Isobavachalcone ameliorates diabetic nephropathy in rats by inhibiting the NF-κB pathway

Molecular mechanisms of diabetic nephropathy: A narrative review

Diabetic nephropathy (DN) is the predominant secondary nephropathy resulting in global end-stage renal disease. It is attracting significant attention in both domestic and international research due to its widespread occurrence, fast advancement, and limited choices for prevention and treatment. The pathophysiology of this condition is intricate and involves multiple molecular and cellular pathways at various levels. This article provides a concise overview of the molecular processes involved in the development of DN. It discusses various factors, such as signaling pathways, cytokines, inflammatory responses, oxidative stress, cellular damage, autophagy, and epigenetics. The aim is to offer clinicians a valuable reference for DN's diagnosis, treatment, and intervention.

A Review of Experimental Studies on Natural Chalcone-Based Therapeutic Targeting of Genes and Signaling Pathways in Type 2 Diabetes Complications

Diabetes mellitus type 2 (T2DM) is a common chronic condition that presents as unsettled hyperglycemia (HG) and results from insulin resistance (IR) and β-cell dysfunction. T2DM is marked by an increased risk of microvascular and macrovascular complications, all of which can be the cause of increasing mortality. Diabetic nephropathy (DNE), neuropathy (DNU), and retinopathy (DR) are the most common complications of diabetic microangiopathy, while diabetic cardiomyopathy (DCM) and peripheral vascular diseases are the major diabetic macroangiopathy complications. Chalcones (CHs) are in the flavonoid family and are commonly found in certain plant species as intermediate metabolites in the biosynthesis of flavonoids and their derivatives. Natural CHs with different substituents exert diverse therapeutic activities, including antidiabetic ones. However, the therapeutic mechanisms of natural CHs through influencing genes and/or signaling pathways in T2DM complications remain unknown. Therefore, this review summarizes the existing results from experimental models which highlight the mechanisms of natural CHs as therapeutic agents for T2DM complications.

Molecular mechanisms and therapeutic potential of natural flavonoids in diabetic nephropathy: Modulation of intracellular developmental signaling pathways

Recognized as a common microvascular complication of diabetes mellitus (DM), diabetic nephropathy (DN) is the principal cause of chronic end-stage renal disease (ESRD). Patients with diabetes have an approximately 25% risk of developing progressive renal disease. The underlying principles of DN control targets the dual outcomes of blood glucose regulation through sodium glucose cotransporter 2 (SGLT 2) blockade and hypertension management through renin-angiotensin-aldosterone inhibition. However, these treatments are ineffective in halting disease progression to kidney failure and cardiovascular comorbidities. Recently, the dysregulation of subcellular signaling pathways has been increasingly implicated in DN pathogenesis. Natural compounds are emerging as effective and side-effect-free therapeutic agents that target intracellular pathways. This narrative review synthesizes recent insights into the dysregulation of maintenance pathways in DN, drawing from animal and human studies. To compile this review, articles reporting DN signaling pathways and their treatment with natural flavonoids were collected from PubMed, Cochrane Library Web of Science, Google Scholar and EMBASE databases since 2000. As therapeutic interventions are frequently based on the results of clinical trials, a brief analysis of data from current phase II and III clinical trials on DN is discussed.

4'-O-methylbavachalcone alleviates ischemic stroke injury by inhibiting parthanatos and promoting SIRT3

Cerebral ischemia-reperfusion injury (CIRI) can induce massive death of ischemic penumbra neurons via oxygen burst, exacerbating brain damage. Parthanatos is a form of caspase-independent cell death involving excessive activation of PARP-1, closely associated with intense oxidative stress following CIRI. 4'-O-methylbavachalcone (MeBavaC), an isoprenylated chalcone component in Fructus Psoraleae, has potential neuroprotective effects. This study primarily investigates whether MeBavaC can act on SIRT3 to alleviate parthanatos of ischemic penumbra neurons induced by CIRI. MeBavaC was oral gavaged to the middle cerebral artery occlusion-reperfusion (MCAO/R) rats after occlusion. The effects of MeBavaC on cerebral injury were detected by the neurological deficit score and cerebral infarct volume. In vitro, PC-12 cells were subjected to oxygen and glucose deprivation/reoxygenation (OGD/R), and assessed cell viability and cell injury. Also, the levels of ROS, mitochondrial membrane potential (MMP), and intracellular Ca2+ levels were detected to reflect mitochondrial function. We conducted western blotting analyses of proteins involved in parthanatos and related signaling pathways. Finally, the exact mechanism between the neuroprotection of MeBavaC and parthanatos was explored. Our results indicate that MeBavaC reduces the cerebral infarct volume and neurological deficit scores in MCAO/R rats, and inhibits the decreased viability of PC-12 cells induced by OGD/R. MeBavaC also downregulates the expression of parthanatos-related death proteins PARP-1, PAR, and AIF. However, this inhibitory effect is weakened after the use of a SIRT3 inhibitor. In conclusion, the protective effect of MeBavaC against CIRI may be achieved by inhibiting parthanatos of ischemic penumbra neurons through the SIRT3-PARP-1 axis.

Isobavachalcone alleviates ischemic stroke by suppressing HDAC1 expression and improving M2 polarization

Ischemic stroke is a serious cerebrovascular condition. Isobavachalcone (ISO) has been documented to exhibit an anti-inflammatory effect across a variety of diseases; however, its protective impact on ischemic stroke remains unexplored. In this study, we evaluated the influence of ISO in both transient middle cerebral artery occlusion/reperfusion (tMCAO/R) rat models and oxygen-glucose deprivation/reperfusion (OGD/R) cell models. We observed that pretreatment with 50 mg/kg ISO diminished the volume of brain infarction, reduced brain edema, and ameliorated neurological deficits in rats. A reduction in Nissl bodies was noted in the tMCAO/R group, which was reversed following treatment with 50 mg/kg ISO. TUNEL/NeuN double staining revealed a decrease in TUNEL-positive cells in tMCAO/R rats treated with ISO. Furthermore, ISO treatment suppressed the expression of cleaved caspase-3 and BAX, while elevating the expression of BCL-2 in tMCAO/R rats. The levels of CD86 and iNOS were elevated in tMCAO/R rats; conversely, ISO treatment enhanced the expression of CD206 and Arg-1. Additionally, the expression of TNF-α, IL-6, and IL-1β was elevated in tMCAO/R rats, whereas ISO treatment counteracted this effect. ISO treatment also increased the expression of TGF-β and IL-10 in the ischemic penumbra of tMCAO/R rats. It was found that ISO treatment hindered microglial M1 polarization and favored M2 polarization. Histone Deacetylase 1 (HDAC1) is the downstream target protein of ISO, with ISO treatment resulting in decreased HDAC1 expression in both tMCAO/R rats and OGD/R-induced cells. Overexpression of HDAC1 was shown to promote microglial M1 polarization and inhibit M2 polarization in OGD/R+ISO cells. Overall, ISO treatment mitigated brain damage following ischemic stroke by promoting M2 polarization and attenuated ischemic injury by repressing HDAC1 expression.

An integrated network pharmacology, molecular docking and experiment validation study to investigate the potential mechanism of Isobavachalcone in the treatment of osteoarthritis

BACKGROUND

In many different plants, including Dorstenia and Psoralea corylifolia L., Isobavachalcone (IBC) is a naturally occurring flavonoid chemical having a range of biological actions, including anti-inflammatory, immunomodulatory, and anti-bacterial. The "Theory of Medicinal Properties" of the Tang Dynasty states that Psoralea corylifolia L. has the ability to alleviate discomfort in the knees and waist. One of the most widespread chronic illnesses, osteoarthritis (OA), is characterized by stiffness and discomfort in the joints. However, there hasn't been much research done on the effectiveness and underlying processes of IBC in the treatment of osteoarthritis.

AIM OF THE STUDY

To investigate the potential efficacy and mechanism of IBC in treating osteoarthritis, we adopted an integrated strategy of network pharmacology, molecular docking and experiment assessment.

MATERIALS AND METHODS

The purpose of this research was to determine the impact of IBC on OA and the underlying mechanisms. IBC and OA possible targets and processes were predicted using network pharmacology, including the relationship between IBC and OA intersection targets, Cytoscape protein-protein interaction (PPI) to obtain key potential targets, and GO and KEGG pathway enrichment analysis to reveal the probable mechanism of IBC on OA. Following that, in vitro tests were carried out to confirm the expected underlying processes. Finally, in vivo tests clarified IBC's therapeutic efficacy on OA.

RESULTS

We anticipated and validated that the impact of IBC on osteoarthritis is mostly controlled by the PI3K-AKT-NF-κB signaling pathway by combining the findings of network pharmacology analysis, molecular docking and Experiment Validation.

CONCLUSIONS

This study reveals the IBC has potential to delay OA development.

NF-ĸB axis in diabetic neuropathy, cardiomyopathy and nephropathy: A roadmap from molecular intervention to therapeutic strategies

Diabetes mellitus (DM) is a metabolic illness defined by elevated blood glucose levels, mediating various tissue alterations, including the dysfunction of vital organs. Diabetes mellitus (DM) can lead to many consequences that specifically affect the brain, heart, and kidneys. These issues are known as neuropathy, cardiomyopathy, and nephropathy, respectively. Inflammation is acknowledged as a pivotal biological mechanism that contributes to the development of various diabetes consequences. NF-κB modulates inflammation and the immune system at the cellular level. Its abnormal regulation has been identified in several clinical situations, including cancer, inflammatory bowel illnesses, cardiovascular diseases, and Diabetes Mellitus (DM). The purpose of this review is to evaluate the potential impact of NF-κB on complications associated with DM. Enhanced NF-κB activity promotes inflammation, resulting in cellular harm and compromised organ performance. Phytochemicals, which are therapeutic molecules, can potentially decline the NF-κB level, therefore alleviating inflammation and the progression of problems correlated with DM. More importantly, the regulation of NF-κB can be influenced by various factors, such as TLR4 in DM. Highlighting these factors can facilitate the development of novel therapies in the future.

Role of polyphenolic compounds and their nanoformulations: a comprehensive review on cross-talk between chronic kidney and cardiovascular diseases

Chronic kidney disease (CKD) affects a huge portion of the world's population and frequently leads to cardiovascular diseases (CVDs). It might be because of common risk factors between chronic kidney disease and cardiovascular diseases. Renal dysfunction caused by chronic kidney disease creates oxidative stress which in turn leads to cardiovascular diseases. Oxidative stress causes endothelial dysfunction and inflammation in heart which results in atherosclerosis. It ends in clogging of veins and arteries that causes cardiac stroke and myocardial infarction. To develop an innovative therapeutic approach and new drugs to treat these diseases, it is important to understand the pathophysiological mechanism behind the CKD and CVDs and their interrelationship. Natural phytoconstituents of plants such as polyphenolic compounds are well known for their medicinal value. Polyphenols are plant secondary metabolites with immense antioxidant properties, which can protect from free radical damage. Nowadays, polyphenols are generating a lot of buzz in the scientific community because of their potential health benefits especially in the case of heart and kidney diseases. This review provides a detailed account of the pathophysiological link between CKD and CVDs and the pharmacological potential of polyphenols and their nanoformulations in promoting cardiovascular and renal health.

The role of discoid domain receptor 1 on renal tubular epithelial pyroptosis in diabetic nephropathy

Pyroptosis, a form of cell death associated with inflammation, is known to be involved in diabetic nephropathy (DN), and discoid domain receptor 1 (DDR1), an inflammatory regulatory protein, is reported to be associated with diabetes. However, the mechanism underlying DDR1 regulation and pyroptosis in DN remains unknown. We aimed to investigate the effect of DDR1 on renal tubular epithelial cell pyroptosis and the mechanism underlying DN. In this study, we used high glucose (HG)-treated HK-2 cells and rats with a single intraperitoneal injection of streptozotocin as DN models. Subsequently, the expression of pyroptosis-related proteins (cleaved caspase-1, GSDMD-N, Interleukin-1β [IL-1β], and interleukin-18 [IL-18]), DDR1, phosphorylated NF-κB (p-NF-κB), and NLR family pyrin domain-containing 3 (NLRP3) inflammasomes were determined through Western blotting. IL-1β and IL-18 levels were determined using ELISA. The rate of pyroptosis was assessed by propidium iodide (PI) staining. The results revealed upregulated expression of pyroptosis-related proteins and increased concentration of IL-1β and IL-18, accompanied by DDR1, p-NF-κB, and NLRP3 upregulation in DN rat kidney tissues and HG-treated HK-2 cells. Moreover, DDR1 knockdown in the background of HG treatment resulted in inhibited expression of pyroptosis-related proteins and attenuation of IL-1β and IL-18 production and PI-positive cell frequency via the NF-κB/NLRP3 pathway in HK-2 cells. However, NLRP3 overexpression reversed the effect of DDR1 knockdown on pyroptosis. In conclusion, we demonstrated that DDR1 may be associated with pyroptosis, and DDR1 knockdown inhibited HG-induced renal tubular epithelial cell pyroptosis. The NF-κB/NLRP3 pathway is probably involved in the underlying mechanism of these findings.

Investigation of the mechanism of Isobavachalcone in treating rheumatoid arthritis through a combination strategy of network pharmacology and experimental verification

ETHNOPHARMACOLOGY RELEVANCE

Isobavachalcone (IBC) is a natural chalcone compound widely distributed in traditional Chinese medicine Psoralea corylifolia L., and Tibetan medicine Abelmoschus manihot (L.) Medik. Etc.. Among them, Psoralea corylifolia has the effect of tonifying the kidney and strengthening Yang, and it is recorded in the Medicinal theory that it can be used in managing rheumatism and arthralgia. In addition, It has been included in many prescriptions in traditional Chinese medicine as the main herb for managing rheumatoid arthritis (RA). Similarly, Abelmoschus manihot is a common Tibetan medicinal herb and is a common medicinal material in Tibetan medicine and reported in ancient medicinal books such as Jing Zhu Ben Cao and Si Bu Yi Dian to possess the effect of Ganhuangshui and thus can be used in treating Huangshui diseases (such as RA). Previous research has demonstrated IBC to possess numerous biological activities, including anti-cancer, anti-inflammatory, antibacterial and immunomodulatory. Nevertheless, its efficacy and potential mechanism in treating rheumatoid arthritis are yet to be investigated.

AIM OF THE STUDY

This study aimed at investigating the therapeutic efficacy and mechanism of IBC in treating RA through a combined strategy of network pharmacology, in vitro, and in vivo evaluation.

MATERIALS AND METHODS

The Swiss Target Prediction and GeneCards databases were consulted to predict the potential targets of IBC and RA. Additionally, the potential targets for IBC in treating RA were predicted by consulting databases such as String, Cytoscape, MCODE, and Cytohubba. R software was utilized for enrichment analysis of GO and KEGG pathways, followed by in vitro experimentation using cell lines and in vivo experimentation using animals to explore the potential mechanism of IBC in RA treatment.

RESULTS

By integrating the results of network pharmacological analysis, 17 genes were found to be strongly associated with RA, such as TNF, MAPK13, EGFR, PTGS2, MMP3, etc. The enrichment analysis indicated that IBC possessed tremendous therapeutic efficacy in managing RA through PI3K-AKT, rheumatoid arthritis, and TNF signaling pathways. The in vitro experimentation indicated that IBC inhibited the proliferation, migration, and invasion, and promoted apoptosis and inhibition of inflammation of MH7A cell lines stimulated with TNF-α. The IBC might also have an increasing effect on the intracellular ROS and reducing effect on the mitochondrial membrane potential. The western blotting results indicated that IBC markedly inhibited the expression of p-PI3K, p-AKT, p-JAK1, p-STAT3 and SOCS3 proteins in TNF-α stimulated MH7A cells. Furthermore, we found that IBC also significantly reduced paw swelling and arthritis severity in CIA model rats through in vivo animal studies.

CONCLUSIONS

In short, this study explored the effect of IBC by combining network pharmacology prediction with in vitro and in vivo experimentation. The results indicated that IBC exerts its anti-rheumatoid arthritis effect by regulating cell proliferation and survival via PI3K/AKT and JAK/STAT signaling pathways. This may open a new horizon and provide a theoretical foundation for further development and utilization of IBC in RA management.

Isobavachalcone disrupts mitochondrial respiration and induces cytotoxicity through ROS accumulation and Akt suppression

Isobavachalcone (IBC) is one of the flavonoid components in Fructus Psoraleae, and has been found multiple pharmacological effects. However, the hepatotoxicity of IBC has been overlooked and not been carefully studied. We aim to find out the cytotoxicity of IBC on HepG2 cells, and explore the underlying mechanisms. HepG2 cells were treated with IBC for 24 h, then MTT assay and LDH assay were used to detect the cell viability. The apoptosis and reactive oxygen species (ROS) production were reflected by the flow cytometry. Using Seahorse Analyzer, we measured the mitochondrial respiratory capacity. The expression of oxidative stress and mitochondrial apoptosis-related proteins were determined by Western blot. The results showed that IBC induced the cell death and apoptosis of HepG2 cells. IBC initiated the accumulation of ROS in cells and impaired the mitochondrial function, triggered apoptosis and suppressed the phosphorylation of Akt. Additionally, scavenging ROS by the antioxidant N-acetyl-l-cysteine (NAC) reduced IBC-induced mitochondria damage and increased Akt phosphorylation. Taken together, IBC caused mitochondrial damage and induced hepatotoxicity by ROS accumulation and Akt suppression. Targeting oxidative stress and depressing mitochondrial damage may provide a theoretical basis for the treatment and prevention of IBC-induced hepatotoxicity in clinic.

Prognostic Value of Serum Interleukin-6, NF-κB plus MCP-1 Assay in Patients with Diabetic Nephropathy

Objective

To assess the prognostic value of serum interleukin-6 (IL-6), nuclear factor-κB (NF-κB), and monocyte chemoattractant protein 1(MCP-1) assay in patients with diabetic nephropathy.

Methods

From May 2019 to March 2020, 104 patients with diabetic nephropathy treated in our institution assessed for eligibility were recruited and assigned at a ratio of 1 : 1 to either the observation group ([urinary albumin excretion rate (UAER)] of 30 mg-300 mg/24 h) or the research group ([UAER] >300 mg/24 h). IL-6, MCP-1, renal function indices, and NF-κB levels were determined, and their correlation with DN was analyzed. Logistic regression was used to analyze the influencing factors of end-stage renal disease in patients with diabetic nephropathy. The receiver operating characteristic (ROC) curve was drawn, and the area under the curve (AUC) was calculated to analyze the predictive value of combined detection of IL-6, MCP-1, and NF-κB in the prognosis of patients with diabetic nephropathy.

Results

The eligible patients with UAER of 30 mg-300 mg/24 h were associated with significantly higher levels of IL-6, MCP-1, NF-κB, blood urea nitrogen (BUN), and serum creatinine (Scr) versus those with UAER >300 mg/24 h (P < 0.05). During the follow-up, a total of 38 patients progressed to end-stage renal diseases. Eligible patients with end-stage renal diseases showed significantly higher serum IL-6, MCP-1, and NF-κB levels versus those without end-stage renal diseases (P < 0.05). Serum IL-6, MCP-1, and NF-κB are independent risk factors for the occurrence of end-stage renal disease in patients with diabetic nephropathy. The AUCs of IL-6, MCP-1, and NF-κB for predicting the prognosis of patients with diabetic nephropathy were 0.562, 0.634, and 0.647, respectively, and the AUC of the three combined detection for predicting the prognosis of patients with diabetic nephropathy was 0.889.

Conclusion

Serum IL-6, NF-κB, and MCP-1 levels are closely related to renal injury and poor prognosis in patients with diabetic nephropathy, and the combined assay is valuable for assessing patients' condition and prognosis.

Isobavachalcone: A comprehensive review of its plant sources, pharmacokinetics, toxicity, pharmacological activities and related molecular mechanisms

Isobavachalcone (IBC), also known as isobapsoralcone, is a natural flavonoid widely derived from many medicinal plants, including Fabaceae, Moraceae, and so forth. IBC has been paid more and more attention by researchers in recent years due to its pharmacological activity in many diseases. This review aims to describe in detail the plant sources, pharmacokinetics, toxicity, pharmacological activities, and molecular mechanisms of IBC on various diseases. We found that IBC can be obtained not only by extraction but also by chemical synthesis. Pharmacokinetic studies have shown that IBC has low bioavailability, but can penetrate the blood-brain barrier and is widely distributed in the brain. Its pharmacological activities mainly include anticancer, antibacterial, anti-inflammatory, antiviral, neuroprotective, bone protection, and other activities. In particular, IBC shows strong anti-tumor and anti-inflammatory therapeutic potential due to its anti-cancer and anti-inflammatory activities. However, due to its hepatotoxicity, there may be more drug interactions. Therefore, more and more in-depth studies are needed for its clinical application. Mechanically, IBC can induce the production of reactive oxygen species (ROS), inhibit AKT, ERK, and Wnt pathways, and promote apoptosis of cancer cells through mitochondrial or endoplasmic reticulum pathways. IBC can inhibit the NF-κB pathway and the production of multiple inflammatory mediators by activating NRF2/HO-1 pathway, thus producing anti-inflammatory effects. Moreover, we discussed the limitations of current research on IBC and put forward some new perspectives and challenges, which provide a strong basis for clinical application and new drug development of IBC in the future.

The benzofuran glycosides from the fruits of Psoralea corylifolia L

Six new glucosides of benzofuran (1-6), together with three known glucosides of benzofuran (8, 9, 14), nine flavonoids (12, 13, 15, 18, 19, 20, 21, 22 and 24), three coumarins (16, 17, 23) and four other-typic compounds (7, 10, 11 and 25) were isolated from the fruits of Psoralia corylifolia L. Their structures were elucidated by extensive spectroscopic methods. The biosynthesis pathway of benzofuran system was discussed. Besides, all isolated compounds and additional ring-opening derivatives of psoralen/isopsoralen (P-1, P-2, IP-1 and IP-2) were assayed for inhibition of nitric oxide (NO) production on lipopolysaccharides-induced RAW 264.7 macrophage cells. The results of the assay showed that the glycosides showed weaker or no effects, while most isolated non-glycoside compounds showed moderate or high activities. And the structure-activity relationships of non-glycoside compounds were discussed.

Nucleoporin 160 (NUP160) inhibition alleviates diabetic nephropathy by activating autophagy

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide. Autophagy was reported to be related to the pathogenesis of DN. This research investigated the function of the Nucleoporin 160 (Nup160) gene in regulating autophagy in DN. A mouse model of DN was established through an intraperitoneal injection of streptozotocin (STZ). Normal rat kidney tubular epithelial cells (NRK-52E) were treated with high glucose to induce DN in vitro. Real-time quantitative polymerase chain reaction (RT-qPCR), western blot, immunofluorescence assays were conducted to measure the expression of NUP160, autophagy-associated proteins, and inflammatory cytokines in vitro and in vivo. Pathological changes of kidney and liver tissues were analyzed using hematoxylin and eosin (H&E), Masson and periodic acid-silver (PAS) staining. The body weight, blood glucose, renal and lipid profiles of DN mice were examined. In this study, DN mice showed serious pathological injury. NUP160 expression was upregulated, autophagy was inhibited, and inflammatory response was increased in DN mice. Depletion of NUP160 restored autophagy and inhibited inflammation and fibrosis in high glucose (HG)-treated NRK-52E cells and STZ-induced DN mice by downregulating the expression of p62 and Collagen IV (Col-Ⅳ), increasing the ratio of LC3II/LC3I, and inactivating nuclear factor (NF)-κB signaling. Moreover, NUP160 knockdown could ameliorate pathological damage and glucose tolerance in DN mice. Overall, this study is the first to demonstrate the key role of NUP160 silencing in promoting autophagy against diabetic injury in DN.

Therapeutic potential of isobavachalcone, a natural flavonoid, in murine experimental colitis by inhibiting NF-κB p65

The incidence of ulcerative colitis (UC), one of the two types of inflammatory bowel disease, is increasing in many countries. Various natural products have been demonstrated with therapeutic potentials for UC. Herein, the therapeutic effects and mechanisms of isobavachalcone (IBC), a natural chalcone, were evaluated in dextran sulfate sodium (DSS)-induced colitis mice and lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The results demonstrated that IBC treatment significantly improved the clinical symptoms, assessed by the disease activity index (DAI) scores and the histological changes of the colon. The levels of myeloperoxidase (MPO), TNF-α, IL-6, IL-1β, and prostaglandin E2 (PGE2) in colon tissues were suppressed by IBC. The upregulation of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and NF-κB p65 in colon tissues were reversed by IBC as well. Furthermore, IBC significantly inhibited LPS-triggered secretion of TNF-α, IL-6, and nitrite, and nuclear translocation of NF-κB p65, in RAW264.7 cells. The luciferase reporter assay indicated that IBC significantly inhibited LPS-triggered transcription of toll-like receptor 4 (TLR4). Molecular docking results showed that the binding pocket of IBC was adjacent to Ser276 of p65-p50 heterodimer and IBC could form H-bond with Thr191. Collectively, these results demonstrated that IBC ameliorated colitis in mice possibly through inhibition of NF-κB p65.

Isobacachalcone induces autophagy and improves the outcome of immunogenic chemotherapy

A number of natural plant products have a long-standing history in both traditional and modern medical applications. Some secondary metabolites induce autophagy and mediate autophagy-dependent healthspan- and lifespan-extending effects in suitable mouse models. Here, we identified isobacachalcone (ISO) as a non-toxic inducer of autophagic flux that acts on human and mouse cells in vitro, as well as mouse organs in vivo. Mechanistically, ISO inhibits AKT as well as, downstream of AKT, the mechanistic target of rapamycin complex 1 (mTORC1), coupled to the activation of the pro-autophagic transcription factors EB (TFEB) and E3 (TFE3). Cells equipped with a constitutively active AKT mutant failed to activate autophagy. ISO also stimulated the AKT-repressible activation of all three arms of the unfolded stress response (UPR), including the PERK-dependent phosphorylation of eukaryotic initiation factor 2α (eIF2α). Knockout of TFEB and/or TFE3 blunted the UPR, while knockout of PERK or replacement of eIF2α by a non-phosphorylable mutant reduced TFEB/TFE3 activation and autophagy induced by ISO. This points to crosstalk between the UPR and autophagy. Of note, the administration of ISO to mice improved the efficacy of immunogenic anticancer chemotherapy. This effect relied on an improved T lymphocyte-dependent anticancer immune response and was lost upon constitutive AKT activation in, or deletion of the essential autophagy gene Atg5 from, the malignant cells. In conclusion, ISO is a bioavailable autophagy inducer that warrants further preclinical characterization.