The protective activity of natural flavonoids against osteoarthritis by targeting NF-κB signaling pathway

Cathelicidin-BF regulates the AMPK/SIRT1/NF-κB pathway to ameliorate murine osteoarthritis: In vitro and in vivo studie

Osteoarthritis (OA) is a chronic degenerative disease with a significant prevalence that causes cartilage damage and can lead to disability. The main factors contributing to the onset and progression of OA include inflammation and degeneration of the extracellular matrix. Cathelicidin-BF (BF-30), a natural peptide derived from Bungarus fasciatus venom, has shown multiple important pharmacological effects. However, the action mechanism of BF-30 in OA treatment remains to be elucidated. In this research, X-ray and Safranin O staining were employed to evaluate the imageology and histomorphology differences in the knee joints of mice in vivo. Techniques such as Western blot analysis, RT-qPCR, ELISA, and immunofluorescence staining were applied to examine gene and protein level changes in in vitro experiments. It was found that BF-30 significantly decreased inflammation and enhanced extracellular matrix metabolism. For the first time, it was demonstrated that the positive effects of BF-30 are mediated through the activation of the AMPK/SIRT1/NF-κB pathway. Moreover, when BF-30 was co-administered with Compound C, an AMPK inhibitor, the therapeutic benefits of BF-30 were reversed in both in vivo and in vitro settings. In conclusion, the findings suggest that BF-30 could be a novel therapeutic agent for OA improvement.

Characterization of Secondary Metabolites of Leaf Buds from Some Species and Hybrids of Populus by Gas Chromatography Coupled with Mass Detection and Two-Dimensional High-Performance Thin-Layer Chromatography Methods with Assessment of Their Antioxidant Activity

Poplars provide medicinal raw plant materials used in pharmacy. Leaf buds are one of the herbal medicinal products collected from poplars, having anti-inflammatory and antiseptic properties, but there are no quality standards for their production and there is a need to determine their botanical sources. Therefore, the chemical compositions of the leaf buds from four species and varieties of poplars, Populus balsamifera, P. × berolinensis, P. × canadensis 'Marilandica', and P. wilsonii were investigated and compared using gas chromatography coupled with mass detection (GC-MS) and two-dimensional high-performance thin-layer chromatography (2D-HPTLC) in order to search for taxa characterized by a high content of biologically active compounds and with a diverse chemical composition that determines their therapeutic effects. The presence of 163 compounds belonging to the groups of flavonoids, phenolic acids derivatives, glycerides, and sesquiterpenes was revealed. Moreover, the conditions for the separation and identification of biologically active compounds occurring in analyzed leaf buds using 2D-HPTLC were optimized and used for metabolomic profiling of the studied poplars, enabling their fast and simple botanical identification. The total phenolic (TPC) and flavonoid (TFC) contents of examined extracts were determined and their antioxidant capacities were estimated by spectrophotometric DPPH, ABTS, and FRAP assays. Based on the analysis of phytochemicals and antioxidant activity, P. × berolinensis buds were selected as the raw plant material for medicinal purposes with the highest content of active compounds and the strongest antioxidant activity.

Glycyrrhizin alleviates varicellovirus bovinealpha 1-induced oxidative stress, inflammation, and apoptosis in MDBK cells by inhibiting NF-κB/NLRP3 axis through the Nrf2 signalling pathway

Varicellovirus bovinealpha 1 (BoAHV-1) is one of the crucial pathogens of bovine respiratory diseases, and its pathogenic mechanism involves oxidative stress, inflammation response, and apoptosis. Glycyrrhizin (GLY) possesses powerful antiviral, antioxidant, anti-inflammatory, and anti-apoptotic bioactivities. However, the anti-BoAHV-1 activity of GLY and its role in BoAHV-1-induced oxidative stress, inflammation, and apoptosis remain unclear. Therefore, the current study investigated the anti-BoAHV-1 effect of GLY and its ability to alleviate BoAHV-1-induced oxidative stress, inflammation, and apoptosis using an in vitro model (MDBK cells). Our results showed that BoAHV-1 titers significantly increased in MDBK cells after infection, and GLY reduced the BoAHV-1 titers in MDBK cells exposed to it. Furthermore, Interleukin (IL)-1β, IL-8, tumor necrosis factor (TNF)-α, phosphorylated NF-κB p65 (p-NF-κB p65), the NLR pyrin domain containing 3 (NLRP3), Caspase-1, and Cleaved Caspase-3 levels were significantly upregulated when MDBK cells were challenged with BoAHV-1. In BAY 11-7085 (a specific NF-κB inhibitor) treated MDBK cells, IL-1β, IL-8, TNF-α, p-NF-κB p65, NLRP3, Caspase-1, and Cleaved Caspase-3 levels were downregulated. Notably, GLY treatment had the same trend as the BAY 11-7085 treatment. Thus, these results suggested that GLY exerted anti-inflammatory and anti-apoptotic activities by blocking NF-κB/NLRP3 axis. In addition, after BoAHV-1 infection, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and p-NF-κB p65 and apoptosis rate were increased, and catalase (CAT) and glutathione peroxidase (GSH-Px) enzyme activities, as well as NF-E2-related nuclear factor erythroid-2 (Nrf2) protein expression were repressed. Compared with BoAHV-1-infected MDBK cells, GLY treatment significantly downregulated intracellular ROS, MDA, and p-NF-κB p65 levels and apoptotic rates and significantly increased intracellular CAT and GSH-Px enzyme activities and Nrf2 expression. Additionally, ML385 (a specific Nrf2 inhibitor) abolished the enhancing effect of GLY on Nrf2 and the attenuating effect on ROS, p-NF-κB p65, and apoptosis. These results suggested that GLY had an anti-BoAHV-1 effect and could mitigate BoAHV-1-induced oxidative stress, inflammation, and apoptosis by activating the Nrf2 signalling and restraining NF-κB/NLRP3 axis.

J-shaped association of dietary catechins intake with the prevalence of osteoarthritis and moderating effect of physical activity: an American population-based cohort study

Background

Catechins are a class of natural compounds with a variety of health benefits, The relationship between catechins and the prevalence of osteoarthritis (OA) is unknown. This study investigated the associations between daily intake of catechins and the prevalence of OA among American adults and assessed the moderating effect of physical activity (PA).

Methods

This study included 10,039 participants from the National Health and Nutrition Examination Survey (2007-2010,2017-2018). The logistic regression, weighted quantile sum (WQS) regression, and restricted cubic spline (RCS) regression models were conducted to explore the associations between daily intake of catechins and the prevalence of OA. Moreover, interaction tests were performed to assess the moderating effect of PA.

Results

After multivariable adjustment, the weighted multivariable logistic regression and RCS regression analyses revealed significant J-shaped non-linear correlations between intakes of epigallocatechin and epigallocatechin 3-gallate had significant associations with the prevalence of OA among in U.S. adults. WQS regression analysis showed that excessive epigallocatechin intake was the most significant risk factor for OA among all subtypes of catechins. In the interaction assay, PA showed a significant moderating effect in the relationship between epigallocatechin intake and OA prevalence.

Conclusions

The intake of gallocatechin and gallocatechin 3-gallate had a significant negative correlation with the prevalence of OA and the dose-response relationship was J-shaped.PA below 150 MET-min/week and the threshold intakes of 32.70mg/d for epigallocatechin and 76.24mg/d for epigallocatechin 3-gallate might be the targets for interventions to reduce the risk of developing OA.

Osteoarthritis in the Elderly Population: Preclinical Evidence of Nutrigenomic Activities of Flavonoids

Osteoarthritis (OA) is a degenerative joint disease that is age-related and progressive. It causes the destruction of articular cartilage and underlying bone, often aggravated by inflammatory processes and oxidative stresses. This pathology impairs the quality of life of the elderly, causing pain, reduced mobility, and functional disabilities, especially in obese patients. Phytochemicals with anti-inflammatory and antioxidant activities may be used for long-term treatment of OA, either in combination with current anti-inflammatories and painkillers, or as an alternative to other products such as glucosamine and chondroitin, which improve cartilage structure and elasticity. The current systematic review provides a comprehensive understanding of the use of flavonoids. It highlights chondrocyte, cartilage, and subchondral bone activities, with a particular focus on their nutrigenomic effects. The molecular mechanisms of these molecules demonstrate how they can be used for the prevention and treatment of OA in the elderly population. However, clinical trials are still needed for effective use in clinical practice.

Quinic acid ameliorates ulcerative colitis in rats, through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways

OBJECTIVE

In this study, the therapeutic effect of quinic acid (QA), which has anti-inflammatory activity, was investigated on acetic acid-induced colitis in male Wistar rats.

METHODS

Ulcerative colitis (UC) was induced in rats by acetic acid intrarectally, and the protective effects of QA in 10, 30, 60, and 100 mg/kg doses were investigated. Rats were treated for 5 days and their colon tissues were dissected out at the end. Macroscopic and histopathological examinations were performed in colon tissues. Also, the expression of inflammatory and apoptotic genes, including TLR4, IL-1β, INOS, IL-6, TNF-α, NF-κB, Caspase-3, Caspase-8, Bax, and Bcl-2, was measured. Biochemistry indices, such as malondialdehyde (MDA) and nitrite oxide (NO) content, in addition to, total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), and enzymes activities were also assessed.

RESULTS

Colitis increased the levels of MDA and NO, and enhanced the inflammatory and apoptotic gene expressions, while reducing the SOD and CAT enzymes activity, and TAC levels in the colitis rats. Also, results showed that colitis was associated with the infiltration of inflammatory cells, epithelium damage, and edema in colon tissue. QA significantly ameliorated histopathological indices, oxidative stress, inflammation, and apoptosis in colitis rats.

CONCLUSION

QA ameliorated UC through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways, which results in the reduction of colitis complications, including oxidative stress, inflammation, apoptosis and histopathological injuries in rats. Therefore it can be concluded, that QA exerts its therapeutic effects through antiapoptotic, antioxidant, and anti-inflammatory properties.

Effect of the Fermented Soy Q-CAN® Product on Biomarkers of Inflammation and Oxidation in Adults with Cardiovascular Risk, and Canonical Correlations between the Inflammation Biomarkers and Blood Lipids

Systemic low-grade inflammation plays a key role in the development of cardiovascular disease (CVD) but the process may be modulated by consuming fermented soy foods. Here, we aim to evaluate the effect of a fermented soy powder Q-CAN^® on inflammatory and oxidation biomarkers in subjects with cardiovascular risk. In a randomized crossover trial, 27 adults (mean age ± SD, 51.6 ± 13.5 y) with a mean BMI ± SD of 32.3 ± 7.3 kg/m² consumed 25 g daily of the fermented soy powder or an isoenergic control powder of sprouted brown rice for 12 weeks each. Between-treatment results showed a 12% increase in interleukin-1 receptor agonist (IL-1Ra) in the treatment group, whereas within-treatment results showed 23% and 7% increases in interleukin-6 (IL-6) and total antioxidant status (TAS), respectively. The first canonical correlation coefficient (r = 0.72) between inflammation markers and blood lipids indicated a positive association between high-sensitivity C-reactive protein (hsCRP) and IL-1Ra with LDL-C and a negative association with HDL-C that explained 62% of the variability in the biomarkers. These outcomes suggest that blood lipids and inflammatory markers are highly correlated and that ingestion of the fermented soy powder Q-CAN^® may increase IL-1Ra, IL-6, and TAS in individuals with CVD risk factors.