Supplementation with Tetrahydrocurcumin Enhances the Therapeutic Effects of Dexamethasone in a Murine Model of Allergic Asthma

Curcumin as a regulator of Th17 cells: Unveiling the mechanisms

Curcumin, a polyphenol natural product derived from turmeric, possesses diverse pharmacological effects due to its interactions with various cells and molecules. Recent studies have highlighted its immunomodulatory properties, including its impact on immune cells and mediators involved in immune responses. Th17 cells play a crucial role in promoting immune responses against extracellular pathogens by recruiting neutrophils and inducing inflammation. These cells produce inflammatory cytokines such as TNF-α, IL-21, IL-17A, IL-23, IL-17F, IL-22, and IL-26. Curcumin has been shown to significantly inhibit the proliferation of Th17 cells and reduce the production of inflammatory cytokines, including TNF-α, IL-22, and IL-17. This review aims to assess the effectiveness of curcumin and its underlying mechanisms in modulating Th17 cells.

The role of tetrahydrocurcumin in disease prevention and treatment

In recent decades, natural compounds derived from herbal medicine or dietary sources have played important roles in prevention and treatment of various diseases and have attracted more and more attention. Curcumin, extracted from the Curcumae Longae Rhizoma and widely used as food spice and coloring agent, has been proven to possess high pharmacological value. However, the pharmacological application of curcumin is limited due to its poor systemic bioavailability. As a major active metabolite of curcumin, tetrahydrocurcumin (THC) has higher bioavailability and stability than curcumin. Increasing evidence confirmed that THC had a wide range of biological activities and significant treatment effects on diseases. In this paper, we reviewed the research progress on the biological activities and therapeutic potential of THC on different diseases such as neurological disorders, metabolic syndromes, cancers, and inflammatory diseases. The extensive pharmacological effects of THC involve the modulation of various signaling transduction pathways including MAPK, JAK/STAT, NF-κB, Nrf2, PI3K/Akt/mTOR, AMPK, Wnt/β-catenin. In addition, the pharmacokinetics, drug combination and toxicology of THC were discussed, thus providing scientific basis for the safe application of THC and the development of its dietary supplements and drugs.

Dietary Polyphenols, Plant Metabolites, and Allergic Disorders: A Comprehensive Review

Given the ongoing rise in the occurrence of allergic disorders, alterations in dietary patterns have been proposed as a possible factor contributing to the emergence and progression of these conditions. Currently, there is a significant focus on the development of dietary therapies that utilize natural compounds possessing anti-allergy properties. Dietary polyphenols and plant metabolites have been intensively researched due to their well-documented anti-inflammatory, antioxidant, and immunomodulatory characteristics, making them one of the most prominent natural bioactive chemicals. This study seeks to discuss the in-depth mechanisms by which these molecules may exert anti-allergic effects, namely through their capacity to diminish the allergenicity of proteins, modulate immune responses, and modify the composition of the gut microbiota. However, further investigation is required to fully understand these effects. This paper examines the existing evidence from experimental and clinical studies that supports the idea that different polyphenols, such as catechins, resveratrol, curcumin, quercetin, and others, can reduce allergic inflammation, relieve symptoms of food allergy, asthma, atopic dermatitis, and allergic rhinitis, and prevent the progression of the allergic immune response. In summary, dietary polyphenols and plant metabolites possess significant anti-allergic properties and can be utilized for developing both preventative and therapeutic strategies for targeting allergic conditions. The paper also discusses the constraints in investigating and broad usage of polyphenols, as well as potential avenues for future research.

Dietary Polyphenols-Natural Bioactive Compounds with Potential for Preventing and Treating Some Allergic Conditions

In light of the constantly increasing prevalence of allergic diseases, changes in dietary patterns have been suggested as a plausible environmental explanation for the development and progression of these diseases. Nowadays, much attention has been paid to the development of dietary interventions using natural substances with anti-allergy activities. In this respect, dietary polyphenols have been studied extensively as one of the most prominent natural bioactive compounds with well-documented anti-inflammatory, antioxidant, and immunomodulatory properties. This review aims to discuss the mechanisms underlying the potential anti-allergic actions of polyphenols related to their ability to reduce protein allergenicity, regulate immune response, and gut microbiome modification; however, these issues need to be elucidated in detail. This paper reviews the current evidence from experimental and clinical studies confirming that various polyphenols such as quercetin, curcumin, resveratrol, catechins, and many others could attenuate allergic inflammation, alleviate the symptoms of food allergy, asthma, and allergic rhinitis, and prevent the development of allergic immune response. Conclusively, dietary polyphenols are endowed with great anti-allergic potential and therefore could be used either for preventive approaches or therapeutic interventions in relation to allergic diseases. Limitations in studying and widespread use of polyphenols as well as future research directions are also discussed.

Oxidative Stress, Reductive Stress and Antioxidants in Vascular Pathogenesis and Aging

This review is focused on the mechanisms that regulate health, disease and aging redox status, the signal pathways that counteract oxidative and reductive stress, the role of food components and additives with antioxidant properties (curcumin, polyphenols, vitamins, carotenoids, flavonoids, etc.), and the role of the hormones irisin and melatonin in the redox homeostasis of animal and human cells. The correlations between the deviation from optimal redox conditions and inflammation, allergic, aging and autoimmune responses are discussed. Special attention is given to the vascular system, kidney, liver and brain oxidative stress processes. The role of hydrogen peroxide as an intracellular and paracrine signal molecule is also reviewed. The cyanotoxins β-N-methylamino-l-alanine (BMAA), cylindrospermopsin, microcystins and nodularins are introduced as potentially dangerous food and environment pro-oxidants.

The Effects of Curcumin on Inflammasome: Latest Update

Curcumin, a traditional Chinese medicine extracted from natural plant rhizomes, has become a candidate drug for the treatment of different diseases due to its anti-inflammatory, anticancer, antioxidant, and antibacterial activities. Curcumin is generally beneficial to improve human health with anti-inflammatory and antioxidative properties as well as antitumor and immunoregulatory properties. Inflammasomes are NLR family, pyrin domain-containing 3 (NLRP3) proteins that are activated in response to a variety of stress signals and that promote the proteolytic conversion of pro-interleukin-1β and pro-interleukin-18 into active forms, which are central mediators of the inflammatory response; inflammasomes can also induce pyroptosis, a type of cell death. The NLRP3 protein is involved in a variety of inflammatory pathologies, including neurological and autoimmune disorders, lung diseases, atherosclerosis, myocardial infarction, and many others. Different functional foods may have preventive and therapeutic effects in a wide range of pathologies in which inflammasome proteins are activated. In this review, we have focused on curcumin and evidenced its therapeutic potential in inflammatory diseases such as neurodegenerative diseases, respiratory diseases, and arthritis by acting on the inflammasome.

-Sitosterol inhibits ovalbumin-induced asthma-related inflammation by regulating dendritic cells

AIM

To investigate the effects of β-sitosterol (B-SIT) and the underlying mechanisms of action in an ovalbumin-induced rat model of asthma.

METHODS

The pathological and morphological changes in lung and tracheal tissues were observed by H&E, PAS, and Masson's staining. The levels of IgE, TNF-α, and IFN-γ in the bronchoalveolar lavage fluid (BALF) and those of IL-6, TGF-β1, and IL-10 in serum were measured by ELISA. The relative expression levels of IL-5, IL-13, IL-21, CD11c, CD80, and CD86 mRNA in lung tissue were examined by RT-qPCR. Flow cytometry was performed to assess the levels of immune cells, including macrophages and neutrophils in spleen tissue and Th cells, Tc cells, NK cells, and DCs in peripheral blood. The protein expression levels of CD68, MPO, CD11c, CD80, and CD86 were detected by western blotting or immunohistochemistry.

RESULTS

B-SIT improved the injury in OVA-induced pathology, decreased the levels of inflammatory factors of IgE, TNF-α, IL-6, TGF-β1, IL-5, IL-13, and IL-21 and increased the levels of IFN-γ and IL-10. In addition, B-SIT decreased the number of macrophages and neutrophils and the relative expression levels of CD68 and MPO in the spleen. Moreover, B-SIT increased the number of Th cells, Tc cells, NK cells, and DCs in peripheral blood and upregulated the levels of CD11c, CD80, and CD86 in the spleen and lung.

CONCLUSION

B-SIT improved symptoms in a rat model of asthma likely via the inhibition of inflammation by regulating dendritic cells.

Therapeutic potency of curcumin for allergic diseases: A focus on immunomodulatory actions

In light of increasing research evidence on the molecular mechanisms of allergic diseases, the crucial roles of innate and acquired immunity in the disease's pathogenesis have been well highlighted. In this respect, much attention has been paid to the modulation of unregulated and unabated inflammatory responses aiming to suppress pathologic immune responses in treating allergic diseases. One of the most important natural compounds with a high potency of immune modulation is curcumin, an active polyphenol compound derived from turmeric, Curcuma longa L. Curcumin's immunomodulatory action mainly arises from its interactions with an extensive collection of immune cells such as mast cells, eosinophils, epithelial cells, basophils, neutrophils, and lymphocytes. Up to now, there has been no detailed investigation of curcumin's immunomodulatory actions in allergic diseases. So, the present review study aims to prepare an overview of the immunomodulatory effects of curcumin on the pathologic innate immune responses and dysregulated functions of T helper (T_H) subtypes, including T_H1, T_H2, T_H17, and regulator T cells (Tregs) by gathering evidence from several studies of In-vitro and In-vivo. As the second aim of the present review, we also discuss some novel strategies to overcome the limitation of curcumin in clinical use. Finally, this review also assesses the therapeutic potential of curcumin regarding its immunomodulatory actions in allergic diseases.

Tetrahydrocurcumin improves lipopolysaccharide-induced myocardial dysfunction by inhibiting oxidative stress and inflammation via JNK/ERK signaling pathway regulation

BACKGROUND

Acute myocardial dysfunction in patients with sepsis is attributed to oxidative stress, inflammation, and cardiomyocyte loss; however, specific drugs for its prevention are still lacking. Tetrahydrocurcumin (THC) has been proven to contribute to the prevention of various cardiovascular diseases by decreasing oxidative stress and inflammation. This study was performed to investigate the functions and mechanism of action of THC in septic cardiomyopathy.

METHODS

After the oral administration of THC (120 mg/kg) for 5 consecutive days, a mouse model of sepsis was established via intraperitoneal lipopolysaccharide (LPS, 10 mg/kg) injection. Following this, cardiac function was assessed, pathological section staining was performed, and inflammatory markers were detected.

RESULTS

Myocardial systolic function was severely compromised in parallel with the accumulation of reactive oxygen species and enhanced cardiomyocyte apoptosis in mice with sepsis. These adverse changes were markedly reversed in response to THC treatment in septic mice as well as in LPS-treated H9c2 cells. Mechanistically, THC inhibited the release of pro-inflammatory cytokines, including tumor necrosis factor alpha, interleukin (IL)-1β, and IL-6, by upregulating mitogen-activated protein kinase phosphatase 1, to block the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated protein kinase (ERK). Additionally, THC enhanced the levels of antioxidant proteins, including nuclear factor-erythroid 2-related factor 2, superoxide dismutase 2, and NAD(P)H quinone oxidoreductase 1, while decreasing gp91^phox expression. Furthermore, upon THC treatment, Bcl-2 expression was significantly increased, along with a decline in Bax and cleaved caspase-3 expression, which reduced cardiomyocyte loss.

CONCLUSION

Our findings indicate that THC exhibited protective potential against septic cardiomyopathy by reducing oxidative stress and inflammation through the regulation of JNK/ERK signaling. The findings of this study provide a basis for the further evaluation of THC as a therapeutic agent against septic cardiomyopathy.

Tetrahydrocurcumin alleviates allergic airway inflammation in asthmatic mice by modulating the gut microbiota

Dietary factors can reshape the gut microbiota and consequently affect disease progression. We previously reported that tetrahydrocurcumin (THC), the major active metabolite of curcumin (Cur), could ameliorate allergic inflammation in asthmatic mice. Herein, we aimed to investigate whether THC or Cur exerts anti-inflammatory effects on allergic asthma via modulating gut microbiota. Ovalbumin (OVA)-induced asthmatic mice were treated with Cur or THC, and the gut microbiota profiles were analyzed by 16S rRNA sequencing. Fecal microbiota transplantation (FMT) from Cur- or THC-fed donor mice was administered to OVA-induced asthmatic mice. Nasal symptoms and inflammation patterns of lungs and colons were evaluated in control, OVA-induced and Cur-or THC-treated mice. Both Cur and THC treatment could alter the compositions of the gut microbiota in asthmatic mice, characterized by a significant decrease in the ratio of Firmicutes to Bacteroidetes; Cur or THC supplementation also reduced the relative abundances of pro-inflammatory bacteria, e.g., Proteobacteria, Intestinimonas, Unidentified-Ruminococcaceae, and Lachnospiraceae, in OVA-induced mice. The relative abundances of Unidentified-Ruminococcaceae, Romboutsia, Intestinimonas, Akkermansia, and Mucispirillum were positively associated with the levels of Th2-related factors in asthmatic mice upon Cur or THC treatment. Moreover, THC-FMT showed better preventive effects than Cur-FMT on the development of allergic inflammation in OVA-induced mice, resulting in a reduction in symptoms and Th2-mediated inflammation in both lung and colon tissues. The results reveal that Cur- or THC-mediated alleviation of airway allergic inflammation is dependent on gut microbiota modulation. THC-induced gut microbiota may have therapeutic potential for asthma treatment.