A simple phenolic antioxidant protocatechuic acid enhances tumor promotion and oxidative stress in female ICR mouse skin: dose-and timing-dependent enhancement and involvement of bioactivation by tyrosinase

Compound Similarity Network as a Novel Data Mining Strategy for High-Throughput Investigation of Degradation Pathways of Organic Pollutants in Industrial Wastewater Treatment

Identification of degradation products and pathways is crucial for investigating emerging pollutants and evaluation of wastewater treatment methods. Nontargeted analysis is a powerful tool to comprehensively investigate the degradation pathways of organic pollutants in real-world wastewater samples but often generates large data sets, making it difficult to effectively locate the exact information on interests. Herein, to efficiently establish the linkages among compounds in the same degradation pathways, we introduce a compound similarity network (CSN) as a novel data mining strategy for LC-MS-based nontargeted analysis of complex wastewater samples. Different from molecular networks that cluster compounds based on MS/MS spectra similarity, our CSN strategy harnesses molecular fingerprints to establish linkages among compounds and thus is spectra-independent. The effectiveness of CSN was demonstrated by nontargeted identification of degradation pathways and products of organic pollutants in leather industrial wastewater that underwent laboratory-scale activated carbon adsorption (ACD) and ozonation treatments. Utilizing CSN in interpreting nontargeted data, we tentatively annotated 4324 compounds in the untreated leather industrial wastewater, 3246 after ACD, and 3777 after ACD/ozonation. We located 145 potential degradation pathways of organic pollutants in the ACD/ozonation process using CSN and validated 7 pathways with 15 chemical standards. CSN also revealed 5 clusters of emerging pollutants, from which 3 compounds were selected for in vitro cytotoxicity study to evaluate their potential biohazards as new pollutants. As CSN offers an efficient way to connect massive compounds and to find multiple degradation pathways in a high-throughput manner, we anticipate that it will find wide applications in nontargeted analysis of diverse environmental samples.

Role of SIRT1 in Potentially Toxic Trace Elements (Lead, Fluoride, Aluminum and Cadmium) Associated Neurodevelopmental Toxicity

The formation of the central nervous system is a meticulously planned and intricate process. Any modification to this process has the potential to disrupt the structure and operation of the brain, which could result in deficiencies in neurological growth. When neurotoxic substances are present during the early stages of development, they can be exceptionally dangerous. Prenatally, the immature brain is extremely vulnerable and is therefore at high risk in pregnant women associated with occupational exposures. Lead, fluoride, aluminum, and cadmium are examples of possibly toxic trace elements that have been identified as an environmental concern in the aetiology of a number of neurological and neurodegenerative illnesses. SIRT1, a member of the sirtuin family has received most attention for its potential neuroprotective properties. SIRT1 is an intriguing therapeutic target since it demonstrates important functions to increase neurogenesis and cellular lifespan by modulating multiple pathways. It promotes axonal extension, neurite growth, and dendritic branching during the development of neurons. Additionally, it contributes to neurogenesis, synaptic plasticity, memory development, and neuroprotection. This review summarizes the possible role of SIRT1 signalling pathway in potentially toxic trace elements -induced neurodevelopmental toxicity, highlighting some molecular pathways such as mitochondrial biogenesis, CREB/BDNF and PGC-1α/NRF1/TFAM.

Spice-Derived Phenolic Compounds: Potential for Skin Cancer Prevention and Therapy

Skin cancer is a condition characterized by the abnormal growth of skin cells, primarily caused by exposure to ultraviolet (UV) radiation from the sun or artificial sources like tanning beds. Different types of skin cancer include melanoma, basal cell carcinoma, and squamous cell carcinoma. Despite the advancements in targeted therapies, there is still a need for a safer, highly efficient approach to preventing and treating cutaneous malignancies. Spices have a rich history dating back thousands of years and are renowned for their ability to enhance the flavor, taste, and color of food. Derived from various plant parts like seeds, fruits, bark, roots, or flowers, spices are important culinary ingredients. However, their value extends beyond the culinary realm. Some spices contain bioactive compounds, including phenolic compounds, which are known for their significant biological effects. These compounds have attracted attention in scientific research due to their potential health benefits, including their possible role in disease prevention and treatment, such as cancer. This review focuses on examining the potential of spice-derived phenolic compounds as preventive or therapeutic agents for managing skin cancers. By compiling and analyzing the available knowledge, this review aims to provide insights that can guide future research in identifying new anticancer phytochemicals and uncovering additional mechanisms for combating skin cancer.

Gallic acid markedly stimulates GLUT1-mediated glucose uptake by the AsPC-1 pancreatic cancer cell line

Phenolic acids are recognized as chemopreventive and chemotherapeutic agents. Altered glucose and glutamine metabolism are recognized hallmarks of cancer cells. We aimed to test the influence of phenolic acids on glucose and glutamine cellular uptake by a breast (MCF-7) and a pancreatic (AsPC-1) cancer cell line. Several phenolic acids (caffeic, ferrulic, proctocatechuic, coumaric and gallic acid) affected ³H-glutamine and/or ³H-deoxy-d-glucose (³H-DG) uptake. Gallic acid (100 µM) caused a 3-fold increase in ³H-DG uptake by AsPC-1 cells, associated with a 3.7-fold increase in lactic acid production. Gallic acid stimulated GLUT1-mediated ³H-DG uptake and increased the affinity of this transporter for ³H-DG. We further verified that gallic acid does not change GLUT1 transcription rates and cellular redox state and that its effect does not involve PI3K, mTOR and MAP kinases and is not associated with a proproliferative effect. Gallic acid also increased ³H-DG uptake by MCF-7 cells, although less potently. Further investigation is necessary to elucidate the cellular pathways involved in this effect of gallic acid.

Ethyl Protocatechuate Encapsulation in Solid Lipid Nanoparticles: Assessment of Pharmacotechnical Parameters and Preliminary In Vitro Evaluation for Colorectal Cancer Treatment

Colorectal cancer is one of the most diffused tumoral diseases. Since most medicaments employed for its treatment are debilitating, the use of naturally derived products, which can be effective against the mutated cells and, in addition, can reduce most inflammatory-related effects, could be extremely beneficial for the continued treatment of this disease. In this research, ethyl protocatechuate (PCAEE), a protocatechuic acid prodrug, was encapsulated in solid lipid nanoparticles (SLN) (prepared without and with Tween 80), which were characterized in terms of size, polydispersity index (PDI), zeta potential and thermotropic behavior. Encapsulation efficiency, release profile and interaction with a model of biomembrane were also assessed. The nanoparticles were tested in vitro on both healthy cells and on a model of tumoral cells. SLN prepared with Tween 80 was promising in terms of physicochemical properties (z-average of 190 nm, PDI 0.150 and zeta potential around -20 mV) and encapsulation efficiency (56%); they showed a desirable release profile, demonstrated an ability to penetrate and release the encapsulated PCAEE into a biomembrane model and were nontoxic on healthy cells. In addition, they caused a greater dose-dependent decrease in the viability of CaCo-2 cells than PCAEE alone. In conclusion, the formulation could be proposed for further studies to assess its suitability for the treatment of colorectal cancer.

RP-HPLC-based phytochemical screening of different polyphenolic compounds from floral extract of four species of Saraca L. (Leguminosae)

Background

Saraca L. is one of the treasures throve of medicinally important plants in Indian subcontinent with its four species among which two are naturally distributed. It is one of the important resources of highly active phytochemicals due to which it proclaims a legendary position from ancient medicinal practices to modern ages. The crude extracts of flowers of four species were prepared using Soxhlet apparatus in petroleum benzene, ethyl acetate and 90% methanol sequentially. RP-HPLC (reverse-phase high-performance liquid chromatography)-based analysis of the presence of different phytochemicals using 15 different polyphenolic phytochemical standards was done to assess and quantify different phytochemicals.

Results

RP-HPLC-based evaluation revealed the presence different polyphenolic compounds like catechins, chlorogenic acid, vanillic acid, caffeic acid, gallic acid, t-cinnamic acid, anthrol, p-coumaric acid, biochanin A, etc., in a considerable amount which is very crucial for the phytomedicinal field. The correlations of the presence of known phytochemicals give a basis of phytochemical correlation among the four species. The RP-HPLC chromatographic data were applied to develop the complete phytochemical coding according to the complete set of chemicals found among the species to evaluate phytochemical correlation among them in a different way. This application also produces strong evidence of distinguishing features of S. indica and S. asoca that were considered as same species by some traditional taxonomy.

Conclusion

Extracts of S. thaipingensis contain highest amount of polyphenolic compounds, and the lowest amount was found in S. declinata. The phytochemical relations among S. asoca and S. declinata are high, and S. indica also has close relations with them, but S. thaipingensis has distinct divergence.

The Effective Analysis for Blue Honeysuckle Extract in the Treatment of Hepatocellular Carcinoma

To further determine how BHE affected the growth of HCC cells, the proportion of each cell cycle phase was explored in HCC cells by flow cytometry. Blue honeysuckle (Lonicera caerulea L.) is a species of bush that grows in eastern Russia. Blue honeysuckle extract (BHE) is rich in bioactive phytochemicals which can inhibit the proliferation of tumor cells. The mechanism underlying the anticancer activity of BHE in primary liver cancer is poorly understood. The purpose of this study was to evaluate the growth inhibition mechanism of bioactive substances from blue honeysuckle on hepatocellular carcinoma (HCC) cells and to explore its protein and gene targets. The compounds in BHE were determined by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). Cell counting kit-8 (CCK8) assay was used to evaluate the effects of BHE on HCC cell proliferation, and flow cytometry assay (FCA) was used to determine how BHE arrested the proportion of each cell cycle phase in HCC cells. Western blot (WB) was performed to determine the expression of cell cycle-related proteins in HCC cells treated with different concentrations of BHE. The xenograft tumor animal models were established by HCC cell implantation. The results showed that cyanidin-3-o-glucoside and cyanidin-3-o-sophoroside which are the main biologically active components were detected in BHE. BHE is highly effective in inhibiting the proliferation of HCC cells by arresting the HCC cell cycle in the G2/M phase. BHE also downregulated the expression of conventional or classical dendritic cells-2 (cDC2) and cyclin B1 by promoting the expression of myelin transcription factor 1 (MyT1) in HCC cells. The weight and volume of xenografts were significantly decreased in the BHE treated groups when compared to the control group. BHE increased the expression of MyT1 in xenograft tissues. These findings showed that blue honeysuckle extract inhibits proliferation in vivo and in vitro by downregulating the expression of cDC2 and cyclin B1 and upregulating the expression of MyT1 in HCC cells.

Healthy ageing and Mediterranean diet: A focus on hormetic phytochemicals

Mediterranean diet (MedDiet) is rich in fruits and vegetables associated with longevity and a reduced risk of several age-related diseases. It is demonstrated that phytochemicals in these plant products enhance the positive effects of MedDiet by acting on the inflammatory state and reducing oxidative stress. Evidence support that these natural compounds act as hormetins, triggering one or more adaptive stress-response pathways at low doses. Activated stress-response pathways increase the expression of cytoprotective proteins and multiple genes that act as lifespan regulators, essential for the ageing process. In these ways, the hormetic response by phytochemicals such as resveratrol, ferulic acid, and several others in MedDiet might enhance cells' ability to cope with more severe challenges, resist diseases, and promote longevity. This review discusses the role of MedDiet phytochemicals in healthy ageing and the prevention of age-related diseases.

Protocatechuic Acid, a Simple Plant Secondary Metabolite, Induced Apoptosis by Promoting Oxidative Stress through HO-1 Downregulation and p21 Upregulation in Colon Cancer Cells

Gastrointestinal cancers, particularly colorectal cancer, are mainly influenced by the dietary factor. A diet rich in fruits and vegetables can help to reduce the incidence of colorectal cancer thanks to the phenolic compounds, which possess antimutagenic and anticarcinogenic properties. Polyphenols, alongside their well-known antioxidant properties, also show a pro-oxidative potential, which makes it possible to sensitize tumor cells to oxidative stress. HO-1 combined with antioxidant activity, when overexpressed in cancer cells, is involved in tumor progression, and its inhibition is considered a feasible therapeutic strategy in cancer treatment. In this study, the effects of protocatechuic acid (PCA) on the viability of colon cancer cells (CaCo-2), annexin V, LDH release, reactive oxygen species levels, total thiol content, HO-1, γ-glutamylcysteine synthetase, and p21 expression were evaluated. PCA induced, in a dose-dependent manner, a significantly reduced cell viability of CaCo-2 by oxidative/antioxidant imbalance. The phenolic acid induced modifications in levels of HO-1, non-proteic thiol groups, γ-glutamylcysteine synthetase, reactive oxygen species, and p21. PCA induced a pro-oxidant effect in cancer cells, and the in vitro pro-apoptotic effect on CaCo-2 cells is mediated by the modulation of redox balance and the inhibition of the HO-1 system that led to the activation of p21. Our results suggest that PCA may represent a useful tool in prevention and/or therapy of colon cancer.

Kaempferol Blocks the Skin Fibroblastic Interleukin 1β Expression and Cytotoxicity Induced by 12-O-tetradecanoylphorbol-13-acetate by Suppressing c-Jun N-terminal Kinase

Kaempferol, a bioflavonoid present in fruits and vegetables, has a variety of antioxidant and anti-inflammatory capacities, but the functional role of kaempferol in oxidative skin dermal damage has yet to be well studied. In this study, we examine the role of kaempferol during the inflammation and cell death caused by 12-O-tetradecanoylphorbol-13-acetate (TPA) in normal human dermal fibroblasts (NHDF). TPA (5 μM) significantly induced cytotoxicity of NHDF, where a robust increase in the interleukin (IL)-1β mRNA among the various pro-inflammatory cytokines. The skin fibroblastic cytotoxicity and IL-1β expression induced by TPA were significantly ameliorated by a treatment with 100 nM of kaempferol. Kaempferol blocked the production of the intracellular reactive oxygen species (ROS) responsible for the phosphorylation of c-Jun N-terminal kinase (JNK) induced by TPA. Interestingly, we found that kaempferol inhibited the phosphorylation of nuclear factor-kappa B (NF-κB) and the inhibitor NF-κB (IκBα), which are necessary for the expression of cleaved caspase-3 and the IL-1β secretion in TPA-treated NHDF. These results suggest that kaempferol is a functional agent that blocks the signaling cascade of the skin fibroblastic inflammatory response and cytotoxicity triggered by TPA.

Protective role of protocatechuic acid in carbon tetrachloride-induced oxidative stress via modulation of proinflammatory cytokines levels in brain and liver of Wistar rats

OBJECTIVES

Protocatechuic acid (PCA) possesses numerous pharmacological activities, including antioxidative and anti-inflammatory activities. This study seeks to investigate its underlying mechanism of action in the liver and brain toxicity induced by CCl₄ in male albino rats.

METHODS

Rats were given PCA at 10 and 20 mg/kg daily and orally as a pretreatment for seven days. A single injection of CCl₄ was given 2 h later to induce brain and liver toxicity.

RESULTS

CCl₄ moderately elevated the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). PCA lowered AST level significantly when compared to control. Total protein and albumin levels presented insignificant changes (p>0.05) in all groups while lipid profile showed increased total cholesterol level and reduced high-density lipoprotein (HDL) by CCl₄. PCA (10 mg/kg) significantly reduced the cholesterol level while the 20 mg/kg dose moderately prevented HDL reduction. There was an increased MDA production with a corresponding low GSH level in the group treated with CCl₄. Activities of superoxide dismutase, catalase, and glutathione-S-transferase in both organs also declined. PCA, especially at 10 mg/kg attenuated lipid peroxidation by increasing GSH level in the organs. Biochemical assays revealed the improvement of antioxidant enzyme activities by PCA in these organs. Furthermore, PCA lowered the level of proinflammatory cytokine COX 2 in the brain and liver while NF-kB expression was inhibited in the brain. Histopathology reports validated the effects of PCA.

CONCLUSIONS

PCA exhibited protection against toxicity in these tissues through antioxidant and anti-inflammatory activities and the potential mechanism might be through modulation of the NF-κB/COX-2 pathway.

A comprehensive review of the therapeutic potential of α-arbutin

Cosmetic dermatology preparations such as bleaching agents are ingredients with skin-related biological activities for increasing and improving skin beauty. The possibility of controlling skin hyperpigmentation disorders is one of the most important research goals in cosmetic preparations. Recently, cosmetics containing herbal and botanical ingredients have attracted many interests for consumers of cosmetic products because these preparations are found safer than other preparations with synthetic components. However, high-quality trial studies in larger samples are needed to confirm safety and clinical efficacy of phytotherapeutic agents with high therapeutic index. Arbutin (p-hydroxyphenyl-β-d-glucopyranoside) is a bioactive hydrophilic polyphenol with two isomers including alpha-arbutin (4-hydroxyphenyl-α-glucopyranoside) and β-arbutin (4-hydroxyphenyl-β-glucopyranoside). It is used as a medicinal plant in phytopharmacy. Studies have shown that alpha-arbutin is 10 times more effective than natural arbutin. A comparison of IC50 values showed that α-arbutin (with concentration 2.0 mM) has a more potent inhibitory activity on human tyrosinase against natural arbutin (with higher concentration than 30 mM). A review of recent studies showed that arbutin could be beneficial in treatment of various diseases such as hyperpigmentation disorders, types of cancers, central nervous system disorders, osteoporosis, diabetes, etc. This study was designed to describe the therapeutic efficiencies of arbutin.

Protective Effect of Lemon Peel Polyphenols on Oxidative Stress-Induced Damage to Human Keratinocyte HaCaT Cells Through Activation of the Nrf2/HO-1 Signaling Pathway

Lemon peel can be used as traditional Chinese medicine. Flavonoids are the most important components in lemon peel, which can be developed as natural medicine without side effects. This study investigated the protective effect of lemon peel polyphenols (LPP) on human keratinocyte HaCaT cells under oxidative stress. The active components of LPP were determined by high performance liquid chromatography. The abilities of LPP to scavenge DPPH and ABTS+ free radicals were studied for detection of antioxidation in vitro. Cell survival rates were determined by MTT assay. The antioxidant enzyme activity and antioxidant index of cells were determined using kit. The mRNA and protein expression of cells were determined by qPCR and western blot. The ability of LPP to scavenge DPPH and ABTS+ free radicals were stronger than those of vitamin C (Vc) at the same concentration. As expected, compared with the normal group of cells, the model group had decreased cell survival, increased lactate dehydrogenase (LDH), decreased levels of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH), and increased malondialdehyde (MDA) content. qPCR and western blot results indicated that the expression of Bcl-2-related X protein (Bax), caspases-3, erythroid-derived nuclear factor 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were decreased and the expression of B-cell lymphoma-2 (Bcl-2) was increased in the model group, compared with the normal group. LPP treatment improved cell survival rate, reduced intracellular LDH and MDA levels, increased intracellular SOD, CAT, GSH levels, down-regulated Bax, caspases-3, Nrf2, HO-1 expression, and up-regulated Bcl-2 expression. Component analyses found that LPP contains gallic acid, neochlorogenic acid, (+)-catechin, caffeic acid, (-)-Catechin gallate, isochlorogenic acid A, rosmarinic acid, and protocatechuic acid. LPP was found to regulate the Nrf2/HO-1 signaling pathway through 8 active substances to protect HaCaT cells against oxidative stress in vitro.

New progress in the pharmacology of protocatechuic acid: A compound ingested in daily foods and herbs frequently and heavily

Protocatechuic acid is a natural phenolic acid, which widely exists in our daily diet and herbs. It is also one of the main metabolites of complex polyphenols, such as anthocyanins and proanthocyanins. In recent years, a large number of studies on the pharmacological activities of protocatechuic acid have emerged. Protocatechuic acid has a wide range of pharmacological activities including antioxidant, anti-inflammatory, neuroprotective, antibacterial, antiviral, anticancer, antiosteoporotic, analgesia, antiaging activties; protection from metabolic syndrome; and preservation of liver, kidneys, and reproductive functions. Pharmacokinetic studies showed that the absorption and elimination rate of protocatechuic acid are faster, with glucuronidation and sulfation being the major metabolic pathways. However, protocatechuic acid displays a dual-directional regulatory effect on some pharmacological activities. When the concentration is very high, it can inhibit cell proliferation and reduce survival rate. This review aims to comprehensively summarize the pharmacology, pharmacokinetics, and toxicity of protocatechuic acid with emphasis on its pharmacological activities discovered in recent 5 years, so as to provide more up-to-date and thorough information for the preclinical and clinical research of protocatechuic acid in the future. Moreover, it is hoped that the clinical application of protocatechuic acid can be broadened, giving full play to its characteristics of rich sources, low toxicity and wide pharmacological activites.

Biodegradation of olive mill wastewater phenolic compounds in a thermophilic anaerobic upflow packed bed reactor and assessment of their toxicity in digester effluents

The extent of phenolic compounds' biodegradation was assessed utilizing un-treated olive mill wastewater (OMWW) fed to a high-rate thermophilic (55 ^οC) anaerobic upflow packed bed reactor (UPBR) and digester effluents (DEs) collected in different hydraulic retention times (HRTs) under steady-state operating conditions. In parallel, the toxicity of each sample was evaluated by performing the microbiotest Thamnotoxkit F™. The outcomes indicate complete biodegradation of 6 phenolic compounds-vanillic acid (VA), caffeic acid (CA), syringic acid (SA), o-coumaric acid (o-CA), oleuropein (OLEU), 4-ethylphenol (4-EP)-and notable removals of hydroxytyrosol (HT) and tyrosol (TYR), reaching up to 94.87 ± 0.04% and 93.92 ± 0.33%, respectively. 4-hydroxybenzoic acid (PHBA), p-coumaric acid (p-CA) and 3,4-dihydroxybenzoic acid (DBA) were recognized as the most recalcitrant and persistent compounds in the anaerobic effluents, being capable of modulating the toxic potential of DEs.

Betula etnensis Raf. (Betulaceae) Extract Induced HO-1 Expression and Ferroptosis Cell Death in Human Colon Cancer Cells

Betula etnensis Raf. (Birch Etna) belonging to the Betulaceae family grows on the eastern slope of Etna. Many bioactive compounds present in Betula species are considered promising anticancer agents. In this study, we evaluated the effects of B. etnensis Raf. bark methanolic extract on a human colon cancer cell line (CaCo2). In order to elucidate the mechanisms of action of the extract, cellular redox status, cell cycle, and heme oxygenase-1 (HO-1) expression in ferroptosis induction were evaluated. Cell viability and proliferation were tested by tetrazolium (MTT) assayand cell cycle analysis, while cell death was evaluated by annexin V test and lactic dehydrogenase (LDH) release. Cellular redox status was assessed by measuring thiol groups (RSH) content, reactive oxygen species (ROS) production, lipid hydroperoxide (LOOH) levels and (γ-glutamylcysteine synthetase) γ-GCS and HO-1 expressions. The extract significantly reduced cell viability of CaCo2, inducing necrotic cell death in a concentration-depending manner. In addition, an increase in ROS levels and a decrease of RSH content without modulation in γ-GCS expression were detected, with an augmentation in LOOH levels and drastic increase in HO-1 expression. These results suggest that the B. etnensis Raf. extract promotes an oxidative cellular microenvironment resulting in CaCo2 cell death by ferroptosis mediated by HO-1 hyper-expression.

Dual Drugs Anticancer Nanoformulation using Graphene Oxide-PEG as Nanocarrier for Protocatechuic Acid and Chlorogenic Acid

BACKGROUND

The chemotherapy of cancer has been complicated by poor bioavailability, adverse side effects, high dose requirement, drug resistance and low therapeutic indices. Cancer cells have different ways to inhibit the chemotherapeutic drugs, use of dual/multiple anticancer agents may be achieve better therapeutic effects in particular for drug resistant tumors. Designing a biocompatible delivery system, dual or multiple drugs could addressing these chemotherapy drawbacks and it is the focus of many current biomedical research.

METHODS

In the present study, graphene oxide-polyethylene glycol (GOPEG) nanocarrier is designed and loaded with two anticancer drugs; Protocatechuic acid (PCA) and Chlorogenic acid (CA). The designed anticancer nanocomposite was further coated with folic acid to target the cancer cells, as their surface membranes are overexpressed with folate receptors.

RESULTS

The particle size distribution of the designed nanocomposite was found to be narrow, 9-40 nm. The release profiles of the loaded drugs; PCA and CA was conducted in human body simulated PBS solutions of pH 7.4 (blood pH) and pH 4.8 (intracellular lysosomal pH). Anticancer properties were evaluated against cancerous cells i.e. liver cancer, HEPG2 and human colon cancer, HT-29 cells. The cytocompatbility was assessed on normal 3T3 fibroblasts cells.

CONCLUSION

The size of the final designed anticancer nanocomposite formulation, GOPEG-PCACA-FA was found to be distributed at 9-40 nm with a median of 8 nm. The in vitro release of the drugs PCA and CA was found to be of sustained manner which took more than 100 h for the release. Furthermore, the designed formulation was biocompatible with normal 3T3 cells and showed strong anticancer activity against liver and colon cancer cells.

Graphene Oxide⁻PEG⁻Protocatechuic Acid Nanocomposite Formulation with Improved Anticancer Properties

The treatment of cancer through chemotherapy is limited by its toxicity to healthy tissues and organs, and its inability to target the cancer site. In this study, we have designed an anticancer nanocomposite delivery system for protocatechuic acid (PCA) using graphene oxide–polyethylene glycol as the nanocarrier, and coated with folic acid (GO–PEG–PCA–FA) for targeting the cancer cells. The designed anticancer delivery system was found to show much better anticancer activity than the free drug PCA against liver cancer HEP-G2 cells and human colon cancer HT-29 cells; at same time, it was found to be less toxic to normal fibroblast 3T3 cells. The folate-coated anticancer delivery system was found to show better activity then the free drug and the uncoated anticancer delivery system. The in vitro release of the PCA was found to be sustained in human physiological pHs, i.e., blood pH 7.4 and intracellular lysosomal pH 4.8. These in vitro findings are highly encouraging for further in vivo evaluation studies.

An Experimental Validated Computational Method for pKa Determination of Substituted 1,2-Dihydroxybenzenes

1,2-dihydroxybenzenes (DHBs) are organic compounds which are widely studied as they are applied to advanced oxidation processes (AOPs). These compounds are also related to the development of oxidative stress, wood biodegradation, and neuronal disease in humans. DHBs are metal ligands with pro-oxidant and antioxidant properties. These activities are related to their chelation properties and a consequence of the deprotonation of their hydroxyl groups. In literature, there are several pKa values for the hydroxyl groups of DHBs. These values vary depending on the experimental conditions or the algorithm used for calculation. In this work, an experimentally validated computational method was implemented in aqueous solution for pKa determination of 24 DHBs. The deprotonation order of the hydroxyl groups in DHB was determined observing a selective deprotonation, which depended on the ability of the substituent to donate or withdraw electron density over the ring.

Impact of Thermal Degradation of Cyanidin-3-O-Glucoside of Haskap Berry on Cytotoxicity of Hepatocellular Carcinoma HepG2 and Breast Cancer MDA-MB-231 Cells

Cyanidin-3-O-glucoside (C3G), the predominant anthocyanin in haskap berries (Lonicera caerulea L.), possesses antioxidant and many other biological activities. This study investigated the impact of temperature and pH on the degradation of the C3G-rich haskap fraction. The effect of the thermal degradation products on the viability of hepatocellular carcinoma HepG2 and breast cancer MDA-MB-231 cells was also studied in vitro. Using column chromatography, the C3G-rich fraction was isolated from acetone extracts of haskap berries. The C3G stability in these fractions was studied under elevated temperatures (70 °C and 90 °C) at three different pH values (2.5, 4, and 7) by monitoring the concentration of C3G and its major degradation products, protocatechuic acid (PCA) and phloroglucinaldehyde (PGA), using liquid chromatography mass spectrometry. Significant degradation of C3G was observed at elevated temperatures and at neutral pH. Conversely, the PCA and PGA concentration increased at higher pH and temperature. Similar to C3G, neutral pH also has a prominent effect on the degradation of PGA, which is further accelerated by heating. The C3G-rich fraction exhibited dose-dependent inhibitory effects on cell metabolic activity when the HepG2 cells were exposed for 48 h. Interestingly, PGA but not PCA exhibited cytotoxic effects against both MDA-MB-231 and HepG2 cells. The results suggest that thermal food processing of haskap could influence its biological properties due to the degradation of C3G.

Mechanisms of 2,3,7,8-tetrachlorodibenzo-p-dioxin- induced cardiovascular toxicity: An overview

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant and its toxicity is mediated by the aryl hydrocarbon receptor (AHR). Mechanisms of TCDD cardiovascular toxicity consist of oxidative stress, growth factor modulation, and ionic current alteration. It is indicated that the rodent cardiovascular system is a target for TCDD cardiomyopathy. Here, our understanding of TCDD cardiovascular toxicity is reviewed.

Mediterranean diet and inflammaging within the hormesis paradigm

A coherent set of epidemiological data shows that the Mediterranean diet has beneficial effects capable of preventing a variety of age-related diseases in which low-grade, chronic inflammation/inflammaging plays a major role, but the underpinning mechanism(s) is/are still unclear. It is suggested here that the Mediterranean diet can be conceptualized as a form of chronic hormetic stress, similar to what has been proposed regarding calorie restriction, the most thoroughly studied nutritional intervention. Data on the presence in key Mediterranean foods of a variety of compounds capable of exerting hormetic effects are summarized, and the mechanistic role of the nuclear factor erythroid 2 pathway is highlighted. Within this conceptual framework, particular attention has been devoted to the neurohormetic and neuroprotective properties of the Mediterranean diet, as well as to its ability to maintain an optimal balance between pro- and anti-inflammaging. Finally, the European Commission-funded project NU-AGE is discussed because it addresses a number of variables not commonly taken into consideration, such as age, sex, and ethnicity/genetics, that can modulate the hormetic effect of the Mediterranean diet.

Highly Efficient and Stable Novel NanoBiohybrid Catalyst to Avert 3,4-Dihydroxybenzoic Acid Pollutant in Water

The present study reported for the first time covalent immobilization of protocatechuate 3,4-dioxygenase (3,4-POD) onto functionalized multi-walled carbon nanotubes (F-MWCNT) for degrading the toxic 3,4-dihydroxybenzoic acid (3,4-DHBA) pollutant in water. The F-MWCNTs had a maximum 3,4-POD loading of 1060 μg/mg. Immobilized 3,4 POD had 44% of relative structural changes to its free configurations. Nevertheless, >90% of relative activity and about 50% of catalytic efficiency were retained to the free enzyme. Immobilized 3,4-POD demonstrated higher alkaline stability and thermostability than the free 3,4-POD. The free and immobilized 3,4-POD lost 82% and 66% of relative activities, respectively after 180 min of incubations at 90 °C. Excellent shelf-life was observed for the immobilized 3,4-POD with residual activity of 56% compared with 41% and 39% of the free 3,4-POD at 4 °C and 25 °C over 30 days storage. Immobilized 3,4-POD showed >60% of catalytic activity retention even after ten-cycle uses, defraying the expenses of free 3,4-POD productions for long term uses. Finally, the immobilized 3,4-POD removed 71% of 3,4-DHBA from water in <4 h, paving its future application for water purification with reduced costs and time.

Urolithin A suppresses the proliferation of endometrial cancer cells by mediating estrogen receptor-α-dependent gene expression

SCOPE

Obese and overweight women are at high risk of developing endometrial cancer; indeed, many of endometrial cancer patients are obese. The increased number and size of adipocytes due to obesity elevate levels of circulating estrogens that stimulate cell proliferation in the endometrium. However, black raspberries are a promising approach to preventing endometrial cancer.

METHODS AND RESULTS

We examined 17 black raspberry constituents and metabolites (10 μM or 10 μg/mL, 48 h) for their ability to prevent endometrial cancer cells from proliferating. Urolithin A (UA) was most able to suppress proliferation in a time- and dose-dependent manner (p < 0.05). It arrested the G2/M phase of the cell cycle by upregulating cyclin-B1, cyclin-E2, p21, phospho-cdc2, and CDC25B. UA also acted as an estrogen agonist by modulating estrogen receptor-α (ERα) dependent gene expression in ER-positive endometrial cancer cells. UA enhanced the expression of ERβ, PGR, pS2, GREB1 while inhibiting the expression of ERα and GRIP1. Coincubating UA-treated cells with the estrogen antagonist ICI182,780 abolished UA's estrogenic effects. Knocking down ERα suppressed PGR, pS2, and GREB gene expression but increased GRIP1 expression. Thus, UA's actions appear to be mediated through ERα.

CONCLUSION

This study suggests that UA modulates ERα-dependent gene expression, thereby inhibiting endometrial cancer proliferation.

Arbutin and decrease of potentially toxic substances generated in human blood neutrophils

Neutrophils, highly motile phagocytic cells, constitute the first line of host defense and simultaneously they are considered to be central cells of chronic inflammation. In combination with standard therapeutic procedures, natural substances are gaining interest as an option for enhancing the effectiveness of treatment of inflammatory diseases. We investigated the effect of arbutin and carvedilol and of their combination on 4β-phorbol-12β-myristate-13α-acetate- stimulated functions of human isolated neutrophils. Cells were preincubated with the drugs tested and subsequently stimulated. Superoxide (with or without blood platelets, in the rate close to physiological conditions [1:50]) and HOCl generation, elastase and myeloperoxidase release were determined spectrophotometrically and phospholipase D activation spectrofluorometrically. The combined effect of arbutin and carvedilol was found to be more effective than the effect of each compound alone.

Our study provided evidence supporting the potential beneficial effect of arbutin alone or in combination with carvedilol in diminishing tissue damage by decreasing phospholipase D, myeloperoxidase and elastase activity and by attenuating the generation of superoxide and the subsequently derived reactive oxygen species. The presented data indicate the ability of arbutin to suppress the onset and progression of inflammation.

Wushen, a food mixture containing 55 different natural ingredients, inhibits S180 tumor growth in vivo

As cancer has become a worldwide threat to human life and health, developing a safe and effective tumor-inhibiting agent is presently a major scientific challenge. In this study, a food mixture produced from 55 different natural ingredients called wushen was fed to S180 tumor-bearing mice, and the antitumor effects were investigated in vivo. Kunming mice were implanted subcutaneously in the armpit with murine sarcoma S180 cells to construct the S180 tumor-bearing mouse model. The mice were randomly divided into three groups: control, wushen and 5-fluorouracil (5-Fu). 5-Fu was used as the positive drug treatment to confirm the reliability of the model. The food intake, antitumor rate, and spleen and thymus indices were recorded. Tumor histopathology was conducted using hematoxylin and eosin (H&E) staining. The catalase, glutathione peroxidase, and superoxide dismutase activities and the malondialdehyde concentration were measured to evaluate the antioxidative effects of the treatments. The antitumor rate of the mice fed wushen was 48.52%. Wushen-treated mice exhibited alterations in antioxidative enzyme activity and reduced liver lipid peroxidation. The results demonstrated that wushen has antitumor effects on S180 tumor-bearing mice in vivo, and the underlying mechanism is partially due to its antioxidant activity. Wushen, which contains various natural products, can be eaten directly and may be beneficial to human health.

Thiol modification by bioactivated polyphenols and its potential role in skin inflammation

In the present study, we evaluated the modifying behavior of simple phenolic compounds on the sulfhydryl groups of glutathione and proteins. The catechol-type polyphenols, including protocatechuic acid, but neither the monophenols nor O-methylated catechol, can modify the sulfhydryl groups in a phenol oxidase-dependent manner. The possible involvement of polyphenol bioactivation in the enhancement of skin inflammation was also suggested.

Naturally occurring phenolic acids modulate TPA-induced activation of EGFR, AP-1, and STATs in mouse epidermis

Epidermal growth factor receptor (EGFR) plays an important role in epithelial carcinogenesis and appears to be involved in STATs activation. In this study we investigated the possible interference of naturally occurring phenolic acids with EGFR, activator protein-1 (AP-1), and signal transducers and activators of transcription (STATs) pathways activated by topical application of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in Balb/c mice epidermis. Pretreatment with tannic or chlorogenic acid resulted in a significant decrease in the phosphorylation of EGFR Y-1068 and Y-1173 tyrosine residues, which was accompanied by reduced activation of AP-1. Tannic acid decreased also the c-Jun AP-1 subunit level and binding to TPA response element (TRE) (3- and 2-fold in comparison with TPA-treated group respectively). Simultaneous reduction of JNK activity might be responsible for reduced activation of AP-1. In contrast to these more complex phenolics, protocatechuic acid increased the activity of JNK and was also the most efficient inhibitor of STATs activation. These results indicate that naturally occurring phenolic acids, by decreasing EGFR, AP-1, and STATs activation, may modulate other elements both upstream and downstream in these pathways and thus inhibit the tumor development. Although more complex phenolics affect mainly the EGFR/AP-1 pathway, STATs seem to be the most important targets for simple compounds, such as protocatechuic acid.

Preparation and controlled-release studies of a protocatechuic acid-magnesium/aluminum-layered double hydroxide nanocomposite

In the study reported here, magnesium/aluminum (Mg/Al)-layered double hydroxide (LDH) was intercalated with an anticancer drug, protocatechuic acid, using ion-exchange and direct coprecipitation methods, with the resultant products labeled according to the method used to produce them: "PANE" (ie, protocatechuic acid-Mg/Al nanocomposite synthesized using the ion-exchange method) and "PAND" (ie, protocatechuic acid-Mg/Al nanocomposite synthesized using the direct method), respectively. Powder X-ray diffraction and Fourier transform infrared spectroscopy confirmed the intercalation of protocatechuic acid into the inter-galleries of Mg/Al-LDH. The protocatechuic acid between the interlayers of PANE and PAND was found to be a monolayer, with an angle from the z-axis of 8° for PANE and 15° for PAND. Thermogravimetric and differential thermogravimetric analysis results revealed that the thermal stability of protocatechuic acid was markedly enhanced upon intercalation. The loading of protocatechuic acid in PANE and PAND was estimated to be about 24.5% and 27.5% (w/w), respectively. The in vitro release study of protocatechuic acid from PANE and PAND in phosphate-buffered saline at pH 7.4, 5.3, and 4.8 revealed that the nanocomposites had a sustained release property. After 72 hours incubation of PANE and PAND with MCF-7 human breast cancer and HeLa human cervical cancer cell lines, it was found that the nanocomposites had suppressed the growth of these cancer cells, with a half maximal inhibitory concentration of 35.6 μg/mL for PANE and 36.0 μg/mL for PAND for MCF-7 cells, and 19.8 μg/mL for PANE and 30.3 μg/mL for PAND for HeLa cells. No half maximal inhibitory concentration for either nanocomposite was found for 3T3 cells.

Protective effects of protocatechuic acid on TCDD-induced oxidative and histopathological damage in the heart tissue of rats

2,3,7,8-Tetracholorodibenzo- p-dioxin (TCDD) is a highly toxic environmental contaminant that causes severe toxic effects in animal and human. In this study, we investigated the toxic effects of TCDD and the preventive effects of protocatechuic acid (PCA), a widespread phenolic compound, in the heart tissue of rats. For this purpose, 3–4 months old 28 rats with 280–310 g body weights were equally divided into 4 groups (control, TCDD, PCA, TCDD + PCA group). A 2 μg/kg dose of 2,3,7,8-TCDD and 100 mg/kg dose of PCA were dissolved in corn oil and given orally to the rats for 45 days. The results indicated that TCDD induced oxidative stress by increasing the level of thiobarbituric acid reactive substance and by decreasing the levels of glutathione, catalase, glutathione peroxidase and superoxide dismutase in the heart tissue of rats. In contrast, PCA treatment prevents the toxic effects of TCDD on oxidative stress. In addition, histopathological alterations such as necrosis and hemorrhage occurred in TCDD group, and PCA treatment partially prevents these alterations in heart tissue. In this study, it was concluded that TCDD exposure led to toxic effects in heart tissue and PCA treatment could prevent the toxicity of TCDD.

Protocatechuic acid prevents reproductive damage caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in male rats

In this study, it was aimed to determinate beneficial effects of protocatechuic acid (PCA) against reproductive toxicity caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an environmental contaminant. For this purpose, 28 rats were equally divided into four groups (control, TCDD 2 μg kg(-1) per week, PCA 100 mg kg(-1) per day and TCDD + PCA group), and compounds were orally administered for 45 days. The results indicated that TCDD induced oxidative stress via an increase in thiobarbituric acid-reactive substances levels and a decrease in reduced glutathione, catalase, glutathione peroxidise and SOD levels in male rats. In contrast, PCA treatment prevented toxic effects of TCDD in terms of oxidative stress. Additionally, sperm motility, sperm concentration and serum testosterone levels significantly decreased, and pathologic testicular damage increased with TCDD exposure. However, these effects of TCDD on sperm characteristics, histopathological changes and hormone levels were reversed by PCA treatment. In conclusion, it was found that TCDD exposure induced reproductive toxicity (oxidative, hormonal, histopathological and spermatological alternations) in male rats and PCA treatment could prevent toxic effects of TCDD. Thus, PCA may be useful for the prevention and treatment of reproductive toxicity caused by TCDD.

Nordihydroguaiaretic Acid from Creosote Bush (Larrea tridentata) Mitigates 12-O-Tetradecanoylphorbol-13-Acetate-Induced Inflammatory and Oxidative Stress Responses of Tumor Promotion Cascade in Mouse Skin

Nordihydroguaiaretic acid (NDGA) is a phenolic antioxidant found in the leaves and twigs of the evergreen desert shrub, Larrea tridentata (Sesse and Moc. ex DC) Coville (creosote bush). It has a long history of traditional medicinal use by the Native Americans and Mexicans. The modulatory effects of topically applied NDGA was studied on acute inflammatory and oxidative stress responses in mouse skin induced by stage I tumor promoting agent, 12-O-tetradecanoylphorbol-13-acetate (TPA). Double TPA treatment adversely altered many of the marker responses of stage I skin tumor promotion cascade. Pretreatment of NDGA in TPA-treated mice mitigated cutaneous lipid peroxidation and inhibited production of hydrogen peroxide. NDGA treatment also restored reduced glutathione level and activities of antioxidant enzymes. Elevated activities of myeloperoxidase, xanthine oxidase and skin edema formation in TPA-treated mice were also lowered by NDGA indicating a restrained inflammatory response. Furthermore, results of histological study demonstrated inhibitory effect of NDGA on cellular inflammatory responses. This study provides a direct evidence of antioxidative and anti-inflammatory properties of NDGA against TPA-induced cutaneous inflammation and oxidative stress corroborating its chemopreventive potential against skin cancer.

Antigenotoxicity, cytotoxicity, and apoptosis induction by apigenin, bisabolol, and protocatechuic acid

Medicinal plants represent an important resource in new drug research. Antioxidant properties of plants can help to scavenge reactive oxygen species. The objective of this work was to evaluate the genotoxic, antigenotoxic, tumoricidal, and apoptotic effect of some major phenols (apigenin, bisabolol, and protocatechuic acid) from two medicinal plants, Matricaria chamomilla and Uncaria tomentosa. The wing spot test of Drosophila melanogaster was used to evaluate the genotoxicity and antigenotoxicity of the three phenols. The human model of HL-60 leukemia cells was used for the assessment of the cytotoxic effect, growth, and cellular viability. The apoptotic effect was evaluated using a DNA fragmentation assay based on the formation of internucleosomal units. Protocatechuic acid (0.25 and 1 mM), apigenin (0.46 and 1.85 mM), and bisabolol (0.56 and 2.24 mM) did not exhibit any genotoxic effect. The three phenols showed an antigenotoxic effect against the hydrogen peroxide effect and also exhibited tumoricidal activity. Apigenin (2.24-35.96 mM) showed a lower 50% inhibitory concentration (0.75 and 3.87 mM for the trypan blue test and WST-8 colorimetric assay, respectively) than bisabolol and protocatechuic acid. These phenolics also induced apoptosis in HL-60 leukemia cells. This study suggests that the antioxidant activity of Chamomilla and Uncaria could be partially responsible of their beneficial activity.