Anti-inflammatory effects of new catechin derivatives in a hapten-induced mouse contact dermatitis model

Planar catechin increases bone mass by regulating differentiation of osteoclasts in mice

OBJECTIVES

While catechins have been reported to exhibit potential to benefit osteoporosis patients, the effects of planar catechin (PCat), synthesized during the development of drugs for Alzheimer's disease, have not been clearly elucidated. Here, we examined the effects of PCat on mouse bone metabolism both in vivo and in vitro.

METHODS

Six week old female mice were orally administered PCat (30 mg/kg) every other day for four weeks, and their femurs were analyzed using micro-computed tomography imaging. Osteoclasts and osteoblasts were collected from mice and cultured with PCat. Subsequently, osteoclast formation and differentiation and osteoblast differentiation were observed.

RESULTS

Mice orally administered PCat displayed significantly increased femur bone mass compared to the control group. Quantitative polymerase chain reaction findings indicated that PCat addition to osteoclast progenitor cultures suppressed osteoclast formation and decreased osteoclast marker expression without affecting the proliferative potential of the osteoclast progenitor cells. Addition of PCat to osteoblast cultures increased osteoblast marker expression.

CONCLUSIONS

PCat inhibits osteoclast differentiation and promotes osteoblast differentiation, resulting in increased bone mass in mice. These results suggest that PCat administration is a promising treatment option for conditions associated with bone loss, including osteoporosis.

Combining nano-curcumin with catechin improves COVID-19-infected patient's inflammatory conditions

AIMS

A hyperinflammatory condition is brought on by the development of Coronavirus disease 2019 (COVID-19), which is characterized by an elevation of T helper (Th) 17 cells, high levels of pro-inflammatory cytokines, and a depletion of regulatory T (Treg) cells.

METHODS

In this research, we examined the effect of nano-curcumin and catechin on the TCD4+, TCD8+, Th17, and Treg cells and their associated factors in COVID-19 patients. For this purpose, 160 (50 patients excluded during the study) COVID-19 patients were divided into four groups: placebo, nano-curcumin, catechin, and nano-curcumin + catechin. The frequency of TCD4+, TCD8+, Th17, and Treg cells, the gene expression of transcription factors (STAT3, RORt, and FoxP3) relevant to Th17 and Treg, as well as the serum levels of cytokines (IL-6, IL17, IL1-b, IL-10, and TGF-), were all evaluated intra- and inter-group, before and after treatment, in all groups.

RESULTS

Our study showed that TCD4 + and TCD8 + cells were significantly higher in the nano-curcumin + catechin group compared to the control group, whereas Th17 was lower than the initial value. Furthermore, compared to the placebo-received group, cytokines and transcription factors associated with Th17 were significantly lower in the nano-curcumin + catechin group. Additionally, combined therapy increased Treg cells and transcription factors compared to the placebo group.

CONCLUSION

Overall, our results show that combining nano-curcumin with catechin has a more notable impact on the enhancement of TCD4+, TCD8+, and Treg cells, as well as a decrease in Th17 cells and their mediators, suggesting a promising combination therapy in reducing the inflammatory conditions of COVID-19 infected patients.

Possible Mechanisms of Oxidative Stress-Induced Skin Cellular Senescence, Inflammation, and Cancer and the Therapeutic Potential of Plant Polyphenols

As the greatest defense organ of the body, the skin is exposed to endogenous and external stressors that produce reactive oxygen species (ROS). When the antioxidant system of the body fails to eliminate ROS, oxidative stress is initiated, which results in skin cellular senescence, inflammation, and cancer. Two main possible mechanisms underlie oxidative stress-induced skin cellular senescence, inflammation, and cancer. One mechanism is that ROS directly degrade biological macromolecules, including proteins, DNA, and lipids, that are essential for cell metabolism, survival, and genetics. Another one is that ROS mediate signaling pathways, such as MAPK, JAK/STAT, PI3K/AKT/mTOR, NF-κB, Nrf2, and SIRT1/FOXO, affecting cytokine release and enzyme expression. As natural antioxidants, plant polyphenols are safe and exhibit a therapeutic potential. We here discuss in detail the therapeutic potential of selected polyphenolic compounds and outline relevant molecular targets. Polyphenols selected here for study according to their structural classification include curcumin, catechins, resveratrol, quercetin, ellagic acid, and procyanidins. Finally, the latest delivery of plant polyphenols to the skin (taking curcumin as an example) and the current status of clinical research are summarized, providing a theoretical foundation for future clinical research and the generation of new pharmaceuticals and cosmetics.

Antioxidant Effects of Bioactive Glasses (BGs) and Their Significance in Tissue Engineering Strategies

Elevated levels of oxidative stress are usually observed following injuries, leading to impaired tissue repair due to oxidation-related chronic inflammation. Several attempts have been made to manage this unfavorable situation, and the use of biomaterials with antioxidant activity is showing great promise in tissue engineering and regenerative medicine approaches. Bioactive glasses (BGs) are a versatile group of inorganic substances that exhibit an outstanding regenerative capacity for both hard and soft damaged tissues. The chemical composition of BGs provides a great opportunity for imparting specific biological activities to them. On this point, BGs may easily become antioxidant substances through simple physicochemical modifications. For example, particular antioxidant elements (mostly cerium (Ce)) can be added to the basic composition of the glasses. On the other hand, grafting natural antioxidant substances (e.g., polyphenols) on the BG surface is feasible for making antioxidant substitutes with promising results in vitro. Mesoporous BGs (MBGs) were demonstrated to have unique merits compared with melt-derived BGs since they make it possible to load antioxidants and deliver them to the desired locations. However, there are actually limited in vivo experimental studies on the capability of modified BGs for scavenging free radicals (e.g., reactive oxygen species (ROS)). Therefore, more research is required to determine the actual potential of BGs in decreasing oxidative stress and subsequently improving tissue repair and regeneration. The present work aims to highlight the potential of different types of BGs in modulating oxidative stress and subsequently improving tissue healing.

Evaluation of the healing properties of Garcinia brasiliensis extracts in a cutaneous wound model

ETHNOPHARMACOLOGICAL RELEVANCE

Wound healing is a complex process that can leave pathological scars, especially in case of infections from opportunistic microorganisms. In this context, herbal medicines open up great possibilities for investigation. One of the species of interest native to Brazil is Garcinia brasiliensis ("bacupari"). Traditionally known for treating wounds and ulcers, G. brasiliensis presents anti-inflammatory, antioxidant and antimicrobials properties. But, its wound healing profile in experimental models, in order to validate its efficacy, is still litle studied.

AIM OF THE STUDY

Thus, the objective of this work was to evaluate, in an infected cutanous wound model, the potential of formulations incorporated with G. brasiliensis leaves extracts.

MATERIALS AND METHODS

Crude extract (CE), Ethyl Acetate Fraction (EAF) and Hexanic Fraction (HF) were submitted to phytochemical assays, high performance thin layer chromatography (HTPLC) and cytotoxicity studies. CE and EAF were also tested for microbicidal properties and incorporated in cream and gel formulations at 10% concentration. After stability testing, the gel formulations with CE or EAF at 10% were selected and applied to skin wounds infected or not with Staphylococcus aureus in Wistar rats. The healing potenttial of the extracts was verified by the expression of the protein Annexin A1 (AnxA1), related to the processes of inflammation and antifibrotic function, the cells immunostaining for Gasdermin-D (GSDM-D), a marker of pyroptotic cell death, and the dosage of interleukin-10 (IL-10) and monocyte chemotactic protein (MCP)-1 inflammatory mediators.

RESULTS

Phytochemical studies indicated the presence of compounds of pharmacological interest, including Catechin, Quercetin and Berberine in addition to low cytotoxicity of CE and EAF at 10%. After the 6-day topical treatments, CE and EAF gel formulations demonstrated to control the pruritus formation process. The treatments decreased AnxA1 expression and the amount of cells immunostained for GSDM-D, and increased the expression of MCP-1 in infected wounds.

CONCLUSIONS

Together, the results show important anti-inflammatory profile and skin healing potential of CE and EAF from G. brasiliensis leaves, even in infected lesions, with therapeutic perspectives.

Two new catechins from Zijuan green tea enhance the fitness and lifespan of Caenorhabditis elegans via insulin-like signaling pathways

Green tea polyphenols show positive effects on human health and longevity. However, knowledge of the antiaging properties of green tea is limited to the major catechin epigallocatechin gallate (EGCG). The search for new ingredients in tea with strong antiaging activity deserves further study. Here we isolated and identified two new catechins from Zijuan green tea, named zijuanin E (1) and zijuanin F (2). Their structures were identified by extensive high-resolution mass spectroscopy (HR-MS), nuclear magnetic resonance (NMR), ultraviolet-vis (UV), infrared (IR) and circular dichroism (CD) spectroscopic analyses, and their ¹³C NMR and CD data were calculated. We used the nematode Caenorhabditis elegans (C. elegans) to analyze the health benefits and longevity effects of 1 and 2. Compounds 1 and 2 (100 μM) remarkably prolonged the lifespan of C. elegans by 67.2% and 56.0%, respectively, delaying the age-related decline of phenotypes, enhancing stress resistance, and reducing ROS and lipid accumulation. Furthermore, 1 and 2 did not affect the lifespan of daf-16, daf-2, sir-2.1, and skn-1 mutant worms, suggesting that they might work via the insulin/IGF and SKN-1/Nrf2 signaling pathways. Meanwhile, 1 and 2 also exhibited strong antioxidant activity in vitro. Surface plasmon resonance (SPR) evidence suggests that zijuanins E and F have strong human serum albumin (HSA) binding ability. Together, zijuanins E and F represent a new valuable class of tea components that promote healthspan and could be developed as potential dietary therapies against aging.

Ceratonia siliqua leaves ethanol extracts exert anti-nociceptive and anti-inflammatory effects

Background

Ceratonia siliqua L. (Leguminosae) has neuroprotective, mutagenic, hypotensive, anti-bacterial, hypoglycaemic, and anti-inflammatory effects through extracts from its leaves. Therefore, the aim of this study is to assess the anti-nociceptive activity of ethanol extracts of Ceratonia siliqua leaves.

Methods

Ethanol extract of Ceratonia siliqua leaves were studied using well-established animal models of inflammation and pain. A hot plate latency assay (55 °C) was used to assess the analgesic effect of 10, 31.6, 100, and 316 mg/kg doses of ethanol extracts in addition to paw licking time in early and late phase using a formalin-induced paw licking assay test. Paw oedema induction using carrageenan and cotton pellet granuloma assays were used to assess the anti-inflammatory effect of 10, 31.6, 100, and 316 mg/kg doses of ethanol extract.

Results

The ethanol extract of Ceratonia siliqua leaves reduces paw licking time in early and late phase after formalin injection. The same effect was also observed when the hotplate test was performed. Ethanol extract of Ceratonia siliqua leaves caused dose dependent inhibition in paw oedema after the injection of carrageenan and cotton pellet granuloma in mice. These effects were not antagonized when opioid receptors were blocked by naloxone (5 mg/kg). The preliminary phytochemical analysis of the ethanol extract of Ceratonia siliqua leaves showed the presence of tannins, alkaloids, flavonoids and terpenoids.

Conclusion

The present data indicate that ethanol extract of Ceratonia siliqua leaves might possess anti-inflammatory and anti-nociception properties and should be considered for further therapeutic research.

Integrated transcriptome and metabolome analyses revealed regulatory mechanisms of flavonoid biosynthesis in Radix Ardisia

Background

Radix Ardisia (Jab Bik Lik Jib) is a common Miao medicine and is widely distributed in the Guizhou region of southern China. The botanical origin of Radix Ardisia includes the dry root and rhizome of Ardisia Crenata Sims (ACS) or Ardisia Crispa (Thunb.) A.DC. (AC), which are closely related species morphologically. However, the secondary metabolites in their roots are different from one another, especially the flavonoids, and these differences have not been thoroughly explored at the molecular level. This project preliminarily identified regulatory molecular mechanisms in the biosynthetic pathways of the flavonoids between ACS and AC using a multi-omics association analysis.

Methods

In this study, we determined the total levels of saponin, flavonoid, and phenolic in Radix Ardisia from different origins. Integrated transcriptome and metabolome analyses were used to identify the differentially expressed genes (DEGs) and differentially expressed metabolites (DEM). We also performed conjoint analyses on DEGs and DEMs to ascertain the degree pathways, and explore the regulation of flavonoid biosynthesis.

Results

The total flavonoid and phenolic levels in ACS were significantly higher than in AC (P < 0.05). There were 17,685 DEGs between ACS vs. AC, 8,854 were upregulated and 8,831 were downregulated. Based on this, we continued to study the gene changes in the flavonoid biosynthesis pathway, and 100 DEGs involving flavonoid biosynthesis were differentially expressed in ACS and AC. We validated the accuracy of the RNA-seq data using qRT-PCR. Metabolomic analyses showed that 11 metabolites were involved in flavonoid biosynthesis including: Naringenin, Luteolin, Catechin, and Quercetin. A conjoint analysis of the genome-wide connection network revealed the differences in the types and levels of flavonoid compounds between ACS and AC. The correlation analysis showed that Naringenin, Luteolin, Catechin, and Quercetin were more likely to be key compounds in the flavonoid biosynthesis pathway also including 4CL, AOMT, CHS, CHI, DFR, F3'5'H, FLS, and LAR.

Conclusions

This study provides useful information for revealing the regulation of flavonoid biosynthesis and the regulatory relationship between metabolites and genes in the flavonoid biosynthesis pathway in Radix Ardisia from different origins.

Spatholobus suberectus Dunn Water Extract Ameliorates Atopic Dermatitis–Like Symptoms by Suppressing Proinflammatory Chemokine Production In Vivo and In Vitro

S. patholobus suberectus Dunn, a traditional Chinese herbal medicine, has various pharmacological activities, such as anti-inflammatory properties. However, to the best of our knowledge, its therapeutic effect on atopic dermatitis (AD) has not been investigated. In this study, we explored the effect of S. suberectus Dunn water extract (SSWex) on AD in vivo and in vitro. In Dermatophagoides farina extract (DfE)–treated NC/Nga mice, the oral administration of SSWex alleviated AD-like symptoms, such as ear thickness, dermatitis score, epidermal thickness, immune cell infiltration, and levels of AD-related serum parameters (immunoglobulin E, histamine, and proinflammatory chemokines). In HaCaT cells, the production of proinflammatory chemokines induced by interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) was inhibited by SSWex pretreatment. SSWex treatment inhibited the phosphorylation of mitogen-activated protein kinase and activation and translocation of transcriptional factors, such as signal transducer and activator of transcription 1 and nuclear factor kappa B in IFN-γ/TNF-α–stimulated HaCaT cells. These results indicate that SSWex may be developed as an efficient therapeutic agent for AD.

Dynamic Microbial Shifts and Signatures of Long-Term Remission in Allergic Rhinitis After an Herbal Formula Treatment

A mixed Chinese herbal formula, Xiao-Qing-Long-Decoction (XQLD), may contribute to sustained remission in allergic rhinitis (AR), but it is unknown which factors determine such long-term effect. Here, we aimed to identify bacterial signatures associated with sustained remission. To this end, samples from AR patients at four different times were analyzed to compare the dynamic bacterial community and structure shifts. Diversity indices Chao1 showed significant difference across different time (p<0.05), and the Kruskal-Wallis test identified that Dialister (OTU_31), Roseburia (OTU_36), Bacteroides (OTU_22), Bacteroides (OTU_2040), and Prevotella_9 (OTU_5) were the significant differential bacterial taxa (p<0.05). These distinctive genera were significantly associated with the change of AR clinical indices and the predicted functional pathways such as PPAR signaling pathway, peroxisome, and citrate cycle (TCA cycle) (p<0.05), indicating that they may be important bacterial signatures involving in the sustained remission in AR (p<0.05). Besides, lower Firmicutes/Bacteroidetes (F/B) ratio at 6 months follow-up may also contribute to the long-term remission of AR. No seriously adverse events and safety concerns were observed in this study. In conclusion, XQLD is a meaningful, long-term efficient and safe medication for AR treatment. The underlying mechanisms of sustained remission in AR after XQLD treatment may be associated with the dynamic alteration of featured gut bacteria taxa.

Catechins: Therapeutic Perspectives in COVID-19-Associated Acute Kidney Injury

Data obtained from several intensive care units around the world have provided substantial evidence of the strong association between impairment of the renal function and in-hospital deaths of critically ill COVID-19 patients, especially those with comorbidities and requiring renal replacement therapy (RRT). Acute kidney injury (AKI) is a common renal disorder of various etiologies characterized by a sudden and sustained decrease of renal function. Studies have shown that 5–46% of COVID-19 patients develop AKI during hospital stay, and the mortality of those patients may reach up to 100% depending on various factors, such as organ failures and RRT requirement. Catechins are natural products that have multiple pharmacological activities, including anti-coronavirus and reno-protective activities against kidney injury induced by nephrotoxic agents, obstructive nephropathies and AKI accompanying metabolic and cardiovascular disorders. Therefore, in this review, we discuss the anti-SARS-CoV-2 and reno-protective effects of catechins from a mechanistic perspective. We believe that catechins may serve as promising therapeutics in COVID-19-associated AKI due to their well-recognized anti-SARS-CoV-2, and antioxidant and anti-inflammatory properties that mediate their reno-protective activities.

Hepatoprotective Effects of Different Extracts From Triphala Against CCl4-Induced Acute Liver Injury in Mice

Background:Triphala is a traditional polyherbal formula used in Indian Ayurvedic and Chinese Tibetan medicine. A wide range of biological activities have been attributed to Triphala, but the impact of various extraction methods on efficacy has not been determined.

Purpose: The study aimed to evaluate Triphala extracts obtained by various methods for their hepatoprotective effects and molecular mechanisms in a mouse model of carbon tetrachloride (CCl₄)-induced liver injury.

Methods: HPLC fingerprinting was used to characterize the chemical characteristics of Triphala extracts obtained by (a) 0.5 h ultrasonication, (b) 2 h reflux, and (c) 4 h reflux. Hepatoprotective efficacy was evaluated in a mouse model of CCl₄-induced liver damage. Serum levels of alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured, as well as the liver antioxidant and inflammatory markers malondialdehyde superoxide dismutase glutathione peroxidase (GSH-Px), TNF-α, and IL-6. Gene and protein expression of Nrf-2 signaling components Nrf-2, heme oxygenase (HO-1), and NADPH Quinone oxidoreductase (NQO-1) in liver tissue were evaluated by real-time PCR and western blotting.

Results: Chemical analysis showed a clear difference in content between extracts produced by ultrasonic and reflux methods. The pharmacological analysis showed that all three Triphala extracts reduced ALT, AST, MDA, TNF-α, and IL-6 levels and increased SOD and GSH-Px. Triphala extracts also induced transcript and protein expression of Nrf-2, HO-1, and NQO-1.

Conclusion: Triphala extract prevents CCl₄-induced acute liver injury. The ultrasonic extract of Triphala was most effective, suggesting that hepatoprotection may be related to the larger tannins via activation of Nrf-2 signaling.

Evaluation of bioactive compounds, phytochemicals profile and antioxidant potential of the aqueous and ethanolic extracts of some traditional fruit tree leaves used in Brazilian folk medicine

The aim of this study was to analyze eight selected species of leaves, used in the traditional medicine of the Northeast region of Brazil obtained from several fruit trees (grageru, soursop, jambolanum, passion fruit, insulin, nogueira, pedra ume kaá and stévia), regarding their polyphenols contents and antioxidant activity. Condensed and hydrolysable tannins, phenolics and flavonoids contents were determined and the antioxidant activities measured by ABTS, FRAP and ORAC assays. Organic acids were analyzed by HPLC-DAD system. Phenolic compounds of aqueous and ethanolic extracts were determined by UHPLC-DAD-MS. The results revealed high contents of total phenolics (13.34 ± 0.19 - 127.65 ± 0.21 mg.g^-1 of GAE:QE (2:1) of sample) and flavonoids (12.30 ± 0.42 - 71.79 ± 0.00 mg.g^-1 QE of sample). The ABTS results exhibited extraordinary activity in the extracts (74.48 ± 6.23 - 1487.33 ± 2.67 µmol Trolox.g^-1 of sample). Acids quinic, tartaric, citric, gallic, chlorogenic, p-coumaric, ferulic and vanillic along with naringenin, rutin, vanillin, catechin, epicatechin, kaempferol were the most important compounds. Thus, these leaves extracts may be considered as sources of phenolics compounds having a high potential as natural antioxidants. In addition, the polyphenols present in these leaves have many beneficial effects and can also be used in medicinal and nutraceuticals products with enhanced bioactivities.

In vitro anti-inflammatory properties of honey flavonoids: A review

Honey is a natural ready-to-eat product rich in flavonoids, which is known by the wound healing properties due to both antibacterial and antioxidant activity. Flavonoids mitigate inflammatory processes, and thus it could currently support studies of anti-inflammatory potential of honeys. In this review, in vitro anti-inflammatory properties of flavonoids found in honey were prioritized. Mechanistic information of specific isolated flavonoids as modulators of inflammatory processes are summarized aiming to stimulate studies regarding the action of honey in inflammatory events. Lastly, a structure-activity relationship (SAR) of flavonoids was also included. Flavonoids found in honey have demonstrated antioxidant properties and ability to inhibit pro-inflammatory enzymes such as COX, LOX, iNOS, and pro-inflammatory mediators, including nitric oxide, cytokines and chemokines. Transcriptional factors such as NF-κB are also modulated by flavonoids, controlling the expression of several inflammatory mediators. SAR studies demonstrate the effect of flavonoids in the prevention of inflammatory cascades. Despite the promising reports of in vitro anti-inflammatory activity, well-designed clinical trials need yet to be performed to confirm the benefits of honeys from different botanical sources in diseases that include episodes of inflammation.

Catechins as Model Bioactive Compounds for Biomedical Applications

Research regarding polyphenols has gained prominence over the years because of their potential as pharmacological nutrients. Most polyphenols are flavanols, commonly known as catechins, which are present in high amounts in green tea. Catechins are promising candidates in the field of biomedicine. The health benefits of catechins, notably their antioxidant effects, are related to their chemical structure and the total number of hydroxyl groups. In addition, catechins possess strong activities against several pathogens, including bacteria, viruses, parasites, and fungi. One major limitation of these compounds is low bioavailability. Catechins are poorly absorbed by intestinal barriers. Some protective mechanisms may be required to maintain or even increase the stability and bioavailability of these molecules within living organisms. Moreover, novel delivery systems, such as scaffolds, fibers, sponges, and capsules, have been proposed. This review focuses on the unique structures and bioactive properties of catechins and their role in inflammatory responses as well as provides a perspective on their use in future human health applications.

Synthesis and activity of a coumarin-based fluorescent probe for hydroxyl radical detection

As a type of reactive oxygen species (ROS), hydroxyl radical (·OH) is closely associated with many kinds of diseases. The present study aimed to develo p a novel OH fluorescent probe based on coumarin, a new compound that has not been previously reported. This probe exhibited good linear range and selectivity for ·OHl, and is able to avoid interference from some metal ions and other kinds of ROS (H₂ O₂ , O₂ ^.- , ¹ O₂ , and HClO). Meanwhile, this probe has been used to evaluate the ·OH-scavenging efficiency of different compounds, such as isopropyl alcohol, cytosine, uracil, Tempo, Glutathione (GSH), and dimethyl sulfoxide (DMSO). Therefore, the present study shows that this probe not only can effectively measure the level of ·OH, but also can assess the ·OH-scavenging efficiency of different compounds. Furthermore this current study suggested that following further optimization, this probe may be potentially applied in the diagnosis of oxidative stress in human body.