In vitro evidences of the traditional use of Rhus coriaria L. fruits against skin inflammatory conditions

Assessment of In Vitro Airway Smooth Muscle Relaxant Activity of Rhus coriaria L. Fruit Ethanolic Extract and Its Possible Mechanisms

Rhus coriaria L. (Anacardiaceae), also known as Sumac, is commonly used as a spice, flavoring agent, and as a traditional medicinal herb. This includes also the traditional use for treating asthma, catarrh, and common colds. The accumulating evidence supports its cardioprotective, antidiabetic, neuroprotective, anticancer, gastroprotective, antibacterial, anti-inflammatory, antiviral, antioxidant, and respiratory effects. However, there are no previous studies that have shown its effects and mechanism in the airway smooth muscle tone, and therefore, the aim of our study was to investigate the in vitro pharmacological action of R. coriaria L. extract (RCE) on the rat isolated tracheal and bronchial preparations by exploring its relaxant activity and mechanism of action. The direct relaxant effect of RCE (0.1-0.7 mg/mL) was tested in the rat bronchi and trachea rings precontracted by carbachol (CCh). In addition, the pretreatment with RCE (1 mg/mL) was tested on the bronchial and tracheal reactivity induced by CCh, potassium chloride (KCl), or CaCl2. In addition, the cyclooxygenase inhibitor indomethacin and the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME), respectively, were used for exploring the mechanisms of RCE-induced relaxation and reduction of reactivity. Our findings demonstrated that RCE induced a concentration-dependent relaxation and a significant reduction of reactivity, significantly reduced with either indomethacin or L-NAME. In addition, RCE decreased the responsiveness to KCl and affected the extracellular Ca2+-induced contraction in the tissues with added CCh or KCl in Ca2+-free Krebs-Henseleit solution. In summary, we have shown that RCE displayed relaxant activities in the in vitro airway smooth muscles, and the possible mechanisms seems to involve the prostaglandin, nitric oxide, and Ca2+ pathways. Taken together, our findings indicate the potential role of RCE in the treatment of respiratory diseases with limited airflow, or obstructive respiratory diseases, and could justify its traditional use in the respiratory diseases.

The Nutraceutical Properties of Rhus coriaria Linn: Potential Application on Human Health and Aging Biomedicine

Rhus coriaria Linn is a little plant growing in the Mediterranean basin, including Sicily, where it is known as Sicilian Sumac. Since antiquity, it has been used as a medicinal herb, considering its pharmacological properties and its recognized anti-inflammatory, antioxidant, and antimicrobial effects. Multiple studies have highlighted that the beneficial properties of Sumac extracts depend on the abundance of phytochemicals such as polyphenols, fatty acids, minerals, and fibers. Despite its wide use as a spice, the literature on Sumac effects on humans’ health and aging is still scarce. Considering its great nutraceutical potential, Sumac could be used to treat age-related diseases such as those in which the inflammatory process plays a crucial role in manifestation and progression. Thus, Sumac could be an interesting new insight in the biomedical field, especially in aging biomedicine.

Tannin in Ruminant Nutrition: Review

Tannins are polyphenols characterized by different molecular weights that plants are able to synthetize during their secondary metabolism. Macromolecules (proteins, structural carbohydrates and starch) can link tannins and their digestion can decrease. Tannins can be classified into two groups: hydrolysable tannins and condensed tannins. Tannins are polyphenols, which can directly or indirectly affect intake and digestion. Their ability to bind molecules and form complexes depends on the structure of polyphenols and on the macromolecule involved. Tannins have long been known to be an "anti-nutritional agent" in monogastric and poultry animals. Using good tannins' proper application protocols helped the researchers observe positive effects on the intestinal microbial ecosystem, gut health, and animal production. Plant tannins are used as an alternative to in-feed antibiotics, and many factors have been described by researchers which contribute to the variability in their efficiencies. The objective of this study was to review the literature about tannins, their effects and use in ruminant nutrition.

Hydrolyzable Tannins in the Management of Th1, Th2 and Th17 Inflammatory-Related Diseases

Plants rich in hydrolyzable tannins were traditionally used all over the world for a variety of chronic inflammatory disorders, including arthritis, colitis, and dermatitis. However, the knowledge of their immunological targets is still limited though fundamental for their rational use in phytotherapy. The recent advances regarding the pathogenesis of inflammatory-based diseases represent an opportunity to elucidate the pharmacological mechanism of plant-derived metabolites with immunomodulatory activity. This review collects recent articles regarding the role of hydrolyzable tannins and their gut metabolites in Th1, Th2, and Th17 inflammatory responses. In line with the traditional use, rheumatoid arthritis (RA), inflammatory bowel diseases (IBDs), psoriasis, atopic dermatitis (AD), and asthma were the most investigated diseases. A substantial body of in vivo studies suggests that, beside innate response, hydrolyzable tannins may reduce the levels of Th-derived cytokines, including IFN-γ, IL-17, and IL-4, following oral administration. The mode of action is multitarget and may involve the impairment of inflammatory transcription factors (NF-κB, NFAT, STAT), enzymes (MAPKs, COX-2, iNOS), and ion channels. However, their potential impact on pathways with renewed interest for inflammation, such as JAK/STAT, or the modulation of the gut microbiota demands dedicate studies.

The Effect of Sumac Fruit on Serum Lipids and Body Mass Index in Hemodialysis Patients

Background

Sumac fruit is an antioxidant and reduces serum triglyceride (TG) and cholesterol (CHOL) levels. Therefore, this study aimed to investigate the effect of sumac fruit on serum lipids and body mass index (BMI) of hemodialysis (HD) patients.

Materials and Methods

This triple-blind randomized clinical trial study was conducted for 12 weeks on HD patients. Participants were randomly divided into three groups of 2-gram sumac (N = 40), 3-gram sumac (N = 40), and placebo (N = 40) by nonprobability consecutive sampling and stratified block randomization method based on inclusion criteria. Serum lipids and BMI were measured at the beginning of the study and also at the end of the sixth and the twelfth weeks. The physical activity and 24-hour dietary recall questionnaires were used to collect data.

Results

No significant difference was found between the level of nutrient and micronutrient intake (P > 0.05), physical activity (P=0.159), and BMI (P=0.718) of patients in the three groups before and after the intervention. However, the difference in serum low-density lipoprotein (LDL) levels in each studied group was significant over time (P < 0.001). The difference was not statistically significant between the groups before the intervention, 6 and 12 weeks after the intervention (group effect), and between the study groups over time (time-group interaction). No statistically significant difference was observed between the mean levels of TG (P=0.875), CHOL level (P=0.969), LDL level (P=0.998), high-density lipoprotein (HDL) level (P=0.136), and BMI (P=0.608) in the groups over time.

Conclusion

Consumption of sumac fruit significantly changed the LDL level over time. Although BMI and serum lipids changed in HD patients, these changes were not significant. Future studies are needed to determine the effective dose of sumac and any dose increase should take toxicity into account and consider a larger sample size and longer intervention and follow-up times.

The Nutraceutical Properties of Sumac (Rhus coriaria L.) against Gastritis: Antibacterial and Anti-Inflammatory Activities in Gastric Epithelial Cells Infected with H. pylori

Sumac (Rhus coriaria L.) is a spice and medicinal herb traditionally used in the Mediterranean region and the Middle East. Since we previously demonstrated Sumac biological activity in a model of tumor necrosis factor alpha (TNF-α)-induced skin inflammation, the present work is aimed at further demonstrating a potential role in inflammatory disorders, focusing on gastritis. For this purpose, different polar extracts (water-W, ethanol-water-EW, ethanol-E, ethanol macerated-Em, acetone-Ac, ethylacetate-EtA) were investigated in gastric epithelial cells (GES-1) challenged by TNF-α or H. pylori infection. The ethanolic extracts (E, EW, Em) showed the major phenolic contents, correlating with lower half maximal inhibitory concentrations (IC50s) on the release of interleukin-8 (IL-8, <15 μg/mL) and interleukin-6 (IL-6, <20 μg/mL) induced by TNF-α. Similarly, they inhibited IL-8 release (IC50s < 70 μg/mL) during Helicobacter pylori (H. pylori) infection and exhibited a direct antibacterial activity at comparable concentrations (minimum inhibitory concentration (MIC) = 100 μg/mL). The phenolic content and the bioactivity of EW were maintained after simulated gastric digestion and were associated with nuclear factor kappa B (NF-κB) impairment, considered the main putative anti-inflammatory mechanism. On the contrary, an anti-urease activity was excluded. To the best of our knowledge, this is the first demonstration of the potential role of Sumac as a nutraceutical useful in H. pylori-related gastritis.

The Modulatory Influence of Plant-Derived Compounds on Human Keratinocyte Function

The plant kingdom is a rich source of secondary metabolites with numerous properties, including the potential to modify keratinocyte biology. Keratinocytes are important epithelial cells that play a protective role against various chemical, physical and biological stimuli, and participate in reactive oxygen scavenging and inflammation and wound healing processes. The epidermal cell response may be modulated by phytochemicals via changes in signal transduction pathways. Plant extracts and single secondary compounds can possess a high antioxidant capacity and may suppress reactive oxygen species release, inhibit pro-apoptotic proteins and apoptosis and activate antioxidant enzymes in keratinocytes. Moreover, selected plant extracts and single compounds also exhibit anti-inflammatory properties and exposure may result in limited production of adhesion molecules, pro-inflammatory cytokines and chemokines in keratinocytes. In addition, plant extracts and single compounds may promote keratinocyte motility and proliferation via the regulation of growth factor production and enhance wound healing. While such plant compounds may modulate keratinocyte functions, further in vitro and in vivo studies are needed on their mechanisms of action, and more specific toxicity and clinical studies are needed to ensure their effectiveness and safety for use on human skin.

Repressive effect of Rhus coriaria L. fruit extracts on microglial cells-mediated inflammatory and oxidative stress responses

ETHNOPHARMACOLOGICAL RELEVANCE

Rhus coriaria L. represents a herbal shrub that is used widely in traditional medicine in the Middle East region to treat different diseases including inflammation-related disorders. R. coriaria extracts have been well characterized in terms of their biological activities, pharmacological potential and phytochemical components. However, the effect of R. coriaria on neuro-inflammation has not been studied previously in detail.

AIM OF THE STUDY

In the present study, we performed a qualitative phytochemical analysis and investigated the antioxidant and anti-neuro-inflammatory potential of R. coriaria extracts on BV-2 microglial cells.

MATERIALS AND METHODS

R. coriaria extracts were prepared using two different solvents: distilled water and ethanol. Phytochemical screening was performed to determine the principal bioactive components. The radical scavenging activity was assessed by DPPH method (2,2-diphenyl-1-picrylhydrazyl). The effect of R. coriaria on neuro-inflammation was studied upon measuring the production of oxidative stress and inflammatory factors using DCF (2',7'-dichlorofluorescein) and Nitric oxide (NO) assays respectively, and by analyzing the mRNA (TNFα, IL-10, iNOS and COX-2) and protein (NFκβ) levels of genes involved BV-2 microglia cells-mediated inflammation using quantitative Real Time PCR and Western blot, respectively.

RESULTS

We found that R. coriaria extracts contain high phenolic and flavonoid contents. Interestingly, the ethanolic extract exerted a potent anti-inflammatory potential on insulted BV-2 cells manifested by: i) inhibition of Reactive Oxygen species (ROS) production and nitric oxide (NO) release; ii) suppressing TNFα, iNOS and COX-2 mRNA levels; iii) reducing NFκβ activation; and iiii) enhancing IL-10 transcription levels.

CONCLUSION

Our results indicate that the neuro-inflammation inhibitory activity of R. coriaria extracts involves the inhibition of NF-κB signaling pathway. These findings suggest that R. coriaria might carry therapeutic potential against neurodegenerative diseases.

Traditional Applications of Tannin Rich Extracts Supported by Scientific Data: Chemical Composition, Bioavailability and Bioaccessibility

Tannins are polyphenolic compounds historically utilized in textile and adhesive industries, but also in traditional human and animal medicines or foodstuffs. Since 20th-century, advances in analytical chemistry have allowed disclosure of the chemical nature of these molecules. The chemical profile of extracts obtained from previously selected species was investigated to try to establish a bridge between traditional background and scientific data. The study of the chemical composition of these extracts has permitted us to correlate the presence of tannins and other related molecules with the effectiveness of their apparent uses. The revision of traditional knowledge paired with scientific evidence may provide a supporting background on their use and the basis for developing innovative pharmacology and food applications based on formulations using natural sources of tannins. This traditional-scientific approach can result useful due to the raising consumers' demand for natural products in markets, to which tannin-rich extracts may pose an attractive alternative. Therefore, it is of interest to back traditional applications with accurate data while meeting consumer's acceptance. In this review, several species known to contain high amounts of tannins have been selected as a starting point to establish a correlation between their alleged traditional use, tannins content and composition and potential bioaccessibility.

By-Products of Agri-Food Industry as Tannin-Rich Sources: A Review of Tannins' Biological Activities and Their Potential for Valorization

During recent decades, consumers have been continuously moving towards the substitution of synthetic ingredients of the food industry by natural products, obtained from vegetal, animal or microbial sources. Additionally, a circular economy has been proposed as the most efficient production system since it allows for reducing and reutilizing different wastes. Current agriculture is responsible for producing high quantities of organic agricultural waste (e.g., discarded fruits and vegetables, peels, leaves, seeds or forestall residues), that usually ends up underutilized and accumulated, causing environmental problems. Interestingly, these agri-food by-products are potential sources of valuable bioactive molecules such as tannins. Tannins are phenolic compounds, secondary metabolites of plants widespread in terrestrial and aquatic natural environments. As they can be found in plenty of plants and herbs, they have been traditionally used for medicinal and other purposes, such as the leather industry. This fact is explained by the fact that they exert plenty of different biological activities and, thus, they entail a great potential to be used in the food, nutraceutical and pharmaceutical industry. Consequently, this review article is directed towards the description of the biological activities exerted by tannins as they could be further extracted from by-products of the agri-food industry to produce high-added-value products.

Pharmacological and Antioxidant Activities of Rhus coriaria L. (Sumac)

Rhus coriaria L. (Anacardiaceae), commonly known as sumac, is a commonly used spice, condiment, and flavoring agent, especially in the Mediterranean region. Owing to its bountiful beneficial values, sumac has been used in traditional medicine for the management and treatment of many ailments including hemorrhoids, wound healing, diarrhea, ulcer, and eye inflammation. This plant is rich in various classes of phytochemicals including flavonoids, tannins, polyphenolic compounds, organic acids, and many others. By virtue of its bioactive, Rhus coriaria possesses powerful antioxidant capacities that have ameliorative and therapeutic benefits for many common diseases including cardiovascular disease, diabetes, and cancer. This review describes the phytochemical properties of R. coriaria and then focuses on the potent antioxidant capacities of sumac. We then dissect the cellular and molecular mechanisms of sumac’s action in modulating many pathophysiological instigators. We show how accumulating evidence supports the antibacterial, antinociceptive, antidiabetic, cardioprotective, neuroprotective, and anticancer effects of this plant, especially that toxicity studies show that sumac is very safe to consume by humans and has little toxicity. Taken together, the findings we summarize here support the utilization of this plant as an attractive target for drug discovery.

Phytochemical Diversity and Pharmacological Properties of Rhus coriaria

Rhus coriaria L. (Anacardiaceae), sumac, is a common condiment, appetizer and souring agent in the Mediterranean region that has a long history in traditional medicine. R. coriaria has been prescribed for the treatment of many ailments including diarrhea, ulcer, hemorrhoids, hemorrhage, wound healing, hematemesis, and eye ailments like ophthalmia and conjunctivitis. The plant is also used as diuresis, antimicrobial, abortifacient and as a stomach tonic. Sumac is known to be rich in different classes of phytochemicals including tannins, polyphenols, flavonoids, organic acids and essential oils and continues to be a hot topic for extensive research work designed for revealing its phytochemical constituents and evaluating its bioactive properties. This review summarizes the recent phytochemical and diverse bioactivity studies on R. coriaria, especially those concerned with antitumor, antioxidant, hypoglycemic, antimicrobial, and anti-inflammatory studies.

Rhus coriaria L. Fruit Extract Prevents UV-A-Induced Genotoxicity and Oxidative Injury in Human Microvascular Endothelial Cells

Rhus coriaria L. (sumac) is a small plant widely diffused in the Mediterranean region. Its fruit are often consumed as a spice but are also present in traditional medicine of several countries. Recently, interest in this plant has increased and many scientific works reported its beneficial effects including antioxidant and anti-inflammatory properties. Plant extracts can be successfully used against ultraviolet rays, which are able to reach and damage the human skin; however, sumac extracts were never applied to this usage. Thus, in this study, we used a macerated ethanol extract of Rhus coriaria L. dried fruit (mERC) to demonstrate its preventive role against the damage induced by ultraviolet-A rays (UV-A) on microvascular endothelial cells (HMEC-1). In vitro effects of the extract pre-treatment and UV-A exposure were evaluated in detail. The antioxidant capacity was assessed by reactive oxygen species (ROS) formation and cellular antioxidant activity measurement. Genoprotective effects of mERC were investigated as well. Our findings indicate that the extract acts as a cell cycle inhibitor or apoptosis inducer, according to the level of damage. The present work provides new insights into the usage of Rhus coriaria extracts against skin injuries.

Sumac (Rhus coriaria) for the prevention and treatment of necrotizing enterocolitis

Leukotrienes, free oxygen radicals, tumor necrosis factor-alpha, and inflammatory mediators play major roles in the development of necrotizing enterocolitis (NEC). Rhus coriaria (RC: sumac) extracts may enhance cell viability by reinforcing defenses against free radical species in several progressive diseases as well as inflammatory diseases. The aim of the present study was to evaluate the effects of RC in a rat NEC model in terms of intestinal damage. Newborn pups were separated into three groups: control, NEC, and NEC treated with RC. Mortality and clinical sickness scores were evaluated. At the end of the study, ileum and proximal colon were obtained from all rats and histopathological and immunohistochemical studies were performed. In this study, the anti-inflammatory, antioxidant, immunomodulatory, and anti-apoptotic activities of RC were demonstrated in a rat NEC model, which suggests RC as a promising treatment option for preventing intestinal tissue damage. PRACTICAL APPLICATIONS: Free oxygen radicals, tumor necrosis factor-alpha, and inflammatory mediators play major roles in the development of NEC. Intestinal tissue damage is caused by necrosis and apoptosis as a result of intestinal inflammation and release of pro-inflammatory cytokines. Anti-inflammatory, antioxidant, immunomodulatory, and anti-apoptotic activities of RC are especially due to its phenolic compounds. In this study, the anti-inflammatory, antioxidant, immunomodulatory, and anti-apoptotic activities of RC were demonstrated in a rat NEC model. RC can suggest as a new treatment option for preventing intestinal injury.

Vitis vinifera L. Leaf Extract Inhibits In Vitro Mediators of Inflammation and Oxidative Stress Involved in Inflammatory-Based Skin Diseases

Psoriasis is a chronic cutaneous condition characterized by the release of pro-inflammatory mediators and oxidative stress. The reduction of these factors is currently the most effective strategy to inhibit the symptoms of pathology. Antioxidants from natural sources are increasingly used to improve skin conditions. Dried red leaves from grapevine (Vitis vinifera L., cv Teinturiers) showed anti-inflammatory and anti-bacterial activities, but their possible effects on keratinocytes have not been previously investigated. In this study we tested the ability of a water extract from grapevine leaves (VVWE) to inhibit inflammatory conditions in human keratinocytes (HaCaT cells), challenged with proinflammatory (tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS)) or prooxidant (ultraviolet B radiation (UVB) or H₂O₂) mediators. VVWE inhibited interleukin-8 (IL-8) secretion induced by proinflammatory stimuli, acting on the IL-8 promoter activity, but the effect was lower when prooxidant mediators were used. The effect was partly explained by the reduction of nuclear factor-κB (NF-κB)-driven transcription and nuclear translocation. Furthermore, vascular endothelial growth factor (VEGF) secretion, a regulator of angiogenesis, was inhibited by VVWE, but not matrix metalloproteinase-9 (MMP-9), a protease involved in matrix remodeling. VVWE, assayed on Franz diffusion cell system, showed a marked reduction of High Performance Liquid Chromatography (HPLC)-identified compounds. Pure molecules individually failed to reduce TNF-α-induced IL-8 release, suggesting synergistic effects or the presence of other bioactive compounds still unknown.