Gallic Acid Improves Health-Associated Biochemical Parameters and Prevents Oxidative Damage of DNA in Type 2 Diabetes Patients: Results of a Placebo-Controlled Pilot Study

Bioactive compounds from nature: Antioxidants targeting cellular transformation in response to epigenetic perturbations induced by oxidative stress

Oxidative stress results from a persistent imbalance in oxidation levels that promotes oxidants, playing a crucial role in the early and sustained phases of DNA damage and genomic and epigenetic instability, both of which are intricately linked to the development of tumors. The molecular pathways contributing to carcinogenesis in this context, particularly those related to double-strand and single-strand breaks in DNA, serve as indicators of DNA damage due to oxidation in cancer cases, as well as factors contributing to epigenetic instability through ectopic expressions. Oxidative stress has been considered a therapeutic target for many years, and an increasing number of studies have highlighted the promising effectiveness of natural products in cancer treatment. In this regard, we present significant research on the therapeutic targeting of oxidative stress using natural molecules and underscore the essential role of oxidative stress in cancer. The consequences of stress, especially epigenetic instability, also offer significant therapeutic prospects. In this context, the use of natural epi-drugs capable of modulating and reorganizing the epigenetic network is beginning to emerge remarkably. In this review, we emphasize the close connections between oxidative stress, epigenetic instability, and tumor transformation, while highlighting the role of natural substances as antioxidants and epi-drugs in the anti-tumoral context.

The Combination of Bioactive Herbal Compounds with Biomaterials for Regenerative Medicine

Regenerative medicine aims to restore the function of diseased or damaged tissues and organs by cell therapy, gene therapy, and tissue engineering, along with the adjunctive application of bioactive molecules. Traditional bioactive molecules, such as growth factors and cytokines, have shown great potential in the regulation of cellular and tissue behavior, but have the disadvantages of limited source, high cost, short half-life, and side effects. In recent years, herbal compounds extracted from natural plants/herbs have gained increasing attention. This is not only because herbal compounds are easily obtained, inexpensive, mostly safe, and reliable, but also owing to their excellent effects, including anti-inflammatory, antibacterial, antioxidative, proangiogenic behavior and ability to promote stem cell differentiation. Such effects also play important roles in the processes related to tissue regeneration. Furthermore, the moieties of the herbal compounds can form physical or chemical bonds with the scaffolds, which contributes to improved mechanical strength and stability of the scaffolds. Thus, the incorporation of herbal compounds as bioactive molecules in biomaterials is a promising direction for future regenerative medicine applications. Herein, an overview on the use of bioactive herbal compounds combined with different biomaterial scaffolds for regenerative medicine application is presented. We first introduce the classification, structures, and properties of different herbal bioactive components and then provide a comprehensive survey on the use of bioactive herbal compounds to engineer scaffolds for tissue repair/regeneration of skin, cartilage, bone, neural, and heart tissues. Finally, we highlight the challenges and prospects for the future development of herbal scaffolds toward clinical translation. Overall, it is believed that the combination of bioactive herbal compounds with biomaterials could be a promising perspective for the next generation of regenerative medicine.

Analysis of the Chemical Composition and Evaluation of the Antioxidant, Antimicrobial, Anticoagulant, and Antidiabetic Properties of Pistacia lentiscus from Boulemane as a Natural Nutraceutical Preservative

Pistacia lentiscus L. has traditionally been employed as a diuretic and stimulant in the treatment of hypertension. Our interest centered on analyzing the chemical profile of the plant's leaves and its in vitro, in vivo, and in silico antioxidant, antimicrobial, anticoagulant, and antidiabetic effects in order to valorize this species and prepare new high-value products that can be used in the agro-food and pharmaceutical industries. When this species' essential oil was hydrodistilled and subjected to GC-MS analysis, the results showed that the principal components were germacrene D (17.54%), spathulenol (17.38%), bicyclogermacrene (12.52%), and terpinen-4-ol (9.95%). The extraction of phenolic compounds was carried out by decoction and Soxhlet. The determination of total polyphenols, flavonoids, and tannins of aqueous and organic extracts by spectrophotometric methods demonstrated the richness of this species in phenolic compounds. Chromatographic analysis by HPLC/UV-ESI-MS of the aqueous extract of P. lentiscus revealed the presence of 3,5-di-O-galloyl quinic acid, gallic acid, and 3,4,5-tri-O-galloyl quinic acid specific to this species. The study of antioxidant activity by three methods (DPPH, FRAP, and Total Antioxidant Capacity) revealed that P. lentiscus is a very promising source of natural antioxidants. The antimicrobial activity of the essential oil and aqueous extract (E0) was studied by microdilution on the microplate. The results revealed the effectiveness of the aqueous extract compared to the essential oil against Gram-negative bacteria (K. pneumoniae, A. baumannii, E. aerogenes, E. cloacae, P. fluorescence, Salmonella sp., Shigella sp., and Y. enterolitica) and candidoses (C. krusei and C. albicans). The measurements of prothrombin time (PT) and activated partial thromboplastin time (aPTT) of the aqueous extract (E0) can significantly prolong these tests from concentrations of 2.875 and 5.750 mg/mL, respectively. The antihyperglycemic effect of the aqueous extract (E0) showed a strong in vitro inhibitory activity of α-amylase and α-glucosidase compared to acarbose. Thus, it significantly inhibited postprandial hyperglycemia in Wistar albino rats. The in-silico study of the major compounds of the essential oil and extract (E0) carried out using PASS, SwissADME, pkCSM, and molecular docking tools confirmed our in vitro and in vivo results. The studied compounds showed a strong ability to be absorbed by the gastrointestinal tract and to passively diffuse through the blood-brain barrier, a similarity to drugs, and water solubility. Molecular docking experiments deduced the probable mode of action of the identified compounds on their respective target proteins, such as NADPH oxidase, thrombin, α-amylase, and α-glucosidase. Furthermore, given the demonstrated antioxidant, antimicrobial, anticoagulant, and antidiabetic effects, we can affirm the richness of P. lentiscus in bioactive molecules and its use in traditional medicine as a source of preservative agent.

Use of the Single Cell Gel Electrophoresis Assay for the Detection of DNA-protective Dietary Factors: Results of Human Intervention Studies

The single cell gel electrophoresis technique is based on the measurement of DNA migration in an electric field and enables to investigate via determination of DNA-damage the impact of foods and their constituents on the genetic stability. DNA-damage leads to adverse effects including cancer, neurodegenerative disorders and infertility. In the last 25 years approximately 90 human intervention trials have been published in which DNA-damage, formation of oxidized bases, alterations of the sensitivity towards reactive oxygen species and chemicals and of repair functions were investigated with this technique. In approximately 50% of the studies protective effects were observed. Pronounced protection was found with certain plant foods (spinach, kiwi fruits, onions), coffee, green tea, honey and olive oil. Also diets with increased contents of vegetables caused positive effects. Small amounts of certain phenolics (gallic acid, xanthohumol) prevented oxidative damage of DNA; with antioxidant vitamins and cholecalciferol protective effects were only detected after intake of doses that exceed the recommended daily uptake values. The evaluation of the quality of the studies showed that many have methodological shortcomings (lack of controls, no calibration of repair enzymes, inadequate control of the compliance and statistical analyses) which should be avoided in future investigations.

Impact of Bariatric Surgery on the Stability of the Genetic Material, Oxidation, and Repair of DNA and Telomere Lengths

Obesity causes genetic instability, which plays a key-role in the etiology of cancer and aging. We investigated the impact of bariatric surgery (BS) on DNA repair, oxidative DNA damage, telomere lengths, alterations of antioxidant enzymes and, selected proteins which reflect inflammation. The study was realized with BS patients (n = 35). DNA damage, base oxidation, BER, and NER were measured before and 1 month and 6 months after surgery with the single-cell gel electrophoresis technique. SOD and GPx were quantified spectrophotometrically, malondealdehyde (MDA) was quantified by HPLC. Telomere lengths were determined with qPCR, and plasma proteome profiling was performed with high-resolution mass spectrophotometry. Six months after the operations, reduction of body weight by 27.5% was observed. DNA damage decreased after this period, this effect was paralleled by reduced formation of oxidized DNA bases, a decline in the MDA levels and of BER and NER, and an increase in the telomere lengths. The activities of antioxidant enzymes were not altered. Clear downregulation of certain proteins (CRP, SAA1) which reflect inflammation and cancer risks was observed. Our findings show that BS causes reduced oxidative damage of DNA bases, possibly as a consequence of reduction of inflammation and lipid peroxidation, and indicate that the surgery has beneficial long-term health effects.

Neurobiological effects of gallic acid: current perspectives

Gallic acid (GA) is a phenolic molecule found naturally in a wide range of fruits as well as in medicinal plants. It has many health benefits due to its antioxidant properties. This study focused on finding out the neurobiological effects and mechanisms of GA using published data from reputed databases. For this, data were collected from various sources, such as PubMed/Medline, Science Direct, Scopus, Google Scholar, SpringerLink, and Web of Science. The findings suggest that GA can be used to manage several neurological diseases and disorders, such as Alzheimer's disease, Parkinson's disease, strokes, sedation, depression, psychosis, neuropathic pain, anxiety, and memory loss, as well as neuroinflammation. According to database reports and this current literature-based study, GA may be considered one of the potential lead compounds to treat neurological diseases and disorders. More preclinical and clinical studies are required to establish GA as a neuroprotective drug.

Investigation of the Material Basis of Xiexin Tang to Alleviate Type 2 Diabetes Mellitus Based on Spectrum-Effect Analysis by UPLC-Q-TOF/MS

Xiexin Tang (XXT) is a classic prescription for treating diabetes in clinical practices for thousands of years in China, which has been also proved by a large number of modern pharmacological studies. However, due to its complex composition, the bioactive ingredients of XXT is still unclear. In present researches, spectrum-effect relationship analysis is widely used to explore the material basis of traditional medical herbs, so this method was adopted in this study. Firstly, the extract of XXT was separated and enriched into 5 fractions by macroporous adsorption resin. Then, UPLC-Q-TOF/MS method was used for qualitative identification of components in each eluting part, and efficacy of each fraction was assessed by the T2DM rat model. Based on grey relational analysis and pearson bivariate correlation analysis, it was found that the components such as berberine, gallic acid, catechin, epicatechin, acteoside, berberastine and 1-O-galloyl-β-D-glucose might be the main effective basis of XXT to improve T2DM.

Characterization of Orange Peel Extract and Its Potential Protective Effect against Aluminum Chloride-Induced Alzheimer's Disease

Alzheimer's disease (AD) is a devastating neurodegenerative disorder without a cure. Hence, developing an effective treatment or protective agent is crucial for public health. The present study aims to characterize orange peel extract (OPE) through in vitro and in silico studies. Furthermore, it examines the protective effect of OPE against experimentally-induced Alzheimer's disease in rats. The total phenolic and flavonoid content of OPE was 255.86 ± 1.77 and 52.06 ± 1.74 (mg/100 g), respectively. Gallic acid, the common polyphenol in OPE detected by HPLC was 3388.60 μg/100 g. OPE antioxidant IC₅₀ was 67.90 ± 1.05, 60.48 ± 0.91, and 63.70 ± 0.30 by DPPH, ABTS and Hydroxyl radical scavenging activity methods, respectively. In vitro anti-acetylcholinesterase (AChE) IC₅₀ was 0.87 ± 0.025 mg/mL for OPE and 2.45 ± 0.001 mg/mL for gallic acid. Molecular docking analysis for human AChE (4EY7) with donepezil, gallic acid, and acetylcholine showed binding energy ΔG values of -9.47, -3.72, and -5.69 Kcal/mol, respectively. Aluminum chloride injection (70 mg/Kg/day for 6 weeks) induced Alzheimer's-like disease in male rats. OPE (100 and 200 mg/kg/d) and gallic acid (50 mg/kg/d) were administered orally to experimental animals for 6 weeks in addition to aluminum chloride injection (as protective). OPE was found to protect against aluminum chloride-induced neuronal damage by decreasing both gene expression and activity of acetylcholinesterase (AChE) and a decrease in amyloid beta (Aβ42) protein level, thiobarbituric acid-reactive substances (TBARS), and nitric oxide (NO), and increased reduced glutathione (GSH) level and activity of the antioxidant enzymes in the brain tissues. Additionally, gene expressions for amyloid precursor protein (APP) and beta secretase enzyme (BACE1) were downregulated, whereas those for presinilin-2 (PSEN2) and beta cell lymphoma-2 (BCL2) were upregulated. Furthermore, the reverse of mitochondrial alternation and restored brain ultrastructure might underlie neuronal dysfunction in AD. In conclusion, our exploration of the neuroprotective effect of OPE in vivo reveals that OPE may be helpful in ameliorating brain oxidative stress, hence protecting from Alzheimer's disease progression.

Polyphenols and atherosclerosis: A critical review of clinical effects on LDL oxidation

Atherosclerosis is a major etiology of cardiovascular disease that causes considerable mortality. Oxidized low-density lipoprotein (oxLDL) is a fundamental attributor to atherosclerosis. Therefore, there seems to be an essential place for antioxidant therapy besides the current treatment protocols for coronary heart disease. Polyphenols are a class of compounds with substantial antioxidant properties that have shown the ability to reduce LDL oxidation in preclinical studies. However, clinical evidence has not been as conclusive although offering many promising signs. This review aims to examine the trials that have evaluated how dietary intake of polyphenols in different forms might influence the oxidation of LDL. Lowering the circulating cholesterol, incorporation into LDL particles, and enhancing systemic antioxidant activity are among the main mechanisms of action for polyphenols for lowering oxLDL. On the other hand, the population under study significantly affects the impact on oxLDL, as the type of the supplement and phenolic content. To conclude, although the polyphenols might decrease inflammation and enhance endothelial function via lowering oxLDL, there are still many gaps in our knowledge that need to be filled with further high-quality studies.

Flavonoid and Phenolic Acid Profiles of Dehulled and Whole Vigna subterranea (L.) Verdc Seeds Commonly Consumed in South Africa

Bambara groundnut (BGN) is an underexploited crop with a rich nutrient content and is used in traditional medicine, but limited information is available on the quantitative characterization of its flavonoids and phenolic acids. We investigated the phenolic profile of whole seeds and cotyledons of five BGN varieties consumed in South Africa using UPLC-qTOF-MS and GC-MS. Twenty-six phenolic compounds were detected/quantified in whole seeds and twenty-four in cotyledon, with six unidentified compounds. Flavonoids include flavan-3-ol (catechin, catechin hexoside-A, catechin hexoside-B), flavonol (quercetin, quercetin-3-O-glucoside, rutin, myricetin, kaempherol), hydroxybenzoic acid (4-Hydroxybenzoic, 2,6 Dimethoxybenzoic, protocatechuic, vanillic, syringic, syringaldehyde, gallic acids), hydroxycinnamic acid (trans-cinnamic, p-coumaric, caffeic, ferulic acids) and lignan (medioresinol). The predominant flavonoids were catechin/derivatives, with the highest content (78.56 mg/g) found in brown BGN. Trans-cinnamic and ferulic acids were dominant phenolic acid. Cotyledons of brown and brown-eyed BGN (317.71 and 378.59 µg/g) had the highest trans-cinnamic acid content, while red seeds had the highest ferulic acid (314.76 µg/g) content. Colored BGN had a significantly (p < 0.05) higher content of these components. Whole BGN contained significantly (p < 0.05) higher amount of flavonoids and phenolic acids, except for the trans-cinnamic acid. The rich flavonoid and phenolic acid content of BGN seeds highlights the fact that it is a good source of dietary phenolics with potential health-promoting properties.

Rhus coriaria L. (Sumac), a Versatile and Resourceful Food Spice with Cornucopia of Polyphenols

In recent years, utilization of Rhus coriaria L. (sumac) is upgrading not only in their culinary use and human nutrition, but also in the pharmaceutical industry, food industry and veterinary practices. This is driven by accumulating evidence that support the ethnobotanical use of this plant; in particular, advanced knowledge of the content of nutritional, medicinal and techno-functional bioactive ingredients. Herein, we discuss polyphenolic compounds as the main bioactive ingredients in Rhus coriaria L., which contribute mainly to the significance and utility of this spice. Most of the antioxidant potential and therapeutic roles of sumac are increasingly attributed to its constituent tannins, flavonoids, and phenolic acids. Hydroxyphenyl pyranoanthocyanins and other anthocynins are responsible for the highly desired red pigments accounting for the strong pigmentation capacity and colorant ability of sumac. Certain polyphenols and the essential oil components are responsible for the peculiar flavor and antimicrobial activity of sumac. Tannin-rich sumac extracts and isolates are known to enhance the food quality and the oxidative stability of animal products such as meat and milk. In conclusion, polyphenol-rich sumac extracts and its bioactive ingredients could be exploited towards developing novel food products which do not only address the current consumers' interests regarding organoleptic and nutritional value of food, but also meet the growing need for 'clean label' as well as value addition with respect to antioxidant capacity, disease prevention, and health promotion in humans.

Pyracantha fortuneana (Maxim.) Li: A comprehensive review of its phytochemistry, pharmacological properties, and product development

Pyracantha fortuneana (Maxim.) Li has been used as a herbal medicine in China in its long history. Since ancient times, the fruits of P. fortuneana has been considered a functional food to improve various diseases. Many bioactive substances, including proanthocyanidins, phenols, polysaccharides, and dietary fibers, have been isolated and identified from the P. fortuneana, which possess diverse biological properties both in vitro and in vivo. Although the researches on the P. fortuneana have achieved extensive progress, the systematic study of its biological activities is still relatively lacking. In addition, accumulating researches focus on the landscape value of the P. fortuneana and the development of its by-products. The by-products of P. fortuneana, which show good development potentials in the field of agricultural production and environmental protection, are important for improving the economic value of P. fortuneana and its significance. After extensive reviewing and analyzing the existing published articles, books, and patents, this study aims to a systematic and summarized research trends of P. fortuneana and its phytochemical compositions, nutritional values, pharmacological effects and health benefits of its extracts/monomers, which would be beneficial for the future development of this medicinal plant as functional food or drugs.

Physiological Effects of Green-Colored Food-Derived Bioactive Compounds on Cardiovascular and Metabolic Diseases

Cardiovascular and metabolic diseases are a leading cause of death worldwide. Epidemiological studies strongly highlight various benefits of consuming colorful fruits and vegetables in everyday life. In this review, we aimed to revisit previous studies conducted in the last few decades regarding green-colored foods and their bioactive compounds in consideration of treating and/or preventing cardiovascular and metabolic diseases. This review draws a comprehensive summary and assessment of research on the physiological effects of various bioactive compounds, mainly polyphenols, derived from green-colored fruits and vegetables. In particular, their health-beneficial effects, including antioxidant, anti-inflammatory, anti-diabetic, anti-obesity, cardioprotective, and lipid-lowering properties, will be discussed. Furthermore, the bioavailability and significance of action of these bioactive compounds on cardiovascular and metabolic diseases will be discussed in detail.

Identification of Ascorbic Acid and Gallic Acid as Novel Inhibitors of Secreted Frizzled-Related Protein for the Treatment of Obesity-Induced Type 2 Diabetes

Type 2 diabetes mellitus (T2D) has been reported as major public health issue rising at an alarming rate worldwide, and obesity is the leading risk factor for the development of T2D. Secreted frizzled-related protein 4 (SFRP4) released with inflammatory mediators from adipose tissues constrains the exocytosis of insulin containing granules from the pancreatic islets that leads towards the development to T2D. The significant overexpression of SFRP4 in diabetic patients and its involvement in islet dysfunction suggest its critical role in the development of diabetes. Thus, this study was designed to explore the potential of ascorbic acid (AA) and gallic acid (GA) against SFRP4 for the treatment of diabetes. Molecular docking approach was used for the prediction of binding interactions of AA and GA at the active pocket of SFRP4. Docking analysis indicated strong binding interactions of AA and GA to the amino acid residues at the active site of SFRP4. A significant reduction in the level of SFRP4 was observed in transfected cells treated with AA and GA. For the evaluation of the cytotoxicity of AA and GA against HepG2 cells, MTT assay was performed. The results of MTT assay demonstrated that AA and GA are non-cytotoxic towards HepG2 cells at concentration of 15 μM. The oral administration of AA and GA to diet-induced obese mice caused significant reduction in body weight, blood glucose level, and SFRP4 expression. The results of this study suggest that AA and GA have potential for the treatment of obesity-induced T2D.

Phytonutrients of Bitter Apricot Seeds Modulate Human Lipid Profile and LDL Subfractions in Adults with Elevated Cholesterol Levels

The objective of the present study was to evaluate the effect of short-term consumption of bitter apricot seeds phytonutrients on cardiovascular risk factors with a special focus on LDL cholesterol subfractions using the Lipoprint system. A group of 34 adult volunteers (21 female/13 male) consumed 60 mg kg⁻¹ of body weight of bitter apricot seeds daily for 42 days. Subjects were divided into two groups: one with normal cholesterol levels (NTC) and one with elevated total cholesterol levels (ETC). Blood serum levels of total cholesterol (T-C), low-density cholesterol (LDL-C), high-density cholesterol (HDL-C), and triglycerides (TG) did not change significantly (p > 0.05) in NTC group. However, there were significant decreasing of T-C (p ˂ 0.05) and LDL-C (p < 0.01) in ETC group. The LDL₁, LDL₂, and atherogenic LDL₃₋₇ subfractions progressively decreased after 42 days of apricot seeds consumption in ETC group (p < 0.05). Apricot seeds consumption was associated with a significant increase in the mean LDL particle size especially in ETC group (p ˂ 0.01). The results of the present study support the hypothesis that daily consumption of bitter apricot seeds for 42 days positively modified the lipoprotein profile in the group with elevated total cholesterol.

Gallic acid attenuates cadmium mediated cardiac hypertrophic remodelling through upregulation of Nrf2 and PECAM-1signalling in rats

Gallic acid (GA) is an abundant natural polyphenolic compound found in vegetable and fruits that reduces the cardiac disease risk factor. This study aims to evaluate GA's role on cadmium (Cd) induced cardiac remodelling in experimental rats. Male Wistar rats were exposed to Cd (15 ppm) in drinking water and administered with GA orally (15 mg/kg/d) for 60 days. The results showed that GA regulated the lipid profile and reduced the LDL to 57 % compared with Cd treated rats. GA inhibited cardiac marker enzymes activity of CK-NAC (to 72.7 %) and CK-MB (to 100.3 %). Moreover, GA attenuated lipid peroxidation and enhanced the cardiac glutathione S transferase (GST) activity (89.2 %), glutathione peroxidase (GPx) (87 %), superoxide dismutase (SOD) (88.4 %) and catalase (CAT) activity (86.5 %). Histopathological examination showed that GA impaired the ventricular hypertrophy and fibrotic proliferation induced by Cd in rats. The combination of GA + Cd, decreased the gene expression of ANP (1-fold), BNP (0.5-fold) and β- MHC (0.9-fold). Furthermore, GA significantly reduced the expression of profibrotic (TGF-β) and proinflammatory (MCP-1) gene in Cd intoxicated rats. GA upregulated the expression of Nrf2 (2-fold), HO-1 (3-fold), and PECAM-1 (0.6-fold), which augments the detoxifying enzyme activity and cellular immunity in Cd intoxicated rats. The increased protein expression of Nrf2, PECAM-1 and decreased AKT-1 levels confirmed the mechanical action of GA during the hypertrophic condition. Thus, our results suggest that GA could act as a potential therapeutic agent regulating Nrf2 and PECAM-1 signalling pathways, thereby ameliorating Cd-induced pathological cardiac remodelling.

Preclinical and Clinical Antioxidant Effects of Natural Compounds against Oxidative Stress-Induced Epigenetic Instability in Tumor Cells

ROS (reactive oxygen species) are produced via the noncomplete reduction in molecular oxygen in the mitochondria of higher organisms. The produced ROS are placed in various cell compartments, such as the mitochondria, cytoplasm, and endoplasmic reticulum. In general, there is an equilibrium between the synthesis of ROS and their reduction by the natural antioxidant defense system, called the redox system. Therefore, when this balance is upset, the excess ROS production can affect different macromolecules, such as proteins, lipids, nucleic acids, and sugars, which can lead to an electronic imbalance than oxidation of these macromolecules. Recently, it has also been shown that ROS produced at the cellular level can affect different signaling pathways that participate in the stimulation of transcription factors linked to cell proliferation and, consequently, to the carcinogenesis process. Indeed, ROS can activate the pathway of tyrosine kinase, MAP kinase, IKK, NF-KB, phosphoinositol 3 phosphate, and hypoxia-inducible factor (HIF). The activation of these signaling pathways directly contributes to the accelerated proliferation process and, as a result, the appearance of cancer. In addition, the use of antioxidants, especially natural ones, is now a major issue in the approach to cancer prevention. Some natural molecules, especially phytochemicals isolated from medicinal plants, have now shown interesting preclinical and clinical results.

Anti-inflammatory and analgesic properties of Moroccan medicinal plants: Phytochemistry, in vitro and in vivo investigations, mechanism insights, clinical evidences and perspectives

Moroccan medicinal plants exhibit several pharmacological properties such as antimicrobial, anticancer, antidiabetic, analgesic, and anti-inflammatory effects, which are related to the presence of numerous bioactive compounds, including phenolic acids, flavonoids, and terpenoids. In the present review, we systematically evaluate previously published reports on the anti-inflammatory and analgesic effects of Moroccan medicinal plants. The in vitro investigations revealed that Moroccan medicinal plants inhibit several enzymes related to inflammatory processes, whereas in vivo studies noted significant anti-inflammatory and analgesic effects as demonstrated using different experimental models. Various bioactive compounds exhibiting in vitro and in vivo anti-inflammatory and analgesic effects, with diverse mechanisms of action, have been identified. Some plants and their bioactive compounds reveal specific secondary metabolites that possess important anti-inflammatory effects in clinical investigations. Our review proposes the potential applications of Moroccan medicinal plants as sources of anti-inflammatory and analgesic agents.

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Anti-inflammatory and analgesic effects of Moroccan medicinal plants were highlighted.

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Chemical nature of Moroccan medicinal plants with anti-inflammatory and analgesic effects was reported.

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Insights into anti-inflammatory mechanisms of bioactive compounds were highlighted.

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Toxicological investigations of Moroccan medicinal plants were reviewed.

Natural Polyphenols in Metabolic Syndrome: Protective Mechanisms and Clinical Applications

Metabolic syndrome (MetS) is a chronic disease, including abdominal obesity, dyslipidemia, hyperglycemia, and hypertension. It should be noted that the occurrence of MetS is closely related to oxidative stress-induced mitochondrial dysfunction, ectopic fat accumulation, and the impairment of the antioxidant system, which in turn further aggravates the intracellular oxidative imbalance and inflammatory response. As enriched anti-inflammatory and antioxidant components in plants, natural polyphenols exhibit beneficial effects, including improving liver fat accumulation and dyslipidemia, reducing blood pressure. Hence, they are expected to be useful in the prevention and management of MetS. At present, epidemiological studies indicate a negative correlation between polyphenol intake and MetS incidence. In this review, we summarized and discussed the most promising natural polyphenols (including flavonoid and non-flavonoid drugs) in the precaution and treatment of MetS, including their anti-inflammatory and antioxidant properties, as well as their regulatory functions involved in glycolipid homeostasis.

Polyphenols in foods: Classification, methods of identification, and nutritional aspects in human health

Polyphenols widely exists in various foods, including main crops, fruits, beverages and some wines. Famous representatives of polyphenols, such as resveratrol in red wine, (-)-epigallocatechin gallate in green tea, chlorogenic acid in coffee, anthocyanins in colored fruits, procyanidins in grape seed have become hot research topics in food science and nutrition. There have been thousands of papers on the biochemistry, chemistry, nutritional values and population-based investigations of dietary polyphenols. In this chapter, we reviewed the published articles and database of dietary polyphenols to draw a profile for the classification, structural identification, and biological activities mainly based on enzymes, cell bioassay and animal models, as well as the population-based investigation results. The typical compound and its health benefits for each category of polyphenols was also introduced. The identification of dietary polyphenols could be solved by combined spectroscopy methods, of which the liquid chromatography tandem mass spectrometry is highlighted to greatly increase the efficiency on structural identification. Although the population-based investigation showed some controversial results for health benefits, the multi-functions of dietary polyphenols on preventing metabolic syndromes, various cancers and neurodegenerative disease have attracted much attention.

Redox biomarkers in dietary interventions and nutritional observation studies - From new insights to old problems

Purpose

The purpose of this review is to give an overview on recently published articles investigating the associations of diet and dietary interventions with biomarkers of oxidative stress with special emphasis on different categories of redox biomarkers.

Findings

Intervention and observational studies both in healthy participants and patients that investigated associations of dietary habits, foodstuffs or isolated nutrients with biomarkers of oxidative stress were included in this review. Recently published observation studies confirm the inverse association between fruit and vegetable intake and oxidative stress markers. Studies investigating the effect of vitamin D and vitamin E, magnesium, zinc, chromium, selenium, probiotic supplementation and several phytochemicals reported consistent changes in redox biomarkers. Of 88 articles included in this review, only seven studies measured biomarkers from the three categories: oxidative damage, endogenous antioxidants, and exogenous antioxidants. Many studies rely on controversial assays for total antioxidant capacity, thus there is potential in many studies to improve biomarker repertoire to cover all three categories of biomarkers and to turn away from such assays.

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Oxidative stress can be assessed by specific biomarker categories.

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Three biomarker categories: oxidative damage, endogenous, exogenous antioxidants.

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Only seven studies performed measurements of all three biomarker categories.

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TAC, TRAP, FRAP, ORAC should not be used as stand-alone redox marker.

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Several interventions reported improvements in markers of oxidative stress.

Promising Medicinal Plants with Diuretic Potential Used in Brazil: State of the Art, Challenges, and Prospects

Medicinal plants are used in traditional medicine to treat a wide range of ailments. The knowledge of them is handed down from generation to generation and is described in several pharmacopoeia and in the general literature. The immense biodiversity of the Brazilian flora, covering about 25% of all plant species worldwide, makes Brazil a huge potential source of medicinal plants. Indeed, many of these plant species are already used in the Brazilian ethnopharmacology for their probable effect to induce diuresis, to reduce fluid retention, and to treat cardiovascular and renal disorders. This review article describes and discusses the main native Brazilian medicinal plants (including some of their isolated compounds) used as diuretics. It also gives a comprehensive analysis of the most relevant scientific studies presented to date, as well as addressing a special topic with future prospects for plant species that have not yet been scientifically studied. In brief, several plants can be indicated for more detailed study, with a view to obtain scientific subsidies for a new and effective diuretic medicine in the future. These include Bauhinia forficata, Leandra dasytricha, and Tropaeolum majus. Other species have reputed medicinal properties but lack experimental assays to demonstrate their pharmacological effects (e.g., Mikania hirsutissima, Phyllanthus niruri, and Tagetes minuta). Several active principles are indicated as responsible for the diuretic effects of the plants studied, with emphasis on phenolic compounds as flavonoids, phenolic acids, and xanthones. These results should encourage more detailed preclinical, clinical, and phytochemical investigations on Brazilian plants in the future.

Traditional use, phytochemistry, toxicology, and pharmacology of Origanum majorana L

ETHNOPHARMACOLOGICAL RELEVANCE

Origanum majorana L., is an aromatic and medicinal plant distributed in different parts of Mediterranean countries. This species is widely used in traditional medicine for the treatment of many diseases such as allergies, hypertension, respiratory infections, diabetes, stomach pain, and intestinal antispasmodic.

AIM OF THE REVIEW

This work reports previous studies on O. majorana concerning its taxonomy, botanical description, geographical distribution, traditional use, bioactive compounds, toxicology, and biological effects.

MATERIALS AND METHODS

Different scientific data bases such as Web of Science, Scopus, Wiley Online, SciFinder, Google Scholar, PubMed, ScienceDirect, and SpringerLink were consulted to collect data about O. majorana. The presented data emphasis bioactive compounds, traditional uses, toxicological investigations, and biological activities of O. majorana.

RESULTS

The findings of this work marked an important correlation between the traditional use of O. majorana as an anti-allergic, antihypertensive, anti-diabetic agent, and its biological effects. Indeed, pharmacological investigations showed that essential oils and extracts from O. majorana exhibit different biological properties, particularly; antibacterial, antifungal, antioxidant, antiparasitic, antidiabetic, anticancer, nephrotoxicity protective, anti-inflammatory, analgesic and anti-pyretic, hepatoprotective, and antimutagenic effects. Toxicological evaluation confirmed the safety and innocuity of this species and supported its medicinal uses. Several bioactive compounds belonging to different chemical family such as terpenoids, flavonoids, and phenolic acids were also identified in O. majorana.

CONCLUSIONS

The results suggest that the pharmacological properties of O. majorana confirm its traditional uses. Indeed, O. majorana essential oils showed remarkable antimicrobial, antioxidant, anticancer, anti-inflammatory, antimutagenic, nephroprotective, and hepatoprotective activities. However, further investigations regarding the evaluation of molecular mechanisms of identified compounds against human cancer cell lines, inflammatory process, and microbial infections are needed to validate pharmacodynamic targets. The toxicological investigation of O. Majorana confirmed its safety and therefore encouraged pharmacokinetic evaluation tests to validate its bioavailability.

Beetroot, a Remarkable Vegetable: Its Nitrate and Phytochemical Contents Can be Adjusted in Novel Formulations to Benefit Health and Support Cardiovascular Disease Therapies

The cardioprotective effects of dietary nitrate from beetroot in healthy and hypertensive individuals are undeniable and irrefutable. Nitrate and nitrate-derived nitrite are precursors for nitric oxide synthesis exhibiting an effect on cardiomyocytes and myocardial ischemia/reperfusion, improving endothelial function, reducing arterial stiffness and stimulating smooth muscle relaxation, decreasing systolic and diastolic blood pressures. Beetroot phytochemicals like betanin, saponins, polyphenols, and organic acids can resist simulated gastrointestinal digestion, raising the hypothesis that the cardioprotective effects of beetroots result from the combination of nitrate/nitrite and bioactive compounds that limit the generation of reactive oxygen species and modulate gene expression. Nitrate and phytochemical concentrations can be adjusted in beet formulations to fulfill requirements for acute or long-term supplementations, enhancing patient adherence to beet intervention. Based on in vitro, in vivo, and clinical trials, beet nitrate and its bioactive phytochemicals are promising as a novel supportive therapy to ameliorate cardiovascular diseases.

Nutritional supplementation of gallic acid ameliorates Alzheimer-type hippocampal neurodegeneration and cognitive impairment induced by aluminum chloride exposure in adult Wistar rats

Prolonged exposure to aluminum through occupational hazards or food/water intake has been linked to the occurrence of Alzheimer's disease (AD). This study aimed at investigating the neuroprotective effects of Gallic Acid (GA) against aluminum-chloride induced AD in adult Wistar rats. Twenty eight (28) adult Wistar rats were divided into four groups (n = 7). Group A received normal saline as placebo; Group B received 200 mg/kg bw of AlCl₃ only; Group C received 100 mg/kg bw of GA only and group D received 100 mg/kg bw of GA and 200 mg/kg bw of AlCl₃. At the end of the 60 days experiment, blood samples were collected to obtain serum for analysis and the brain was harvested. Neurobehavioural tests (Morris Water maze, Y-Maze), neurotransmitter levels, oxidative stress markers, serum electrolytes, antioxidant enzymes and histological assessment were carried out. There was a significant decrease in antioxidant enzymes (CAT, GSH and SOD), serum electrolyte (except K+) and neurotransmitter levels (except norepinephrine) with corresponding increase in stress markers (MDA, H₂O₂ and NO) among group B compared to control but was restored nearly to normal after GA administration. Neurobehavioral tests showed decreased spatial memory impairment and learning deficit in group B compared to control but was ameliorated with GA administration. Histological observation showed neurofibrillary tangles and amyloid plaques in the external granular layer of group B but protected by GA administration. Nutritional supplementation of GA preserve the morphological and physiological integrity of the hippocampus against environmental neurotoxins (AlCl₃) by mopping up free radicals associated with oxidative stress induced AD.

A Role of Gallic Acid in Oxidative Damage Diseases: A Comprehensive Review

Gallic acid is a trihydroxybenzoic acid of plant metabolites widely spread throughout the plant kingdom. It has characteristics of the strong antioxidant and free radical scavenging activities, and can protect biological cells, tissues, and organs from damages caused by oxidative stress. This review aims to summarize the protective roles of gallic acid and the underlying pharmacological mechanisms in the pathophysiological process of the oxidative damage diseases, such as cancer, cardiovascular, degenerative, and metabolic diseases. The studies reviewed herein showed that the main therapeutic effects of gallic acid were attributed to its antioxidant properties. It modulated various signaling pathways through a wide range of inflammatory cytokines, and enzymic and nonenzymic antioxidants. However, the available data were limited to few studies assessing the treatment effects of gallic acid in human subjects to confirm its therapeutic outcomes. Therefore, the clinical trials were urgently needed to investigate the safety and efficacy of gallic acid treatment on human beings. The scientific data summarized in this review highlighted the therapeutic potentials of gallic acid for oxidative damage diseases. It could be developed as versatile adjuvant or therapeutically lead compound in future.

Natural Plants Compounds as Modulators of Epithelial-to-Mesenchymal Transition

Epithelial-to-mesenchymal transition (EMT) is a self-regulated physiological process required for tissue repair that, in non-controled conditions may lead to fibrosis, angiogenesis, loss of normal organ function or cancer. Although several molecular pathways involved in EMT regulation have been described, this process does not have any specific treatment. This article introduces a systematic review of effective natural plant compounds and their extract that modulates the pathological EMT or its deleterious effects, through acting on different cellular signal transduction pathways both in vivo and in vitro. Thereby, cryptotanshinone, resveratrol, oxymatrine, ligustrazine, osthole, codonolactone, betanin, tannic acid, gentiopicroside, curcumin, genistein, paeoniflorin, gambogic acid and Cinnamomum cassia extracts inhibit EMT acting on transforming growth factor-β (TGF-β)/Smads signaling pathways. Gedunin, carnosol, celastrol, black rice anthocyanins, Duchesnea indica, cordycepin and Celastrus orbiculatus extract downregulate vimectin, fibronectin and N-cadherin. Sulforaphane, luteolin, celastrol, curcumin, arctigenin inhibit β-catenin signaling pathways. Salvianolic acid-A and plumbagin block oxidative stress, while honokiol, gallic acid, piperlongumine, brusatol and paeoniflorin inhibit EMT transcription factors such as SNAIL, TWIST and ZEB. Plectranthoic acid, resveratrol, genistein, baicalin, polyphyllin I, cairicoside E, luteolin, berberine, nimbolide, curcumin, withaferin-A, jatrophone, ginsenoside-Rb1, honokiol, parthenolide, phoyunnanin-E, epicatechin-3-gallate, gigantol, eupatolide, baicalin and baicalein and nitidine chloride inhibit EMT acting on other signaling pathways (SIRT1, p38 MAPK, NFAT1, SMAD, IL-6, STAT3, AQP5, notch 1, PI3K/Akt, Wnt/β-catenin, NF-κB, FAK/AKT, Hh). Despite the huge amount of preclinical data regarding EMT modulation by the natural compounds of plant, clinical translation is poor. Additionally, this review highlights some relevant examples of clinical trials using natural plant compounds to modulate EMT and its deleterious effects. Overall, this opens up new therapeutic alternatives in cancer, inflammatory and fibrosing diseases through the control of EMT process.

Maoberry (Antidesma bunius) ameliorates oxidative stress and inflammation in cardiac tissues of rats fed a high-fat diet

Backgound

Chronic fat-rich diets consumption is increased risk associated with cardiovascular diseases (CVD). Prevention or reduction the progression of cardiac tissue deterioration could benefit in CVD. This study aimed to examine the effects of maoberry (Antidesma bunius), a antioxidant-rich tropical fruit, supplementation on oxidative stress and inflammation in cardiac tissues of rats fed a high-fat diet (HFD).

Methods

The male rats orally received HFD with maoberry extract doses of 0.38, 0.76 or 1.52 g/kg or simvastatin (10 mg/kg) for 12 weeks. At the end of the experimental period, the rats were fasted, euthanized and harvested for the hearts.

Results

Significantly reduced oxidative stress (malondialdehyde levels) and enhanced antioxidant capacity (ferric-reducing activities) in cardiac tissues of the rats were found. Maoberry extract remarkably ameliorated the expressions of genes involved with pro-inflammatory such as the tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1) and endothelial nitric oxide synthase (eNOS).

Conclusions

Our findings suggest that maoberry extract has remarkable effects on preventing progression of cardiac tissue deterioration at least through lowering oxidative stress and inflammation.

Gallic Acid Suppresses Cardiac Hypertrophic Remodeling and Heart Failure

SCOPE

Gallic acid (GA) is a dietary phenolic acid found in tea, red wine, and some plants. It exhibits anti-oxidative and anti-inflammatory activities. Recent studies have revealed that GA has beneficial effects against several cardiovascular diseases; however, whether GA attenuates pressure-overload-induced cardiac hypertrophy and the underlying mechanism remains unclear.

METHODS AND RESULTS

Primary cardiomyocyte hypertrophy is stimulated with angiotensin II (Ang II). Cardiac hypertrophic remodeling is induced in mice by transverse aortic constriction (TAC). Myocardial function is evaluated by echocardiographic and hemodynamic analyses, while cardiac tissues are analyzed by histological staining. It is observed that GA significantly decreases Ang II-induced increases in cardiomyocyte size in vitro. Administration of GA in mice markedly improves TAC-induced cardiac dysfunction and attenuates pathological changes, including cardiac myocyte hypertrophy, fibrosis, inflammation, and oxidative stress. Mechanistically, GA inhibits ULK1 and activates autophagy, which induces the degradation of EGFR, gp130, and calcineurin A, thereby inhibiting the downstream signaling cascades (AKT, ERK1/2, JAK2/STAT3, and NFATc1).

CONCLUSIONS

The results demonstrate for the first time that GA prevents myocardial hypertrophy and dysfunction via an autophagy-dependent mechanism. Thus, GA represents a promising therapeutic candidate for treating cardiac hypertrophy and heart failure.

Inhibitory effects of Euphorbia supina on Propionibacterium acnes-induced skin inflammation in vitro and in vivo

Background

Euphorbia supina (ES) plant has been used as treatment for inflammatory conditions. The antibacterial effect and the anti-inflammatory mechanism of ES for Propionibacterium (P.) acnes-induced inflammation in THP-1 cells and acne animal model remain unclear. Therefore, the objective of the present study was to determine the antibacterial and anti-inflammatory activities of ES against P. acnes, the etiologic agent of skin inflammation.

Method

The antibacterial activities of ES were tested with disc diffusion and broth dilution methods. Cytotoxicity of ES at different doses was evaluated by the MTT assay. THP-1 cells were stimulated by heat-killed P. acnes in the presence of ES. The pro-inflammatory cytokines and mRNA levels were measured by ELISA and real-time-PCR. MAPK expression was analyzed by Western blot. The living P. acnes was intradermally injected into the ear of BLBC/c mice. Subsequently, chemical composition of ES was analyzed by liquids chromatography-mass spectrometry (LC-MS).

Result

ES had stronger antibacterial activity against P. acnes and inhibitory activity on lipase. ES had no significant cytotoxicity on THP-1 cells. ES suppressed the mRNA levels and production of IL-8, TNF-a, IL-1β in vitro. ES inhibited the expression levels of pro-inflammatory cytokines and the MAPK signaling pathway. Ear thickness and inflammatory cells were markedly reduced by ES treatment. Protocatechuic acid, gallic acid, quercetin, and kaempferol were detected by LC-MS analysis in ES.

Conclusions

Our results demonstrate antibacterial and anti-inflammatory activities of ES extract against P. acnes. It is suggested that ES extract might be used to treatment anti-inflammatory skin disease.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2320-8) contains supplementary material, which is available to authorized users.

Gallic acid, a common dietary phenolic protects against high fat diet induced DNA damage

Purpose

Aim of the study was to find out if gallic acid (GA), a common phenolic in plant foods, prevents obesity induced DNA damage which plays a key role in the induction of overweight associated cancer.

Methods

Male and female C57BL6/J mice were fed with a low fat or a high fat diet (HFD). The HFD group received different doses GA (0, 2.6–20 mg/kg b.w./day) in the drinking water for 1 week. Subsequently, alterations of the genetic stability in blood and inner organs were monitored in single cell gel electrophoresis assays. To elucidate the underlying molecular mechanisms: oxidized DNA bases, alterations of the redox status, lipid and glucose metabolism, cytokine levels and hepatic NF-κB activity were monitored.

Results

HFD fed animals had higher body weights; increased DNA damage and oxidation of DNA bases damage were detected in colon, liver and brain but not in blood and white adipose tissue. Furthermore, elevated concentrations of insulin, glucose, triglycerides, MCP-1, TNF-α and NF-κB activity were observed in this group. Small amounts of GA, in the range of human consumption, caused DNA protection and reduced oxidation of DNA bases, as well as biochemical and inflammatory parameters.

Conclusions

Obese animals have increased DNA damage due to oxidation of DNA bases. This effect is probably caused by increased levels of glucose and insulin. The effects of GA can be explained by its hypoglycaemic properties and indicate that the consumption of GA-rich foods prevents adverse health effects in obese individuals.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1782-2) contains supplementary material, which is available to authorized users.