Anti-glioma mechanism of pterostilbene by regulating apoptosis and GSDME-mediated pyroptosis pathways: a study based on network pharmacology and experimental research / 中国中药杂志

This study aimed to explore the anti-glioma effect of natural compound pterostilbene(PTE) through regulating pyroptosis and apoptosis pathways, and to analyze the possible anti-glioma pathways and targets of PTE by network pharmacology and molecular docking. In this study, the action targets of PTE and the glioma targets were obtained by network pharmacology to construct a target network and a protein-protein interaction(PPI) network to predict the possible action targets of PTE against glioma. Molecular docking was performed on the core targets by AutoDock and the action pathways of PTE against glioma were predicted by enrichment analysis. In addition, the effect of PTE on the viability of U87MG and GL261 glioma cells was detected by CCK-8 assay. Clone formation assay and cell scratching assay were used to explore the effect of different concentrations of PTE on the proliferation and migration, respectively of glioma cells. Hoechst staining was used to observe PTE-induced apoptosis in glioma cells. The changes in mitochondrial membrane potential were detected by JC-1 staining. The pyroptosis-inducing effect of PTE on glioma cells was observed by inverted microscopy and lactate dehydrogenase(LDH) assay. Hoechst 33342/PI dual staining assay was performed to detect the integrity of glioma cell membranes. The expressions of pyroptosis and apoptosis-related proteins in glioma cells after PTE induction were determined by Western blot. In this study, 37 anti-glioma targets of PTE were obtained, and enrichment analysis suggested that PTE exerted anti-glioma effects through various signaling pathways including cancer pathway, proteoglycan in cancer, PI3K/AKT pathway, and apoptosis regulatory pathway. Molecular docking revealed that PTE had good binding activity with the main targets. Compared with the control group, PTE significantly reduced the viability as well as the proliferation, migration and adhesion abilities of U87MG and GL261 cells; it induced the apoptosis of the two glioma cells and the decrease of mitochondrial membrane potential in U87MG cells, and the effects increased with the increase of drug concentration. Compared with the conditions in the control group, glioma cells in the PTE group had increased pyroptosis-specific appearance and gradually increased LDH release; the number of PI positive cells was significantly elevated with the increase of PTE concentration as revealed by Hoechst 33342/PI staining; the expression levels of apoptosis-related factors cleaved PARP1 and B-cell lymphoma-2(Bcl-2) associated X(BAX) in the PTE group were markedly up-regulated, while the expression level of Bcl-2 was markedly down-regulated; the activation levels of pyroptosis-related proteins cleaved caspase-3 and gasdermin E-N(GSDME-N) had a remarkable rise in the PTE group, while no significant changes were found in the activation levels of gasdermin D-N(GSDMD-N) and cleaved caspase-1. In summary, PTE plays an anti-glioma role by inhibiting cell viability, proliferation, and migration and activating the caspase-3/GSDME-mediated pyroptosis pathway and mitochondrial apoptosis pathway.

Effects and mechanism of pterostilbene on wound healing in diabetic skin ulcer model rats / 中国药房

OBJECTIVE To explore the effects of pterostilbene （PTE） on wound healing in diabetic skin ulcer model rats and its mechanism. METHODS Ten SD rats were grouped into control group； after diabetic skin ulcer model of other rats was induced by giving high-fat and high-sugar diet+intraperitoneal injection of streptozotocin+cutting off the skin and subcutaneous tissue in the marked area of the back， model rats were randomly divided into model group， PTE low-dose group （40 mg/kg）， PTE high-dose group （80 mg/kg）， PTE high-dose+PP2 group （80 mg/kg PTE+2 mg/kg SRC inhibitor PP2）， with 10 rats in each group. On the second day after modeling， the rats in each drug group were intraperitoneally injected with corresponding drug solutions， while the rats in control group and model group were intraperitoneally injected with normal saline， once a day， for 14 consecutive days. The wound healing rate of rats in each group was measured on the 7th and 14th day of administration； the contents of interleukin-1β （IL-1β）， IL-6， tumor necrosis factor-α （TNF-α） and vascular endothelial growth factor （VEGF） in the serum of rats were detected； the pathological changes of wound granulation tissue were observed， and the expressions of SRC/mitogen-activated protein kinase kinase （MEK）/extracellular signal-regulated kinase （ERK） signaling pathway-related proteins in wound granulation tissue were detected. RESULTS Compared with control group， the wound healing rate， serum content of VEGF， the phosphorylation levels of SRC， MEK1/2 and ERK1/2 were decreased significantly （P＜0.05）， while serum contents of IL- 1β， IL-6 and TNF-α were increased significantly （P＜0.05）； there was obvious infiltration of inflammatory cells in the wound granulation tissue， and the number of new blood vessels decreased. Compared with model group， above indexes of PTE low-dose and high-dose groups were improved significantly （P＜0.05）， and the pathological injury of granulation tissue in wound was improved. PP2 significantly reversed the improvement effects of PTE on the above indexes （P＜0.05）. CONCLUSIONS PTE can promote the wound healing of diabetic skin ulcer model rats， the mechanism of which may be related to activating SRC/MEK/ERK signaling pathway.

Pterostilbeno Reduz o Estresse Oxidativo no Pulmão e no Ventrículo Direito Induzido por Infarto do Miocárdio Experimental / Pterostilbene Reduces Experimental Myocardial Infarction-Induced Oxidative Stress in Lung and Right Ventricle

Resumo Fundamento O pterostilbeno (PS), um composto polifenólico natural e antioxidante, surge como uma intervenção promissora para minimizar danos do infarto agudo do miocárdio (IAM). Objetivo Este estudo teve como objetivo avaliar o desempenho do PS na promoção da homeostase redox nos pulmões e no ventrículo direito (VD) de animais infartados. Métodos Ratos Wistar machos (60 dias de idade) foram randomizados em três grupos: SHAM, IAM (infarto) e IAM+PS (IAM + pterostilbeno). Sete dias após o procedimento de IAM, os ratos foram tratados com PS (100 mg/kg/dia) por gavagem por oito dias. Os animais foram depois sacrificados e os pulmões e VD foram coletados para análise do balanço redox (diferenças foram consideradas significativas quando p<0,05). Resultados Nossos resultados mostram que o IAM desencadeia a interrupção redox no VD e nos pulmões, o que pode contribuir para danos induzido pelo IAM nesses órgãos. Consistentemente, o PS mitigou o estresse oxidativo e restaurou as defesas antioxidantes (Glutationa - GSH nos pulmões: SHAM = 0,79 ± 0,07; IAM = 0,67 ± 0,05; IAM + PS = 0,86 ± 0,14; p<0,05), indicando seu papel protetor neste cenário. Conclusão Nosso trabalho evidencia o potencial do uso de PS como abordagem terapêutica adjuvante após IAM para proteção dos tecidos pulmonares e cardíacos direitos.

Abstract Background Pterostilbene (PS), a natural and antioxidant polyphenolic compound emerges as a promising intervention in improving the myocardial infarction (MI) damages. Objetives This study aimed to evaluate PS actions in promoting redox homeostasis in lungs and right ventricle (RV) of infarcted animals. Methods Male Wistar rats (60 day-old) were randomized into three groups: SHAM, MI (infarcted), and MI+PS (MI+pterostilbene). Seven days after MI procedure, rats were treated with PS (100 mg/kg/day) via gavage for eight days. Animals were euthanized and the lungs and RV were harvested for analyses of redox balance (Differences were considered significant when p<0.05). Results Our results show that MI triggers a redox disruption scenario in RV and lungs, which can contribute to MI-induced damage on these organs. Consistently, PS mitigated oxidative stress and restored antioxidant defenses (GSH in lungs: SHAM= 0.79±0.07; MI=0.67±0.05; MI+PS=0.86±0.14; p<0.05), indicating its protective role in this scenario. Conclusions Our work evidences the PS potential use as an adjuvant therapeutic approach after MI focusing on protecting pulmonary and right-sided heart tissues.

Effect of pterostilbene on the growth, apoptosis and autophagy of a human papillomavirus type 16-immortalized cervical epithelial cell line H8 / 中华皮肤科杂志

Objective:To investigate the effect of pterostilbene on the growth, apoptosis and autophagy of a human papillomavirus type 16 (HPV-16) -immortalized cervical epithelial cell line H8.Methods:H8 cells were treated with pterostilbene at different concentrations of 0 (control group) , 25, 50, 75, 100 μmol/L for 24 and 48 hours. Cell counting kit-8 (CCK8) assay was performed to evaluate the cellular proliferative activity, flow cytometry was conducted to detect apoptosis and cell cycle, monodansylcadaverine (MDC) staining and fluorescence microscopy were performed to detect autophagy, and Western blot analysis was conducted to determine the expression of the cell cycle-related protein cyclinD1, apoptosis-related proteins caspase-3 and caspase-9, autophagy-related proteins Beclin1, microtubule-associated protein 1 light chain 3 (LC3) -Ⅱ/Ⅰ, ATG5 and P62, as well as HPV oncoproteins E6 and E7. Statistical analysis was carried out by using one-way analysis of variance, repeated measures analysis of variance and least significant difference- t test. Results:After 48-hour treatment with pterostilbene at different concentrations of 0, 25, 50, 75, 100 μmol/L, the relative cellular proliferation rate significantly differed among the groups (100.00% ± 1.56%, 99.02% ± 4.97%, 93.59% ± 2.01%, 81.28% ± 4.90%, 69.17% ± 7.56%, respectively; F = 77.22, P < 0.05) , and gradually decreased along with the increase in the concentration of pterostilbene; compared with the control group, the pterostilbene groups all showed significantly decreased cellular proliferation rate (all P < 0.05) . After 24-hour treatment with pterostilbene, the proportions of H8 cells at G1, G2 and S phases significantly differed among the above groups ( F = 7 845.00, 51.14, 266.50, respectively, all P < 0.05) ; compared with the control group, the pterostilbene groups showed significantly increased proportions of H8 cells at G1 and G2 phases (all P < 0.05) , but significantly decreased proportions of H8 cells at S phase ( P < 0.05) . After 48-hour treatment with pterostilbene, the apoptosis rate was significantly higher in the 25-, 50-, 75- and 100-μmol/L pterostilbene groups (14.66% ± 0.22%, 13.50% ± 0.49%, 14.56% ± 0.19%, 15.30% ± 0.76%, respectively) than in the control group (11.58% ± 0.50%, all P < 0.05) . After 24-hour treatment with pterostilbene, MDC staining showed only a small number of H8 cells with bright dot-like fluorescence in the control group, but increased number of autophagosome-positive H8 cells with bright dot-like fluorescence in the pterostilbene groups. Western blot analysis revealed that there were significant differences in the protein expression of cyclin D1, caspase-3, caspase-9, Beclin1, LC3-Ⅱ/Ⅰ, ATG5, P62, E6 and E7 among the control and pterostilbene groups after 24- and 48-hour treatment with pterostilbene (all P < 0.05) . The treatment with pterostilbene could down-regulate the expression of cyclin D1, E6 and E7, and up-regulate the expression of caspase-3, caspase-9, Beclin1, LC3-Ⅱ/Ⅰ, ATG5 and P62, with significant differences between the control group and most pterostilbene groups in expression of the above proteins (all P < 0.05) . Conclusion:Pterostilbene can inhibit the proliferation of H8 cells, promote their apoptosis and autophagy, and down-regulate the expression of oncogenes E6 and E7.

Effect of pterostilbene on oxidative stress induced apoptosis in chondrocytes / 中国组织工程研究

BACKGROUND: A variety of antioxidants exhibit anti-arthritis effects by inhibiting the production of inflammatory factors. Pterostilbene is a powerful natural antioxidant; however, there is no report on its effect against oxidative stress in chondrocytes. OBJECTIVE: To investigate the effect of pterostilbene on oxidative stress induced apoptosis in human chondrocytes METHODS: Normal human articular chondrocytes were cultured in medium containing different concentrations of pterostilbene (7.8-32 000 μg/L) for 24 continuous hours to determine the optimal concentration of pterostilbene. Normal human articular chondrocytes cultured in vitro were randomized into control group, pterostilbene group (treatment with 125 μg/L pterostilbene), hydrogen p eroxide (H2O2) group (treatment with 0.2 mmol/L H2O2), and H2O2 plus pterostilbene group (pretreatment with 125 μg/L pterostilbene followed by continuous treatment in the medium containing 125 μg/L pterostilbene and 0.2 mmol/L H2O2). After treating for 24 hours, the cell proliferation rate was detected by MTT experiment, the cell morphology and number by hematoxylin-eosin staining, the cell activity was measured by FDA/PI staining, and the changes of proteoglycan content were observed by saffron O staining. The expression of chondrogenesis marker genes aggrecan and type II collagenase 1 was detected by RT-PCR. An approval for the study protocol was validated by the Ethic Committee of the First Affiliated Hospital of Guangxi Medical University with an approval No. 20180500 8. RESULTS AND CONCLUSION: The results of MTT assay showed that pterostilbene could significantly promote chondrocyte growth at 15.6-250 μg/L, especially at 125 μg/L. The results of hematoxylin-eosin staining and FDA/PI staining further showed that pterostilbene could inhibit H2O2-induced chondrocyte apoptosis, promote chondrocyte proliferation, and increase cell viability. The results of saffron O staining showed that pterostilbene promoted the secretion of proteoglycan by chondrocytes and inhibited the adverse effects of H2O2 on chondrocytes. The results of RT-PCR further revealed that pterostilbene could promote the expression of aggrecan and type II collagenase 1 genes in chondrocytes damaged by oxidative stress and improve the chondrocyte differentiation function. In conclusion, pterostilbene can promote chondrocyte proliferation and inhibit human articular chondrocyte apoptosis caused by oxidative stress.

Effects of pterostilbene on myocardial function, myocardial fibrosis and inflammatory response in rats with acute myocardial infarction and on Notch1/eIF3a signaling pathway / 中国临床药理学与治疗学

AIM: To analyze the effects of pterostilbene on myocardial function, myocardial fibrosis and inflammatory response in rats with acute myocardial infarction and on Notch1/eIF3a signaling pathway. METHODS: Seventy-five Wistar male rats of SPF grade were selected and divided into 5 groups. The low-, medium-, high-dose groups of pterostilbene were pretreated with pterostilbene solution before modeling. The dosage was 10, 20 and 40 mg/kg of the pterostilbene sputum solution, rats of the model group and the normal group were intragastrically administered with the same dose of normal saline; except for the normal group, other rats were prepared with AMI model. The left ventricular function, cardiac blood flow index, myocardial histopathology and fibrosis, myocardial inflammatory factor content, eIF3a and Notch1 protein and mRNA expression were observed. RESULTS: LVFS and LVEF were lower in the model group than in the normal group. LVEDd, LVESd, LVESV and LVEDV were higher than those in the normal group. The LVFS and LVEF in the low, medium and high dose groups of the pterostilbene were higher than those in the model group, LVEDd, LVESd, LVESV, and LVEDV were lower than the model group, and the difference was statistically significant (P<0.05).In the model group, the -dp/dtmax, +dp/dtmax, and LVSP were lower than the normal group, and the LVEDP was higher than the normal group. The -dp/dtmax, +dp/dtmax, and LVSP in the low, medium, and high dose groups of the pterostilbene were increased as compared with model group; while LVEDP was lower than the model group, and the difference was statistically significant (P<0.05).The contents of IL-6, IL-1β and TNF-α in the myocardial tissue of the model group were higher than those in the normal group. The contents of IL-6, IL-1β and TNF-α in the myocardial tissue of rats with low, medium and dose groups of the pterostilbene were decreased as compared with the model group, the difference was statistically significant (P<0.05). The expression of eIF3a and Notch1 protein and mRNA in the myocardial tissue of the model group was higher than that in the normal group. eIF3a, Notch1 protein and mRNA expression in the low-, medium-, and high-dose rat myocardial tissue were lower than the model group, and the difference was statistically significant (P<0.05).CONCLUSION: The development of myocardial inflammation and fibrosis in AMI rats may be associated with the increase of eIF3a expression in the downstream of Notch signaling pathway. Pretreatment of pterostilbene can significantly improve ventricular remodeling in AMI rats, and its mechanism may be related to the inhibition of eIF3a and Notch1 expression.

Resveratrol and pterostilbene: A comparative overview of their chemistry, biosynthesis, plant sources and pharmacological properties

Both resveratrol and pterostilbene are monomeric stilbenes having a 6−2−6 carbon skeleton with two phenyl ringslinked by a double-bonded ethylene bridge. Resveratrol has three hydroxyl (−OH) groups, while pterostilbene hastwo methoxy (–OCH3) groups and one −OH group. They commonly occur in the trans form rather than the cis form.Red grapes and red wines are the main dietary sources of the resveratrol. Pterostilbene occurs in blueberries andgrapes. Resveratrol and pterostilbene exhibit many similarities in pharmacological properties, including antioxidant,neuroprotective anti-cancer, cardioprotective, analgesic, anti-atherosclerosis, anti-aging, anti-diabetic, antiinflammatory, and anti-obesity activities. The stronger pharmacological properties in pterostilbene than resveratrolhave been attributed to its two –OCH3 groups. As a result, pterostilbene is more lipophilic which enhances itsmembrane permeability, bioavailability, and biological potency. Some future studies on resveratrol and pterostilbeneare suggested. The sources of information cited in this comparative overview were from Science Direct, GoogleScholar, and PubMed.

Effect of pterostilbene on apoptosis and glycolysis of ovarian cancer SKOV3 cells and its mechanism / 实用肿瘤学杂志

Objective The aim of this study was to investigate the effect and mechanism of pterostilbene on apoptosis and glycolysis of ovarian cancer SKOV3 cells. Methods SKOV3 cells were treated with 0,25,50,100 and 150 μmol/L of pterostilbene for 24,48 and 72 hours. The proliferation of SKOV3 cells was measured by CCK. The effect of pterostilbene on apoptosis of SKOV3 cells was determined by flow cytometry. The glucose consumption and lactate production were detected by glucose oxidase assay and chemical colorimetry. The expression of signal transducer and activator of transcription 3 ( STAT3 ), phosphorylated STAT3 ( p -STAT3) and hexokinase 2 ( HK2) proteins was detected by Western blot. The expression of glucose transporter 1 ( GLUT1) and M2 pyruvate kinase(PKM2)mRNA was detected by qRT-PCR. Results Pterostilbene inhibited the proliferation of SKOV3 cells in a time- and dose-dependent manner. According to CCK-8 results,100 μmol/L of pterostilbene was selected as the follow-up ex-perimental group and 0 μmol/L as a control group. Pterostilbene could significantly promote the apoptosis of SKOV3 cells in a dose-dependent manner. The higher the concentration,the more obvious apoptosis effect,the difference was statistically significant ( P <0. 05). In addition,the levels of glucose consumption and lactate production in the 100 μmol/L group were significantly lower than those in the 0 μmol/L group(P<0. 01). The expression of p-STAT3 and HK2 protein in the 100 μmol/L group was also significant-ly lower than those in the 0 μmol/L group(P<0. 001). The expression of GLUT1and PKM2 mRNA in the 100 μmol/L group was also significantly decreased than those in the 0 μmol/L group(P<0. 01). Conclusion Pterostilbene can inhibit the proliferation of SK-OV3 cells and promote apoptosis,and may inhibit the glycolysis of ovarian cancer through a STAT3/HK2 pathway.

Effect of pterostilbene on the expression and activity of antioxidant enzymes in ultraviolet B-radiated HaCaT Cells / 中华皮肤科杂志

Objective To evaluate the protective effect of pterostilbene against ultraviolet B (UVB)-induced acute damage in HaCaT cells,and to explore related mechanisms.Methods The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazo1ium (MTS) assay and flow cytometry were performed to estimate the proliferative activity and the apoptosis and necrosis rate of HaCaT cells treated with different concentrations of pterostilbene respectively,so as to screen the non-toxic concentration of pterostilbene.HaCaT cells were randomly divided into several groups:normal control group receiving no treatment,UVB group irradiated with 57 mJ/cm2 UVB,3 pterostilbene groups treated with 2.44,4.88 and 9.75 μmol/L pterostilbene respectively for 24 hours,3 pterostilbene + UVB groups treated with 2.44,4.88 and 9.75 μmol/L pterostilbene respectively for 24 hours followed by UVB radiation.Western blot analysis was conducted to detect changes of the transcription factor NF-E2-related factor 2 (Nrf2) expression in cell nuclei and cytoplasm before and after the treatment with pterostilbene and UVB,quantitative PCR to determine the mRNA expression of catalase and superoxide dismutase in the HaCaT cells,and enzyme-linked immunosorbent assay (ELISA) to evaluate the activity of catalase and superoxide dismutase.Results MTS assay and flow cytometry showed that 2.44,4.88 and 9.75 μmol/L pterostilbene had non-toxic effect on HaCaT cells.The protein expression of Nrf2 in the nuclei and cytoplasm in the normal control group was 1.03 ± 0.08 and 1.04 ± 0.11 respectively.Compared with the normal control group,the protein expression of Nrf2 in the nuclei and cytoplasm experienced no significant changes in the 2.44-,4.88-and 9.75-μmol/L pterostilbene groups,and the UVB group showed similar protein expression of Nrf2 in the cytoplasm,but significantly increased protein expression of Nrf2 in the nuclei (1.77 ± 0.08,q =17.24,P ＜ 0.01).Compared with the normal control group and UVB group,the 2.44-,4.88-and 9.75-μmol/L pterostilbene + UVB groups all showed significantly lower protein expression of Nrf2 in the cytoplasm (0.86 ± 0.10,0.87 ± 0.11 and 0.46 ± 0.11 respectively,all P ＜ 0.05),but significantly higher protein expression of Nrf2 in the nuclei (2.38 ± 0.11,2.57 ± 0.11 and 2.07 ± 0.13,all P ＜ 0.01).As qPCR showed,UVB radiation could significantly inhibit the mRNA expression of CAT (P ＜ 0.05),but had no obvious effect on the mRNA expression of SOD (P ＞ 0.05).The mRNA expression of CAT and SOD experienced no significant changes in the 2.44-,4.88-and 9.75-μmol/L pterostilbene groups compared with the normal control group (P ＞ 0.05).However,2.44,4.88 and 9.75 μmol/L pterostilbene could significantly reduce the inhibitory effect of UVB radiation on the mRNA expression of CAT (P ＜ 0.05) and up-regulate the mRNA expression of SOD in the pterostilbene + UVB groups (P ＜ 0.05).ELISA revealed that UVB radiation could inhibit the activity of CAT and SOD in the HaCaT cells (both P ＜ 0.001),while 2.44,4.88 and 9.75 μmol/L pterostilbene could reduce the inhibitory effect of UVB radiation on the activity of CAT and SOD (all P ＜ 0.05).However,the activity of CAT and SOD were still lower in the 2.44-,4.88-and 9.75-μmol/L pterostilbene + UVB groups than in the normal control group (P ＜ 0.05).Conclusion Pterostilbene can prevent UVB-induced acute damage in HaCaT cells by activating the Nrf2 pathway and up-regulating the expression of the downstream antioxidant enzymes CAT and SOD.

Effects Of Pterostilbene On Activities And Protein Expression Of Cytochrome P450 1a1 (Cyp1a1) And Glutathione S-Transferase (Gst) In BenzoAPyrene-Induced Ht-29 Colorectal Cancer Cell Line / Jurnal Sains Kesihatan Malaysia

Drug Metabolizing Enzyme (DME) has been a target of natural chemopreventive agents to inhibit, retard and reverse theprocess of carcinogenesis. Pterostilbene, an analog to resveratrol has been reported to possess various pharmacologicalbenefits including chemoprevention. In our study, benzo[a]pyrene-induced HT-29 colorectal cell line was used as theDME model. The activity of phase I enzyme CYP1A as determined by the 7-ethoxyresorufin O-deethylation (EROD) assaywas found to be inhibited significantly by pterostilbene at 50 µM, 75 µM and 100 µM (p ≤ 0.01, p ≤ 0.05, p ≤ 0.01respectively) compared to the benzo[a]pyrene treated group. Meanwhile, pterostilbene induced glutathione-S-transferase(GST) activity significantly (p ≤ 0.01) at 50 µM as compared to the untreated. In addition, However, the protein expressionof CYP1A1 and GST in pterostilbene treated group was not significantly affected compared to untreated. On the otherhand, pterostilbene at 25 and 75 µM were able to increase the protein expression of transcription factor Nrf2 significantly(p ≤ 0.01). Results indicated that pterostilbene could reduce metabolic activation of procarcinogens and increase thedetoxification process which can be potentially developed as chemopreventive agent.

Study of Intermolecular Interactions Between Pterostilbene and Human Serum Albumin by Fluorescence Spectrometry-Surface Enhanced Raman Spectroscopy / 分析化学

The binding mechanism between pterostilbene ( PTE) and human serum albumin ( HSA) was investigated by fluorescence spectrometry and surface enhanced Raman spectroscopy (SERS) under simulated physiological conditions. The experiment result showed that the effect between PTE and HSA was a static fluorescence quenching with F?rsterˊ s non-radioactive energy transformation, and PTE could bind HSA strongly with a 1: 1 molar ratio. The binding distances between PTE and HSA was 1. 495 nm, and the binding constants (KA) between PTE and HSA were 1. 12 × 104 (298 K), 4. 07 × 104 (304 K) and 2. 45 × 105 L/ mol (310 K). SERS revealed that PTE combined with HAS by methoxy group. Thermodynamic data indicated that the interaction between PTE and HSA was mainly hydrophobic interaction. Marker competition experiments pointed out that the primary binding site for PTE was located at site Ⅲ in HSA. Three-dimensional, synchronous fluorescence spectrum and SERS showed that the conformation of HSA changed apparently with the addition of PTE, resulting in the tryptophan residue of HSA exposing to a less hydrophobic micro-environment. However, the conformation of PTE did not change apparently with the addition of HSA.

Determination of five active components in Draconis Resina by QAMS method / 中草药

Objective To establish a quantitative analysis of multi-components by single marker (QAMS) for determination of five active components in Draconis Resina and discuss application of QAMS in quality control of ethnic medicines. Methods Using the method of HPLC, the Fortis Xi C18 column (250 mm × 4.6 mm, 5 μm) was used. The mobile phase was composed of acetonitrile (A)-1.0% acetic acid (B) with gradient elution (0-10 min, A: 25%→30%; 10-60 min, A: 30%→50%) at the flow rate of 1.0 mL/min. The detection wavelength was 278 nm, the column temperature was 30 ℃ and the sample size was 10 μL. Pterostilbene was selected as an internal standard to establish the relative correction factors (RCFs) of 7, 4’-dihydroxyflavone, resveratrol, loureirin A, and loureirin B with reference to pterostilbene so as to achieve simultaneous determination of multi-indexed components. The contents of five active components were determined by both external standard method (ESM) and QAMS. Meanwhile, relative error (RE) between QAMS and ESM was analyzed to evaluate QAMS method. Results There were good linearities in the range of 10.23-102.27 μg/mL for 7,4’-dihydroxyflavone, 11.01-110.14 μg/mL for resveratrol, 9.47-94.72 μg/mL for loureirin A, 11.59-115.90 μg/mL for loureirin B and 24.35-243.52 μg/mL for pterostilbene, RCFs of 7,4’-dihydroxyflavone, resveratrol, loureirin A and loureirin B with reference to pterostilbene were 0.626, 1.064, 1.154, and 0.837 respectively, and repeatability was good in different experimental conditions (RSD < 3.0%).There were no significant difference between the quantitative results of the two methods. Conclusion QAMS method is feasible, credible, and can be used to determine multiple components in Draconis Resina. QAMS can be adopted as a novel strategy for quality control of ethnic medicines.

The synergistic antiproliferative effect of pterostilbene and acetylshikonin on B16 F10 cells / 中国药理学通报

Aim Toevaluatethesynergisticeffectof anti-tumor by the pterostilbene and acetylshikonin act-ing on B16F10 cells and investigate the interrelated mechanisms.Methods Theresearchscreenedandan-alyzed the target-related of pterostilbene and ace-tylshikonin by system-pharmacological methods. The proliferative inhibition rate of B16F10 cells were meas-ured by MTT.The apoptosis in B16F10 cells were proved by both cellular morphological and biochemical methods.The expression of apoptotic genes were as-sessed via RT-PCR.The apoptotic rate and cell cycle were measured by flow cytometry.Melanoma models were established in C57BL/6 mice,and the inhibitory rateoftumorgrowthwasmeasured.Results The14 targets of pterostilbene were closely related to cell cy-cle,acetylshikonin′s 12 targets displayed a relationship with apoptosis,and correlated with p53 signaling path-way.Pterostilbene along with acetylshikonin signifi-cantly inhibited cell proliferation of B16F10 cells in a dose-dependent way and resulted a remarkable syner-gistic effect.The apoptotic rate reached highest with a blocked-cell cycle at G1 phase in the co-treatment group.The RT-PCR results showed that the expres-sions of p53,Bax and p21 were up-regulated and the expressions of Bcl-2,CDK2 and Cyclin E were down-regulated with time.The changes of p53,Bax and Bcl-2 were obvious in combined treated group.All treat-ments in vivo showed different tumor inhibition rates while co-treatment group showed highest.Conclusion Pterostilbenecooperatedwithacetylshikonininhibits the proliferation in B16F10 cells,and activates the p53 signaling pathway to induce the B16F10 cells apoptosis and a cell cycle arrest.

Pterostilbene induces retinoblastoma WERI-Rb-1 cell apoptosis via autophagy induction / 中国癌症杂志

Background and purpose:Pterostilbene is a natural antioxidant, whose role in retinoblastoma remains unclear. The aim of this study is to probe the effects of pterostilbene on the proliferation, apoptosis and autophagy in retinoblastoma WERI-Rb-1 cell lines.Methods:Cell counting kit-8 (CCK-8) assays were used to analyze the effects of pterostilbene on the proliferation of WERI-Rb-1 cells. Apoptosis rate was determined by Annexin V/PI. Autophagic vacuoles were observed by acridine orange staining. LC3 and P62 protein expressions were determined using Western blot.Results:Pterostilbene significantly inhibited the proliferation of WERI-Rb-1 cells (P<0.01). The cell viability were (93.02±0.47)%, (55.10±2.04)% and (30.33±1.45)% after WERI-Rb-1 cells were treated with 25, 50 and 100 μmol/L pterostilbene for 24 h, and the cell viability were (88.38±3.70)%, (53.37±1.17)%, (29.60±1.05)% after WERI-Rb-1 cells were treated with 50 μmol/L pterostilbene for 12, 24 and 48 h. Pterostilbene induced cell apoptosis (P<0.01), the apoptosis rates of control group, 24 h treated group and 48 h treated group were (4.08±0.79)%, (13.44±2.12)% and (23.49±2.01)%. Pterostilbene induced autophagy of WERI-Rb-1 cells, increased LC3 expression, downregulated P62 expression and increased the number of autophagic vacuoles in WERI-Rb-1 cells (P<0.01). 3-MA and Beclin1 were able to rescue pterostilbene-induced cell death (P<0.01). After 3-MA was used to blunt autophagosome formation, the apoptosis rate markedly decreased in 3-MA+pterostilbene-treated cells compared with cells treated with pterostilbene alone [(12.97±2.09)%vs (8.35±1.11)%], and after siRNA was used to knockdown Beclin1, the apoptosis rate had the same change [(13.80±2.19)%vs (9.62±0.52)%].Conclusion:Pterostilbene can inhibit the proliferation of WERI-Rb-1 cells and induce cell apoptosis via autophagy activation.

Simultaneous determination of 7-hydroxy-4'-methoxyflavane and pterostilbene in Zhuang Medicine Dracaena cochinchinensis by HPLC / 中草药

Objective: To establish a method for the determination of 7-hydroxy-4'-methoxyflavane and pterostilbene in Zhuang Medicine Dracaena cochinchinensis. Methods: The determination was developed on C18 column. Acetonitrile-0.2% phosphoric acid (36: 64) was used as mobile phase and the detective wavelength was set at 281 and 306 nm, respectively. Results: The linear ranges of 7-hydroxy-4'-methoxyflavane and pterostilbene were 0.4076-1.5285 μg (r = 0.9998) and 1.6408-6.1530 μg (r = 0.9997), respectively. The average recovery was 97.88% (RSD = 0.82%) and 97.10% (RSD = 0.59%), respectively. Conclusion: The method is simple and accurate, which could be used for the quality control of D. cochinchinensis and its extract.

Research progresses in antiproliferative properties of pterostilbene / 国际肿瘤学杂志

Pterostilbene,a dimethyl ester derivative of resveratrol with antioxidant and antiproliferative properties,has been shown to inhibit a variety of primary tumors and act as a potential chemopreventive agent in carcinogenesis.The anticancer mechanisms of pterostilbene include inducing tumor cell apoptosis,causing cell cycle arrest,blocking tumor cell growth and proliferation signal transduction.Pterostilbene is expected to develop to a new generation of anticancer drug,and will be paid more attention in the future.

Determination of pterostilbene in Dragon's Blood with different extraction / 中成药

Objective: To establish HPLC method for determination of pterostilbene in Dragon's Blood with different extraction technology. Method: Applying a C 18 phase column and acetonitrile 1% acetic acid(41∶59) as mobile phase, detecting at 319nm and quantitating with external standard method. Results: The standard curves of pterostilbene was linear in the concentration range of 10.4～104ng, r =0.9992. The average recovery was 98.28%, RSD =1.97%. The content of pterostilbene in Dragon's Blood extracted with ordinary temperature was lower than that with heating technology. Conclusion: The content of pterostilbene extracted with ordinary temperature extraction in Dragon's blood have the advantage of heating extraction.