoacetamide reagent. A number of the compounds displayed potent anti-cancer activity against colorectal (HCT 116) and ovarian (IGROV-1) carcinoma cell lines, via a mechanism of action which may involve ROS generation. Contrary to previous reports, no selective action in cancer cell (MRC-5) was observed for piperlongumine analogues.

Coffee provides a natural multitarget pharmacopeia against the hallmarks of cancer

Coffee is the second most popular beverage in the world after water with a consumption of approximately two billion cups per day. Due to its low cost and ease of preparation, it is consumed in almost all countries and by all social classes of the population through different modes of preparation. Despites its simple appearance, a cup of coffee is in fact a complex mixture that contains hundreds of molecules, the composition and concentration of which vary widely and depend on factors including the origin of the coffee tree or its metabolism. Although an excessive consumption of coffee can be harmful, many molecules that are present in this black decoction exert anticancer properties. This review aims to describe the different primary coffee-containing substances that exert chemopreventive and bioactive activities against the different hallmarks and enabling characteristics of cancer, thus explaining the anticancer health benefit of black coffee.