Pterostilbene: Biomedical applications

Sirtuins and Gut Microbiota: Dynamics in Health and a Journey from Metabolic Dysfunction to Hepatocellular Carcinoma

Metabolic dysfunction leading to non-alcoholic fatty liver disease (NAFLD) exhibits distinct molecular and immune signatures that are influenced by factors like gut microbiota. The gut microbiome interacts with the liver via a bidirectional relationship with the gut-liver axis. Microbial metabolites, sirtuins, and immune responses are pivotal in different metabolic diseases. This extensive review explores the complex and multifaceted interrelationship between sirtuins and gut microbiota, highlighting their importance in health and disease, particularly metabolic dysfunction and hepatocellular carcinoma (HCC). Sirtuins (SIRTs), classified as a group of NAD+-dependent deacetylases, serve as crucial modulators of a wide spectrum of cellular functions, including metabolic pathways, the inflammatory response, and the process of senescence. Their subcellular localization and diverse functions link them to various health conditions, including NAFLD and cancer. Concurrently, the gut microbiota, comprising diverse microorganisms, significantly influences host metabolism and immune responses. Recent findings indicate that sirtuins modulate gut microbiota composition and function, while the microbiota can affect sirtuin activity. This bidirectional relationship is particularly relevant in metabolic disorders, where dysbiosis contributes to disease progression. The review highlights recent findings on the roles of specific sirtuins in maintaining gut health and their implications in metabolic dysfunction and HCC development. Understanding these interactions offers potential therapeutic avenues for managing diseases linked to metabolic dysregulation and liver pathology.

Nanodrugs Targeting Key Factors of Ferroptosis Regulation for Enhanced Treatment of Osteoarthritis

Osteoarthritis (OA) is a globally prevalent degenerative joint disease. Recent studies highlight the role of ferroptosis in OA progression. Targeting ferroptosis regulation presents a promising therapeutic strategy for OA; however, current research primarily focuses on single targets associated with ferroptosis. In this study, a reactive oxygen species (ROS)-responsive nanoparticle is developed by linking deferasirox (DEF) and pterostilbene (PTE) with thioketal and incorporating cerium ions (Ce), creating Ce@D&P nanoparticles (NPs), which offer multitarget regulation of ferroptosis. The characteristics of Ce@D&P NPs are evaluated and their therapeutic effects on IL-1β-stimulated chondrocytes are verified. Results show that Ce@D&P NPs reduce ROS levels, mitigate inflammation, chelate iron to inhibit ferroptosis, and balance extracellular matrix (ECM) metabolism in chondrocytes. Mechanistically, transcriptomics and metabolomics analyses suggest that Ce@D&P NPs exerted their effects by regulating oxidative stress and lipid metabolism in chondrocytes. To better treat destabilization of the medial meniscus (DMM)-induced OA in mice, Ce@D&P NPs via intra-articular injection are delivered. The results show that Ce@D&P NPs alleviate cartilage matrix damage and slow OA progression. Overall, the findings indicate that Ce@D&P NPs represent a promising multitarget drug delivery system, and Ce@D&P NPs may be an effective strategy for OA treatment.

Exploring the anti-inflammatory effects of phytochemicals in attenuating interstitial cystitis-a literature review

Interstitial cystitis is a fierce syndrome affecting the quality of life of thousands of individuals around the globe. It causes immense pain in the bladder and associated viscera along with inflammation-like lesions. The current medicinal and pharmacological research focuses on the protective and curative effects of phytochemicals in several ailments. Phytochemicals derived from many medicinal plants have shown potent outcomes in protection against various pathological conditions including interstitial cystitis. This review has summarized the insights of in vitro and in vivo studies regarding the effects of phytochemicals in fading the inflammation in bladder tissue and exhibiting a protective effect on the urothelium. Hemorrhagic cystitis is a common manifestation in patients undergoing chemotherapy with cyclophosphamide and related alkylating agents. Sodium 2-mercaptoethane sulfonate (Mesna) has traditionally been employed in clinical practice to counter cyclophosphamide-induced cystitis in humans. However, cyclophosphamide has been employed in developing animal models of interstitial cystitis in in vivo studies. Phytochemicals including quercetin, beta-caryophyllene, curcumol, boswellic acid, caftaric acid, some flavonoids and other secondary metabolites being a consequential component of numerous medicinal plants, have displayed a significant reduction in the levels of proinflammatory cytokines including TNF-α, NFĸB, IL-1β, NLRP3 inflammasome, IL-6, IL-2, matrix metalloproteinases etc. Uroprotective outcomes of these phytochemicals have been found to result in diminished oxidative stress and restoration of glutathione, superoxide dismutase, and related proteins in the inflamed bladder tissue. Many in vivo studies involving cyclophosphamide-induced interstitial cystitis have confirmed these findings. The coupling of phytotherapy with novel drug delivery systems such as nanoparticles, liposomes, nanotubes, quantum dots, etc. can help translate these beneficial effects of phytochemicals into clinical practice. Further investigations of these phytochemicals can provide intuition regarding the development of newer drug molecules having exclusive activity for attenuating interstitial cystitis.

Advances in the activity of resveratrol and its derivatives in cardiovascular diseases

Cardiovascular diseases (CVDs), the leading cause of human death worldwide, are diseases that affect the heart and blood vessels and include arrhythmias, coronary atherosclerotic heart disease, hypertension, and so on. Resveratrol (RSV) is a natural nonflavonoid phenolic compound with antioxidant, anti-inflammatory, anticancer, and cardiovascular protection functions. RSV has shown significant protective effects against CVD. However, RSV's clinical application is limited by its tendency to be oxidized and metabolized easily. Therefore, it is necessary to optimize the RSV structure. This review will introduce the activity, synthesis, and structure-activity relationships of RSV derivatives, and the mechanism of the action of RSV in CVDs in recent years.

Antibacterial and antioxidant potentials, detection of host origin compounds, and metabolic profiling of endophytic Bacillus spp. isolated from Rauvolfia serpentina (L.) Benth. ex Kurz

The research highlights the importance of exploring endophytic microbiomes of medicinal plants to uncover their potential for secondary metabolite production and their role in the biosynthesis of host-derived compounds. This study was aimed to isolate leaf endophytic bacteria of Rauvolfia serpentina, investigate their antibacterial, antioxidant potentials and detect host-origin compound reserpine using Reverse Phase High-Performance Liquid Chromatography (RPHPLC). Untargeted analysis via Ultra High-Performance Liquid Chromatography-High-Resolution Mass Spectrometry (UHPLC-HRMS/MS) was conducted for profiling main phytochemicals in the leaves and to explore potential bioactive compounds in bacterial extracts. Nine bacterial isolates were obtained from R. serpentina leaves. These isolates exhibited positive results in various biochemical tests including indole production, methyl red, Voges-Proskauer, citrate utilization, catalase and oxidase production, nitrate reduction, oxidative fermentation, and citrate reduction tests. Endophytic isolates RSLB3 and RSLB18 exhibited most potential antibacterial activity against tested human pathogenic bacteria and were identified as Bacillus sp. The extract of RSLB3 and RSLB18 also showed significant antioxidant activity compared to leaf extract. The total phenol content was similar in both these isolates while flavonoids content and DPPH scavenging activity was higher in isolate RSLB3. RPHPLC analysis confirmed the presence of reserpine in bacterial metabolites when compared to a standard reference. UHPLC-HRMS profiling unveiled a diverse range of host-derived compounds and reaction intermediates with known and unknown bioactive properties in leaf extract, RSLB3, and RSLB18. To our knowledge, this is the first study to achieve a comprehensive profiling.

Advances in antitumor effects of pterostilbene and its derivatives

Pterostilbene (PT) is a naturally occurring small molecule stilbenoid that has garnered significant attention due to its potential therapeutic effects in tumor diseases. In this review, we conducted a comprehensive analysis of the antitumor effects of PT and its derivatives on various cancer types, including colon, breast, liver, lung, and pancreatic cancers in recent 20 years. We have succinctly summarized the PT derivatives that exhibit superior anti-tumor efficacy compared to PT. Additionally, we reviewed the potential structure-activity relationship (SAR) rules and clinical application methods to establish a foundation for chemical modification and clinical utilization of stilbene compounds.

Pterostilbene Induces Pyroptosis in Breast Cancer Cells through Pyruvate Kinase 2/Caspase-8/Gasdermin C Signaling Pathway

The incidence and mortality of breast cancer increase year by year, and it is urgent to find high-efficiency and low-toxicity anti-cancer drugs. Pterostilbene (PTE) is a natural product with antitumor activity, but the specific antitumor mechanism is not very clear. Aerobic glycolysis is the main energy supply for cancer cells. Pyroptosis is an inflammatory, programmed cell death. The aim of this study was to investigate the effect of PTE on glycolysis and pyroptosis in EMT6 and 4T1 cells and the specific mechanism, and to elucidate the role of pyruvate kinase 2 (PKM2), a key enzyme in glycolysis, in the antitumor role of PTE. Our study suggested that PTE induced pyroptosis by inhibiting tumor glycolysis. PKM2 played an important role in both the inhibition of glycolysis and the induction of pyroptosis by PTE.

Effects of Pterostilbene on Cardiovascular Health and Disease

Pterostilbene is a phenolic compound commonly found in blueberries, peanuts, grapes, and other plants. It is a dimethoxy derivative of resveratrol. In recent years, it has gained significant attention due to its remarkable anti-inflammatory and antioxidant effects. In addition, its high bioavailability and low toxicity in many species has contributed to its promising research prospects. Cardiovascular disease is closely related to pathological processes such as inflammation and oxidative stress, which aligns well with the treatment applications of pterostilbene. As a result, numerous studies have investigated the effects of pterostilbene on cardiovascular health and disease. This paper summarizes the current research on pterostilbene, with a specific focus on its potential therapeutic role in treating cardiovascular disease.

Targeting the smooth muscle cell KEAP1-Nrf2-STING axis with pterostilbene attenuates abdominal aortic aneurysm

BACKGROUND

Abdominal aortic aneurysm (AAA) is a life-threatening aortic disease, and to date, there are currently no effective pharmacological treatments to address this condition. Activation of cytosolic DNA sensing adaptor stimulator of interferon genes (STING) signaling is a crucial mechanism in AAA formation.

PURPOSE

This study investigated pterostilbene (Pt), a naturally occurring polyphenol and resveratrol analogue, as a STING inhibitor for preventing AAA.

METHODS

We evaluated the effect of Pt on AAA formation in angiotensin II (AngII)-infused apolipoprotein E-deficient (ApoE-/-) mice. We used histological analysis, MMP activity measurement, western blot, and immunohistochemistry to detect AAA formation and development. We applied RNA sequencing, molecular docking, cellular thermal shift assay (CETSA) and functional studies to dissect the molecular mechanism of Pt-regulating KEAP1-Nrf2-STING signaling. We conditionally knocked down Nrf2 in vascular smooth muscle cells (VSMCs) in vivo to investigate its role in Pt-mediated protective effects on AAA.

RESULTS

Pt effectively blocked the formation of AAA in AngII-infused ApoE-/- mice. Whole transcriptome sequencing analysis revealed that nuclear factor erythroid 2-related factor 2 (Nrf2) and STING pathway in VSMCs were linked to the anti-AAA effects of pterostilbene. Mechanistically, Pt upregulated Nrf2 target genes (e.g., HO-1 and NQO1) through activation of the KEAP1/Nrf2 signaling, which restricted the immunostimulatory axis of mtDNA-STING-TBK1-NF-κB, thereby alleviating VSMC inflammation and preserving the VSMC contractile phenotype. Subsequently, molecular docking and CETSA revealed a binding mode between Pt and KEAP1/Nrf2. Intriguingly, the inhibitory effect of Pt on STING signaling and the protective role of Pt in AAA were largely abrogated by VSMC-specific Nrf2 knockdown in mice.

CONCLUSION

Collectively, naturally derived Pt shows promising efficacy for the treatment of AAA by targeting the KEAP1-Nrf2-STING axis in VSMCs.

A Structure-Activity Relationship Study of Amino Acid Derivatives of Pterostilbene Analogues Toward Human Breast Cancer

Pterostilbene is the dimethylated analogue of Resveratrol, a compound with well-known biological activities, such as antioxidant, chemopreventive, anti-diabetic, anti-obesity, and cardioprotective. Despite many studies on the general effect of such polyphenolic molecules and their derivatives, a deep comprehension of their action and systematic structure-activity relationship studies are still rare. Herein, three different analogues of functionalizable Pterostilbene were efficiently synthesized and derivatized with a selected library of antioxidant amino acids, allowing for a highly diversified exploration of the chemical space. The library was analyzed towards cancer cells. Collectively, our data demonstrated the enhanced anti-proliferative activity of Tryptophan-conjugated compounds. In breast cancer cells, the treatment with Tryptophan-conjugated analogues induced the activation of cellular stress pathways, including autophagy signaling.

Phytonutrients in the promotion of healthspan: a new perspective

Considering a growing, aging population, the need for interventions to improve the healthspan in aging are tantamount. Diet and nutrition are important determinants of the aging trajectory. Plant-based diets that provide bioactive phytonutrients may contribute to offsetting hallmarks of aging and reducing the risk of chronic disease. Researchers now advocate moving toward a positive model of aging which focuses on the preservation of functional abilities, rather than an emphasis on the absence of disease. This narrative review discusses the modulatory effect of nutrition on aging, with an emphasis on promising phytonutrients, and their potential to influence cellular, organ and functional parameters in aging. The literature is discussed against the backdrop of a recent conceptual framework which describes vitality, intrinsic capacity and expressed capacities in aging. This aims to better elucidate the role of phytonutrients on vitality and intrinsic capacity in aging adults. Such a review contributes to this new scientific perspective-namely-how nutrition might help to preserve functional abilities in aging, rather than purely offsetting the risk of chronic disease.

Dietary pterostilbene exerts potential protective effects by regulating lipid metabolism and enhancing antioxidant capacity on liver in broilers

Intensive breeding of broilers met the increasing demands of human for broiler products, but it raised their increased susceptibility to various stressors resulting in the disorder of lipid metabolism. Pterostilbene, the methoxylated analogue of resveratrol, exhibits astonishing functions of antioxidant, anti-inflammatory and glycolipid regulatory. The study aimed to elucidate the protective effects of pterostilbene on broiler liver and to explore the potential mechanisms. A total of 480 one-day-old male Arbor Acres (AA) broilers were randomly divided into four groups: the control group (basal diet) and pterostilbene groups (PT200, PT400, and PT600 feeding with basal diet containing 200, 400 and 600 mg/kg pterostilbene, respectively). The results showed that the dietary pterostilbene supplementation significantly improved the ADG of broilers. Dietary pterostilbene supplementation regulated the expression levels of the genes Sirt1 and AMPK and the downstream genes related to lipid metabolism to protect liver function and reduce lipid accumulation in broilers. Dietary pterostilbene supplementation upregulated the expression levels of the Nrf2 gene and its downstream antioxidant genes (SOD, CAT, HO-1, NQO-1, GPX) and phase II detoxification enzyme-related genes (GST, GCLM, GCLC). Collectively, pterostilbene was confirmed the positive effects as a feed additive on lipid metabolism and antioxidant via regulating Sirt1/AMPK and Nrf2 signalling pathways in broilers.

Polystyrene nanoplastics exposure triggers spermatogenic cell senescence via the Sirt1/ROS axis

Polystyrene nanoplastics (PS-NPs) have been reported to accumulate in the testes and constitute a new threat to reproductive health. However, the exact effects of PS-NPs exposure on testicular cells and the underlying mechanisms remain largely unknown. The C57BL/6 male mice were orally administered with PS-NPs (80 nm) at different dosages (0, 10, and 40 mg/kg/day) for 60 days, and GC-1 cells were treated with PS-NPs in this study. Enlarged seminiferous tubule lumens and a loose and vacuolated layer of spermatogenic cells were observed in PS-NPs-exposed mice. Spermatogenic cells which may be one of the target cells for this reproductive damage, were decreased in the mice from PS-NPs group. PS-NPs caused spermatogenic cells to undergo senescence, manifested as elevated SA-β-galactosidase activity and activated senescence-related signaling p53-p21/Rb-p16 pathways, and induced cell cycle arrest. Mechanistically, Gene Ontology (GO) enrichment suggested the key role of reactive oxygen species (ROS) in PS-NPs-induced spermatogenic cell senescence, and this result was confirmed by measuring ROS levels. Moreover, ROS inhibition partially attenuated the senescence phenotype of spermatogenic cells and DNA damage. Using the male health atlas (MHA) database, Sirt1 was filtrated as the critical molecule in the regulation of testicular senescence. PS-NPs induced overexpression of the main ROS generator Nox2, downregulated Sirt1, increased p53 and acetylated p53 in vivo and in vitro, whereas these disturbances were partially restored by pterostilbene. In addition, pterostilbene intervention significantly alleviated the PS-NPs-induced spermatogenic cell senescence and attenuated ROS burst. Collectively, our study reveals that PS-NPs exposure can trigger spermatogenic cell senescence mediated by p53-p21/Rb-p16 signaling by regulating the Sirt1/ROS axis. Importantly, pterostilbene intervention may be a promising strategy to alleviate this damage.

Folic/lactobionic acid dual-targeted polymeric nanocapsules for potential treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignant tumor that affects many patients diagnosed with hepatic cell inflammation and liver cirrhosis. Targeted polymeric nanocapsules could facilitate the internalization and accumulation of anticancer drugs. Dual-targeted folic acid/lactobionic acid-poly lactic co-glycolic acid nanocapsules (NCs) were prepared and loaded with pterostilbene (PTN) and characterized for their physicochemical properties, as well as in vitro and in vivo anticancer activity. NCs displayed a size of 222 nm, zeta potential of - 16.5 mV, and sustained release for 48 h. The IC50 of PTN NCs (5.87 ± 0.8 µg/mL) was 20 times lower than unencapsulated PTN (121.26 ± 9.42 µg/mL) on HepG2 liver cancer cells owing to the enhanced cellular uptake of the former, as delineated by flow cytometry. In vivo study on HCC-induced animals delineated the superiority of the dual-targeted NCs over the unencapsulated PTN, which significantly reduced the liver markers ALT, AST, and ALP, as well as the tumor-related markers AFP and Bcl2, and elevated the anti-apoptotic marker caspase 3. Furthermore, the NCs significantly reduced the oxidative stress and exhibited almost comparable histological features to the normal group. Therefore, it can be concluded that the dual-ligated folic acid/lactobionic acid nanocapsules can be considered a promising potential treatment option for hepatocellular carcinoma.

Pterostilbene alleviates cafeteria diet-induced obesity and underlying depression in adolescent male Swiss albino mice and affects insulin resistance, inflammation, HPA axis dysfunction and SIRT1 mediated leptin-ghrelin signaling

Cafeteria diet (CD) model for in-vivo studies mimics the western diet having imbalanced nutritional value, high caloric-density and palatability. Uncontrolled eating leads to the development of childhood obesity, poor self-esteem and depression due to its effects on brain development. Herbal supplements are novel inclusion in the management of obesity and mental well-being. Pterostilbene (PTE) found in blueberries and Pterocarpus marsupium heartwood, is known to prevent obesity in invivo models. Adolescent Swiss albino male mice were fed on CD for 70 days and the development of obesity was assessed by gain in body weight, abdominal circumference. Forced swim and tail suspension test confirmed depression in CD fed mice. Obesity induced depressed (OID) mice were treated with PTE (10, 20, 40 mg/kg), standard antiobesity drug cetilistat (10 mg/kg), antidepressant fluoxetine (10 mg/kg) for 28 days. Post treatment, PTE-treated mice showed reduction in BW and depression-like behavior analysed using paradigms such as sucrose preference, open field, marble burying, and resident intruder test in comparison to the CD group. Insulin resistance, lipid profile, antioxidant enzyme, inflammatory cytokines (NF-κB, IL-6, TNF α) and cortisol levels were mitigated by PTE. It also restored normal cellular architecture of the brain and adipose tissue and increased the Silent mating type information regulation 2 homolog1 (SIRT1), leptin and ghrelin receptors gene expression in the brain. Thus, it can be concluded that PTE might have inhibited OID like behavior in mice via inhibition of IR, modulating neuroinflammation and hypothalamic-pituitary-adrenal axis dysfunction and upregulating SIRT1 mediated leptin-ghrelin signaling.

Therapeutic effect and mechanism of action of pterostilbene nano drugs in dry eye models

Dry eye disease is a multifactorial dysfunction of the tear film and ocular surface, with etiology involving inflammation and oxidative stress on the ocular surface. Pterostilbene (PS) is a secondary metabolite extracted from plants, which possesses remarkable anti-inflammatory and antioxidant effects. However, its application is limited by light instability and very poor water solubility. We modified fat-soluble PS into a biparental pterostilbene-glutaric anhydride-arginine-glycine-aspartic acid (PS-GA-RGD) nanomedicine by prodrug ligation of functional peptides. The aim of this study was to explore the protective effect and potential mechanism of PS-GA-RGD on dry eye disease in vitro and in vivo. We demonstrated good long-term biocompatibility of PS-GA-RGD through rabbit eye stimulation test. Lipopolysaccharide (LPS) was used to induce murine macrophages RAW 264.7 to establish an inflammation and oxidative stress model. In this model, PS-GA-RGD effectively reduced the production of ROS and 8-OHdG, enhancing the expression of antioxidant factor Nrf2 and antioxidant enzyme heme oxygenase-1. In addition, the expression of NF-κB inflammatory pathway significantly increased in LPS-induced RAW 264.7 cells, while PS-GA-RGD could significantly reduce this pathway. Hypertonic saline was utilized to establish a hypertonic model of human corneal epithelial cells. PS-GA-RGD was found to significantly reduce the production of ROS and NLRP3 inflammasomes in this model, exhibiting superior efficacy compared to PS. Experimental dry eye animal models were co-induced with subcutaneous injection of scopolamine and an intelligently controlled environmental system. We demonstrated that PS-GA-RGD nano drugs can prevent and reduce corneal epithelial cell defects and apoptosis, protect conjunctival goblet cells, and have an excellent anti-inflammatory effect. Finally, we demonstrated that RGD sequence in PS-GA-RGD can enhance cellular uptake, corneal retention, and penetration, thereby increasing their bioavailability and efficacy by a cell uptake assay and rabbit corneal drug retention experiment. Overall, this study highlights the potential of PS-GA-RGD nanomedicines in the treatment of dry eyes.

Recent advances in drug delivery systems based on natural and synthetic polymes for treating obesity

Obesity stands as a pervasive global public health issue, posing a formidable threat to human well-being as its prevalence continues to surge year by year. Presently, pharmacological treatment remains the favored adjunct strategy for addressing obesity. However, conventional delivery methods suffer from low bioavailability and the potential for side effects, underscoring the pressing need for more efficient and targeted delivery approaches. Recent research has delved extensively into emerging drug delivery systems employing polymers as carriers, with numerous preclinical studies contributing to the growing body of knowledge. This review concentrates on the utilization of natural polymers as drug delivery systems for the treatment of obesity, encompassing recent advancements in both natural and synthetic polymers. The comprehensive exploration includes an analysis of the advantages and disadvantages associated with these polymer carriers. The examination of these characteristics provides valuable insights into potential future developments in the field of drug delivery for obesity treatment.

Therapeutic potential of stilbenes in neuropsychiatric and neurological disorders: A comprehensive review of preclinical and clinical evidence

Neuropsychiatric disorders are anticipated to be a leading health concern in the near future, emphasizing an outstanding need for the development of new effective therapeutics to treat them. Stilbenes, with resveratrol attracting the most attention, are an example of multi-target compounds with promising therapeutic potential for a broad array of neuropsychiatric and neurological conditions. This review is a comprehensive summary of the current state of research on stilbenes in several neuropsychiatric and neurological disorders such as depression, anxiety, schizophrenia, autism spectrum disorders, epilepsy, traumatic brain injury, and neurodegenerative disorders. We describe and discuss the results of both in vitro and in vivo studies. The majority of studies concentrate on resveratrol, with limited findings exploring other stilbenes such as pterostilbene, piceatannol, polydatin, tetrahydroxystilbene glucoside, or synthetic resveratrol derivatives. Overall, although extensive preclinical studies show the potential benefits of stilbenes in various central nervous system disorders, clinical evidence on their therapeutic efficacy is largely missing.

Resveratrol inhibits respiratory syncytial virus replication by targeting heparan sulfate proteoglycans

Resveratrol, renowned as an antioxidant, also exhibits significant potential in combatting severe respiratory infections, particularly the respiratory syncytial virus (RSV). Nevertheless, the specific mechanism underlying its inhibition of RSV replication remains unexplored. Heparan sulfate proteoglycans (HSPGs) play a pivotal role as attachment factors for numerous viruses, offering a promising avenue for countering viral infections. Our research has unveiled that resveratrol effectively curbs RSV infection in a dose-dependent manner. Remarkably, resveratrol disrupts the early stages of RSV infection by engaging with HSPGs, rather than interacting with RSV surface proteins like fusion (F) protein and glycoprotein (G). Resveratrol's affinity appears to be predominantly directed towards the negatively charged sites on HSPGs, thus impeding the binding of viral receptors. In an in vivo study involving RSV-infected mice, resveratrol demonstrates its potential by ameliorating pulmonary pathology. This improvement is attributed to the inhibition of pro-inflammatory cytokine expression and a reduction in viral load within the lungs. Notably, resveratrol specifically alleviates inflammation characterized by an abundance of neutrophils in RSV-infected mice. In summation, our data first shows how resveratrol combats RSV infection through interactions with HSPGs, positioning it as a promising candidate for innovative drug development targeting RSV infections. Our study provides insight into the mechanism of resveratrol antiviral infection.

E-Stilbenes: General Chemical and Biological Aspects, Potential Pharmacological Activity Based on the Nrf2 Pathway

Stilbenes are phytoalexins, and their biosynthesis can occur through a natural route (shikimate precursor) or an alternative route (in microorganism cultures). The latter is a metabolic engineering strategy to enhance production due to stilbenes recognized pharmacological and medicinal potential. It is believed that in the human body, these potential activities can be modulated by the regulation of the nuclear factor erythroid derived 2 (Nrf2), which increases the expression of antioxidant enzymes. Given this, our review aims to critically analyze evidence regarding E-stilbenes in human metabolism and the Nrf2 activation pathway, with an emphasis on inflammatory and oxidative stress aspects related to the pathophysiology of chronic and metabolic diseases. In this comprehensive literature review, it can be observed that despite the broad number of stilbenes, those most frequently explored in clinical trials and preclinical studies (in vitro and in vivo) were resveratrol, piceatannol, pterostilbene, polydatin, stilbestrol, and pinosylvin. In some cases, depending on the dose/concentration and chemical nature of the stilbene, it was possible to identify activation of the Nrf2 pathway. Furthermore, the use of some experimental models presented a challenge in comparing results. In view of the above, it can be suggested that E-stilbenes have a relationship with the Nrf2 pathway, whether directly or indirectly, through different biological pathways, and in different diseases or conditions that are mainly related to inflammation and oxidative stress.

Pterostilbene in the treatment of inflammatory and oncological diseases

Pterostilbene (PTS), a naturally occurring analog of resveratrol (RSV), has garnered significant attention due to its potential therapeutic effects in treating inflammatory and oncological diseases. This comprehensive review elucidates the pharmacological properties, mechanisms of action, and therapeutic potential of PTS. Various studies indicate that PTS exhibits anti-inflammatory, antioxidant, and antitumour properties, potentially making it a promising candidate for clinical applications. Its influence on regulatory pathways like NF-κB and PI3K/Akt underscores its diverse strategies in addressing diseases. Additionally, PTS showcases a favorable pharmacokinetic profile with better oral bioavailability compared to other stilbenoids, thus enhancing its therapeutic potential. Given these findings, there is an increased interest in incorporating PTS into treatment regimens for inflammatory and cancer-related conditions. However, more extensive clinical trials are imperative to establish its safety and efficacy in diverse patient populations.

Pterostilbene alleviates abdominal aortic aneurysm via inhibiting macrophage pyroptosis by activating the miR-146a-5p/TRAF6 axis

Pterostilbene (PTE), a natural stilbene found in blueberries and several varieties of grapes, has several pharmacological activities, including anti-inflammatory and antioxidative activities. However, its role in abdominal aortic aneurysm (AAA), which is a severe inflammatory vascular disease, remains incompletely understood. In this study, we investigated the protective effects of natural stilbene PTE on AAA formation and the underlying mechanism. Two AAA mouse models (Ang II-induced model and PPE-induced model) were used to examine the effect of PTE on AAA formation. We showed that PTE administration attenuated AAA formation in mice. Furthermore, we found that PTE significantly inhibited inflammatory responses in mouse aortas, as PTE suppressed macrophage pyroptosis and prevented macrophage infiltration in aortas, resulting in reduced expression of pro-inflammatory cytokines in aortas. We also observed similar results in LPS + ATP-treated Raw 264.7 cells (a macrophage cell line) and primary peritoneal macrophages in vitro. We showed that pretreatment with PTE restrained inflammatory responses in macrophages by inhibiting macrophage pyroptosis. Mechanistically, miR-146a-5p and TRAF6 interventions in vivo and in vitro were used to investigate the role of the miR-146a-5p/TRAF6 axis in the beneficial effect of PTE on macrophage pyroptosis and AAA. We found that PTE inhibited macrophage pyroptosis by miR-146a-5p-mediated suppression of downstream TRAF6 expression. Moreover, miR-146a-5p knockout or TRAF6 overexpression abrogated the protective effect of PTE on macrophage pyroptosis and AAA formation. These findings suggest that miR-146a-5p/TRAF6 axis activation by PTE protects against macrophage pyroptosis and AAA formation. PTE might be a promising agent for preventing inflammatory vascular diseases, including AAA.

Podophyllotoxin: Recent Advances in the Development of Hybridization Strategies to Enhance Its Antitumoral Profile

Podophyllotoxin is a naturally occurring cyclolignan isolated from rhizomes of Podophyllum sp. In the clinic, it is used mainly as an antiviral; however, its antitumor activity is even more interesting. While podophyllotoxin possesses severe side effects that limit its development as an anticancer agent, nevertheless, it has become a good lead compound for the synthesis of derivatives with fewer side effects and better selectivity. Several examples, such as etoposide, highlight the potential of this natural product for chemomodulation in the search for new antitumor agents. This review focuses on the recent chemical modifications (2017-mid-2023) of the podophyllotoxin skeleton performed mainly at the C-ring (but also at the lactone D-ring and at the trimethoxyphenyl E-ring) together with their biological properties. Special emphasis is placed on hybrids or conjugates with other natural products (either primary or secondary metabolites) and other molecules (heterocycles, benzoheterocycles, synthetic drugs, and other moieties) that contribute to improved podophyllotoxin bioactivity. In fact, hybridization has been a good strategy to design podophyllotoxin derivatives with enhanced bioactivity. The way in which the two components are joined (directly or through spacers) was also considered for the organization of this review. This comprehensive perspective is presented with the aim of guiding the medicinal chemistry community in the design of new podophyllotoxin-based drugs with improved anticancer properties.

Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats

Environmental hazards are an increasing concern due to the rapid pace of industrialization. Among these hazards, noise and carbon monoxide (CO) are common risk factors and have been shown to cause serious health problems. However, existing studies focused on the individual effects of noise and CO exposure and the combined effects of these two factors remain poorly understood. Our study aimed to examine the combined effects of noise and CO exposure on testicular function by constructing individual and combined exposure models. Our findings indicated that combined exposure to noise and CO was associated with a higher risk of testicular damage and male reproductive damage when compared to exposure alone. This was evidenced by poorer semen quality and more severe pathological damage to the testis. This combined exposure led to higher levels of oxidative stress and apoptosis in the testes, with bioinformatics analyses suggesting the signaling pathways involved in these responses. Specifically, activation of the P53 signaling pathway was found to contribute to the testicular damage caused by the combined exposure. Encouragingly, pterostilbene (PTE), a novel phytochemical, alleviated combined exposure-induced testicular damage by reducing oxidative stress and germ cell apoptosis. Overall, we identified joint reproductive toxicity resulting from the exposure to noise and CO, and found that PTE is a promising potential treatment for injuries caused by these factors. The cover image is based on the Research Article Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats by Yingqing Li et al., https://doi.org/10.1002/tox.23927.

The pterostilbene-dihydropyrazole derivative Ptd-1 ameliorates vascular calcification by regulating inflammation

Vascular calcification is an independent risk factor for cardiovascular disease. However, there is still a lack of adequate treatment. This study aimed to examine the potential of (E)-1-(5-(2-(4-fluorobenzyloxy)Styryl)-4,6-dimethoxyphenyl)-3-methyl-4,5-dihydro-1H-pyrazole-1-yl) ethyl ketone (Ptd-1) to alleviate vascular calcification. ApoE-deficient mice were fed a high-fat diet for 12/16 weeks to induce intimal calcification, and wild-type mice were induced with a combination of nicotine and vitamin D3 to induce medial calcification. Human aortic smooth muscle cells (HASMCs) and aortic osteogenic differentiation were induced in vitro with phosphate. In the mouse model of atherosclerosis, Ptd-1 significantly ameliorated the progression of atherosclerosis and intimal calcification, and there were significant reductions in lipid deposition and calcium salt deposition in the aorta and aortic root. In addition, Ptd-1 significantly improved medial calcification in vivo and osteogenic differentiation in vitro. Mechanistically, Ptd-1 reduced the levels of the inflammatory factors IL-1β, TNFα and IL-6 in vivo and in vitro. Furthermore, we demonstrated that Ptd-1 could attenuate the expression of p-ERK1/2 and β-catenin, and that the levels of inflammatory factors were elevated in the presence of ERK1/2 and β-catenin agonists. Interestingly, we determined that activation of the ERK1/2 pathway promoted β-catenin expression, which further regulated the IL-6/STAT3 signaling pathway. Ptd-1 blocked ERK1/2 signaling, leading to decreased expression of inflammatory factors, which in turn improved vascular calcification. Taken together, our study reveals that Ptd-1 ameliorates vascular calcification by regulating the production of inflammatory factors, providing new ideas for the treatment of vascular calcification.

Protective potential of pterostilbene against cyclophosphamide-induced nephrotoxicity and cystitis in rats

PURPOSE

Cyclophosphamide (CYP) is an antitumor drug. However, in addition to its antitumor affect, CYP can also lead to nephrotoxicity and hemorrhagic cystitis. The purpose of this study was to investigate the potential protective effects of Pterostilbene (Pte), a natural antioxidant as a resveratrol analog against CYP-induced nephrotoxicity and cystitis in rats.

METHODS

Twenty-one male Sprague Dawley rats were divided into 3 equal groups. The control group and the CYP group (CYPG) received 1 ml/kg sunflower oil per day, and the CYP + Pte group (CYP + PteG) 40 mg/kg per day Pte dissolved in sunflower oil once a day via the oral route for 14 days. In addition, on day 9 of the experiment, CYPG and CYP + PteG received a single dose of 200 mg/kg CYP dissolved in saline solution, while the control group received a single dose of 10 ml/kg saline solution, via the intraperitoneal route. Bladder and kidney tissues were collected for histological and biochemical evaluations.

RESULTS

Pte was observed to reduce CYP-derived increases in malondialdehyde level, total oxidant status (TOS), the oxidative stress index (OSI), and apoptosis in kidney tissues and to cause an increase in superoxide dismutase levels. It also reduced CYP-derived increases in TOS, OSI, and apoptosis in bladder tissue. Moreover, Pte also ameliorated histopathological findings associated with CYP-induced tissue damage in both the kidney and bladder.

CONCLUSION

Our study findings show that Pte may exhibit a protective effect against CYP-induced nephrotoxicity and cystitis.

Unlocking the therapeutic potential of natural stilbene: Exploring pterostilbene as a powerful ally against aging and cognitive decline

The therapeutic potential of natural stilbenes, with a particular focus on pterostilbene (PTE), has emerged as a promising avenue of research targeting age-associated conditions encompassing cardiovascular diseases (CVD), diabetes mellitus (DM), and cognitive decline. This comprehensive investigation delves into the intricate mechanisms through which PTE, a polyphenolic compound abundant in grapes and blueberries, exerts its advantageous effects as an anti-aging agent. Central to its action is the modulation of hallmark aging processes, including oxidative damage, inflammatory responses, telomere attrition, and cellular senescence. PTE's ability to effectively penetrate the blood-brain barrier amplifies its potential for safeguarding neural health, thereby facilitating the regulation of neuronal signalling cascades, synaptic plasticity, and mitochondrial functionality. Through engagement with sirtuin proteins, it orchestrates cellular resilience, longevity, and metabolic equilibrium. Encouraging findings from preclinical studies portray PTE as a robust candidate for counteracting age-linked cognitive decline, augmenting memory consolidation, and potentially ameliorating neurodegenerative maladies such as Alzheimer's disease (AD). The synthesis of current scientific insights accentuates the promising translational prospects of PTE as a potent, naturally derived therapeutic agent against cognitive impairments associated with aging. Consequently, these collective findings lay a solid groundwork for forthcoming clinical inquiries and innovative therapeutic interventions in this realm.

The Effects of Antioxidants and Pulsed Magnetic Fields on Slow and Fast Skeletal Muscle Atrophy Induced by Streptozotocin: A Preclinical Study

Results

Our findings suggest that antioxidants and PMF may alleviate impaired protein synthesis and degradation pathways in skeletal muscle atrophy. PTS showed a positive effect on the anabolic pathway, while RSV and PMF demonstrated potential for ameliorating the catabolic pathway. Notably, the combination therapy of antioxidants and PMF exhibited a stronger ameliorative effect on skeletal muscle atrophy than either intervention alone.

Conclusion

The present results highlight the benefits of employing a multimodal approach, involving both antioxidant and PMF therapy, for the management of muscle-wasting conditions. These treatments may have potential therapeutic implications for skeletal muscle atrophy.

Characterization of the molecular interactions between resveratrol derivatives and death-associated protein kinase 1

Death-associated protein kinase 1 (DAPK1), a Ca2+/calmodulin-regulated serine/threonine kinase, regulates cell apoptosis and autophagy and has been implicated in the pathogenesis of Alzheimer's disease (AD). Targeting DAPK1 may be a promising approach for treating AD. In our previous study, we found that a natural polyphenol, resveratrol (1), is a moderate DAPK1 inhibitor. In the present study, we investigated the interactions between natural and synthetic derivatives of 1 and DAPK1. Binding assays including intrinsic fluorescence quenching, protein thermal shift and isothermal titration calorimetry indicated that oxyresveratrol (3), a hydroxylated derivative, and pinostilbene (5), a methoxylated derivative, bind to DAPK1 with comparable affinity to 1. The enzymatic assay showed that 3 more effectively inhibits the intrinsic ATPase activity of DAPK1 compared with 1. Crystallographic analysis revealed that the binding modes of the methoxylated derivatives were different from those of 1 and 3, resulting in a unique interaction. Our results suggest that 3 may be helpful in treating AD and provide a clue for the development of promising DAPK1 inhibitors.

Synthesis, In Vitro, and In Vivo Investigations of Pterostilbene-Tethered Analogues as Anti-Breast Cancer Candidates

Pterostilbene has been found to be an active scaffold with anti-breast cancer (BC) action. In this study, fourteen pterostilbene-tethered analogues (2A-2N) were prepared and screened in vitro against MDA-MB-231 and MCF-7 cells. Meanwhile, their structures were characterized using ¹H-NMR, ¹³C-NMR, and HRMS (ESI) spectroscopy techniques. Among them, analogue 2L displayed the most potent anti-proliferation effect on MDA-MB-231 (IC₅₀ = 10.39 μM) and MCF-7 cells (IC₅₀ = 11.73 μM). Furthermore, the meaningful structure-activity relationships suggested that the introduction of a saturated six-membered nitrogen heterocyclic ring into the side chain favored anti-BC capacity. Biological observations indicated that 2L could cause the typical morphological changes in apoptosis, namely an increase in reactive oxygen species level and a loss of mitochondrial membrane potential in BC cells. Importantly, 2L could induce mitochondrial-mediated apoptosis by regulating the expression of caspase-related proteins. Consistent with the results of our in vitro study, 2L apparently inhibited tumor growth in MDA-MB-231 xenograft mice without obvious toxicity. These findings revealed that 2L is expected to be a promising anti-BC lead compound that merits further investigations.

Pterostilbene and Probiotic Complex in Chemoprevention of Putative Precursor Lesions for Colorectal Cancer in an Experimental Model of Intestinal Carcinogenesis with 1,2-Dimethylhydrazine

Dietary supplementation with pterostilbene (PS) and/or a probiotic (PRO) may ameliorate the intestinal microbiota in disease conditions. This study aims to evaluate PS and PRO for the chemoprevention of putative precursor lesions for colorectal cancer (CRC) in an experimental model of intestinal carcinogenesis with 1,2-dimethylhydrazine (1,2-DMH). Sixty male Wistar rats were equally divided into five groups: Sham, 1,2-DMH, 1,2-DMH + PS, 1,2-DMH + PRO, and 1,2-DMH + PS + PRO. PRO (5 × 107/mL) was offered in water, and PS (300 ppm) was provided in the diet ad libitum. 1,2-DMH (20 mg/kg/week) was administered for 15 consecutive weeks. In the 25th week, proctocolectomy was conducted. PRO alone and PRO combined with PS were the best intervention strategies to improve experimental 1,2-DMH-induced CRC regarding several parameters of carcinogenesis. Our findings may contribute to the development of novel preventive strategies for CRC and may help to identify novel modulators of colon carcinogenesis.

Amorphous Pterostilbene Delivery Systems Preparation-Innovative Approach to Preparation Optimization

The aim of our research was to improve the solubility and antioxidant activity of pterostilbene (PTR) by developing a novel amorphous solid dispersion (ASD) with Soluplus^® (SOL). DSC analysis and mathematical models were used to select the three appropriate PTR and SOL weight ratios. The amorphization process was carried out by a low-cost and green approach involving dry milling. An XRPD analysis confirmed the full amorphization of systems in 1:2 and 1:5 weight ratios. One glass transition (T_g) observed in DSC thermograms confirmed the complete miscibility of the systems. The mathematical models indicated strong heteronuclear interactions. SEM micrographs suggest dispersed PTR within the SOL matrix and a lack of PTR crystallinity, and showed that after the amorphization process, PTR-SOL systems had a smaller particle size and larger surface area compared with PTR and SOL. An FT-IR analysis confirmed that hydrogen bonds were responsible for stabilizing the amorphous dispersion. HPLC studies showed no decomposition of PTR after the milling process. PTR's apparent solubility and antioxidant activity after introduction into ASD increased compared to the pure compound. The amorphization process improved the apparent solubility by ~37-fold and ~28-fold for PTR-SOL, 1:2 and 1:5 w/w, respectively. The PTR-SOL 1:2 w/w system was preferred due to it having the best solubility and antioxidant activity (ABTS: IC₅₀ of 56.389 ± 0.151 µg·mL^-1 and CUPRAC: IC_0.5 of 82.52 ± 0.88 µg·mL^-1).

Pterostilbene-Mediated Inhibition of Cell Proliferation and Cell Death Induction in Amelanotic and Melanotic Melanoma

Melanoma is one of the fastest-growing cancers worldwide. Treatment of advanced melanoma is very difficult; therefore, there is growing interest in the identification of new therapeutic agents. Pterostilbene is a natural stilbene that has been found to have several pharmacological activities. The aim of this study was to evaluate the influence of pterostilbene on the proliferation and apoptosis of human melanoma cells. Proliferation of pterostilbene-treated amelanotic (C32) and melanotic (A2058) melanoma cells was determined by BRDU assay. Flow cytometric analyses were used to determine cell cycle progression, and further molecular investigations were performed using real-time RT-qPCR. The expression of the p21 protein and the DNA fragmentation assay were determined by the ELISA method. The results revealed that pterostilbene reduced the proliferation of both amelanotic and melanotic melanoma cells. Pterostilbene induced apoptosis in amelanotic C32 melanoma cells, and this effect was mediated by an increase in the expression of the BAX, CASP9, and CASP9 genes; induction of caspase 3 activity; and DNA degradation. Pterostilbene did not affect the activation of apoptosis in the A2058 cell line. It may be concluded that pterostilbene has anticancer potential against human melanoma cells; however, more studies are still needed to fully elucidate the effects of pterostilbene on amelanotic and melanotic melanoma cells.

Pterostilbene alleviated NAFLD via AMPK/mTOR signaling pathways and autophagy by promoting Nrf2

BACKGROUND

NAFLD is a liver disease that is caused by liver damage or extreme lipid deposition but not alcohol. Nrf2 could mediate resistance to oxidative stress injury. Autophagy can degrade metabolic waste and accumulated toxic endogenous substances. Pterostilbene (PTE) is an active compound extracted from blueberry, and grape, that exhibits many biological effects, such as antiinflammation and antitumor.

PURPOSE

This study provides a mechanism of PTE affecting on oxidative stress and autophagy in NAFLD mice. Tyloxapol, oil acid (OA) and palmitic acid (PA) were used to induce lipid accumulation in mice and HepG2 cells.

METHODS

Western blotting, CRISPR/Cas 9 and other molecular biological approaches were applied to explore the mechanisms of PTE effected on NAFLD.

RESULTS

PTE pretreatment effectively reduced the lipid accumulation in OA and PA induced HepG2 cells and tyloxapol induced mice, and significantly promoted the expression of nNrf2, PPAR-α and HO-1, and AMPK activity, but inhibited the expression of mTORC 1 and SREBP-1c. PTE activated phosphatidylinositide 3-kinase (PI3K) and proteins in the autophagy-related gene (ATG) family, and promoted the transformation of LC3Ⅰ to LC3Ⅱ which indicated the activation of autophagy, however, these effects were abolished after Nrf2 knockout.

CONCLUSION

PTE effectively alleviated oxidative stress damage induced by excessive lipid accumulation in hepatocytes, thus promoting the metabolism and decomposition of fatty acids to improve NAFLD.

A Short-Term Safety Evaluation of Silbinol®- an Extract from Pterocarpus marsupium in Healthy Adults- a Randomized, Double-Blind, Placebo-Controlled Study

Background: Pterostilbene is an active molecule from the bark of the Pterocarpus marsupium tree with antioxidant and anti-inflammatory properties. Objective: This study aimed to evaluate the clinical safety of a standardized P. marsupium extract (PME) containing 90% pterostilbene (200 mg per day) in healthy adults. Methods: In a randomized, double-blind, placebo-controlled study, 60 healthy adult participants (27 males and 33 females) were randomized to receive PME-100 mg or placebo capsule twice a day for two months. The primary objectives of the study were to assess any changes in laboratory parameters, vital signs, and the occurrence of adverse events from screening to the final visit. Serum antioxidant enzyme levels were evaluated as a secondary outcome. Results: The hematological, lipid, glycemic, thyroid profiles and liver and renal functions remained within the normal range in all participants, with no difference between PME and placebo. Vital signs, including blood pressure, pulse rate, body weight, body mass index and electrocardiogram, did not reveal any significant differences between the PME and placebo groups at the beginning and end of the study. No serious adverse events were observed in any participant throughout the study period. The serum antioxidant profile was not significantly different between the treatment groups, although the glutathione levels were relatively higher in the PME group. Conclusions: Scientific evaluation of clinical safety of standardized extract is mandatory for its use as a supplement for various health benefits. The results of this study convincingly establish the safety of PME (>90% Pterostilbene) at 200 mg/day (100 mg bid) for human use. The study was approved by the Institutional Ethics Committee of BGS Global Institute of Medical Sciences & Hospital, Bangalore with the registration number CTRI/2019/08/020736.

Pterostilbene fluorescent probes as potential tools for targeting neurodegeneration in biological applications

Several epidemiological studies suggest that a diet rich in fruit and vegetables reduces the incidence of neurodegenerative diseases. Resveratrol (Res) and its dimethylated metabolite, pterostibene (Ptb), have been largely studied for their neuroprotective action. The clinical use of Res is limited because of its rapid metabolism and its poor bioavailability. Ptb with two methoxy groups and one hydroxyl group has a good membrane permeability, metabolic stability and higher in vivo bioavailability in comparison with Res. The metabolism and pharmacokinetics of Ptb are still sparse, probably due to the lack of tools that allow following the Ptb destiny both in living cells and in vivo. In this contest, we propose two Ptb fluorescent derivatives where Ptb has been functionalised by benzofurazan and rhodamine-B-isothiocyanate, compounds 1 and 2, respectively. Here, we report the synthesis, the optical and structural characterisation of 1 and 2, and, their putative cytotoxicity in two different cell lines.

Pterostilbene Ameliorates Fumonisin B1-Induced Cytotoxic Effect by Interfering in the Activation of JAK/STAT Pathway

Fumonisin B1 (FB1) is a mycotoxin that poses a great threat to agricultural production and the health of humans and animals. Pterostilbene (PTE) is a natural plant polyphenolic compound with good anti-inflammatory, antioxidant and cell regeneration effects, yet its effectiveness in treating FB1-induced cytotoxicity remains to be explored. In this study, we used porcine alveolar macrophages (3D4/21) as a model to characterize the cytotoxicity induced by FB1, and to investigate the potential alleviating effect of PTE on FB1-induced cytotoxicity. We demonstrate that FB1 induces cytotoxicity, apoptosis, pro-inflammatory cytokine production and mitochondrial damage, which can be largely recovered by PTE treatment, suggesting the promising application of PTE to treat FB1-induced damage. Mechanistically, FB1 activates the JAK/STAT signaling pathway, while PTE attenuates FB1-induced cytotoxicity through the inhibition of key JAK/STAT genes such as JAK2 and STAT3. Overall, our study characterized the molecular mechanism for FB1-induced cytotoxicity and found PTE to be a promising component which can alleviate FB1-induced cytotoxicity by interfering in the activation of JAK/STAT pathway.

Pterostilbene attenuates intrauterine growth retardation-induced colon inflammation in piglets by modulating endoplasmic reticulum stress and autophagy

Background

Endoplasmic reticulum (ER) stress and autophagy are implicated in the pathophysiology of intestinal inflammation; however, their roles in intrauterine growth retardation (IUGR)-induced colon inflammation are unclear. This study explored the protective effects of natural stilbene pterostilbene on colon inflammation using the IUGR piglets and the tumor necrosis factor alpha (TNF-α)-treated human colonic epithelial cells (Caco-2) by targeting ER stress and autophagy.

Results

Both the IUGR colon and the TNF-α-treated Caco-2 cells exhibited inflammatory responses, ER stress, and impaired autophagic flux (P < 0.05). The ER stress inducer tunicamycin and the autophagy inhibitor 3-methyladenine further augmented inflammatory responses and apoptosis in the TNF-α-treated Caco-2 cells (P < 0.05). Conversely, pterostilbene inhibited ER stress and restored autophagic flux in the IUGR colon and the TNF-α-treated cells (P < 0.05). Pterostilbene also prevented the release of inflammatory cytokines and nuclear translocation of nuclear factor kappa B p65, reduced intestinal permeability and cell apoptosis, and facilitated the expression of intestinal tight junction proteins in the IUGR colon and the TNF-α-treated cells (P < 0.05). Importantly, treatment with tunicamycin or autophagosome-lysosome binding inhibitor chloroquine blocked the positive effects of pterostilbene on inflammatory response, cell apoptosis, and intestinal barrier function in the TNF-α-exposed Caco-2 cells (P < 0.05).

Conclusion

Pterostilbene mitigates ER stress and promotes autophagic flux, thereby improving colon inflammation and barrier dysfunction in the IUGR piglets and the TNF-α-treated Caco-2 cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00780-6.

New Insights into Dietary Pterostilbene: Sources, Metabolism, and Health Promotion Effects

Pterostilbene (PTS), a compound most abundantly found in blueberries, is a natural analog of resveratrol. Several plant species, such as peanuts and grapes, produce PTS. While resveratrol has been extensively studied for its antioxidant properties, recent evidence also points out the diverse therapeutic potential of PTS. Several studies have identified the robust pharmacodynamic features of PTS, including better intestinal absorption and elevated hepatic stability than resveratrol. Indeed, due to its higher bioavailability paired with reduced toxicity compared to other stilbenes, PTS has become an attractive drug candidate for the treatment of several disease conditions, including diabetes, cancer, cardiovascular disease, neurodegenerative disorders, and aging. This review article provides an extensive summary of the nutraceutical potential of PTS in various disease conditions while discussing the crucial mechanistic pathways implicated. In particular, we share insights from our studies about the Nrf2-mediated effect of PTS in diabetes and associated complications. Moreover, we elucidate the important sources of PTS and discuss in detail its pharmacokinetics and the range of formulations and routes of administration used across experimental studies and human clinical trials. Furthermore, this review also summarizes the strategies successfully used to improve dietary availability and the bio-accessibility of PTS.

Stilbenes: Source plants, chemistry, biosynthesis, pharmacology, application and problems related to their clinical Application-A comprehensive review

Stilbenes are some of the important phenolic compounds originating from plant families like Vitaceae, Leguminaceae, Gnetaceae, and Dipterocarpaceae. Structurally, they have a C6-C2-C6 skeleton, usually with two isomeric forms. Stilbenes are biosynthesized due to biotic and abiotic stresses such as microbial infections, high temperatures, and oxidation. This review aims to provide a comprehensive overview of stilbenes' botanical sources, chemistry, biosynthetic pathways, pharmacology, and clinical applications and challenges based on up-to-date data. All included studies were collected from PubMed, ScienceDirect, Google Scholar, and CNKI, and the presented data from these indexed studies were analyzed and summarized. A total of 459 natural stilbene compounds from 45 plant families and 196 plant species were identified. Pharmacological studies also show that stilbenes have various activities such as anticancer, antimicrobial, antioxidant, anti-inflammatory, anti-degenerative diseases, anti-diabetic, neuroprotective, anti-aging, and cardioprotective effects. Stilbene synthase (STS) is the key enzyme involved in stilbene biosynthetic pathways. Studies on the therapeutic application of stilbenes pinpoint that challenges such as low bioavailability and isomerization are the major bottlenecks for their development as therapeutic drugs. Although the medicinal uses of several stilbenes have been demonstrated in vivo and in vitro, studies on the development of stilbenes deserve more attention in the future.

Thioredoxin-1 Activation by Pterostilbene Protects Against Doxorubicin-Induced Hepatotoxicity via Inhibiting the NLRP3 Inflammasome

Background: Doxorubicin (DOX) has been widely used in cancer treatment. However, DOX can cause a range of significant side effects, of which hepatotoxicity is a common one, and therefore limits its clinical use. Pterostilbene (PTS) has been shown to exhibit anti-oxidant and anti-inflammatory effects in the treatment of liver diseases but whether PTS could protect against hepatotoxicity in DOX-treated mice is unknown.

Methods: In our study, we use C57/BL6J mice and the HepG2 cell line. We divided the mice in 4 groups: the control, the PTS treatment, the DOX treatment, and the DOX + PTS treatment group. Liver histopathology was judged by performing hematoxylin–eosin and Masson staining. Immunohistochemistry was used to perform the expression of NLRP3. The levels of serum alanine transaminase (ALT) and aspartate transaminase (AST) were evaluated. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and DCFH-DA staining were used to evaluate the oxidative injury. Western blot and real-time PCR were applied to evaluate the expressions of proteins and mRNA. MTT was used to evaluate DOX-induced cell injury and the protective effects of PTS. Recombinant Trx-1 was used to analyze the mechanism of PTS. A TUNEL assay was used to detect apoptosis in DOX-induced HepG2 cells and the protective effects of PTS.

Results: PTS ameliorated DOX-induced liver pathological changes and the levels of AST and ALT. PTS also decreased the level of MDA, increased the level of SOD, GSH, and the expression of Trx-1 in DOX-treated mice. PTS decreased the levels of NLRP3 and IL-1β mRNA and the expressions of their proteins in DOX-treated mice. In addition, PTS also decreased the expression of Cleaved Caspase-3 and BAX and increased the expression of BCL-2. In vitro, after treatment with recombinant Trx-1, ROS and NLRP3 inflammasome were both decreased. Treatment with PTS could rescue the downregulation of Trx-1, decreased the ROS level and the NLRP3 inflammasome, and protected HepG2 cells against DOX-induced apoptosis.

Conclusion: The results show that PTS exhibits protective effects against DOX-induced liver injuries via suppression of oxidative stress, fibrosis, NLRP3 inflammasome stimulation, and cell apoptosis which might lead to a new approach of preventing DOX-induced hepatotoxicity.

Pterostilbene downregulates BCR/ABL and induces apoptosis of T315I-mutated BCR/ABL-positive leukemic cells

In this study, we examined the antileukemic effects of pterostilbene, a natural methylated polyphenol analog of resveratrol that is predominantly found in berries and nuts, using various human and murine leukemic cells, as well as bone marrow samples obtained from patients with leukemia. Pterostilbene administration significantly induced apoptosis of leukemic cells, but not of non-malignant hematopoietic stem/progenitor cells. Interestingly, pterostilbene was highly effective in inducing apoptosis of leukemic cells harboring the BCR/ABL fusion gene, including ABL tyrosine kinase inhibitor (TKI)-resistant cells with the T315I mutation. In BCR/ABL⁺ leukemic cells, pterostilbene decreased the BCR/ABL fusion protein levels and suppressed AKT and NF-κB activation. We further demonstrated that pterostilbene along with U0126, an inhibitor of the MEK/ERK signaling pathway, synergistically induced apoptosis of BCR/ABL⁺ cells. Our results further suggest that pterostilbene-promoted downregulation of BCR/ABL involves caspase activation triggered by proteasome inhibition-induced endoplasmic reticulum stress. Moreover, oral administration of pterostilbene significantly suppressed tumor growth in mice transplanted with BCR/ABL⁺ leukemic cells. Taken together, these results suggest that pterostilbene may hold potential for the treatment of BCR/ABL⁺ leukemia, in particular for those showing ABL-dependent TKI resistance.

Multiple Mechanisms Converging on Transcription Factor EB Activation by the Natural Phenol Pterostilbene

Pterostilbene (Pt) is a potentially beneficial plant phenol. In contrast to many other natural compounds (including the more celebrated resveratrol), Pt concentrations producing significant effects in vitro can also be reached with relative ease in vivo. Here we focus on some of the mechanisms underlying its activity, those involved in the activation of transcription factor EB (TFEB). A set of processes leading to this outcome starts with the generation of ROS, attributed to the interaction of Pt with complex I of the mitochondrial respiratory chain, and spreads to involve Ca²⁺ mobilization from the ER/mitochondria pool, activation of CREB and AMPK, and inhibition of mTORC1. TFEB migration to the nucleus results in the upregulation of autophagy and lysosomal and mitochondrial biogenesis. Cells exposed to several μM levels of Pt experience a mitochondrial crisis, an indication for using low doses in therapeutic or nutraceutical applications. Pt afforded significant functional improvements in a zebrafish embryo model of ColVI-related myopathy, a pathology which also involves defective autophagy. Furthermore, long-term supplementation with Pt reduced body weight gain and increased transcription levels of Ppargc1a and Tfeb in a mouse model of diet-induced obesity. These in vivo findings strengthen the in vitro observations and highlight the therapeutic potential of this natural compound.

Alginate with citrus pectin and pterostilbene as healthy food packaging with antioxidant property

A new type of film packaging made from natural polysaccharide materials, with its environmental safety and friendliness, is considered as a potential substitute for plastics. Novel polysaccharide composite films based upon citrus pectin (CP) and sodium alginate (SA) were successfully prepared and characterized, containing pterostilbene (PTE) at various concentrations (0.2, 0.4, 0.8, 1.6, 3.2 mM). The rheological analysis displayed that all film-forming liquids performed no gelation behavior with G" > G' at low frequency and weak gelation with G" < G' at high frequency. The SA-CP films had good tensile strength (TS) and elongation at break (EB), while adding PTE as an antioxidant to the film reduced both the values. Of note, the SA-CP films with PTE had better moisture resistance than that of the pure SA-CP films, which was related to the changes of its microstructure. The increased roughness of the films containing PTE was observed by microscope. After calcium chloride cross-linking, the water solubility of the films was reduced, while its thermal stability was improved. Notably, the accretion of PTE expressively enhanced the antioxidant properties of the SA-CP films. Thus, the SA-CP composite films containing PTE could be utilized as an excellent antioxidant packaging material.

Resveratrol and its derivative pterostilbene attenuate oxidative stress-induced intestinal injury by improving mitochondrial redox homeostasis and function via SIRT1 signaling

Oxidative stress inflicts mitochondrial dysfunction, which has been recognized as a key driver of intestinal diseases. Resveratrol (RSV) and its derivative pterostilbene (PTS) are natural antioxidants and exert a protective influence on intestinal health. However, the therapeutic effects and mechanisms of RSV and PTS on oxidative stress-induced mitochondrial dysfunction and intestinal injury remain unclear. The present study used porcine and cellular settings to compare the effects of RSV and PTS on mitochondrial redox homeostasis and function to alleviate oxidative stress-induced intestinal injury. Our results indicated that PTS was more potent than RSV in reducing oxidative stress, maintaining intestinal integrity, and preserving the mitochondrial function of diquat-challenged piglets. In the in vitro study, RSV and PTS protected against hydrogen peroxide (H₂O₂)-induced mitochondrial dysfunction in intestinal porcine enterocyte cell line (IPEC-J2) by facilitating mitochondrial biogenesis and increasing the activities of mitochondrial complexes. In addition, both RSV and PTS efficiently mitigated mitochondrial oxidative stress by increasing sirtuin 3 protein expression and the deacetylation of superoxide dismutase 2 and peroxiredoxin 3 in H₂O₂-exposed IPEC-J2 cells. Furthermore, RSV and PTS preserved mitochondrial membrane potential, which restrained the release of cytochrome C from mitochondria to the cytoplasm and caspase-3 activation and further reduced apoptotic rates in H₂O_2-exposed IPEC-J2 cells. Mechanistically, depletion of sirtuin 1 (SIRT1) abrogated RSV's and PTS's benefits against mitochondrial reactive oxygen species overproduction, mitochondrial dysfunction, and apoptosis in H₂O₂-exposed IPEC-J2 cells, suggesting that SIRT1 was required for RSV and PTS to protect against oxidative stress-induced intestinal injury. In conclusion, RSV and PTS improve oxidative stress-induced intestinal injury by regulating mitochondrial redox homeostasis and function via SIRT1 signaling pathway. In offering this protection, PTS is superior to RSV.

The modulation of SIRT1 and SIRT3 by natural compounds as a therapeutic target in doxorubicin-induced cardiotoxicity: A review

Doxorubicin (DOX) is a potent antitumor agent with a broad spectrum of activity; however, irreversible cardiotoxicity resulting from DOX treatment is a major issue that limits its therapeutic use. Sirtuins (SIRTs) play an essential role in several physiological and pathological processes including oxidative stress, apoptosis, and inflammation. It has been reported that SIRT1 and SIRT3 can act as a protective molecular against DOX-induced myocardial injury through targeting numerous signaling pathways. Several natural compounds (NCs), such as resveratrol, sesamin, and berberine, with antioxidative, anti-inflammation, and antiapoptotic effects were evaluated for their potential to suppress the cardiotoxicity induced by DOX via targeting SIRT1 and SIRT3. Numerous NCs exerted their therapeutic effects on DOX-mediated cardiac damage via targeting different signaling pathways, including SIRT1/LKB1/AMPK, SIRT1/PGC-1α, SIRT1/NLRP3, and SIRT3/FoxO. SIRT3 also ameliorates cardiotoxicity by enhancing mitochondrial fusion.