The immune-adjuvant activity and the mechanism of resveratrol on pseudorabies virus vaccine in a mouse model

Punicalagin promotes mincle-mediated phagocytosis of macrophages via the NF-κB and MAPK signaling pathways

Punicalagin (PUN) is a polyphenol derived from the pomegranate peel. It has been reported to have many beneficial effects, including anti-inflammatory, anti-oxidant, and anti-proliferation. However, the role of PUN in macrophage phagocytosis is currently unknown. In this study, we found that pre-treatment with PUN significantly enhanced phagocytosis by macrophages in a time- and dose-dependent manner in vitro. Moreover, KEGG enrichment analysis by RNA-sequencing showed that differentially expressed genes following PUN treatment were significantly enriched in phagocyte-related receptors, such as the C-type lectin receptor signaling pathway. Among the C-type lectin receptor family, Mincle (Clec4e) significantly increased at the mRNA and protein level after PUN treatment, as shown by qRT-PCR and western blotting. Small interfering RNA (siRNA) mediated knockdown of Mincle in macrophages resulted in down regulation of phagocytosis. Furthermore, western blotting showed that PUN treatment enhanced the phosphorylation of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) in macrophages at the early stage. Mincle-mediated phagocytosis by PUN was inhibited by PDTC (a NF-κB inhibitor) and SB203580 (a p38 MAPK inhibitor). In addition, PUN pre-treatment enhanced phagocytosis by peritoneal and alveolar macrophages in vivo. After intraperitoneal injection of Escherichia coli (E.coli), the bacterial load of peritoneal lavage fluid and peripheral blood in PUN pre-treated mice decreased significantly. Similarly, the number of bacteria in the lung tissue significantly reduced after intranasal administration of Pseudomonas aeruginosa (PAO1). Taken together, our results reveal that PUN enhances bacterial clearance in mice by activating the NF-κB and MAPK pathways and upregulating C-type lectin receptor expression to enhance phagocytosis by macrophages.

Novel Fermentates Can Enhance Key Immune Responses Associated with Viral Immunity

Fermented foods have long been known to have immunomodulatory capabilities, and fermentates derived from the lactic acid bacteria of dairy products can modulate the immune system. We have used skimmed milk powder to generate novel fermentates using Lb. helveticus strains SC234 and SC232 and we demonstrate here that these fermentates can enhance key immune mechanisms that are critical to the immune response to viruses. We show that our novel fermentates, SC234 and SC232, can positively impact on cytokine and chemokine secretion, nitric oxide (NO) production, cell surface marker expression, and phagocytosis in macrophage models. We demonstrate that the fermentates SC234 and SC232 increase the secretion of cytokines IL-1β, IL-6, TNF-α, IL-27, and IL-10; promote an M1 pro-inflammatory phenotype for viral immunity via NO induction; decrease chemokine expression of Monocyte Chemoattractant Protein (MCP); increase cell surface marker expression; and enhance phagocytosis in comparison to their starting material. These data suggest that these novel fermentates have potential as novel functional food ingredients for the treatment, management, and control of viral infection.

Calorie restriction mimetic, resveratrol, attenuates hepatic ischemia and reperfusion injury through enhancing efferocytosis of macrophages via AMPK/STAT3/S1PR1 pathway

Calorie restriction (CR) mimetic, resveratrol (RSV), has the capacity of promoting phagocytosis. However, its role in hepatic ischemia and reperfusion injury (HIRI) remains poorly understood. This study aimed to investigate the effect of RSV on alleviating HIRI and explore the underlying mechanisms. RSV was intraperitoneally injected in mice HIRI model, while RSV was co-incubated with culture medium for 24 h in RAW 264.7 cells and kupffer cells. Macrophage efferocytosis was assessed by immunostaining of PI and F4/80. The clearance of apoptotic neutrophils in the liver was determined by immunostaining of Ly6-G and cleaved-caspase-3. HE staining, Suzuki's score, serum levels of ALT, AST, TNF-α and IL-1β were analyzed to evaluate HIRI. The efferocytosis inhibitor, Cytochalasin D, was utilized to investigate the effect of RSV on HIRI. Western blot was employed to measure the levels of AMPKα, phospho-AMPKα, STAT3, phospho-STAT3 and S1PR1. SiSTAT3 and inhibitors targeting AMPK, STAT3 and S1PR1, respectively, were used to confirm the involvement of AMPK/STAT3/S1PR1 pathway in RSV-mediated efferocytosis and HIRI. RSV facilitated the clearance of apoptotic neutrophils and attenuated HIRI, which was impeded by Cytochalasin D. RSV boosted macrophage efferocytosis by up-regulating the levels of phospho-AMPKα, phospho-STAT3 and S1PR1, which was reversed by AMPK, STAT3 and S1PR1 inhibitors, respectively. Inhibition of STAT3 suppressed RSV-induced clearance of apoptotic neutrophils and exacerbated HIRI. CR mimetic, RSV, alleviates HIRI by promoting macrophages efferocytosis through AMPK/STAT3/S1PR1 pathway, providing valuable insights into the mechanisms underlying the protective effects of CR on attenuating HIRI.

Dietary resveratrol supplementation on growth performance, immune function and intestinal barrier function in broilers challenged with lipopolysaccharide

This study discusses the effects of resveratrol (RES) on the productive performance, immune function and intestinal barrier function of broiler chickens challenged with lipopolysaccharide (LPS). Two hundred and forty 1-day-old male Arbor Acres broilers were randomly divided into 4 groups of 6 replicates each, with 10 broilers per replicate. This experiment used a 2 × 2 factorial design with dietary factors (basal diets or basal diets supplemented with 400 mg/kg RES were administered from d 1 to 21) and stress factors (intraperitoneal injection of 0.5 mg/kg BW of saline or LPS at 16, 18 and 20 d of age). The results showed that LPS challenge had a significant adverse effect on average daily gain (ADG) in broilers at 16 to 21 d of age (P < 0.05), whereas the addition of RES to the diet inhibited the LPS-induced decrease in ADG (P < 0.05). RES also alleviated LPS-induced immune function damage in broilers, which was manifested by the decrease of spleen index (P < 0.05) and the recovery of serum immunoglobulin M and ileal secretory immunoglobulin A content (P < 0.05). The LPS challenge also disrupts intestinal barrier function and inflammation, and RES mitigates these adverse effects in different ways. RES attenuated LPS-induced reduction of villus height in the jejunum and ileum of broilers (P < 0.05). LPS also caused an abnormal increase in plasma D-lactic acid levels in broilers (P < 0.05), which was effectively mitigated by RES (P < 0.05). LPS challenge resulted in a significant decrease in mRNA expression of occludin in the intestinal mucosa (P < 0.05), which was mitigated by the addition of RES (P < 0.05). RES significantly decreased the mRNA expression of toll-like receptor 4, nuclear factor kappa-B and tumor necrosis factor alpha in the ileum tissue stimulated by LPS (P < 0.05). Taken together, this study shows that RES exerts its beneficial effect on broilers challenged with LPS by alleviating immune function damage, relieving intestinal inflammation and barrier damage, and thus improving growth performance.

Regulation of innate and adaptive immunity using herbal medicine: benefits for the COVID-19 vaccination

Vaccination is a major achievement that has become an effective prevention strategy against infectious diseases and active control of emerging pathogens worldwide. In response to the coronavirus disease 2019 (COVID-19) pandemic, several diverse vaccines against severe acute respiratory syndrome coronavirus 2 have been developed and deployed for use in a large number of individuals, and have been reported to protect against symptomatic COVID-19 cases and deaths. However, the application of vaccines has a series of limitations, including protective failure for variants of concern, unavailability of individuals due to immune deficiency, and the disappearance of immune protection for increasing infections in vaccinated individuals. These aspects raise the question of how to modulate the immune system that contributes to the COVID-19 vaccine protective effects. Herbal medicines are widely used for their immune regulatory abilities in clinics. More attractively, herbal medicines have been well accepted for their positive role in the COVID-19 prevention and suppression through regulation of the immune system. This review presents a brief overview of the strategy of COVID-19 vaccination and the response of the immune system to vaccines, the regulatory effects and mechanisms of herbal medicine in immune-related macrophages, natural killer cells, dendritic cells, and lymphocytes T and B cells, and how they help vaccines work. Later in the article, the potential role and application of herbal medicines in the most recent COVID-19 vaccination are discussed. This article provides new insights into herbal medicines as promising alternative supplements that may benefit from COVID-19 vaccination.

Graphical abstract

http://links.lww.com/AHM/A31.

Efficacy of a gB + gD-based subunit vaccine and the adjuvant granulocyte-macrophage colony stimulating factor for pseudorabies virus in rabbits

Pseudorabies (PR), which is caused by the pseudorabies virus (PRV), is a severe infectious disease that causes abortions in adult sows and fatal encephalitis in piglets; the disease can occur in pigs of all ages and other mammals, which can lead to significant economic loss around the worldwide. The new PRV variant invalidated the available commercial attenuated and inactivated vaccines. Consequently, subunit vaccines have been suggested as novel strategies for PR control, while they are usually formulated with adjuvants due to their lower immunogenicity. We aimed to select a safe and efficient adjuvant for subunit vaccines for PR. In our study, glycoprotein B (gB) and glycoprotein D (gD) were expressed based on a baculovirus expression system, and granulocyte-macrophage colony-stimulating factor (GM-CSF) was expressed using an Escherichia coli (E. coli) expression system; subsequently, a gB + gD subunit vaccine adjuvanted by GM-CSF was constructed. A rabbit model infected with a PRV SD-2017 strain was established, the TCID₅₀ and LD₅₀ were measured, and the typical clinical symptoms were observed. After a lethal challenge of 5 LD₅₀ with a PRV SD-2017 strain, the rabbits exhibited typical clinical symptoms, including itching and high temperature, and histopathology revealed severe inflammation in the brain, which is the dominant target organ of PRV. Rabbits immunized with the gB + gD + GM-CSF subunit vaccines produced higher levels of antibodies than those immunized with gB + gD + ISA 201, which was adjuvanted with a frequently used oil adjuvant. The survival rate of rabbits vaccinated with gB + gD + GM-CSF was 100%, which was superior to that of rabbits vaccinated with gB + gD + ISA 201 (80%), inactivated PRV + GM-CSF (60%) and commercial inactivated vaccine (60%) after challenge with PRV SD-2017. These data suggested that the gB + gD + GM-CSF-based subunit vaccine had good protective efficacy against the PRV SD-2017 strain in rabbits and that GM-CSF could be developed as a candidate adjuvant for use in a vaccine regimen to prevent and even eradicate PR.

Pseudorabies Virus: From Pathogenesis to Prevention Strategies

Pseudorabies (PR), also called Aujeszky’s disease (AD), is a highly infectious viral disease which is caused by pseudorabies virus (PRV). It has been nearly 200 years since the first PR case occurred. Currently, the virus can infect human beings and various mammals, including pigs, sheep, dogs, rabbits, rodents, cattle and cats, and among them, pigs are the only natural host of PRV infection. PRV is characterized by reproductive failure in pregnant sows, nervous disorders in newborn piglets, and respiratory distress in growing pigs, resulting in serious economic losses to the pig industry worldwide. Due to the extensive application of the attenuated vaccine containing the Bartha-K61 strain, PR was well controlled. With the variation of PRV strain, PR re-emerged and rapidly spread in some countries, especially China. Although researchers have been committed to the design of diagnostic methods and the development of vaccines in recent years, PR is still an important infectious disease and is widely prevalent in the global pig industry. In this review, we introduce the structural composition and life cycle of PRV virions and then discuss the latest findings on PRV pathogenesis, following the molecular characteristic of PRV and the summary of existing diagnosis methods. Subsequently, we also focus on the latest clinical progress in the prevention and control of PRV infection via the development of vaccines, traditional herbal medicines and novel small RNAs. Lastly, we provide an outlook on PRV eradication.

Resveratrol regulates intestinal barrier function in cyclophosphamide-induced immunosuppressed mice

BACKGROUND

Resveratrol, a kind of polyphenolic phytoalexin, can be obtained from numerous natural foods. Although resveratrol is demonstrated to have various bioactivities, little is known about the regulation of intestinal barrier function under immunosuppression. The present study is aimed at investigating the regulatory effect of resveratrol on intestinal barrier function in immunosuppression in mice induced by cyclophosphamide.

RESULTS

The effects of resveratrol on intestinal biological barrier were evaluated by 16S rRNA and metagenome sequencing analysis. The results showed that resveratrol could improve diversity of the intestinal microbiota and intestinal flora structure by increasing the abundance of probiotics, and resveratrol regulated the function of gut microbiota to resist immunosuppression. Resveratrol could significantly upregulate the secretion of secretory immunoglobulin A and promote the transcriptional levels of test cytokines, including tumor necrosis factor α, interferon γ, interleukin 4 and interleukin 6 in jejunum and ileum mucosa, suggesting improved intestinal immune barrier by resveratrol. The mRNA and protein levels of tight junction proteins involved in intestinal physical barrier function, including zonula occludens 1 (ZO-1), claudin 1 and occludin, were increased after resveratrol treatment. The protein levels of toll-like receptor 4 (TLR4), phosphorylation nuclear factor kappa-B (NF-κB-p65) and inhibitor of nuclear factor kappa-B kinase α were decreased by resveratrol treatment when compared with the untreated group, indicating inhibition of the TLR4/NF-ĸB signaling pathway.

CONCLUSION

These results provide new insights into regulation of the intestinal barrier function by resveratrol under immunosuppression and potential applications of resveratrol in recovering intestinal function. © 2021 Society of Chemical Industry.

Determination of the interaction between the receptor binding domain of 2019-nCoV spike protein, TMPRSS2, cathepsin B and cathepsin L, and glycosidic and aglycon forms of some flavonols

The novel coronavirus (COVID-19, SARS-CoV-2) is a rapidly spreading disease with a high mortality. In this research, the interactions between specific flavonols and the 2019-nCoV receptor binding domain (RBD), transmembrane protease, serine 2 (TMPRSS2), and cathepsins (CatB and CatL) were analyzed. According to the relative binding capacity index (RBCI) calculated based on the free energy of binding and calculated inhibition constants, it was determined that robinin (ROB) and gossypetin (GOS) were the most effective flavonols on all targets. While the binding free energy of ROB with the spike glycoprotein RBD, TMPRSS2, CatB, and CatL were -5.02, -7.57, -10.10, and -6.11 kcal/mol, the values for GOS were -4.67, -5.24, -8.31, and -6.76, respectively. Furthermore, both compounds maintained their stability for at least 170 ns on respective targets in molecular dynamics simulations. The molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) calculations also corroborated these data. Considering Lipinski's rule of five, ROB and GOS exhibited 3 (MW>500, N or O>10, NH or OH>5), and 1 (NH or OH>5) violations, respectively. Neither ROB nor GOS showed AMES toxicity or hepatotoxicity. The LD50 of these compounds in rats were 2.482 and 2.527 mol/kg, respectively. Therefore, we conclude that these compounds could be considered as alternative therapeutic agents in the treatment of COVID-19. However, the possible inhibitory effects of these compounds on cytochromes (CYPs) should be verified by in vitro or in vivo tests and their adverse effects on cellular energy metabolism should be minimized by performing molecular modifications if necessary.

Effect of resveratrol on the inflammatory status and oxidative stress in thymus gland and spleen of sulfoxaflor-treated rats

Resveratrol (Res), a polyphenolic compound that exerts mitigating consequences against various insults due to its antioxidant, anti-inflammatory, and immunomodulatory properties. Sulfoxaflor (SFX), a neonicotinoid insecticide, has been used worldwide and leading to deleterious effects on the environment and public health. The current study aimed to investigate the protective effect of Res on the inflammatory response and oxidative stress induced by SFX in the thymus and spleen of rats. Thirty-six Sprague Dawley rats were divided randomly into six groups; control group, SFX treated groups (24.8 mg/kg or 79.4 mg/kg/day), Res (alone) treated group (20 mg/kg/day), Res + SFX treated groups (20 mg /kg Res + 24.8 mg/kg SFX or 20 mg/kg Res + 79.4 mg/kg SFX) orally for 28 days. Res treatment reversed the significantly elevated white blood cells' count and the reduced count of red blood corpuscles, platelets as well as hemoglobin content of SFX treated rats. Biochemically, Res administration inhibited the remarkably increased serum levels of the inflammatory cytokines as well as thymic and splenic levels of malondialdehyde following SFX treatment. Res treatment ameliorated the conspicuously reduced antioxidant enzymes' activities due to SFX supplementation. The immunomodulatory effect of Res treatment was detected by suppressing the upregulation of the cluster of differentiation (CD)11b and CD3 gene expressions. Histopathological alterations attributed to SFX administration were ameliorated by Res treatment. In conclusion, Res can be used as a protective agent to counteract SFX toxic effects on lymphatic organs through alleviation of the antioxidant defense mechanism and modulation of the inflammatory response.

Chlorogenic acid is a positive regulator of MDA5, TLR7 and NF-κB signaling pathways mediated antiviral responses against Gammacoronavirus infection

Chlorogenic acid (CGA) is a phenolic compound that has been well studied for its antiviral, anti-inflammatory and immune stimulating properties. This research was aimed to focus on the antiviral properties of CGA on infectious bronchitis virus (IBV) in vivo and in vitro for the very first time. The outcome of in vitro experiments validated that, out of five previously reported antiviral components, CGA significantly reduced the relative mRNA expression of IBV-N in CEK cells. At high concentration (400 mg/kg), CGA supplementation reduced IBV-N mRNA expression levels and ameliorated the injury in trachea and lungs. The mRNA expression levels of IL-6, IL-1β, IL-12, and NF-κB were considerably turned down, but IL-22 and IL-10 were enhanced in trachea. However, CGA-H treatment had considerably increased the expression levels of MDA5, MAVS, TLR7, MyD88, IRF7, IFN-β and IFN-α both in trachea and lungs. Moreover, CGA-H notably induced the CD3+, CD3+ CD4+ and CD4+/CD8+ proliferation and significantly increased the IgA, IgG, and IgM levels in the serum. In conclusion, these results showed that at high concentration CGA is a strong anti-IBV compound that can effectively regulate the innate immunity through MDA5, TLR7 and NF-κB signaling pathways and have the potential to induce the cell mediated and humoral immune response in IBV infected chickens.

Ghonaim A, Wu H, Sun Q, Fan S, He Q. Recombinant Pseudorabies Virus with TK/gE Gene Deletion and Flt3L Co-Expression Enhances the Innate and Adaptive Immune Response via Activating Dendritic Cells

Owing to viral evolution and recombination, emerging pseudorabies virus (PRV) strains have caused unprecedented outbreaks in swine farms even when the pigs were previously vaccinated, which might indicate that traditional vaccines were unable to provide effective protection. The development of safe and efficacious vaccines presents prospects to minimize the clinical signs and eventually eradicate the infection. In this study, we used an emerging PRV strain, HNX, as the parental strain to construct a recombinant PRV with TK/gE gene deletion and Fms-related tyrosine kinase 3 ligand (Flt3L) expression, named HNX-TK⁻/gE⁻-Flt3L. HNX-TK⁻/gE⁻-Flt3L enhanced the maturation of bone marrow derived dendritic cells (DCs) in vitro. Significantly more activated DCs were detected in HNX-TK⁻/gE⁻-Flt3L-immunized mice compared with those immunized with HNX-TK⁻/gE⁻. Subsequently, a remarkable increase of neutralizing antibodies, gB-specific IgG antibodies, and interferon-gamma (IFN-γ) was observed in mice vaccinated with HNX-TK⁻/gE⁻-Flt3L. In addition, a lower mortality and less histopathological damage were observed in HNX-TK⁻/gE⁻-Flt3L vaccinated mice with upon PRV lethal challenge infection. Taken together, our results revealed the potential of Flt3L as an ideal adjuvant that can activate DCs and enhance protective immune responses and support the further evaluation of HNX-TK⁻/gE⁻-Flt3L as a promising PRV vaccine candidate.

Potential therapeutic applications of phytoconstituents as immunomodulators: Pre-clinical and clinical evidences

Autoimmune and infectious diseases are the major public health issues and have gained great attention in the last few years for the search of new agents with therapeutic benefits on the host immune functions. In recent years, natural products (NPs) have been studied broadly for their multi-targeted activities under pathological conditions. Interestingly, several attempts have been made to outline the immunomodulatory properties of NPs. Research on in-vitro and in-vivo models have shown the immunomodulatory activity of NPs, is due to their antiinflammatory property, induction of phagocytosis and immune cells stimulation activity. Moreover, studies on humans have suggested that phytomedicines reduce inflammation and could provide appropriate benefits either in single form or complex combinations with other agents preventing disease progression, subsequently enhancing the efficacy of treatment to combat multiple malignancies. However, the exact mechanism of immunomodulation is far from clear, warranting more detailed investigations on their effectiveness. Nevertheless, the reduction of inflammatory cascades is considered as a prime protective mechanism in a number of inflammation regulated autoimmune diseases. Altogether, this review will discuss the biological activities of plant-derived secondary metabolites, such as polyphenols, alkaloids, saponins, polysaccharides and so forth, against various diseases and their potential use as an immunomodulatory agent under pathological conditions.

Current Status and Challenge of Pseudorabies Virus Infection in China

Pseudorabies (PR), also called Aujeszky’s disease, is a highly infectious disease caused by pseudorabies virus (PRV). Without specific host tropism, PRV can infect a wide variety of mammals, including pig, sheep, cattle, etc., thereby causing severe clinical symptoms and acute death. PRV was firstly reported in China in 1950s, while outbreaks of emerging PRV variants have been documented in partial regions since 2011, leading to significant economic losses in swine industry. Although scientists have been devoting to the design of diagnostic approaches and the development of vaccines during the past years, PR remains a vital infectious disease widely prevalent in Chinese pig industry. Especially, its potential threat to human health has also attracted the worldwide attention. In this review, we will provide a summary of current understanding of PRV in China, mainly focusing on PRV history, the existing diagnosis methods, PRV prevalence in pig population and other susceptible mammals, molecular characteristics, and the available vaccines against its infection. Additionally, promising agents including traditional Chinese herbal medicines and novel inhibitors that may be employed to treat this viral infection, are also discussed.

Preparation of resveratrol dry suspension and its immunomodulatory and anti-inflammatory activity in mice

Context: Resveratrol is a natural polyphenol compound. It exhibits antitumor, immunostimulatory, and antiviral activities. However, poor water solubility and structural instability limit its administration and storage.Objective: A resveratrol dry suspension (RDS) was prepared and immunomodulatory effect in immunosuppressive mice induced by cyclophosphamide and anti-inflammatory activities in mice were evaluated.Materials and methods: The preparation of RDS was optimized by the orthogonal design method. To evaluate the immunomodulatory effects, SPF Kunming mice were divided into seven groups comprising of nine males and nine females for each group. The RDS supplemented group was administrated doses of 3.33, 1.67, and 0.83 g/kg/d. Then visceral index, lymphocyte proliferation, the ratio of CD3⁺ CD4⁺/CD3⁺ CD8⁺, and the contents of cytokines in serum were tested. To ameliorate effects of acetic acid induced capillary permeability, xylene-based ear oedema, and cotton pellet granuloma, RDS as anti-inflammatory agent was administered at doses of 1, 0.33, and 0.1 g/kg/d as compared to indomethacin (IM) provided as a positive control at 10 mg/kg.Results: RDS inhibited the degradation of resveratrol and enhanced the CD3⁺ CD4⁺/CD3⁺ CD8⁺ ratio, spleen index, IL-2 level, and splenic lymphocytes in immunosuppressive mice. RDS (0.1 g/kg/d) significantly inhibited the acetic acid-induced capillary permeability, and at doses of 0.33 and 1 g/kg/d repressed the ear swelling and granuloma formation in immunocompromised mice.Discussion and Conclusion: RDS is a stable, cheaper, and suitable preparation with potent immunoregulatory and anti-inflammatory activities. Keeping in view these remarkable properties, RDS could be an appropriate preparation for clinic use of resveratrol.

Resveratrol: nanocarrier-based delivery systems to enhance its therapeutic potential

Resveratrol (3,5,4'-trihydroxystilbene) is a polyphenolic compound existing in trees, peanuts and grapes and exhibits a broad spectrum of promising therapeutic activities, but it is unclear whether this entity targets the sites of action after oral administration. In vivo applicability of resveratrol has limited success so far, mainly due to its incompetent systemic delivery resulting from its low water solubility, poor bioavailability and short biological half-life. First-pass metabolism and presence of enterohepatic recirculation create doubt on the biological application of high doses typically used for in vitro trials. To augment bioavailability, absorption and uptake of resveratrol by cellular internalization, countless approaches have been implemented which involve the use of nanocarriers. Nanocarriers are a well-known delivery system used to reduce first-pass hepatic metabolism, overcome enterohepatic recirculation and accelerate the absorption of drugs via lymphatic pathways.

Dietary Flavonoids in p53-Mediated Immune Dysfunctions Linking to Cancer Prevention

The p53 protein plays a central role in mediating immune functioning and determines the fate of the cells. Its role as a tumor suppressor, and in transcriptional regulation and cytokine activity under stress conditions, is well defined. The wild type (WT) p53 functions as a guardian for the genome, while the mutant p53 has oncogenic roles. One of the ways that p53 combats carcinogenesis is by reducing inflammation. WT p53 functions as an anti-inflammatory molecule via cross-talk activity with multiple immunological pathways, such as the major histocompatibility complex I (MHCI) associated pathway, toll-like receptors (TLRs), and immune checkpoints. Due to the multifarious roles of p53 in cancer, it is a potent target for cancer immunotherapy. Plant flavonoids have been gaining recognition over the last two decades to use as a potential therapeutic regimen in ameliorating diseases. Recent studies have shown the ability of flavonoids to suppress chronic inflammation, specifically by modulating p53 responses. Further, the anti-oxidant Keap1/Nrf2/ARE pathway could play a crucial role in mitigating oxidative stress, leading to a reduction of chronic inflammation linked to the prevention of cancer. This review aims to discuss the pharmacological properties of plant flavonoids in response to various oxidative stresses and immune dysfunctions and analyzes the cross-talk between flavonoid-rich dietary intake for potential disease prevention.