Determination of pterostilbene in rat plasma by a simple HPLC-UV method and its application in pre-clinical pharmacokinetic study

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.

Research progress of SIRTs activator resveratrol and its derivatives in autoimmune diseases

Autoimmune diseases (AID) have emerged as prominent contributors to disability and mortality worldwide, characterized by intricate pathogenic mechanisms involving genetic, environmental, and autoimmune factors. In response to this challenge, a growing body of research in recent years has delved into genetic modifications, yielding valuable insights into AID prevention and treatment. Sirtuins (SIRTs) constitute a class of NAD-dependent histone deacetylases that orchestrate deacetylation processes, wielding significant regulatory influence over cellular metabolism, oxidative stress, immune response, apoptosis, and aging through epigenetic modifications. Resveratrol, the pioneering activator of the SIRTs family, and its derivatives have captured global scholarly interest. In the context of AID, these compounds hold promise for therapeutic intervention by modulating the SIRTs pathway, impacting immune cell functionality, suppressing the release of inflammatory mediators, and mitigating tissue damage. This review endeavors to explore the potential of resveratrol and its derivatives in AID treatment, elucidating their mechanisms of action and providing a comprehensive analysis of current research advancements and obstacles. Through a thorough examination of existing literature, our objective is to advocate for the utilization of resveratrol and its derivatives in AID treatment while offering crucial insights for the formulation of innovative therapeutic approaches.

Identification of Drug Targets and Agents Associated with Ferroptosis-related Osteoporosis through Integrated Network Pharmacology and Molecular Docking Technology

BACKGROUND

Osteoporosis is a systemic bone disease characterized by progressive reduction of bone mineral density and degradation of trabecular bone microstructure. Iron metabolism plays an important role in bone; its imbalance leads to abnormal lipid oxidation in cells, hence ferroptosis. In osteoporosis, however, the exact mechanism of ferroptosis has not been fully elucidated.

OBJECTIVE

The main objective of this project was to identify potential drug target proteins and agents for the treatment of ferroptosis-related osteoporosis.

METHODS

In the current study, we investigated the differences in gene expression of bone marrow mesenchymal stem cells between osteoporosis patients and normal individuals using bioinformatics methods to obtain ferroptosis-related genes. We could predict their protein structure based on the artificial intelligence database of AlphaFold, and their target drugs and binding sites with the network pharmacology and molecular docking technology.

RESULTS

We identified five genes that were highly associated with osteoporosis, such as TP53, EGFR, TGFB1, SOX2 and MAPK14, which, we believe, can be taken as the potential markers and targets for the diagnosis and treatment of osteoporosis. Furthermore, we observed that these five genes were highly targeted by resveratrol to exert a therapeutic effect on ferroptosis-related osteoporosis.

CONCLUSION

We examined the relationship between ferroptosis and osteoporosis based on bioinformatics and network pharmacology, presenting a promising direction to the pursuit of the exact molecular mechanism of osteoporosis so that a new target can be discovered for the treatment of osteoporosis.

Resveratrol Derivatives Inhibit Transthyretin Fibrillization: Structural Insights into the Interactions between Resveratrol Derivatives and Transthyretin

Hereditary ATTR amyloidosis is a disease caused by the deposition of amyloid fibrils formed by mutated transthyretin (TTR), a protein that binds to thyroid hormone in the serum, in the organs. The development of a small molecule that binds to and stabilizes TTR is a promising strategy for the treatment of ATTR amyloidosis. In the present study, we demonstrated that the resveratrol derivatives including pterostilbene available as a dietary supplement inhibit the fibrillization of V30M-TTR to the same extent as the approved drug tafamidis. Furthermore, based on a thermodynamic and X-ray crystallographic analysis, the binding of the resveratrol derivative to TTR was shown to be enthalpy-driven, with the binding enthalpy being acquired by hydrogen bonding to S117. Moreover, direct observation of hydrogen atoms by neutron crystallography provided details of the hydrogen bond network by S117 and emphasized the importance of the CH···π interaction by L110 in the ligand binding.

HPLC-UV evaluation of a microwave assisted method as an active drug loading technique for exosome-based drug delivery system

This paper evaluates the potential of a microwave radiation (MR) assisted method as an active drug loading technique for exosomes using polyphenolic nutraceuticals as model drugs (i.e. resveratrol (RV), rosmarinic acid (RA), pterostilbene (PT) and epigallocatechin gallate (EG)). MR is evaluated as a single step method and as part of a two-step method consisting of incubation (IN) followed by MR. The effect of exposure time, loading method and type of nutraceutical on the loading efficiency were investigated using high performance liquid chromatography (HPLC), X-ray diffraction (XRD) and flow cytometry. Additionally, dynamic light scattering (DLS) was used to determine the size of exosomes. Loading efficiency results indicated that MR is a promising method to be used as loading process. Results also suggested that due to different levels of hydrophobicity, related to the number of OH groups, the absorption of polyphenols into the bilayer of EVs is different for each molecule. According to XRD results, MR could not be used with any cargo drug since radiation could affect the chemical composition and the degree of crystallinity of such molecules, consequently affecting their performance. Flow cytometry results indicated that loading methods negatively affect exosome concentration.

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 and Biological Evaluation of Resveratrol Methoxy Derivatives

Resveratrol, a naturally occurring stilbene, exhibits numerous beneficial health effects. Various studies have demonstrated its diverse biological actions, including anti-oxidant, anti-inflammatory, and anti-platelet properties, thereby supporting its potential for cardio protection, neuroprotection, and anti-cancer activity. However, a significant limitation of resveratrol is its weak bioavailability. To overcome this challenge, multiple research groups have investigated the synthesis of new resveratrol derivatives to enhance bioavailability and pharmacological activities. Nevertheless, there are limited data on the effects of resveratrol derivatives on platelet function. Therefore, the objective of this study was to synthesize resveratrol methoxy derivatives and evaluate their anti-platelet and anti-proliferative activity. Platelet-rich plasma (PRP) obtained from healthy volunteers was utilized to assess the derivatives' ability to inhibit platelet aggregation induced by platelet activating factor (PAF), adenosine diphosphate (ADP), and thrombin receptor activating peptide (TRAP). Additionally, the derivatives' anti-tumor activity was evaluated against the proliferation of PC-3 and HCT116 cells. The results revealed that some methoxy derivatives of resveratrol exhibited comparable or even superior anti-platelet activity compared to the original compound. The most potent derivative was the 4'-methoxy derivative, which demonstrated approximately 2.5 orders of magnitude higher anti-platelet activity against TRAP-induced platelet aggregation, indicating its potential as an anti-platelet agent. Concerning in silico studies, the 4'-methyl group of 4'-methoxy derivative is oriented similarly to the fluorophenyl-pyridyl group of Vorapaxar, buried in a hydrophobic cavity. In terms of their anti-tumor activity, 3-MRESV exhibited the highest potency in PC-3 cells, while 3,4'-DMRESV and TMRESV showed the greatest efficacy in HCT116 cells. In conclusion, methoxy derivatives of resveratrol possess similar or improved anti-platelet and anti-cancer effects, thereby holding potential as bioactive compounds in various pathological conditions.

Reactive oxygen species-responsive nanocarrier ameliorates murine colitis by intervening colonic innate and adaptive immune responses

Ulcerative colitis (UC) is a chronic or relapsing inflammatory disease with limited therapeutic outcomes. Pterostilbene (PSB) is a polyphenol-based anti-oxidant that has received extensive interest for its intrinsic anti-inflammatory and anti-oxidative activities. This work aims to develop a reactive oxygen species (ROS)-responsive, folic acid (FA)-functionalized nanoparticle (NP) for efficient PSB delivery to treat UC. The resulting PSB@NP-FA had a nano-scaled diameter of 231 nm and a spherical shape. With ROS-responsive release and ROS-scavenging properties, PSB@NP could effectively scavenge H2O2, thereby protecting cells from H2O2-induced oxidative damage. After FA modification, the resulting PSB@NP-FA could be internalized by RAW 264.7 and Colon-26 cells efficiently and preferentially localized to the inflamed colon. In dextran sulfate sodium (DSS)-induced colitis models, PSB@NP-FA showed a prominent ROS-scavenging capacity and anti-inflammatory activity, therefore relieving murine colitis effectively. Mechanism results suggested that PSB@NP-FA ameliorated colitis by regulating dendritic cells (DCs), promoting macrophage polarization, and regulating T cell infiltration. Both innate and adaptive immunity were involved. More importantly, the combination of the PSB and dexamethasone (DEX) enhanced the therapeutic efficacy of colitis. This ROS-responsive and ROS-scavenging nanocarrier represents an alternative therapeutic approach to UC. It can also be used as an enhancer for classic anti-inflammatory drugs.

Determination of Pterostilbene in Pharmaceutical Products Using a New HPLC Method and Its Application to Solubility and Stability Samples

The quantification of a natural bioactive compound, pterostilbene (PTT), in commercial capsule dosage form, solubility, and stability samples was carried out using a rapid and sensitive high-performance liquid chromatography (HPLC) approach. PTT was quantified on a Nucleodur (150 mm × 4.6 mm) RP C18 column with a particle size of 5 µm. Acetonitrile and water (90:10 v/v) made up the mobile phase, which was pumped at a flow speed of 1.0 mL/min. At a wavelength of 254 nm, PTT was detected. The developed HPLC approach was linear in 1–75 µg/g range, with a determination coefficient of 0.9995. The developed HPLC approach for PTT estimation was also rapid (Rt = 2.54 min), accurate (%recoveries = 98.10–101.93), precise (%CV = 0.59–1.25), and sensitive (LOD = 2.65 ng/g and LOQ = 7.95 ng/g). The applicability of developed HPLC approach was revealed by determining PTT in commercial capsule dosage form, solubility, and stability samples. The % assay of PTT in marketed capsules was determined to be 99.31%. The solubility of PTT in five different green solvents, including water, propylene glycol, ethanol, polyethylene glycol-400, and Carbitol was found to be 0.0180 mg/g, 1127 mg/g, 710.0 mg/g, 340.0 mg/g, and 571.0 mg/g, respectively. In addition, the precision and accuracy of stability samples were within the acceptable limit, hence PTT was found to be stable in solution. These results suggested that PTT in commercial products, solubility, and stability samples may be routinely determined using the established HPLC method.

Electrospun membranes of carboxylated poly(ester urethane)urea/gelatin encapsulating pterostilbene for adaptive and antioxidative purposes

Oxidative stress caused by the harsh microenvironment after implantation of an artificial graft with mismatching mechanical properties usually triggers inflammation responses, which have adverse impacts on tissue regeneration. For coping with these problems, in this work, bioactive fibrous scaffolds were developed from specially synthesized carboxylated poly(ester urethane)urea (PEUU) and gelatin (Gel) by encapsulating pterostilbene (Pte) for the first time. The prepared electrospun membranes exhibited self-adaptable mechanical properties with high elasticity owing to the bonded electrospun fibers, cross-linking network between PEUU and Gel, and the inherent flexibility of the PEUU polymer in the fibrous matrix. The PEUU/Gel/Pte electrospun membrane containing 7% Pte could promote in vitro proliferation of human umbilical vein endothelial cells, and regulate vascular smooth muscle cells with excellent antioxidant properties via free radical scavenging. In vivo results in a rat subcutaneous implantation model further demonstrated the positive effect of the specially prepared PEUU/Gel/Pte scaffold on both normal cell growth and anti-inflammatory by promoting cellularization and polarizing macrophages toward the M2 phenotype. These PEUU/Gel/Pte electrospun membranes with adaptability benefit to tissue regeneration by modulating inflammation responses, especially applications in vascular regeneration.

Resveratrol and Some of Its Derivatives as Promising Prophylactic Treatments for Neonatal Hypoxia-Ischemia

Due to the rate of occurrence of neonatal hypoxia-ischemia, its neuronal sequelae, and the lack of effective therapies, the development of new neuroprotective strategies is required. Polyphenols (including resveratrol) are molecules whose anti-apoptotic, anti-inflammatory, and anti-oxidative properties could be effective against the damage induced by neonatal hypoxia-ischemia. In this review article, very recent data concerning the neuroprotective role of polyphenols and the mechanisms at play are detailed, including a boost in brain energy metabolism. The results obtained with innovative approaches, such as maternal supplementation at nutritional doses, suggest that polyphenols could be a promising prophylactic treatment for neonatal hypoxia-ischemia.

Pterostilbene attenuates intestinal epithelial barrier loss induced by high loading intensity of exercise

Mounting evidence suggested that high loading intensity of exercise might be detrimental to human health, especially the gastrointestinal tract. Pterostilbene (PTE), derived from grapes and blueberries, might reach a high concentration of intestinal contents. Our study aimed to evaluate PTE’s ability to prevent the loss of intestinal epithelial barrier in high loading intensity of exercise. The exercise model was established by the forced running of mice. An effective HPLC-UV method was developed to quantify PTE concentration in intestinal content. The mRNA changes were detected by quantitative polymerase chain reaction (qPCR). The structure of intestinal flora was analyzed by 16S rRNA sequencing. The PTE (100 mg/kg/d) could significantly attenuate exercise-induced intestinal epithelial barrier loss. Moreover, the HPLC-UV assay showed that the PTE concentration of intestinal content could last 12 h. Furthermore, the exercise increased the abundance of Alistipes, which was related to lipopolysaccharide (LPS) production but could not be reversed by PTE intervention. Besides, cell experiments showed that PTE could promote the expression of intestinal epithelial tight junction (TJ) molecules in vitro. In conclusion, PTE has a significant interest in preventing exercise-induced intestinal damage.

Protective Effect of Resveratrol on Knee Osteoarthritis and its Molecular Mechanisms: A Recent Review in Preclinical and Clinical Trials

Osteoarthritis (OA) is one of the progressing chronic joint associated with by many complex factors such as age, obesity, and trauma. Knee osteoarthritis (KOA) is the most common type of OA. KOA is characterized by articular cartilage destruction and degeneration, synovial inflammation, and abnormal subchondral bone changes. To date, no practical clinical approach has been able to modify the pathological progression of KOA. Drug therapy is limited to pain control and may lead to serious side effects when taken for a long time. Therefore, searching for safer and more reliable treatments has become necessary. Interestingly, more and more research has focused on natural products, and monomeric compounds derived from natural products have received much attention as drug candidates for KOA treatment. Resveratrol (RES), a natural phenolic compound, has various pharmacological and biological activities, including anti-cancer, anti-apoptotic, and anti-decay. Recently, studies on the effects of RES on maintaining the normal homeostasis of chondrocytes in KOA have received increasing attention, which seems to be attributed to the multi-targeted effects of RES on chondrocyte function. This review summarizes preclinical trials, clinical trials, and emerging tissue engineering studies of RES for KOA and discusses the specific mechanisms by which RES alleviates KOA. A better understanding of the pharmacological role of RES in KOA could provide clinical implications for intervention in the development of KOA.

Targeting Breast Cancer Stem Cells Using Naturally Occurring Phytoestrogens

Breast cancer therapies have made significant strides in improving survival for patients over the past decades. However, recurrence and drug resistance continue to challenge long-term recurrence-free and overall survival rates. Mounting evidence supports the cancer stem cell model in which the existence of a small population of breast cancer stem cells (BCSCs) within the tumor enables these cells to evade conventional therapies and repopulate the tumor, giving rise to more aggressive, recurrent tumors. Thus, successful breast cancer therapy would need to target these BCSCs, as well the tumor bulk cells. Since the Women’s Health Initiative study reported an increased risk of breast cancer with the use of conventional hormone replacement therapy in postmenopausal women, many have turned their attention to phytoestrogens as a natural alternative. Phytoestrogens are plant compounds that share structural similarities with human estrogens and can bind to the estrogen receptors to alter the endocrine responses. Recent studies have found that phytoestrogens can also target BCSCs and have the potential to complement conventional therapy eradicating BCSCs. This review summarized the latest findings of different phytoestrogens and their effect on BCSCs, along with their mechanisms of action, including selective estrogen receptor binding and inhibition of molecular pathways used by BCSCs. The latest results of phytoestrogens in clinical trials are also discussed to further evaluate the use of phytoestrogen in the treatment and prevention of breast cancer.

Resveratrol and neuroprotection: an insight into prospective therapeutic approaches against Alzheimer's disease from bench to bedside

Alzheimer's disease (AD) is the most common cause of dementia and cognitive impairment; yet, there is currently no treatment. A buildup of Aβ, tau protein phosphorylation, oxidative stress, and inflammation in AD is pathogenic. The accumulation of amyloid-beta (Aβ) peptides in these neurocognitive areas is a significant characteristic of the disease. Therefore, inhibiting Aβ peptide aggregation has been proposed as the critical therapeutic approach for AD treatment. Resveratrol has been demonstrated in multiple studies to have a neuroprotective, anti-inflammatory, and antioxidant characteristic and the ability to minimize Aβ peptides aggregation and toxicity in the hippocampus of Alzheimer's patients, stimulating neurogenesis and inhibiting hippocampal degeneration. Furthermore, resveratrol's antioxidant effect promotes neuronal development by activating the silent information regulator-1 (SIRT1), which can protect against the detrimental effects of oxidative stress. Resveratrol-induced SIRT1 activation is becoming more crucial in developing novel therapeutic options for AD and other diseases that have neurodegenerative characteristics. This review highlighted a better knowledge of resveratrol's mechanism of action and its promising therapeutic efficacy in treating AD. We also highlighted the therapeutic potential of resveratrol as an AD therapeutic agent, which is effective against neurodegenerative disorders.

Metastasis-associated protein 1-mediated antitumor and anticancer activity of dietary stilbenes for prostate cancer chemoprevention and therapy

Dietary bioactive polyphenols that demonstrate beneficial biological functions including antioxidant, anti-inflammatory, and anticancer activity hold immense promise as effective and safe chemopreventive and chemosensitizing natural anticancer agents. The underlying molecular mechanisms of polyphenols' multiple effects are complex and these molecules are considered promising targets for chemoprevention and therapy. However, the development of novel personalized targeted chemopreventive and therapeutic strategies is essential for successful therapeutic outcomes. In this review, we highlight the potential of metastasis-associated protein 1 (MTA1)-targeted anticancer and antitumor effects of three dietary stilbenes, namely resveratrol, pterostilbene, and gnetin C, for prostate cancer management. MTA1, an epigenetic reader and master transcriptional regulator, plays a key role in all stages of prostate cancer progression and metastasis. Stilbenes inhibit MTA1 expression, disrupt the MTA1/histone deacetylase complex, modulate MTA1-associated Epi-miRNAs and reduce MTA1-dependent inflammation, cell survival, and metastasis in prostate cancer in vitro and in vivo. Overall, the MTA1-targeted strategies involving dietary stilbenes may be valuable for effective chemoprevention in selected subpopulations of early stage prostate cancer patients and for combinatorial strategies with conventional chemotherapeutic drugs against advanced metastatic prostate cancer.

Pterostilbene Promotes Mean Lifespan in Both Male and Female Drosophila Melanogaster Modulating Different Proteins in the Two Sexes

Aging is a multifactorial phenomenon characterized by degenerative processes closely connected to oxidative damage and chronic inflammation. Recently, many studies have shown that natural bioactive compounds are useful in delaying the aging process. In this work, we studied the effects of an in vivo supplementation of the stilbenoid pterostilbene on lifespan extension in Drosophila melanogaster. We found that the average lifespan of flies of both sexes was increased by pterostilbene supplementation with a higher effect in females. The expression of longevity related genes (Sir2, Foxo, and Notch) was increased in both sexes but with different patterns. Pterostilbene counteracted oxidative stress induced by ethanol and paraquat and up-regulated the antioxidant enzymes Ho e Trxr-1 in male but not in female flies. On the other hand, pterostilbene decreased the inflammatory mediators dome and egr only in female flies. Proteomic analysis revealed that pterostilbene modulates 113 proteins in male flies and only 9 in females. Only one of these proteins was modulated by pterostilbene in both sexes: vacuolar H[+] ATPase 68 kDa subunit 2 (Vha68-2) that was strongly down-regulated. These findings suggest a potential role of pterostilbene in increasing lifespan both in male and female flies by mechanisms that seem to be different in the two sexes, highlighting the need to conduct nutraceutical supplementation studies on males and females separately in order to give more reliable results.

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.

Mechanism of Pterostilbene-Induced Cell Death in HT-29 Colon Cancer Cells

Pterostilbene is a dietary phytochemical that has been found to possess several biological activities, such as antioxidant and anti-inflammatory. Recent studies have shown that it exhibits the hallmark characteristics of an anticancer agent. The aim of the study was to investigate the anticancer activity of pterostilbene against HT-29 human colon cancer cells, focusing on its influence on cell growth, differentiation, and the ability of this stilbene to induce cell death. To clarify the mechanism of pterostilbene activity against colon cancer cells, changes in the expression of several genes and proteins that are directly related to cell proliferation, signal transduction pathways, apoptosis, and autophagy were also evaluated. Cell growth and proliferation of cells exposed to pterostilbene (5-100 µM) were determined by SRB and BRDU assays. Flow cytometric analyses were used for cell cycle progression. Further molecular investigations were performed using quantitative real-time RT-PCR. The expression of the signaling proteins studied was determined by the ELISA method. The results revealed that pterostilbene inhibited proliferation and induced the death of HT-29 colon cancer cells. Pterostilbene, depending on concentration, caused inhibition of proliferation, G1 cell arrest, and/or triggered apoptosis in HT-29 cells. These effects were mediated by the down-regulation of the STAT3 and AKT kinase pathways. It may be concluded that pterostilbene could be considered as a potential therapeutic option in the treatment of colon cancer in the future.

Novel pterostilbene-loaded pro-phytomicelles: preclinical pharmacokinetics, distribution, and treatment efficacy against acetaminophen-induced liver injury

A novel pro-phytomicelle formulation with small molecule phytochemicals as nanomaterials was developed for the oral delivery of pterostilbene (PTE).

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 cyclodextrins, an easy alliance: Applications in nanomedicine, green chemistry and biotechnology

Most drugs or the natural substances reputed to display some biological activity are hydrophobic molecules that demonstrate low bioavailability regardless of their mode of absorption. Resveratrol and its derivatives belong to the chemical group of stilbenes; while stilbenes are known to possess very interesting properties, these are limited by their poor aqueous solubility as well as low bioavailability in animals and humans. Among the substances capable of forming nanomolecular inclusion complexes which can be used for drug delivery, cyclodextrins show spectacular physicochemical and biomedical implications in stilbene chemistry for their possible application in nanomedicine. By virtue of their properties, cyclodextrins have also demonstrated their possible use in green chemistry for the synthesis of stilbene glucosylated derivatives with potential applications in dermatology and cosmetics. Compared to chemical synthesis and genetically modified microorganisms, plant cell or tissue systems provide excellent models for obtaining stilbenes in few g/L quantities, making feasible the production of these compounds at a large scale. However, the biosynthesis of stilbenes is only possible in the presence of the so-called elicitor compounds, the most commonly used of which are cyclodextrins. We also report here on the induction of resveratrol production by cyclodextrins or combinatory elicitation with methyljasmonate in plant cell systems as well as the mechanisms by which they are able to trigger a stilbene response. The present article therefore discusses the role of cyclodextrins in stilbene chemistry both at the physico-chemical level as well as the biomedical and biotechnological levels, emphasizing the notion of "easy alliance" between these compounds and stilbenes.

Rapid, Sensitive, and Sustainable Reversed-Phase HPTLC Method in Comparison to the Normal-Phase HPTLC for the Determination of Pterostilbene in Capsule Dosage Form

The greenness evaluation of literature analytical methods for pterostilbene (PT) analysis was not performed. Accordingly, the rapid, sensitive, and green/sustainable reversed-phase high-performance thin-layer chromatography (RP-HPTLC) method was developed and compared to the normal-phase (NP)-HPTLC (NP-HPTLC) for the estimation of PT with a classical univariate calibration. The RP quantification of PT was performed using green solvent systems; however, the NP analysis of PT was performed using routine solvent systems. The PT was detected at 302 nm for both of the methods. The greenness scores for the current analytical assays were evaluated by the analytical GREEnness (AGREE) metric approach. The classical univariate calibration for RP and NP methods indicated the linearity range as 10–1600 and 30–400 ng band−1, respectively. The RP method was more reliable for PT analysis compared to the NP method. The PT contents in commercial capsule dosage form were found to be 100.84% using the RP method; however, the PT contents in commercial capsule dosage form were determined as 92.59% using the NP method. The AGREE scores for RP and NP methods were 0.78 and 0.46, respectively. The sustainable RP-HPTLC assay was able to detect PT in the presence of its degradation products, and hence it can be considered as a selective and stability-indicating method. Accordingly, the RP-HPTLC method with univariate calibration has been considered as a superior method over the NP-HPTLC method for PT analysis.

Nanoparticles prepared from pterostilbene reduce blood glucose and improve diabetes complications

BACKGROUND

Diabetes complications are the leading cause of mortality in diabetic patients. The common complications are decline in antioxidant capacity and the onset of micro-inflammation syndrome. At present, glucose-responsive nanoparticles are widely used, as they can release insulin-loaded ultrafine particles intelligently and effectively reduce blood sugar. However, the toxicology of this method has not been fully elucidated. The plant extracts of pterostilbene (PTE) have a wide range of biological applications, such as antioxidation and inflammatory response improvement. Therefore, we have proposed new ideas for the cross application of plant extracts and biomaterials, especially as part of a hypoglycaemic nano-drug delivery system.

RESULTS

Based on the PTE, we successfully synthesised poly(3-acrylamidophenyl boric acid-b-pterostilbene) (p[AAPBA-b-PTE]) nanoparticles (NPs). The NPs were round in shape and ranged between 150 and 250 nm in size. The NPs possessed good pH and glucose sensitivity. The entrapment efficiency (EE) of insulin-loaded NPs was approximately 56%, and the drug loading (LC) capacity was approximately 13%. The highest release of insulin was 70%, and the highest release of PTE was 85%. Meanwhile, the insulin could undergo self-regulation according to changes in the glucose concentration, thus achieving an effective, sustained release. Both in vivo and in vitro experiments showed that the NPs were safe and nontoxic. Under normal physiological conditions, NPs were completely degraded within 40 days. Fourteen days after mice were injected with p(AAPBA-b-PTE) NPs, there were no obvious abnormalities in the heart, liver, spleen, lung, or kidney. Moreover, NPs effectively reduced blood glucose, improved antioxidant capacity and reversed micro-inflammation in mice.

CONCLUSIONS

p(AAPBA-b-PTE) NPs were successfully prepared using PTE as raw material and effectively reduced blood glucose, improved antioxidant capacity and reduced the inflammatory response. This novel preparation can enable new combinations of plant extracts and biomaterials to adiministered through NPs or other dosage forms in order to regulate and treat diseases.

Resveratrol and its derivative pterostilbene ameliorate intestine injury in intrauterine growth-retarded weanling piglets by modulating redox status and gut microbiota

Background

Intestinal disorder is an important factor contributing to growth lag and high rates of morbidity and mortality of piglets with intrauterine growth retardation (IUGR). Resveratrol (RSV) and its derivative pterostilbene (PT) are natural stilbenes possessing various bioactivities, such as antioxidative and anti-inflammatory effects. This study compared the protective potential of RSV and PT on the intestinal redox status and gut microbiota in weanling piglets with IUGR.

Methods

Eighteen male piglets of normal body weight (NBW) and 54 same-sex IUGR piglets were chosen according to their birth and weaning weights. The NBW piglets accepted a basal diet, while the IUGR piglets were allotted to one of three groups according to their body weight at weaning and received a basal diet, an RSV-supplemented diet (300 mg/kg), or a PT-supplemented diet (300 mg/kg), respectively.

Results

Compared with IUGR piglets, both RSV and PT improved the IUGR-associated decrease in jejunal villus height and increases in plasma diamine oxidase activity and D-lactate level and jejunal apoptosis of piglets (P < 0.05). Administering RSV and PT also enhanced jejunal superoxide dismutase activity and the mRNA and protein expression of superoxide dismutase 2 of IUGR piglets by promoting nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation (P < 0.05). Comparatively, PT was more effective than RSV in elevating the villus height/crypt depth ratio and occludin mRNA and protein levels in the jejunum of IUGR piglets (P < 0.05). PT was also superior to RSV in increasing Nrf2 nuclear translocation and inhibiting malondialdehyde accumulation in the jejunum of IUGR piglets (P < 0.05). Additionally, RSV modulated the composition of cecal microbiota of IUGR piglets, as evidenced by increasing the prevalence of the phylum Bacteroidetes and the genera Prevotella, Faecalibacterium, and Parabacteroides and inhibiting the growth of the phylum Proteobacteria and its genera Escherichia and Actinobacillus (P < 0.05). Moreover, RSV significantly increased the butyrate concentration in the cecum of IUGR piglets (P < 0.05).

Conclusion

PT is more potent than RSV to prevent intestinal oxidative stress, while RSV has a stronger capacity to regulate gut microbiota compared to PT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-021-00589-9.

Pterostilbene Improves Stress-Related Behaviors and Partially Reverses Underlying Neuroinflammatory and Hormonal Changes in Stress-Challenged Mice

Pterostilbene is a natural compound contained in various dietary sources that has received tremendous attention due to its antioxidant properties with promising benefits in cancers and vascular diseases. Currently, little is known about pterostilbene-associated neuroimmune endocrine effects. We aimed to examine the efficacy of pterostilbene for improving stress-related behaviors, neuroinflammation, and hormonal changes in a mouse stress model. To evaluate the efficacy of oral administration of pterostilbene or vehicle for 16 days for improving behavior, inflammation, and hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, mice were divided into a normal control group or one of five restraint stress groups-the vehicle group; the 20, 40, or 80 mg/[kg·day] pterostilbene treatment group; or the 20 mg/[kg·day] resveratrol treatment group. Open field and forced swimming tests were conducted. Hippocampal brain-derived neurotrophic factor (BDNF) levels, endocrine hormone levels, oxidative stress parameters, and histopathological features were assessed. Oral pterostilbene administration significantly increased the measured times in the open field and forced swimming tests, elevated the BDNF levels, decreased the inducible nitric oxide synthase and superoxide dismutase levels in the brain, and reduced the plasma adrenocorticotropic hormone and corticosterone levels. Compared with vehicle treatment, pterostilbene dose dependently increased the numbers of neurons and decreased the numbers of glial and tumor necrosis factor alpha-immunolabeled cells in the hypothalamus. These findings suggest that pterostilbene may effectively modulate stress-related abnormal behaviors, neuroinflammation, and HPA axis hyperactivity.

Pterostilbene, a Dimethylether Analogue of Resveratrol, Possesses High Potency in the Prevention of Platelet Activation in Humans and the Reduction of Vascular Thrombosis in Mice

Platelets play a crucial role in cardiovascular disorders (CVDs); thus, development of a therapeutic target that prevents platelet activation reduces CVDs. Pterostilbene (PTE) has several remarkable pharmacological activities, including anticancer and neuroprotection. Herein, we examined the inhibitory mechanisms of PTE in human platelets and its role in the prevention of vascular thrombosis in mice. At very low concentrations (1-5 μmol/L), PTE strongly inhibited collagen-induced platelet aggregation, but it did not have significant effects against thrombin and 9,11-dideoxy-11α,9α-epoxymethanoprostaglandin (U46619). PTE markedly reduced P-selectin expression on isolated α-granules by a novel microchip. Moreover, PTE inhibited adenosine triphosphate (ATP) release, intracellular ([Ca²⁺]i) mobilization (resting, 216.6 ± 14.0 nmol/L; collagen-activated platelets, 396.5 ± 25.7 nmol/L; 2.5 μmol/L PTE, 259.4 ± 8.8 nmol/L; 5 μmol/L PTE, 231.8 ± 9.7 nmol/L), phospholipase C (PLC)γ2/protein kinase C (PKC), Akt, and mitogen-activated protein kinase (MAPK) phosphorylation. Neither 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ22536) nor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) reversed platelet aggregation inhibited by PTE. PTE did not affect vasodilator-stimulated phosphoprotein phosphorylation. In mice, PTE obviously reduced the mortality (from 100 to 37.5%) associated with acute pulmonary thromboembolism without increasing the bleeding time. Thus, PTE could be used to prevent CVDs.

Amelioration of Pterostilbene Antiproliferative, Proapoptotic, and Oxidant Potentials in Human Breast Cancer MCF7 Cells Using Zein Nanocomposites

Purpose

This study aimed to explain the influence of zein nanosphere (ZN NS) formulation on the pharmacotherapeutic profile of PTS in MCF7 cells.

Methods

Liquid–liquid phase separation was used to formulate PTS-ZN NSs. The formulations developed were evaluated for particle-size analysis, encapsulation efficiency, and in vitro diffusion. Also, assays of cytotoxicity, uptake, cell-cycle progression, annexin V, apoptotic gene mRNA expression and biochemical assays were carried out.

Results

The PTS-ZN NS formulation selected showed 104.5±6.2 nm, 33.4±1.8 mV, 95.1%±3.6%, and 89.1%±2.65% average particle size, zeta-potential, encapsulation efficiency and in vitro diffusion, respectively. With MCF7 cells, IC₅₀ was reduced approximately 15-fold, with increased cellular uptake, accumulation in the G₂/M phase, increased percentage of cells in the pre-G₁ phase, amelioration of early and late apoptosis, raised mRNA expression of CASP3 and CASP7, lower expression of cyclin-CDK1, and enhanced oxidant potential through decreased glutathione reductase (GR) activity, and enhanced reactive oxygen–species generation and lipid-peroxidation products.

Conclusion

PTS-ZN NSs indicated enhanced antiproliferative, proapoptotic, and oxidant potential toward MCF7 cells compared to free PTS. Ameliorated results of nanosized carriers, cellular uptake, and sustained diffusion may contribute to these outcomes.

Pterostilbene Ameliorates DSS-Induced Intestinal Epithelial Barrier Loss in Mice via Suppression of the NF-κB-Mediated MLCK-MLC Signaling Pathway

The integrity of the intestinal barrier is critical for homeostasis. In this study, we investigated the protective effect of pterostilbene (PTE) on the intestinal epithelium barrier. In vitro results of transepithelial electrical resistance (TEER) in Caco-2 cells indicated that PTE counteracted tumor necrosis factor α (TNFα)-induced barrier damage. In vivo PTE pretreatment markedly ameliorated intestinal barrier dysfunction induced by dextran sulfate sodium (DSS). Notably, intestinal epithelial tight junction (TJ) molecules were restored by PTE in mice exposed to DSS. The mechanism study revealed that PTE prevented myosin light-chain kinase (MLCK) from driving phosphorylation of MLC (p-MLC), which is crucial for maintaining intestinal TJ stability. Furthermore, PTE blunted translocation of NF-κB subunit p65 into the nucleus to downregulate MLCK expression and then to safeguard TJs and barrier integrity. These findings suggest that PTE protected the intestinal epithelial barrier through the NF-κB- MLCK/p-MLC signal pathway.

The Antithrombotic Agent Pterostilbene Interferes with Integrin αIIbβ3-Mediated Inside-Out and Outside-In Signals in Human Platelets

Platelets play a crucial role in the physiology of primary hemostasis and pathological processes such as arterial thrombosis; thus, developing a therapeutic target that prevents platelet activation can reduce arterial thrombosis. Pterostilbene (PTE) has remarkable pharmacological activities, including anticancer and neuroprotection. Few studies have reported the effects of pterostilbene on platelet activation. Thus, we examined the inhibitory mechanisms of pterostilbene in human platelets and its role in vascular thrombosis prevention in mice. At low concentrations (2–8 μM), pterostilbene strongly inhibited collagen-induced platelet aggregation. Furthermore, pterostilbene markedly diminished Lyn, Fyn, and Syk phosphorylation and hydroxyl radical formation stimulated by collagen. Moreover, PTE directly hindered integrin α_IIbβ₃ activation through interfering with PAC-1 binding stimulated by collagen. In addition, pterostilbene affected integrin α_IIbβ₃-mediated outside-in signaling, such as integrin β₃, Src, and FAK phosphorylation, and reduced the number of adherent platelets and the single platelet spreading area on immobilized fibrinogen as well as thrombin-stimulated fibrin clot retraction. Furthermore, pterostilbene substantially prolonged the occlusion time of thrombotic platelet plug formation in mice. This study demonstrated that pterostilbene exhibits a strong activity against platelet activation through the inhibition of integrin α_IIbβ₃-mediated inside-out and outside-in signaling, suggesting that pterostilbene can serve as a therapeutic agent for thromboembolic disorders.

Nutraceuticals in the Prevention of Neonatal Hypoxia-Ischemia: A Comprehensive Review of their Neuroprotective Properties, Mechanisms of Action and Future Directions

Neonatal hypoxia-ischemia (HI) is a brain injury caused by oxygen deprivation to the brain due to birth asphyxia or reduced cerebral blood perfusion, and it often leads to lifelong limiting sequelae such as cerebral palsy, seizures, or mental retardation. HI remains one of the leading causes of neonatal mortality and morbidity worldwide, and current therapies are limited. Hypothermia has been successful in reducing mortality and some disabilities, but it is only applied to a subset of newborns that meet strict inclusion criteria. Given the unpredictable nature of the obstetric complications that contribute to neonatal HI, prophylactic treatments that prevent, rather than rescue, HI brain injury are emerging as a therapeutic alternative. Nutraceuticals are natural compounds present in the diet or used as dietary supplements that have antioxidant, anti-inflammatory, or antiapoptotic properties. This review summarizes the preclinical in vivo studies, mostly conducted on rodent models, that have investigated the neuroprotective properties of nutraceuticals in preventing and reducing HI-induced brain damage and cognitive impairments. The natural products reviewed include polyphenols, omega-3 fatty acids, vitamins, plant-derived compounds (tanshinones, sulforaphane, and capsaicin), and endogenous compounds (melatonin, carnitine, creatine, and lactate). These nutraceuticals were administered before the damage occurred, either to the mothers as a dietary supplement during pregnancy and/or lactation or to the pups prior to HI induction. To date, very few of these nutritional interventions have been investigated in humans, but we refer to those that have been successful in reducing ischemic stroke in adults. Overall, there is a robust body of preclinical evidence that supports the neuroprotective properties of nutraceuticals, and these may represent a safe and inexpensive nutritional strategy for the prevention of neonatal HI encephalopathy.

Resveratrol and Its Analogs as Functional Foods in Periodontal Disease Management

Periodontitis is a common chronic inflammatory disease driven by the interaction between a dysbiotic oral microbiome and the dysregulated host immune-inflammatory response. Naturally derived nutraceuticals, such as resveratrol and its analogs, are potential adjunctive therapies in periodontal treatment due to their antimicrobial and anti-inflammatory properties. Furthermore, different analogs of resveratrol and the choice of solvents used may lead to varying effects on therapeutic properties. This review presents the current findings and gaps in our understanding on the potential utility of resveratrol and its analogs in periodontal treatment.

Protective Effects of Pterostilbene on Lipopolysaccharide-Induced Acute Lung Injury in Mice by Inhibiting NF-κB and Activating Nrf2/HO-1 Signaling Pathways

Pterostilbene (PTER) is a kind of stilbene compound with biological activity isolated from plants such as red sandalwood, blueberry and grape. It has anti-tumor, anti-bacterial, anti-oxidation and other pharmacological activities. However, the underlying mechanism of the protective effect of PTER on lipopolysaccharide (LPS)-induced acute lung injury (ALI) remained not clarified. In this study, LPS was used to establish a mouse model of ALI. Bronchoalveolar lavage fluid (BALF) was collected for inflammatory cells, and the wet-to-dry weight ratio of the lungs was measured. The activities of myeloperoxidase (MPO), antioxidant indexes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and oxidation index such as malondialdehyde (MDA) in lung tissues of mice were measured by the corresponding kits. The levels of Cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), TNF-α, IL-6 and IL-1β in lung tissues of mice were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The activities of Nrf2, HO-1, p-p65 and p-IκB were determined by western blotting. The results showed that the model of LPS-induced ALI was successfully replicated, and it was found that PTER could significantly improve the pathological degree of ALI such as sustained the integrity of the lung tissue structure, alleviated pulmonary interstitial edema and alveolar wall thickening, reduced infiltrated inflammatory cells. PTER could decrease the number of inflammatory cells and obviously inhibit the increase of W/D ratio caused by LPS. PTER could also significantly reduce LPS-induced MPO and MDA, and increase LPS-decreased SOD, CAT and GSH-Px in the lungs. In addition, it was also found that PTER has the ability to decrease LPS-induced production of COX-2, iNOS, TNF-α, IL-6 and IL-1β. The underlying mechanism involved in the protective effect of PTER on ALI were via activating Nrf2 and HO-1, and inhibiting the phosphorylation of p65 and IκB. These results suggested that PTER can protect LPS-induced ALI in mice by inhibiting inflammatory response and oxidative stress, which provided evidence that PTER may be a potential therapeutic candidate for LPS-induced ALI intervention.

Phytostilbenes as agrochemicals: biosynthesis, bioactivity, metabolic engineering and biotechnology

Covering: 1976 to 2020. Although constituting a limited chemical family, phytostilbenes represent an emblematic group of molecules among natural compounds. Ever since their discovery as antifungal compounds in plants and their ascribed role in human health and disease, phytostilbenes have never ceased to arouse interest for researchers, leading to a huge development of the literature in this field. Owing to this, the number of references to this class of compounds has reached the tens of thousands. The objective of this article is thus to offer an overview of the different aspects of these compounds through a large bibliography analysis of more than 500 articles. All the aspects regarding phytostilbenes will be covered including their chemistry and biochemistry, regulation of their biosynthesis, biological activities in plants, molecular engineering of stilbene pathways in plants and microbes as well as their biotechnological production by plant cell systems.

Occurrence, Bioavailability, Anti-inflammatory, and Anticancer Effects of Pterostilbene

Supplementation with natural compounds found in fruits and vegetables has long been associated with a reduced risk of several types of cancer. Pterostilbene is a natural stilbenoid and a dimethylated analogue of resveratrol which is found primarily in blueberries. Pterostilbene exhibits a range of pharmacological properties, particularly anti-inflammatory and anticancer effects. Due to two methoxy groups in its skeleton, pterostilbene is more lipophilic than resveratrol and thus possesses higher intestinal permeability and cellular uptake and enhanced stability. Moreover, pterostilbene exhibits less toxicity and fewer adverse effects, providing it with superior potential in cancer chemoprevention and chemotherapy applications. Numerous research studies have demonstrated that pterostilbene possesses detoxification activities, mediating the anti-inflammation response, regulating the cell cycle, augmenting apoptosis, enhancing autophagy, and inhibiting tumor angiogenesis, invasion, and metastasis by modulating signal transduction pathways which block multiple stages of carcinogenesis. In this review, we illustrate that pterostilbene is a natural compound having bioavailability. The extensive metabolism of pterostilbene will be discussed. We also summarize recent research on pterostilbene's anti-inflammatory and anticancer properties in the multistage carcinogenesis process and related molecular mechanism and conclude that it should contribute to improved cancer management.

Recent Advances in Synthesis, Bioactivity, and Pharmacokinetics of Pterostilbene, an Important Analog of Resveratrol

Pterostilbene is a natural 3,5-dimethoxy analog of resveratrol. This stilbene compound has a strong bioactivity and exists widely in Dalbergia and Vaccinium spp. Besides natural extraction, pterostilbene can be obtained by biosynthesis. Pterostilbene has become popular because of its remarkable pharmacological activities, such as anti-tumor, anti-oxidation, anti-inflammation, and neuroprotection. Pterostilbene can be rapidly absorbed and is widely distributed in tissues, but it does not seriously accumulate in the body. Pterostilbene can easily pass through the blood-brain barrier because of its low molecular weight and good liposolubility. In this review, the studies performed in the last three years on resources, synthesis, bioactivity, and pharmacokinetics of pterostilbene are summarized. This review focuses on the effects of pterostilbene on certain diseases to explore its targets, explain the possible mechanism, and look for potential therapeutic applications.

The protective effect of stilbenes resveratrol and pterostilbene individually and combined with mycotoxin citrinin in human adenocarcinoma HT-29 cell line in vitro

This study was focused to determine an individual and combined effect of mycotoxin citrinin (CIT) and two compounds of the stilbene family- resveratrol (RES) and his dimethyl ether analogue pterostilbene (PTE) which have many health benefits. As a model the human adenocarcinoma cell line HT-29 was used which may exhibits the properties of small intestine cells. Viability, plasma membrane integrity, lysosomal functionality, intracellular production of superoxide anions and superoxide dismutase activity were examined. The results indicate that concentrations of 50 and 100 μg/mL of the tested compounds were cytotoxic in mostly monitored parameters and probably caused apoptosis. HT-29 cells were more sensitive to PTE than to RES with a higher antioxidant effect of PTE than RES, which may be caused by its chemical structure. Both stilbenes at medium doses act as effective superoxide anions scavengers leading to reduction of oxidative stress and consequent cell damage. The nontoxic concentration of RES (25 µg/mL) protects the HT-29 cell line faced to the toxicity of CIT at 25 µg/mL by increasing viability of cells and by reducing the superoxide production induced by CIT concentrations of 12.5 µg/mL and 25 µg/mL.

Pterostilbene Sensitizes Cisplatin-Resistant Human Bladder Cancer Cells with Oncogenic HRAS

Simple Summary

RAS oncoproteins are considered undruggable cancer targets. Nearly 15% of cases of bladder cancer have a mutation of HRAS. The active HRAS contributes to the tumor progression and the risk of recurrence. Using our novel gene expression screening platform, pterostilbene was identified to sensitize cisplatin-resistant bladder cancer cells with HRAS alterations via RAS-related autophagy and cell senescence pathways, suggesting a potentially chemotherapeutic role of pterostilbene for cisplatin treatment of human bladder cancer with oncogenic HRAS. Pterostilbene is a safe and readily available food ingredient in edible plants worldwide. Exploiting the principle of combination therapy on pterostilbene-enhanced biosensitivity to identify undruggable molecular targets for cancer therapy may have a great possibility to overcome the cisplatin resistance of bladder cancer. Our data make HRAS a good candidate for modulation by pterostilbene for targeted cancer therapy in combination with conventional chemotherapeutic agents cisplatin plus gemcitabine.

Abstract

Analysis of various public databases revealed that HRAS gene mutation frequency and mRNA expression are higher in bladder urothelial carcinoma. Further analysis revealed the roles of oncogenic HRAS, autophagy, and cell senescence signaling in bladder cancer cells sensitized to the anticancer drug cisplatin using the phytochemical pterostilbene. A T24 cell line with the oncogenic HRAS was chosen for further experiments. Indeed, coadministration of pterostilbene increased stronger cytotoxicity on T24 cells compared to HRAS wild-type E7 cells, which was paralleled by neither elevated apoptosis nor induced cell cycle arrest, but rather a marked elevation of autophagy and cell senescence in T24 cells. Pterostilbene-induced autophagy in T24 cells was paralleled by inhibition of class I PI3K/mTOR/p70S6K as well as activation of MEK/ERK (a RAS target) and class III PI3K pathways. Pterostilbene-induced cell senescence on T24 cells was paralleled by increased pan-RAS and decreased phospho-RB expression. Coadministration of PI3K class III inhibitor 3-methyladenine or MEK inhibitor U0126 suppressed pterostilbene-induced autophagy and reversed pterostilbene-enhanced cytotoxicity, but did not affect pterostilbene-elevated cell senescence in T24 cells. Animal study data confirmed that pterostilbene enhanced cytotoxicity of cisplatin plus gemcitabine. These results suggest a therapeutic application of pterostilbene in cisplatin-resistant bladder cancer with oncogenic HRAS.

Development and validation of a specific-stability indicating liquid chromatography method for quantitative analysis of pterostilbene: application in food and pharmaceutical products

Pterostilbene is a natural constituent with numerous preventive and therapeutic properties used for treating a wide range of human diseases. It has been isolated from blueberries in high concentrations. A versatile specific-stability indicating liquid chromatography method for reliable quantitative determination of pterostilbene in blueberry extracts was developed. In the stability-indicating analysis, pterostilbene samples were exposed to stress conditions: temperature, UV light, and oxidative, acid and alkaline media. The robustness of the method was evaluated using a Box-Behnken experimental design. Pterostilbene was stable in acid and alkaline media, but unstable when exposed to oxidation, high temperature, and UV light. Using the proposed method, it was demonstrated that degradation products did not interfere in the analyte analysis. The method revealed to be simple, fast, selective, linear, precise and accurate for the quantitative analysis of pterostilbene in Vaccinium myrtillus extract. Besides being a specific-stability indicating method, it demonstrated to be applicable to quantify pterostilbene in pterostilbene:β-cyclodextrin complexes and pterostilbene:β-cyclodextrin:hydrophilic polymer ternary systems. These findings are relevant for the development of food, pharmaceutical or cosmetic products containing pterostilbene or blueberry extracts.

Histopathological effect of pterostilbene as chemoprevention in N-nitroso-tri-chloroethylurea (NTCU)-induced lung squamous cell carcinoma (SCC) mouse model

BACKGROUND

Lung cancer is the leading cause of cancer-related deaths, and squamous cell carcinoma (SCC) is one of the most common types of lung cancer. Chemoprevention of lung cancer has gained increasing popularity as an alternative to treatment in reducing the burden of lung cancer. Pterostilbene (PS) may be developed as a chemopreventive agent due to its pharmacological activities, such as anti-proliferative, anti-inflammatory and antioxidant properties. This study aimed to investigate the effect of PS on the development of lung SCC in the mouse model.

METHODS

A total of 24 seven-week-old female Balb/C mice were randomly categorised into four groups, including two control groups comprising the N-nitroso-trischloroethylurea (NTCU)-induced lung SCC and vehicle control (VC) groups and two treatment groups comprising the 10mg/kg PS (PS10) and 50mg/kg PS (PS50) groups. All lung organs were harvested at week 26 for histopathological analysis.

RESULTS

All PS treatment groups showed chemopreventive activity by inhibiting the progression of lung SCC formation with PS10, resulting in mild hyperplasia, and PS50 was completely reversed in the normal bronchial epithelium layer compared with the VC group. PS treatment also reduced the expression of cytokeratin 5/6 in the bronchial epithelium layer. Both PS10 and PS50 significantly reduced the epithelium thickness compared to the NTCU group (p<0.05). PS is a potential chemopreventive agent against lung SCC growth by suppressing the progression of pre-malignant lesions and reducing the thickness of the bronchial epithelium.

CONCLUSIONS

The underlying molecular mechanisms of PS in lung SCC should be further studied.

Pterostilbene attenuates liver injury and oxidative stress in intrauterine growth-retarded weanling piglets

OBJECTIVES

The aim of the present study was to investigate the potential of pterostilbene, a beneficial component primarily found in blueberries, to alleviate the intrauterine growth retardation (IUGR)-induced early liver injury and oxidative stress in a porcine model.

METHODS

Thirty-six IUGR piglets and an equal number of normal birth weight (NBW) counterparts received a diet with or without pterostilbene (250 mg/kg diet) during the first week post-weaning. Parameters related to the hepatic injury, oxidative stress, and antioxidant defense mechanisms were analyzed.

RESULTS

Relative to NBW, IUGR induced liver injury, which corresponded to increments in circulating alanine transaminase activity and hepatic apoptotic cell rate, superoxide radical generation, and the accumulation of oxidative damage products (P < 0.05). Administering pterostilbene reduced plasma transaminase activities, decreased hepatocyte apoptosis rate, and prevented the augmented levels of hepatic superoxide anion, 8-hydroxy-2 deoxyguanosine, and 4-hydroxynonenal-modified protein (P < 0.05). In terms of the hepatic antioxidant function, pterostilbene was efficient in improving the superoxide dismutase activity and the metabolic cycle between reduced glutathione and its oxidized form (P < 0.05). The pterostilbene-supplemented diet facilitated the nuclear translocation of nuclear factor erythroid-2-related factor 2 (NRF2) and promoted the expression levels of superoxide dismutase 2 in the liver of IUGR piglets (P < 0.05).

CONCLUSION

This study indicates that pterostilbene treatment has an auxiliary therapeutic potential to ameliorate early liver injury in IUGR neonates, presumably by stimulating the NRF2 signals and the associated antioxidant function.

Comparison of the protective effects of resveratrol and pterostilbene against intestinal damage and redox imbalance in weanling piglets

BACKGROUND

Evidence indicates that early weaning predisposes piglets to intestinal oxidative stress and increases the risk of intestinal dysfunction; however, there are minimal satisfactory treatment strategies for these conditions. This study investigated the potential of resveratrol and its analog, pterostilbene, as antioxidant protectants for regulating intestinal morphology, barrier function, and redox status among weanling piglets.

METHODS

A total of 144 piglets were selected at 21 days of age and randomly allocated into one of four treatment groups, each of which included six replicates. Piglets in a sow-reared control group were suckling normally between ages 21 and 28 days, while those in weaned groups were fed a basal diet, supplemented with either 300 mg/kg of resveratrol or with 300 mg/kg of pterostilbene. Parameters associated with intestinal injury and redox status were analyzed at the end of the feeding trial.

RESULTS

Early weaning disrupted the intestinal function of young piglets, with evidence of increased diamine oxidase activity and D-lactate content in the plasma, shorter villi, an imbalance between cell proliferation and apoptosis, an impaired antioxidant defense system, and severe oxidative damage in the jejunum relative to suckling piglets. Feeding piglets with a resveratrol-supplemented diet partially increased villus height (P = 0.056) and tended to diminish apoptotic cell numbers (P = 0.084) in the jejunum compared with those fed a basal diet. Similarly, these beneficial effects were observed in the pterostilbene-fed piglets. Pterostilbene improved the feed efficiency of weanling piglets between the ages of 21 and 28 days; it also resulted in diminished plasma diamine oxidase activity and D-lactate content relative to untreated weaned piglets (P < 0.05). Notably, pterostilbene restored jejunal antioxidant capacity, an effect that was nearly absent in the resveratrol-fed piglets. Pterostilbene reduced the malondialdehyde and 8-hydroxy-2´-deoxyguanosine contents of jejunal mucosa possibly through its regulatory role in facilitating the nuclear translocation of nuclear factor erythroid-2-related factor 2 and the expression levels of NAD(P)H quinone dehydrogenase 1 and superoxide dismutase 2 (P < 0.05).

CONCLUSIONS

The results indicate that pterostilbene may be more effective than its parent compound in alleviating early weaning-induced intestinal damage and redox imbalance among young piglets.

Pterostilbene induces Nrf2/HO-1 and potentially regulates NF-κB and JNK-Akt/mTOR signaling in ischemic brain injury in neonatal rats

Hypoxic-ischemic (HI) brain injury has a high occurrence rate of 1-4 per 1000 live births and is the leading cause of neurological disabilities. Despite the improvement in neonatal care, the effectiveness of current therapeutic strategies is limited, and thus, additional therapies with better results are of much needed. Pterostilbene is a stilbenoid possessing numerous preventive and therapeutic properties. The current study aimed to assess whether pterostilbene exerted protective effects in neonatal rats against experimentally induced ischemic brain injury. Pterostilbene was administered via oral gavage from postnatal day 3 to day 8. Rat pups that were seven-day-old were exposed to hypoxic-ischemic insult via ligation of the common carotid artery and hypoxic environment exposure. Pterostilbene treatment reduced neuronal loss and infarct volume. Pterostilbene administration regulated the NF-κB pathway, and the levels of inflammatory mediators (Nitric oxide, TNF-α, IL-1β, and IL-6) were reduced. HI-induced oxidative stress was significantly reduced by pterostilbene, as presented by decreased production of malondialdehyde and reactive oxygen species. Levels of glutathione were enhanced by pterostilbene. Pterostilbene regulated Nrf2/HO-1 and JNK expression and activated the PI3K/Akt-mTOR signals. These findings suggest that pterostilbene is a candidate compound for the treatment of neonatal HI.

Comparison of the effects of resveratrol and its derivative pterostilbene on hepatic oxidative stress and mitochondrial dysfunction in piglets challenged with diquat

This study investigated the potential of resveratrol (RSV) and its derivative pterostilbene (PT) to prevent diquat (DQ)-induced hepatic oxidative damage and mitochondrial dysfunction in piglets. Seventy-two weanling piglets were randomly divided into the following treatment groups: non-challenged control group, DQ-challenged control group, and DQ-challenged groups supplemented with either 300 mg RSV per kg of diet or an equivalent amount of PT. Each treatment group consisted of six replicates with three piglets per replicate (n = 6). After a two-week feeding trial, piglets were intraperitoneally injected with either 10 mg DQ per kg of body weight or sterile saline. At 24 hours post-injection, one piglet from each replicate (six piglets per treatment) was randomly selected for sample collection and biochemical analysis. Compared with the DQ-challenged control group, PT attenuated the growth loss of piglets after the DQ challenge (P < 0.05). Administration of PT was more effective than its parent compound in inhibiting the DQ-induced hepatic apoptosis and the increased generation of total cholesterol, superoxide anion, and lipid peroxidation products (P < 0.05). Specifically, PT facilitated nuclear factor erythroid 2-related factor 2 signals and the expression and activity of manganese superoxide dismutase, while it also prevented mitochondrial swelling, membrane potential collapse, and adenosine triphosphate depletion, possibly through the activation of sirtuin 1 (P < 0.05). These results indicate that PT may be superior to RSV as an antioxidant to protect the liver of young piglets from oxidative insults.

Resveratrol Derivatives as Potential Treatments for Alzheimer's and Parkinson's Disease

Neurodegenerative diseases are characterized by the progressive loss of neurons in different regions of the nervous system. Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the two most prevalent neurodegenerative diseases, and the symptoms associated with these pathologies are closely related to the regions that are most affected by the process of neurodegeneration. Despite their high prevalence, currently, there is no cure or disease-modifying drugs for the treatment of these conditions. In the last decades, due to the need for the development of new treatments for neurodegenerative diseases, several authors have investigated the neuroprotective actions of naturally occurring molecules, such as resveratrol. Resveratrol is a stilbene found in several plants, including grapes, blueberries, raspberries, and peanuts. Studies have shown that resveratrol presents neuroprotective actions in experimental models of AD and PD, however, its clinical application is limited due to its rapid metabolism and low bioavailability. In this context, studies have proposed that structural changes in the resveratrol molecule, including glycosylation, alkylation, halogenation, hydroxylation, methylation, and prenylation could lead to the development of derivatives with enhanced bioavailability and pharmacological activity. Therefore, this review article aims to discuss how resveratrol derivatives could represent viable molecules in the search for new drugs for the treatment of AD and PD.

Dietary pterostilbene supplementation attenuates intestinal damage and immunological stress of broiler chickens challenged with lipopolysaccharide

The present study explored the potential effect of pterostilbene as a prophylactic treatment on the lipopolysaccharide (LPS)-induced intestinal injury of broiler chickens by monitoring changes in mucosal injury indicators, redox status, and inflammatory responses. In total, 192 one-day-old male Ross 308 broiler chicks were randomly divided into four groups. This trial consisted of a 2 × 2 factorial design with a diet factor (supplemented with 0 or 400 mg/kg pterostilbene from 1 to 22 d of age) and a stress factor (intraperitoneally injected with saline or LPS at 5.0 mg/kg BW at 21 da of age). The results showed that LPS challenge induced a decrease in BW gain (P < 0.001) of broilers during a 24-h period postinjection; however, this decrease was prevented by pterostilbene supplementation (P = 0.031). Administration of LPS impaired the intestinal integrity of broilers, as indicated by increased plasma diamine oxidase (DAO) activity (P = 0.014) and d-lactate content (P < 0.001), reduced jejunal villus height (VH; P < 0.001) and the ratio of VH to crypt depth (VH:CD; P < 0.001), as well as a decreased mRNA level of jejunal tight junction protein 1 (ZO-1; P = 0.002). In contrast, pterostilbene treatment increased VH:CD (P = 0.018) and upregulated the mRNA levels of ZO-1 (P = 0.031) and occludin (P = 0.024) in the jejunum. Consistently, pterostilbene counteracted the LPS-induced increased DAO activity (P = 0.011) in the plasma. In addition, the LPS-challenged broilers exhibited increases in nuclear accumulation of nuclear factor kappa B (NF-κB) p65 (P < 0.001), the protein content of tumor necrosis factor α (P = 0.033), and the mRNA abundance of IL-1β (P = 0.042) and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3; P = 0.019). In contrast, pterostilbene inhibited the nuclear translocation of NF-κB p65 (P = 0.039) and suppressed the mRNA expression of IL-1β (P = 0.003) and NLRP3 (P = 0.049) in the jejunum. Moreover, pterostilbene administration induced a greater amount of reduced glutathione (P = 0.017) but a lower content of malondialdehyde (P = 0.023) in the jejunum of broilers compared with those received a basal diet. Overall, the current study indicates that dietary supplementation with pterostilbene may play a beneficial role in alleviating the intestinal damage of broiler chicks under the conditions of immunological stress.