Grape seed proanthocyanidin extract (GSPE) attenuates collagen-induced arthritis

Grape seed extract prevents chlorpyrifos-induced toxicity in rat liver through the modulation of phase I detoxification pathway

Chlorpyrifos (CPF) poisoning is a public health problem for which there is not currently any effective prophylaxis. In this study, we investigated the protective effect of grape seed extract (GSE) against CPF-induced hepatotoxicity. Rats were daily treated either with CPF (2 mg/kg) or CPF and GSE (20 mg/kg) for 1 week, sacrificed, and their livers dissected for biochemical, molecular, and histopathological analyses. CPF generated liver dysfunction by altering carbohydrate, lipid, amino acid, ammonia and urea metabolism, and provoked mitochondrial impairment through disturbing tricarboxylic acid (TCA) cycle, oxidative phosphorylation (OXPHOS), and mitochondrial viability. CPF also induced cholinergic excitotoxicity along with oxidative stress and histopathological alterations. Interestingly, treatment with GSE prevented all the detrimental effects of CPF through the regulation of cytochrome P450 (CYP450) gene expression. Molecular docking analysis indicated that GSE-containing polyphenols acted as epigenetic modulators through inhibiting DNA (cytosine-5)-methyltransferase 1 (DNMT1), thus favoring the CYP2C6 detoxification pathway. Thereby, GSE might be a promising strategy in the protection of the liver against CPF toxicity.

Research progress of procyanidins in repairing cartilage injury after anterior cruciate ligament tear

Anterior cruciate ligament (ACL) tear is a common sports-related injury, and cartilage injury always emerges as a serious complication following ACL tear, significantly impacting the physical and psychological well-being of affected individuals. Over the years, efforts have been directed toward finding strategies to repair cartilage injury after ACL tear. In recent times, procyanidins, known for their anti-inflammatory and antioxidant properties, have emerged as potential key players in addressing this concern. This article focuses on summarizing the research progress of procyanidins in repairing cartilage injury after ACL tear. It covers the roles, mechanisms, and clinical significance of procyanidins in repairing cartilage injury following ACL tear and explores the future prospects of procyanidins in this domain. This review provides novel insights and hope for the repair of cartilage injury following ACL tear.

The Effect of Grape Seed Extract on the Alveolar, Jaw, and Skeletal Bone Remodeling: A Scoping Review

Herbal medicine has an important part in promoting and maintaining human health. One of them was grape seed extract (GSE). Various potentials of GSE in human health have been explored, and its potential for maintaining bone health is promising. Some initial research has provided evidence that the GSE was able to affect bone remodeling (bone resorption and bone formation). This scoping review analyzed and discussed all the reports on the effect of GSE on bone healing and bone remodeling in animals in the alveolar bone, jaw bone, and skeletal bone. The further purpose is to give an opportunity to research and development of supplementation of GSE for humans.The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines were used to compose this scoping review through database on Scopus, PubMed, Science Direct, Web of Science, Embase, and manual search until December 2022. The inclusion criteria were a study that analyzed the effect of supplementation GSE on all bones.All included study was in vivo study with supplementation of GSE. The supplementation of GSE affects the alveolar bone, jaw bones, and skeletal bone by promoting bone formation and inhibiting bone resorption by suppressing inflammation, apoptosis pathways, and osteoclastogenesis. It not only supports bone remodeling in bone inflammation, osteonecrosis, osteoporosis, and arthritis but also the GSE increases bone health by increasing the density and mineral deposition in trabecula and cortical bone.The supplementation of GSE supports bone remodeling by interfering with the inflammation process and bone formation not only by preventing bone resorption but also by maintaining bone density.

Promising antioxidant activity of crude extract from Calliandra tweedii Benth

The interest in medicinal plants encourages new research studies on plant extracts, as they are sources for treatments in medicine, agriculture, and veterinary. Calliandra tweedii is a native Brazilian species with broad use in folk medicine. This study aimed to examine the leaf crude extract (CE) of C. tweedii and its methanolic (MP) and hexane (HP) phases concerning total phenolic compounds (TPC), proanthocyanidins (PRO), and flavonoid profile, and correlate it to their antioxidant activity (DPPH and FRAP). CE and MP revealed high contents of TPC, PRO and high antioxidant activity (DPPH and FRAP) in relation to HP. Opposite, HP showed reduced antioxidant activity, according to the scarce phenolic constituents obtained from the partition. Five flavonols were detected by HPLC-UV-DAD, being quercitrin the major constituent. Also, one kaempferol derivate, and a series of three quercetin derivates were detected. Strong positive correlations were observed between DPPH, FRAP, and phenolic compounds. These discoveries are important to highlight the promising antioxidant activity of CE of C. tweedii, which could contribute to the expansion of popular herbal medicines and new drug discovery.

Muscadine Grape (Vitis rotundifolia) and Wine Polyphenols Alleviated Arthritis and Restored the Gut Microbial Composition in Mice

This study aimed to investigate the effect of muscadine grape polyphenols (MGP) and muscadine wine polyphenols (MWP) on the onset and progression of arthritis in mice. Arthritis in male DBA/1J mice was induced by two intradermal injections of type II collagen. MGP or MWP (400 mg/kg) were orally gavaged to mice. MGP and MWP were found to delay the onset and reduce the severity and clinical symptoms of collagen induced arthritis (CIA) (p≤0.05). In addition, MGP and MWP significantly reduced the plasma concentration of TNF-α, IL-6, anti-collagen antibodies, and matrix metalloproteinase-3 in CIA mice. Based on nano CT and histological analysis, MGP and MWP reduced pannus formation, cartilage destruction, and bone erosion in CIA mice. Analysis of 16S ribosomal RNA revealed that arthritis in mice is associated with gut dysbiosis. MWP was more effective than MGP at alleviating such dysbiosis by shifting the microbiome composition towards the direction of healthy mice. Relative abundance of several genera of gut microbiome correlated with plasma inflammatory biomarkers and bone histology scores, suggesting they play a role in the development and progression of arthritis. This study suggests that muscadine grape or wine polyphenols can be used as a diet-based strategy to prevent and manage arthritis in humans.

The Utilization of Physiologically Active Molecular Components of Grape Seeds and Grape Marc

Nutritional interventions may highly contribute to the maintenance or restoration of human health. Grapes (Vitis vinifera) are one of the oldest known beneficial nutritional components of the human diet. Their high polyphenol content has been proven to enhance human health beyond doubt in statistics-based public health studies, especially in the prevention of cardiovascular disease and cancer. The current review concentrates on presenting and classifying polyphenol bioactive molecules (resveratrol, quercetin, catechin/epicatechin, etc.) available in high quantities in Vitis vinifera grapes or their byproducts. The molecular pathways and cellular signaling cascades involved in the effects of these polyphenol molecules are also presented in this review, which summarizes currently available in vitro and in vivo experimental literature data on their biological activities mostly in easily accessible tabular form. New molecules for different therapeutic purposes can also be synthesized based on existing polyphenol compound classes available in high quantities in grape, wine, and grape marc. Therefore an overview of these molecular structures is provided. Novel possibilities as dendrimer nanobioconjugates are reviewed, too. Currently available in vitro and in vivo experimental literature data on polyphenol biological activities are presented in easily accessible tabular form. The scope of the review details the antidiabetic, anticarcinogenic, antiviral, vasoprotective, and neuroprotective roles of grape-origin flavonoids. The novelty of the study lies in the description of the processing of agricultural by-products (grape seeds and skins) of industrial relevance, and the detailed description of the molecular mechanisms of action. In addition, the review of the clinical therapeutic applications of polyphenols is unique as no summary study has yet been done.

Grape seed proanthocyanidin extract induces apoptotic and autophagic cell death in rheumatoid arthritis fibroblast-like synoviocytes

Objectives

In this study, we aimed to evaluate the association between grape seed proanthocyanidin extract (GSPE) and rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLSs) and to investigate whether GSPE induces cell death in RA-FLSs.

Materials and methods

The FLSs were isolated from RA synovial tissues. Cell viability and cell cycle staging were analyzed using a hemocytometer and flow cytometry. Caspase 3 and poly (ADP-ribose) polymerase (PARP) proteins were analyzed using Western blotting with z-VAD-fmk. Protein LC3 and polyubiquitin-binding protein p62 that were degraded by autophagy were evaluated using Western blotting with 3-methyladenine and chloroquine. Reactive oxygen species (ROS) were also evaluated.

Results

When RA-FLSs were treated with GSPE, cell viability decreased, the number of cells in sub-G1 and G2/M phases increased, and the expression of pro-PARP and pro-caspase 3 proteins decreased in a concentration-dependent manner. This result was offset, when the cells were co-treated with the pan-caspase inhibitor z-VAD-fmk. The reduced cell viability, increased expression of LC3-II protein, and reduced expression of p62 protein with GSPE treatment were offset, when RA-FLSs were co-treated with GSPE and autophagy inhibitors 3-methyladenine and chloroquine. The level of ROS in RA-FLSs treated with GSPE was significantly lower than treatment with N-acetyl-cysteine, a ROS inhibitor.

Conclusion

Our study results show that GSPE induces apoptotic and autophagic cell death and inhibites reactive oxygen species in RA-FLSs.

Flavonoids as Potential Anti-Inflammatory Molecules: A Review

Hydroxylated polyphenols, also called flavonoids, are richly present in vegetables, fruits, cereals, nuts, herbs, seeds, stems, and flowers of numerous plants. They possess numerous medicinal properties such as antioxidant, anti-cancer, anti-microbial, neuroprotective, and anti-inflammation. Studies show that flavonoids activate antioxidant pathways that render an anti-inflammatory effect. They inhibit the secretions of enzymes such as lysozymes and β-glucuronidase and inhibit the secretion of arachidonic acid, which reduces inflammatory reactions. Flavonoids such as quercetin, genistein, apigenin, kaempferol, and epigallocatechin 3-gallate modulate the expression and activation of a cytokine such as interleukin-1beta (IL-1β), Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8); regulate the gene expression of many pro-inflammatory molecules such s nuclear factor kappa-light chain enhancer of activated B cells (NF-κB), activator protein-1 (AP-1), intercellular adhesion molecule-1 (ICAM), vascular cell adhesion molecule-1 (VCAM), and E-selectins; and also inhibits inducible nitric oxide (NO) synthase, cyclooxygenase-2, and lipoxygenase, which are pro-inflammatory enzymes. Understanding the anti-inflammatory action of flavonoids provides better treatment options, including coronavirus disease 2019 (COVID-19)-induced inflammation, inflammatory bowel disease, obstructive pulmonary disorder, arthritis, Alzheimer’s disease, cardiovascular disease, atherosclerosis, and cancer. This review highlights the sources, biochemical activities, and role of flavonoids in enhancing human health.

Grape Seed Proanthocyanidin Extract Prevents Bone Loss via Regulation of Osteoclast Differentiation, Apoptosis, and Proliferation

Dietary procyanidin has been shown to be an important bioactive component that regulates various pharmacological activities to maintain metabolic homeostasis. In particular, grape seed proanthocyanidin extract (GSPE) is a commercially available medicine for the treatment of venous and lymphatic dysfunction. This study aimed to investigate whether GSPE protects against lipopolysaccharide (LPS)-induced bone loss in vivo and the related mechanism of action in vitro. The administration of GSPE restored the inflammatory bone loss phenotype stimulated by acute systemic injection of LPS in vivo. GSPE strongly suppressed receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation and bone resorption activity of mature osteoclasts by decreasing the RANKL-induced nuclear factor-κB transcription activity. GSPE mediates this effect through decreased phosphorylation and degradation of NF-κB inhibitor (IκB) by IκB kinaseβ, subsequently inhibiting proto-oncogene cellular Fos and nuclear factor of activated T cells. Additionally, GSPE promotes osteoclast proliferation by increasing the phosphorylation of components of the Akt and mitogen-activated protein kinase signaling pathways and it also inhibits apoptosis by decreasing the activity of caspase-8, caspase-9, and caspase-3, as corroborated by a decrease in the Terminal deoxynucleotidyl transferase dUTP nick end labeling -positive cells. Our study suggests a direct effect of GSPE on the proliferation, differentiation, and apoptosis of osteoclasts and reveals the mechanism responsible for the therapeutic potential of GSPE in osteoclast-associated bone metabolism disease.

Effect of Flavonoid Supplementation on Alveolar Bone Healing-A Randomized Pilot Trial

We investigated the effects of two common dietary supplements on bone healing in dental extraction sockets in humans. In this randomized pilot trial, male subjects took Grape Seed Extract [GSE] or Grapefruit Extract [GFE] starting two weeks prior to dental extraction and maintained this regimen for sixty days after surgery. Extraction sockets were filled with a collagen plug. After 24 h, a socket sample was collected and processed for quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and an 84-gene wound healing assay. Sixty days after tooth extraction, a core of newly formed bone was obtained prior to dental implant placement and processed for histology. qRT-PCR revealed that GFE led to a significant decrease in platelet-derived growth factor and interleukin (IL)1-β compared to GSE, and a significant decrease in IL-6 and CXCL2 compared to control. GSE led to a significant increase in coagulation factor Von Willebrand and inflammatory marker IL1-β compared to GFE. WISP1 and CXCL5 were upregulated in both groups. Overall, GFE showed a downregulation of inflammation and GSE led to a decrease in collagen density and increased osteoclasts. This pilot trial highlights the need for further investigation on the mechanism of action of such supplements on bone healing and oral health.

Tart Cherry Prevents Bone Loss through Inhibition of RANKL in TNF-Overexpressing Mice

Current drugs for the treatment of rheumatoid arthritis-associated bone loss come with concerns about their continued use. Thus, it is necessary to identify natural products with similar effects, but with fewer or no side effects. We determined whether tart cherry (TC) could be used as a supplement to prevent inflammation-mediated bone loss in tumor necrosis factor (TNF)-overexpressing transgenic (TG) mice. TG mice were assigned to a 0%, 5%, or 10% TC diet, with a group receiving infliximab as a positive control. Age-matched wild-type (WT) littermates fed a 0% TC diet were used as a normal control. Mice were monitored by measurement of body weight. Bone health was evaluated via serum biomarkers, microcomputed tomography (µCT), molecular assessments, and mechanical testing. TC prevented TNF-mediated weight loss, while it did not suppress elevated levels of interleukin (IL)-1β and IL-6. TC also protected bone structure from inflammation-induced bone loss with a reduced ratio of receptor activator of nuclear factor kappa-B ligand (RANKL)/osteoprotegerin (OPG) to a degree comparable to infliximab. Furthermore, unlike with infliximab, TC exhibited a moderate improvement in TNF-mediated decline in bone stiffness. Thus, TC could be used as a prophylactic regimen against future fragility fractures in the context of highly chronic inflammation.

Alpha-mangostin: Anti-inflammatory and antioxidant effects on established collagen-induced arthritis in DBA/1J mice

Rheumatoid arthritis (RA) is an autoimmune disease that causes physical disability in people worldwide. Despite progress made in RA treatment in the past decade, new drugs with high efficacy but few long-term adverse effects are still needed. This study focused on evaluating the therapeutic potential of α-mangostin on established collagen-induced arthritis (CIA) in DBA/1J mice. Arthritic DBA/1J mice were orally administered with two doses of α-mangostin (10 and 40 mg/kg) daily, for 33 days. Alpha-mangostin significantly decreased the clinical score in the short term at both doses and decreased the histopathological score at the higher dose. This improvement was accompanied by a reduction on serum levels of anti-collagen IgG2a autoantibodies and of the production of LIX/CXCL5, IP-10/CXCL10, MIG/CXCL9, RANTES/CCL5, IL-6 and IL-33 in the joints of CIA mice. Alpha-mangostin also exhibited an anti-oxidant effect decreasing the NADPH oxidase activity and lipid peroxidation and preserving the levels of reduced glutathione in the arthritic joints. In vitro this xanthone demonstrated modulatory properties on LPS-activated dendritic cells, although in Th1 and Th17-polarized lymphocytes promotes a pro-apoptotic phenotype. Altogether this study illustrates the capacity of α-mangostin to ameliorate the early clinical and histological signs of established CIA by reducing the inflammatory and oxidative responses.

Polyphenol uses in biomaterials engineering

Polyphenols are micronutrients obtained from diet that have been suggested to play an important role in health. The health benefits of polyphenols and their protective effects in food systems as antioxidant compounds are well known and have been extensively investigated. However, their functional roles as a "processing cofactor" in tissue engineering applications are less widely known. This review focuses on the functionality of polyphenols and their application in biomaterials. Polyphenols have been used to stabilize collagen and to improve its resistance to degradation in biological systems. Therefore, they have been proposed to improve the performance of biomedical devices used in cardiovascular systems by improving the mechanical properties of grafted heart valves, enhancing microcirculation through the relaxation of the arterial walls and improving the capillary blood flow and pressure resistance. Polyphenols have been found to stimulate bone formation, mineralization, as well as the proliferation, differentiation, and the survival of osteoblasts. These effects are brought about by the stimulatory effect of polyphenols on osteoblast cells and their protective effect against oxidative stress and inflammatory cytokines. In addition, polyphenols inhibit the differentiation of the osteoclast cells. Collectively, these actions lead to promote bone formation and to reduce bone resorption, respectively. Moreover, polyphenols can increase the cross-linking of dentine and hence its mechanical stability. Overall, polyphenols provide interesting properties that will stimulate further research in the bioengineering field.

Grape seed proanthocyanidin extract ameliorates murine autoimmune arthritis through regulation of TLR4/MyD88/NF-κB signaling pathway

BACKGROUND/AIMS

Grape seed proanthocyanidin extract (GSPE) has been reported to have a beneficial effect on regulating inf lammation. However, the anti-inflammatory mechanism of GSPE remains unclear. The aim of this study was to verify the influence of GSPE on the Toll-like receptor 4 (TLR4)-mediated signaling pathway in the regulation of murine autoimmune arthritis.

METHODS

Collagen-induced arthritis (CIA) was induced in dilute brown non-agouti (DBA)/1J mice. The mice were treated with GSPE (0 or 100 mg/kg) intraperitoneally. The severity of arthritis was assessed clinically, biochemically, and histologically. Immunostaining for TLR4 was performed. The expressions of TLR4 and downstream signaling molecules were analyzed by Western blot. The effect of GSPE on lipopolysaccharide (LPS)-induced TLR4 activation was also evaluated using RAW264.7 cells and fibroblast-like synoviocytes (FLSs) from patients with rheumatoid arthritis and from those with osteoarthritis.

RESULTS

GSPE attenuated the clinical severity of arthritis and decreased histological damage. GSPE treatment reduced the number of TLR4-stained cells in the synovium of mice with CIA. GSPE also downregulated the expression of TLR4, myeloid differentiation factor 88 (MyD88) and phosphorylated IκBα synovial protein in CIA mice. Concurrently, GSPE inhibited the nuclear translocation of nuclear factor-κB (NF-κB) subunits (p65 and p50). LPS-induced TLR4 activation was suppressed by GSPE in human FLS as well as in murine macrophages in vitro.

CONCLUSIONS

Our results demonstrated that GSPE ameliorated CIA by regulating the TLR4-MyD88-NF-κB signaling pathway.

The Role of Flavonoids in Inhibiting Th17 Responses in Inflammatory Arthritis

Flavonoids have been considered powerful anti-inflammatory agents, and their exact immunomodulatory action as therapeutic agents in autoimmune diseases has started to emerge. Their role in the manipulation of immunoregulation is less understood. Several studies attempted to investigate the role of various flavonoids mainly in experimental models of autoimmune diseases, especially in the context of their potential effect on the increase of regulatory T cells (Tregs) and their ability to stimulate an overexpression of anti-inflammatory cytokines, in particular that of IL-10. The emergence of IL-17, a cytokine largely produced by Th17 cells, as a powerful proinflammatory stimulus which attenuates the induction of Tregs has prompted a series of studies investigating the role of flavonoids on Th17 cells in experimental models as well as human autoimmune diseases. This review thoroughly discusses accumulated data on the role of flavonoids on Th17 in rheumatoid arthritis and experimental autoimmune arthritis.

Effects of a Standard American Diet and an anti-inflammatory diet in male and female mice

BACKGROUND

Obesity and chronic pain are prevalent concerns. Pain is frequently experienced in weight-bearing joints, but is common in other areas of the body as well, suggesting other factors. Poor diet often contributes to obesity and can directly influence the immune system. We have shown that poor diet prolongs recovery from inflammatory injury. Therefore, our goal was to determine whether poor-quality diet-induced consequences could be prevented or reversed by an anti-inflammatory diet (AID).

METHODS

A Standard American Diet (SAD) was developed to investigate the effects of poor diet on pain. The SAD includes amounts of refined sugar, carbohydrates and fats that better model the typical American diet, as compared to high-fat diets. We developed an AID to explore whether the effects of the SAD could reverse or whether the AID would enhance recovery prophylactically. The AID was developed using ingredients (epigallocatechin gallate, sulforaphane, resveratrol, curcumin and ginseng) with known anti-inflammatory properties. Following 15 weeks of diet [SAD, AID or regular (REG)] exposure, male and female mice underwent inflammatory injury, at which point some animals had their diets switched for the remainder of the study.

RESULTS

Animals who consumed the SAD showed longer recovery compared to the AID- and REG-fed animals. Animals switched off the SAD had faster recovery times, with AID-fed animals recovering as fast as REG-fed animals.

CONCLUSIONS

Poor diet prolonged recovery from inflammatory injury. Substitution of SAD with AID or REG promoted faster recovery. These findings suggest diet can be used as a non-pharmacological intervention following injury.

SIGNIFICANCE

Obesity may increase susceptibility to chronic pain often due to poor diet. Diet has potential to be used as treatment for pain. This study investigates the use of a novel translatable diet to act as a preventative (i.e. prior to surgery) or an intervention (i.e. following an injury).

Morphometric and histopathological evaluation of the effect of grape seed proanthocyanidin on alveolar bone loss in experimental diabetes and periodontitis

OBJECTIVE

Grape seed proanthocyanidine extract (GSPE) is a strong antioxidant derived from the grape seeds (Vitis vinifera, Terral J.F.) and has a polyphenolic structure with a wide range of biological activity. The aim of the present study was to evaluate the effects of GSPE on alveolar bone loss and histopathological changes in rats with diabetes mellitus and ligature-induced periodontitis.

MATERIAL AND METHODS

Forty rats were divided into 6 study groups. Control (C, 6 rats) group, periodontitis (P, 6 rats) group, diabetes (D, 6 rats) group, diabetes and periodontitis (D+P, 6 rats) group, diabetes, periodontitis and 100 mg/kg/day GSPE (GSPE-100, 8 rats), and diabetes, periodontitis and 200 mg/kg/day GSPE (GSPE-200, 8 rats) group. Diabetes mellitus was induced by intraperitoneal injection of a single dose of streptozotocin (60 mg/kg). Periodontitis was induced via ligation method. Silk ligatures were placed at the mandibular right first molars. GSPE was administered by oral gavage. After 30 days, all rats were killed. Alveolar bone loss was measured morphometrically via a stereomicroscope. For histopathological analyses, Alizarin red staining, and matrix metalloproteinase (MMP)-8, vascular endothelial growth factor and hypoxia inducible factor (HIF)-1α immunohistochemistry were performed. Tartrate-resistant acid phosphatase-positive osteoclast cells and relative total inflammatory cells were also determined.

RESULTS

The highest alveolar bone loss was observed in the D+P group (P < .05). GSP-200 group decreased alveolar bone loss (P < .05). The D+P group had the highest osteoclast counts, but the difference was not significant compared to the P, GSPE-100 and GSPE-200 groups (P > .05). The inflammation in the D+P group was also higher than the other groups (P < .05). The osteoblast numbers increased in the GSPE-100 and GSPE-200 groups compared to the P and D+P groups (P < .05). MMP-8 and HIF-1α levels were highest in the D+P group and GSPE significantly decreased these levels (P < .05).

CONCLUSION

Within the limits of this animal study, it can be suggested that GSPE administration may decrease periodontal inflammation and alveolar bone loss via decreasing MMP-8 and HIF-1α levels and increase osteoblastic activity in diabetic rats with experimental periodontitis.

Modulation of Inflammatory Response to Implanted Biomaterials Using Natural Compounds

Tissue engineering offers a promising strategy to restore injuries resulting from trauma, infection, tumor resection, or other diseases. In spite of significant progress, the field faces a significant bottleneck; the critical need to understand and exploit the interdependencies of tissue healing, angiogenesis, and inflammation. Inherently, the balance of these interacting processes is affected by a number of injury site conditions that represent a departure from physiological environment, including reduced pH, increased concentration of free radicals, hypoglycemia, and hypoxia. Efforts to harness the potential of immune response as a therapeutic strategy to promote tissue repair have led to identification of natural compounds with significant anti-inflammatory properties. This article provides a concise review of the body's inflammatory response to biomaterials and describes the role of oxygen as a physiological cue in this process. We proceed to highlight the potential of natural compounds to mediate inflammatory response and improve host-graft integration. Herein, we discuss the use of natural compounds to map signaling molecules and checkpoints that regulate the cross-linkage of immune response and skeletal repair.

Potent Antiarthritic Properties of Phloretin in Murine Collagen-Induced Arthritis

In the exploration of potential therapeutic agents for rheumatoid arthritis (RA), DBA/1J mice are used as the RA model of collagen-induced arthritis (CIA). Phloretin, a flavonoid compound extracted from Prunus mandshurica, has been found to exhibit anti-inflammatory activity, making it a potential candidate for treatment of RA. The objective of this study was to evaluate the therapeutic effects of phloretin on CIA mice. CIA mice were dosed daily with phloretin at either 50 or 100 mg/kg among two treatment groups. CIA treated mice showed mitigation of clinical symptoms of RA in addition to reduced inflammation of hind-limbs compared to mice who did not receive phloretin. Histological analysis showed that phloretin suppressed the severity of RA and effectively mitigated joint inflammation and cartilage- and bone-destruction via reducing proinflammatory cytokine productions (TNF-α, IL-6, IL-1β, and IL-17). This was at least partially mediated by causing inadequate splenocyte activation and proliferation. Moreover, phloretin-treated CIA mice showed decreased oxidative stress and diminished levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in paw tissues as well as reduced productivity of anti-collagen antibodies in serum. We have concluded that phloretin could be a potent and effective antiarthritis agent, demonstrating anti-inflammatory, antioxidative, and immunomodulatory effects in CIA mice.

Modulation of the neurological and vascular complications by grape seed extract in a rat model of spinal cord ischemia–reperfusion injury by downregulation of both osteopontin and cyclooxygenase-2

In this study, we investigated the effects of grape seed extract (GSE) on the expression of osteopontin (OPN) and cyclooxygenase-2 (COX-2) in a rat model of spinal cord ischemia–reperfusion injury (SC-IRI). Fifty male rats were divided into 5 groups: control (CON); control + GSE (CON + GSE) (received GSE for 28 days); sham operated (Sham); IRI; and IRI + GSE. SC-IRI was induced by clamping the aorta just above the bifurcation for 45 min, and then the clamp was released for 48 h for reperfusion. IRI + GSE group received GSE for 28 days before SC-IRI. Sensory, motor, and placing/stepping reflex assessment was performed. Prostaglandin E2 (PGE2), thiobarbituric acid reactive substances (TBARs), and total antioxidant capacity (TAC) were measured in spinal cord homogenate. Immunohistochemical examination of the spinal cord for OPN and COX-2 were carried out. SC-IRI resulted in significant increase in plasma nitrite/nitrate level and spinal cord homogenate levels of TBARs and PGE2, and OPN and COX-2 expression with significant decrease in TAC. GSE improves the sensory and motor functions through decreasing OPN and COX-2 expression with reduction of oxidative stress parameters. We conclude a neuroprotective effect of GSE in SC-IRI through downregulating COX-2 and OPN expression plus its antioxidants effects.

Grape-seed proanthocyanidins inhibit the lipopolysaccharide-induced inflammatory mediator expression in RAW264.7 macrophages by suppressing MAPK and NF-κb signal pathways

Grape-seed proanthocyanidins (GSPs) have been shown to function as an anti-oxidant and anti-inflammatory agent with little toxicity in vivo and in vitro. However, little is known about their anti-inflammatory properties and mechanisms of action. The specific focus being its effects on the MAP kinases and nuclear factor-kappaB (NF-κB) signal transduction pathways in lipopolysaccharide (LPS) -stimulated RAW264.7 cells. GSPs extract has been found to suppress the mRNA expression of pro-inflammatory cytokines like tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and inflammatory molecule of cyclooxygenase-2 (COX-2) while mRNA level of IL-10 was greatly promoted. Furthermore, GSPs extract inhibited the expression of phosphorylated ERK, JNK and P38, as well as phosphorylated IKKα/β and NF-κB p65 subunit. In conclusion, our results show that GSPs extract showed its anti-inflammatory and immunomodulatory properties by suppressing the activation of MAP kinases and NF-κB signal transduction pathways.

The Role of IL-17 and Th17 Lymphocytes in Autoimmune Diseases

The end of twentieth century has introduced some changes into T helper (Th) cells division. The identification of the new subpopulation of T helper cells producing IL-17 modified model of Th1-Th2 paradigm and it was named Th17. High abilities to stimulate acute and chronic inflammation made these cells ideal candidate for crucial player in development of autoimmune disorders. Numerous publications based on animal and human models confirmed their pivotal role in pathogenesis of human systemic and organ-specific autoimmune diseases. These findings made Th17 cells and pathways regulating their development and function a good target for therapy. Therapies based on inhibition of Th17-dependent pathways are associated with clinical benefits, but on the other hand are frequently inducing adverse effects. In this review, we attempt to summarize researches focused on the importance of Th17 cells in development of human autoimmune diseases as well as effectiveness of targeting IL-17 and its pathways in pre-clinical and clinical studies.

Grape seed proanthocyanidin protects liver against ischemia/reperfusion injury by attenuating endoplasmic reticulum stress

AIM: To explore the effect of grape seed proanthocyanidin (GSP) in liver ischemia/reperfusion (IR) injury and alleviation of endoplasmic reticulum stress.

METHODS: Male Sprague-Dawley rats (220-250 g) were divided into three groups, namely, sham, IR, and GSP groups (n = 8 each). A liver IR (70%) model was established and reperfused for 6 h. Prior to reperfusion, the GSP group was administered with GSP (100 mg/kg) for 15 d, and liver histology was then investigated. Serum aminotransferase and inflammatory mediators coupled with superoxide dismutase and methane dicarboxylic aldehyde were detected. Western blot was conducted to analyze the expression of glucose-regulated protein 78, CCAAT/enhancer-binding protein homologous protein, activating transcription factor-4, inositol-requiring enzyme-1, procaspase-12, and nuclear factor-κb. Apoptotic cells were detected by TUNEL staining.

RESULTS: The serum aminotransferase, apoptotic cells, and Suzuki scores decreased in the GSP group compared with the IR group (Ps < 0.05). The methane dicarboxylic aldehyde level was decreased in the GSP group, but the superoxide dismutase level was reversed (Ps < 0.05). Similarly, GSP downregulated the proinflammatory factors and upregulated the levels of anti-inflammatory factors (Ps < 0.05). Western blot data showed that GSP increased glucose-regulated protein 78 expression and suppressed expression of CCAAT/enhancer-binding protein homologous protein, activating transcription factor-4, inositol-requiring enzyme-1, procaspase-12, and nuclear factor-κb compared with the IR group.

CONCLUSION: GSP possesses antioxidative, anti-inflammatory, and antiapoptotic effects by relieving endoplasmic reticulum stress through regulation of related signaling pathways to protect the liver against IR injury.

Proanthocyanidins from the bark of Metasequoia glyptostroboides ameliorate allergic contact dermatitis through directly inhibiting T cells activation and Th1/Th17 responses

OBJECTIVE

The leaves and bark of Metasequoia glyptostroboides are used as anti-microbic, analgesic and anti-inflammatory drug for dermatic diseases in Chinese folk medicine. However, the pharmacological effects and material basis responsible for the therapeutic use of this herb have not yet been well studied. The objectives of this study were to evaluate the anti-inflammatory effects of the proanthocyanidin fraction from the bark of M. glyptostroboides (MGEB) and to elucidate its immunological mechanisms.

MATERIALS AND METHODS

The anti-inflammatory activity of MGEB was evaluated using 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) in mice. Its potential mechanisms were further investigated by determining its effects on Con A-induced T cell activation and Th1/Th17 responses in vitro.

RESULTS

Both intraperitoneal injection and oral administration of MGEB significantly reduced the ear swelling in DNFB-induced ACD mice. MGEB inhibited Con A-induced proliferation and the expression levels of cell surface molecules CD69 and CD25 of T cells in vitro. MGEB also significantly decreased the production of Th1/Th17 specific cytokines (IL-2, IFN-γ and IL-17) and down-regulated their mRNA expression levels in activated T-cells.

CONCLUSIONS

MGEB could ameliorate ACD, at least in part, through directly inhibiting T cells activation and Th1/Th17 responses.

Grape seed proanthocyanidins inhibit H2O2-induced osteoblastic MC3T3-E1 cell apoptosis via ameliorating H2O2-induced mitochondrial dysfunction

Oxidative stress represents a major cause of cellular damage and death in pathological conditions including osteoporosis, in which oxidative stress is associated with increased bone resorption and low bone mass. And grape seed proanthocyanidins are a group of polyphenolic bioflavonoids which are known to possess broad pharmacological activity and therapeutic potential, exerting a protective role against oxidant injury. The aim of our study was to investigate whether proanthocyanidins exert an anti-apoptosis effect in osteoblastic MC3T3-E1 cells, via their antioxidant activity. Firstly, we determined the anti-apoptosis effect of proanthocyanidins in osteoblastic MC3T3-E1 cells, which were subject to H2O2 treatment, then we determined the association of the antioxidant activity exerted by proanthocyanidins with their anti-apoptosis effect. Results demonstrated that proanthocyanidins inhibit H2O2-promoted apoptosis in MC3T3-E1 cells, via ameliorating the viability of MC3T3-E1 cells post H2O2 treatment and reducing the apoptotic cell numbers. And the proanthocyanidins treatment also ameliorates the H2O2-induced mitochondrial dysfunction via promoting the mitochondrial membrane potential (MMP) and respiratory chain complex IV, and reducing the mitochondrial free radical production, ROS and mitochondrial superoxide. Moreover, the proanthocyanidins inhibit H2O2-induced apoptosis signaling which is mediated by p53. This study implied a possible anti-osteoporosis effect of proanthocyanidins via their antioxidant and anti-apoptosis activity.

A targeted approach for evaluating preclinical activity of botanical extracts for support of bone health

Using a sequential in vitro/in vivo approach, we tested the ability of botanical extracts to influence biomarkers associated with bone resorption and bone formation. Pomegranate fruit and grape seed extracts were found to exhibit anti-resorptive activity by inhibiting receptor activator of nuclear factor-κB ligand (RANKL) expression in MG-63 cells and to reduce IL-1β-stimulated calvarial ⁴⁵Ca loss. A combination of pomegranate fruit and grape seed extracts were shown to be effective at inhibiting bone loss in ovariectomised rats as demonstrated by standard histomorphometry, biomechanical and bone mineral density measurements. Quercetin and licorice extract exhibited bone formation activity as measured by bone morphogenetic protein-2 (BMP-2) promoter activation, increased expression of BMP-2 mRNA and protein levels, and promotion of bone growth in cultured mouse calvariae. A combination of quercetin and licorice extract demonstrated a potential for increasing bone mineral density in an intact female rat model as compared with controls. The results from this sequential in vitro/in vivo research model yielded botanical extract formulas that demonstrate significant potential benefits for bone health.

Grape seed extract dose-responsively decreases disease severity in a rat model of mucositis; concomitantly enhancing chemotherapeutic effectiveness in colon cancer cells

OBJECTIVE

Mucositis is a serious disorder of the gastrointestinal tract that results from cancer chemotherapy. We investigated the effects of increasing grape seed extract doses on the severity of chemotherapy in a rat model and its coincident impact on chemotherapeutic effectiveness in colon cancer cells.

DESIGN

Female Dark Agouti rats were gavaged with grape seed extract (400-1000 mg/kg) or water (day 3-11) and were injected intraperitoneally with 5-Fluorouracil (150 mg/kg) or saline (control) on day 9 to induce mucositis. Daily metabolic data were collected and rats were sacrificed on day 12. Intestinal tissues were collected for histological and myeloperoxidase analyses. Caco-2 cell viability was examined in response to grape seed extract in combination with 5-Fluorouracil by 3-(4,5-Dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide) assay.

RESULTS

Compared with 5-Fluorouracil controls, grape seed extract (400-1000 mg/kg) significantly decreased the histological damage score (P<0.05) in the jejunum. Grape seed extract (1000 mg/kg) increased jejunal crypt depth by 25% (P<0.05) in 5-Fluorouracil treated rats compared to 5-Fluorouracil controls, and attenuated the 5-Fluorouracil -induced reduction of mucosal thickness (25%, P<0.05). Grape seed extract (600 mg/kg) decreased myeloperoxidase activity by 55% (P<0.01) compared to 5-Fluorouracil controls. Grape seed extract was more effective at ameliorating 5-Fluorouracil induced intestinal injury, with effects most pronounced in the proximal jejunum. Grape seed extract (10-25 ug/mL) significantly enhanced the growth-inhibitory effects of 5-Fluorouracil by 26% (P<0.05) in Caco-2 cells and was more potent than 5-Fluorouracil at 50-100 µg/mL.

CONCLUSION

Grape seed extract may represent a new therapeutic option to decrease the symptoms of intestinal mucositis while concurrently impacting on the viability of colon cancer cells.

The Effects of Platycodin D, a Saponin Purified from Platycodi Radix, on Collagen-Induced DBA/1J Mouse Rheumatoid Arthritis

The object of this study is to observe the effects of platycodin D, a saponin purified from Platycodi Radix, on mice collagen-induced arthritis (CIA). A daily dose of 200, 100, and 50 mg/kg platycodin D was administered orally to male DBA/1J mice for 40 days after initial collagen immunization. To ascertain the effects administering the collagen booster, CIA-related features (including body weight, poly-arthritis, knee and paw thickness, and paw weight increase) was measured from histopathological changes in the spleen, left popliteal lymph node, third digit, and the knee joint regions. CIA-related bone and cartilage damage improved significantly in the platycodin D-administered CIA mice. Additionally, myeloperoxidase (MPO) levels in the paw were reduced in platycodin D-treated CIA mice compared to CIA control groups. The level of malondialdehyde (MDA), an indicator of oxidative stress, decreased in a dose-dependent manner in the platycodin D group. Finally, the production of IL-6 and TNF-α, involved in rheumatoid arthritis pathogenesis, was suppressed by treatment with platycodin D. Taken together, these results suggest that platycodin D is a promising new effective antirheumatoid arthritis agent, exerting anti-inflammatory, antioxidative and immunomodulatory effects in CIA mice.

Grape seed proanthocyanidin extract protects from cisplatin-induced nephrotoxicity by inhibiting endoplasmic reticulum stress-induced apoptosis

Cisplatin (CP) is used as an antineoplastic drug in the clinic, but its nephrotoxicity limits its use. Grape seed proanthocyanidin extract (GSPE) is a powerful antioxidant. In this study, we investigated whether GSPE can prevent CP-induced nephrotoxicity and explored the underlying mechanism. Male C57/BL6 mice were randomly divided into four groups: control group (N), CP group (C), receiving an intraperitoneal (ip) injection of 20 mg/kg CP, GSPE group (G), receiving an intragastric (ig) dose of 500 mg/kg GSPE, and CP+GSPE group (C+G), where ig administration of GSPE was performed 30 min prior to ip injection of CP, followed by an additional ig administration of GSPE 72 h later. Blood and kidney samples were collected 120 h after treatment. The pathological changes in the kidney were examined by periodic acid-Schiff (PAS) staining, while the protein levels of glucose-regulated protein 78 (GRP78), phosphorylated‑extracellular signal-regulated kinase (p-ERK) and caspase-12 were examined by western blotting and immunohistochemical staining. Apoptosis was examined by a terminal deoxynucleotidyl transferase dUTP nick‑end labeling (TUNEL) assay. Compared to the CP group, the CP+GSPE group had a significant decrease in the level of blood urea nitrogen (BUN), serum creatinine (Scr) and reduced renal index (RI) (P<0.05), and showed limited histopathological damage. The number of TUNEL-positive cells was significantly reduced in the CP+GSPE group compared to the CP group (P<0.05), and the protein expression of GRP78, p-ERK and caspase-12 was significantly reduced in the CP+GSPE group (P<0.05). We conclude that GSPE can protect the renal function from CP-induced nephrotoxicity and can attenuate the endoplasmic reticulum (ER) stress‑induced apoptosis via regulation of the caspase-12 pathway.

Effects of Calcium Gluconate, a Water Soluble Calcium Salt on the Collagen-Induced DBA/1J Mice Rheumatoid Arthritis

This study examined the effects of calcium (Ca) gluconate on collagen-induced DBA mouse rheumatoid arthritis (CIA). A single daily dose of 200, 100 or 50 mg/kg Ca gluconate was administered orally to male DBA/1J mice for 40 days after initial collagen immunization. To ascertain the effects administering the collagen booster, CIA-related features (including body weight, poly-arthritis, knee and paw thickness, and paw weight increase) were measured from histopathological changes in the spleen, left popliteal lymph node, third digit and the knee joint regions. CIA-related bone and cartilage damage improved significantly in the Ca gluconate- administered CIA mice. Additionally, myeloperoxidase (MPO) levels in the paw were reduced in Ca gluconate-treated CIA mice compared to CIA control groups. The level of malondialdehyde (MDA), an indicator of oxidative stress, decreased in a dosedependent manner in the Ca gluconate group. Finally, the production of IL-6 and TNF-α, involved in rheumatoid arthritis pathogenesis, were suppressed by treatment with Ca gluconate. Taken together, these results suggest that Ca gluconate is a promising candidate anti-rheumatoid arthritis agent, exerting anti-inflammatory, anti-oxidative and immunomodulatory effects in CIA mice.

Grape seed proanthocyanidin extract-mediated regulation of STAT3 proteins contributes to Treg differentiation and attenuates inflammation in a murine model of obesity-associated arthritis

Grape seed proanthocyanidin extract (GSPE) is a natural flavonoid that exerts anti-inflammatory properties. Obesity is an inflammatory condition and inflammatory cells and their secretion of pro-inflammatory molecules contribute to the pathogenesis of obesity. Rheumatoid arthritis (RA) is a chronic autoimmune disease that is characterized by inflammation of joints lined by synovium. Previously, we demonstrated that obesity augmented arthritis severity in collagen induced arthritis (CIA), a murine model of human RA. Here, we investigated whether oral administration of GSPE showed antiobesity and anti-arthritic effects in high-fat diet-induced obese (DIO) mice and in obese CIA mice, respectively. The pathophysiologic mechanisms by which GSPE attenuates weight gain and arthritis severity in vivo were also investigated. In DIO mice, GSPE administration significantly inhibited weight gain, reduced fat infiltration in liver and improved serum lipid profiles. The antiobesity effect of GSPE was associated with increased populations of regulatory T (Treg) cells and those of decreased Th17 cells. Decrease of Th17 cells was associated with significant inhibition of their key transcriptional factors, pSTAT3(Tyr705) and pSTAT3(Ser727). On the contrary, GSPE-induced Treg induction was associated with enhanced pSTAT5 expression. To identify the anti-arthritis effects of GSPE, GSPE was given orally for 7 weeks after type II collagen immunization. GSPE treatment significantly attenuated the development of autoimmune arthritis in obese CIA model. In line with DIO mice, GSPE administration decreased Th17 cells and reciprocally increased Treg cells by regulating STAT proteins in autoimmune arthritis model. The expressions of pro-inflammatory cytokines and nitrotyrosine in synovium were significantly inhibited by GSPE treatment. Taken together, GSPE functions as a reciprocal regulator of T cell differentiation - suppression of Th17 cells and induction of Tregs in both DIO and obese CIA mice. GSPE may act as a therapeutic agent to treat immunologic diseases related with enhanced STAT3 activity such as metabolic disorders and autoimmune diseases.

Therapeutic potential of interleukin-17 in inflammation and autoimmune diseases

INTRODUCTION

Interleukin-17 (IL-17) is a proinflammatory cytokine that mainly produced by T helper 17 (Th17) cells. In this article, we discussed the role of IL-17 in inflammation and autoimmune diseases, and the therapeutic strategies targeting IL-17.

AREAS COVERED

In this article, we discussed the proinflammatory cytokine IL-17 and IL-17 receptors signals, and their regulation. IL-17 expression was abnormal in the bacterium, virus and fungus infection, and its higher level caused the tissue inflammation. IL-17 was involved in the pathological process of autoimmune diseases, such as systemic sclerosis, rheumatoid arthritis, ankylosing spondylitis and systemic lupus erythematosus, and IL-17 has been put as a therapeutic target in the clinic.

EXPERT OPINION

IL-17/IL-17R signals and their application in inflammation process still need to be explored. Therapeutic strategies targeting IL-17 in autoimmune diseases ameliorated the inadequate response to anti-TNF-α therapy.

Malvidin-3-O-β glucoside, major grape anthocyanin, inhibits human macrophage-derived inflammatory mediators and decreases clinical scores in arthritic rats

Polyphenolic anthocyanins are major colorful compounds in red fruits, known to prevent cardiovascular and other diseases. Grape polyphenols are a mixture of various molecules and their exact contribution to above bioactivities remains to be clarified. In the present study, we first analyzed the effect of purified grape-derived compounds on human peripheral blood mononuclear cell (PBMC) survival, proliferation, as well as for their ability to inhibit the activation of human normal macrophages. Data indicated that malvidin-3-O-β glucoside (Malβg), the major grape anthocyanin, is bioactive with no toxicity on human PBMC. Malβg decreased the transcription of genes encoding inflammatory mediators, confirmed by the inhibition of TNFα, IL1, IL-6 and iNOS-derived nitric oxide (NO) secretion from activated macrophages. As Malβg also inhibited inflammatory response of rat macrophages, we investigated the anti-inflammatory potential of Malβg in chronic rat adjuvant-induced arthritis (AIA). Malβg significantly diminished inflammatory cachexia and arthritic paw scores in AIA rats at both therapeutic and preventive levels. In vivo effects of Malβg correlated with down-regulation of NO generation from AIA rats' peritoneal macrophages ex vivo. These data indicate that Malβg, major grape anthocyanin, is a potent anti-inflammatory agent in vitro and in vivo, without detectable toxic effect.

Effect of selenium and grape seed extract on indomethacin-induced gastric ulcers in rats

Indomethacin (IND) is a non-steroid anti-inflammatory agent that is known to induce severe gastric mucosal lesions. In this study, we investigated the protective effect of selenium (SEL), grape seed extract (GSE), and both on IND-induced gastric mucosal ulcers in rats. Sprague-Dawley rats (200-250 g) were given SEL, GSE, and both by oral gavage for 28 days, and then gastric ulcers were induced by oral administration of 25 mg/kg IND. Malondialdehyde (MDA), non-enzymatic (reduced glutathione, GSH) and enzymatic (superoxide dismutase, catalase, and glutathione peroxidase) antioxidants, prostaglandin E2 (PGE2) in gastric mucosa, and serum tumor necrosis factor alpha (TNF-α) were measured. Moreover, gastric ulcer index and preventive index were determined. Indomethacin increased the gastric ulcer index, MDA, TNF-α, and decreased PGE2 and non-enzymatic (GSH) and enzymatic (superoxide dismutase, catalase, and glutathione peroxidase) antioxidants. Pretreatment with SEL, GSE, and both significantly decreased the gastric ulcer index, MDA, and TNF and increased antioxidants and PGE2. Histopathological observations confirm the gastric ulcer index and biochemical parameters. Selenium and GSE have a protective effect against IND-induced gastric ulcers through prevention of lipid peroxidation, increase of GSH, activation of radical scavenging enzymes, PGE2 generation, and anti-inflammatory activity. Co-administration of GSE and SEL is more effective than GSE or SEL alone.

Carvedilol alleviates adjuvant-induced arthritis and subcutaneous air pouch edema: modulation of oxidative stress and inflammatory mediators

Rheumatoid arthritis (RA) is a systemic inflammatory disease with cardiovascular complications as the leading cause of morbidity. Carvedilol is an adrenergic antagonist which has been safely used in treatment of several cardiovascular disorders. Given that carvedilol has powerful antioxidant/anti-inflammatory properties, we aimed to investigate its protective potential against arthritis that may add further benefits for its clinical usefulness especially in RA patients with concomitant cardiovascular disorders. Two models were studied in the same rat; adjuvant arthritis and subcutaneous air pouch edema. Carvedilol (10mg/kg/day p.o. for 21days) effectively suppressed inflammation in both models with comparable efficacy to the standard anti-inflammatory diclofenac (5mg/kg/day p.o.). Notably, carvedilol inhibited paw edema and abrogated the leukocyte invasion to air pouch exudates. The latter observation was confirmed by the histopathological assessment of the pouch lining that revealed mitigation of immuno-inflammatory cell influx. Carvedilol reduced/normalized oxidative stress markers (lipid peroxides, nitric oxide and protein thiols) and lowered the release of inflammatory cytokines (TNF-α & IL-6), and eicosanoids (PGE2 & LTB4) in sera and exudates of arthritic rats. Interestingly, carvedilol, per se, didn't present any effect on assessed biochemical parameters in normal rats. Together, the current study highlights evidences for the promising anti-arthritic effects of carvedilol that could be mediated through attenuation of leukocyte migration, alleviation of oxidative stress and suppression of proinflammatory cytokines and eicosanoids.

Grape-seed proanthocyanidin extract as suppressors of bone destruction in inflammatory autoimmune arthritis

Chronic autoimmune inflammation, which is commonly observed in rheumatoid arthritis (RA), disrupts the delicate balance between bone resorption and formation causing thedestruction of the bone and joints. We undertook this study to verify the effects of natural grape-seed proanthocyanidin extract (GSPE), an antioxidant, on chronic inflammation and bone destruction. GSPE administration ameliorated the arthritic symptoms of collagen-induced arthritis (CIA), which are representative of cartilage and bone destruction. GSPE treatment reduced the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells and osteoclast activity and increased differentiation of mature osteoblasts. Receptor activator of NFκB ligand expression in fibroblasts from RA patients was abrogated with GSPE treatment. GSPE blocked human peripheral blood mononuclear cell-derived osteoclastogenesis and acted as an antioxidant. GSPE improved the arthritic manifestations of CIA mice by simultaneously suppressing osteoclast differentiation and promoting osteoblast differentiation. Our results suggest that GSPE may be beneficial for the treatment of inflammation-associated bone destruction.

Treatment with 4Jointz reduces knee pain over 12 weeks of treatment in patients with clinical knee osteoarthritis: a randomised controlled trial

OBJECTIVE

To assess the efficacy of thrice daily topical 4Jointz utilizing Acteev technology (a combination of a standardized comfrey extract and a pharmaceutical grade tannic acid, 3.5 g/day) on osteoarthritic knee pain, markers of inflammation and cartilage breakdown over 12 weeks.

PATIENTS AND METHODS

Adults aged 50-80 years (n = 133) with clinical knee OA were randomised to receive 4Jointz or placebo in addition to existing medications. Pain and function were measured using a visual analogue scale (VAS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) scale at baseline, 4, 8 and 12 weeks. Inflammation was measured analysing IL-6 expression and CTX-2 presence as representative for cartilage breakdown using ELISA, at baseline and 12 weeks.

RESULTS

Pain scores significantly reduced in the group who received 4Jointz compared to the group who received placebo after 12 weeks using both the VAS (-9.9 mm, P = 0.034) and the KOOS pain scale (+5.7, P = 0.047). Changes in IL-6 and CTX-2 were not significant (-0.04, P = 0.5; -0.01, P = 0.68). Post-hoc analyses suggested that treatment may be most effective in women (VAS -16.8 mm, P = 0.008) and those with milder radiographic osteoarthritis (OA) (VAS -16.1 mm, P = 0.009). Rates of adverse events were similar in both groups, excepting local rash that was more common amongst participants receiving 4Jointz (21% vs 1.6%, IRR 13.2, P = 0.013), but only 26% (n = 4) of participants with rashes discontinued treatment. There were no changes in systemic blood results.

CONCLUSIONS

Topical treatment using 4Jointz reduced pain but had no effect on inflammation or cartilage breakdown over 12 weeks of treatment.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials registry ACTRN12610000877088.

Grape seed proanthocyanidin extract attenuates allergic inflammation in murine models of asthma

BACKGROUND

Antioxidants have been suggested to alleviate the pathophysiological features of asthma, and grape seed proanthocyanidin extract (GSPE) has been reported to have powerful antioxidant activity.

PURPOSE

This study was performed to determine whether GSPE has a therapeutic effect on allergic airway inflammation in both acute and chronic murine model of asthma.

METHODS

Acute asthma model was generated by intraperitoneal sensitization of ovalbumin (OVA) with alum followed by aerosolized OVA challenges, whereas chronic asthma model was induced by repeated intranasal challenges of OVA with fungal protease twice a week for 8 weeks. GSPE was administered by either intraperitoneal injection or oral gavage before OVA challenges. Airway hyperresponsiveness (AHR) was measured, and airway inflammation was evaluated by bronchoalveolar lavage (BAL) fluid analysis and histopathological examination of lung tissue. Lung tissue levels of various cytokines, chemokines, and growth factors were analyzed by quantitative polymerase chain reaction and ELISA. Glutathione assay was done to measure oxidative burden in lung tissue.

RESULTS

Compared to untreated asthmatic mice, mice treated with GSPE showed significantly reduced AHR, decreased inflammatory cells in the BAL fluid, reduced lung inflammation, and decreased IL-4, IL-5, IL-13, and eotaxin-1 expression in both acute and chronic asthma models. Moreover, airway subepithelial fibrosis was reduced in the lung tissue of GSPE-treated chronic asthmatic mice compared to untreated asthmatic mice. Reduced to oxidized glutathione (GSH/GSSG) ratio was increased after GSPE treatment in acute asthmatic lung tissue.

CONCLUSION

GSPE effectively suppressed inflammation in both acute and chronic mouse models of asthma, suggesting a potential role of GSPE as a therapeutic agent for asthma.

Grape seed proanthocyanidin extract ameliorates monosodium iodoacetate-induced osteoarthritis

Osteoarthritis (OA) is an age-related joint disease that is characterized by degeneration of articular cartilage and chronic pain. Oxidative stress is considered one of the pathophysiological factors in the progression of OA. We investigated the effects of grape seed proanthocyanidin extract (GSPE), which is an antioxidant, on monosodium iodoacetate (MIA)-induced arthritis of the knee joint of rat, which is an animal model of human OA. GSPE (100 mg/kg or 300 mg/kg) or saline was given orally three times per week for 4 weeks after the MIA injection. Pain was measured using the paw withdrawal latency (PWL), the paw withdrawal threshold (PWT) and the hind limb weight bearing ability. Joint damage was assessed using histological and microscopic analysis and microcomputerized tomography. Matrix metalloproteinase-13 (MMP13) and nitrotyrosine were detected using immunohistochemistry. Administration of GSPE to the MIA-treated rats significantly increased the PWL and PWT and this resulted in recovery of hind paw weight distribution (P < 0.05). GSPE reduced the loss of chondrocytes and proteoglycan, the production of MMP13, nitrotyrosine and IL-1β and the formation of osteophytes, and it reduced the number of subchondral bone fractures in the MIA-treated rats. These results indicate that GSPE is antinociceptive and it is protective against joint damage in the MIA-treated rat model of OA. GSPE could open up novel avenues for the treatment of OA.

Modulation of the oxidative stress and inflammatory cytokine response by thymoquinone in the collagen induced arthritis in Wistar rats

Thymoquinone (TQ) is the major active compound derived from Nigella sativa. Our aim of this work was to evaluate the antioxidant and antiarthritic activity of TQ in Wistar rat by collagen induced arthritis (CIA). TQ was administered at a dose of 5mgkg(-1) body weight once daily for 21days. The effects of treatment in the rats were assessed by biochemical (articular elastase, MPO, LPO, GSH, catalase, SOD and NO), inflammatory mediators (IL-1β, IL-6, TNF-α, IL-10, IFN-γ and PGE(2)) and histological studies in joints. TQ was effective in bringing significant changes on all the parameters (articular elastase, MPO, LPO, GSH, catalase, SOD and NO) studied. Oral administration of TQ resulted in significantly reduced the levels of pro-inflammatory mediators (IL-1β, IL-6, TNF-α, IFN-γ and PGE(2)) and increased level of IL-10. The protective effects of TQ against RA were also evident from the decrease in arthritis scoring and bone histology. In conclusion, the fact that TQ abolished a number of factors known to be involved in RA pathogenesis indicates that the administration of thymoquinone may have potential value in the treatment of inflammatory disease.