Antioxidative activity of natural isorhapontigenin

Isorhapontigenin (ISO) inhibits malignant cell transformation, migration, and invasion through MEG3/NEDD9 signaling in Cr(VI)-transformed cells

Cr(VI) compounds are confirmed human carcinogens. Maternally expression 3 (MEG3) is the first long non-coding RNA to be identified as a tumor suppressor. MEG3 is frequently downregulated or lost in various primary human tumor tissues and cancer cell lines. Downregulation of MEG3 is associated with cancer initiation, progression, and metastasis. Our previous study has revealed that MEG3 was lost and NEDD9 was upregulated in Cr(VI)-transformed cells compared to those in passage-matched normal BEAS-2B cells. Overexpression of MEG3 reduced NEDD9. β-Catenin was activated in Cr(VI)-transformed cells, overexpression of MEG3 or knockdown of NEDD9 inhibited the activation of β-Catenin. The results from the present study showed that isorhapontigenin (ISO) treatment is able to suppress cell proliferation, migration, and invasion of Cr(VI)-transformed cells. Further study showed that ISO treatment in Cr(VI)-transformed cells decreases the levels of Ki67, a biomarker for cell proliferation, and of cyclin D1, a regulator for the cell cycle. ISO elevated the MEG3 expression level in Cr(VI)-transformed cells. The DNA methylation transferases DNMT3a, DNMT3b, and DNMT1 levels were reduced upon ISO treatment. ISO treatment decreased both mRNA and protein levels of NEDD9. In addition, ISO treatment reduced the activation of β-catenin. Slug was upregulated and E-Cadherin was downregulated in Cr(VI)-transformed cells, treatment with ISO decreased Slug and increased E-Cadherin. This study demonstrated that ISO is a potent therapeutical agent against lung cancer induced by Cr(VI).

Cytotoxic Compounds from Belamcanda chinensis (L.) DC Induced Apoptosis in Triple-Negative Breast Cancer Cells

Four compounds (1, 5, 7, and 8) were first isolated from the genus Belamcanda Adans. nom. conserv., and six known compounds (2-4, 6, 9, and 10) were isolated from the rhizome of Belamcanda chinensis (L.) DC. Their structures were confirmed by spectroscopic data. Herein, compounds 1-10 were rhapontigenin, trans-resveratrol, 5,7,4'-trihydroxy-6,3',5'-trimethoxy-isoflavone, irisflorentin, 6-hydroxybiochannin A, iridin S, pinoresinol, 31-norsysloartanol, isoiridogermanal, and iristectorene B, respectively. All compounds were evaluated for their antiproliferative effects against five tumor cell lines (BT549, 4T1, MCF7, MDA-MB-231, and MDA-MB-468). Among them, compound 9 (an iridal-type triterpenoid) showed the highest activity against 4T1 and MDA-MB-468 cells. Further studies displayed that compound 9 inhibited cell metastasis, induced cells cycle arrest in the G1 phase, exhibited significant mitochondrial damage in 4T1 and MDA-MB-468 cells including excess reactive oxygen species, decreased mitochondrial membrane potential, and induced 4T1 and MDA-MB-468 cell apoptosis for the first time. In summary, these findings demonstrate that compound 9 exerts promising potential for triple-negative breast cancer treatment and deserves further evaluation.

Isorhapontigenin Attenuates Cardiac Microvascular Injury in Diabetes via the Inhibition of Mitochondria-Associated Ferroptosis Through PRDX2-MFN2-ACSL4 Pathways

Ferroptosis is a newly identified form of regulated cell death that is driven by iron overload and uncontrolled lipid peroxidation, but the role of ferroptosis in cardiac microvascular dysfunction remains unclear. Isorhapontigenin (ISO) is an analog of resveratrol and possesses strong antioxidant capacity and cardiovascular-protective effects. Moreover, ISO has been shown to alleviate iron-induced oxidative damage and lipid peroxidation in mitochondria. Therefore, the current study aimed to explore the benefits of ISO treatment on cardiac microvascular dysfunction in diabetes and the possible mechanisms involved, with a focus on ferroptosis and mitochondria. Our data revealed that ISO treatment improved microvascular density and perfusion in db/db mice by mitigating vascular structural damage, normalizing nitric oxide (NO) production via endothelial NO synthase activation, and enhancing angiogenetic ability via vascular endothelial growth factor receptor 2 phosphorylation. PRDX2 was identified as a downstream target of ISO, and endothelial-specific overexpression of PRDX2 exerted effects on the cardiac microvascular function that were similar to those of ISO treatment. In addition, PRDX2 mediated the inhibitive effects of ISO treatment on ferroptosis by suppressing oxidative stress, iron overload, and lipid peroxidation. Further study suggested that mitochondrial dynamics and dysfunction contributed to ferroptosis, and ISO treatment or PRDX2 overexpression attenuated mitochondrial dysfunction via MFN2-dependent mitochondrial dynamics. Moreover, MFN2 overexpression suppressed the mitochondrial translocation of ACSL4, ultimately inhibiting mitochondria-associated ferroptosis. In contrast, enhancing mitochondria-associated ferroptosis via ACSL4 abolished the protective effects of ISO treatment on cardiac microcirculation. Taken together, the results of the present work demonstrated the beneficial effects of ISO treatment on cardiac microvascular protection in diabetes by suppressing mitochondria-associated ferroptosis through PRDX2-MFN2-ACSL4 pathways.

Isorhapontigenin ameliorates high glucose-induced podocyte and vascular endothelial cell injuries via mitigating oxidative stress and autophagy through the AMPK/Nrf2 pathway

BACKGROUND

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes mellitus and a primary reason for end-stage renal disease (ESRD). Isorhapontigenin (ISO), a natural derivative of stilbene, has significant anti-inflammatory and antioxidant effects. Nevertheless, its impact on DN remains elusive.

METHODS

Human vascular endothelial cells (HUVECs) and podocytes were damaged by high glucose (HG). Cell viability and apoptosis were testified by the cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The mRNA profiles of antioxidant factors HO-1, NQO1, and Prx1 were monitored by real-time quantitative polymerase chain reaction (RT-qPCR). Western blotting (WB) was implemented to verify the expression of apoptosis-related proteins (Bax, Bad, and Bcl-XL), antioxidant factors (HO-1, NQO1, and Prx1), autophagy-related proteins (Beclin-1, ATG5, p62), podocalyxin (podocin, nephrin, and synaptopodin) and the AMPK/Nrf2 pathway. The levels of oxidative stress-related markers MDA, SOD and CAT were assessed with the corresponding kits. Compound C (CC), an inhibitor of AMPK, was deployed to probe the effects of modulating the AMPK/Nrf2 pathway on ISO in oxidative stress and autophagy in HUVECs and podocytes. Streptozotocin (STZ) was injected intraperitoneally into mice to establish an animal model of diabetes mellitus and to clarify the impact of ISO on the renal parameters such as serum creatinine, urea nitrogen and urinary protein in diabetic mice.

RESULTS

ISO notably facilitated cell proliferation, impeded apoptosis, elevated the expression of antioxidant-related factors, alleviated HG-induced oxidative stress and activated autophagy in HUVECs and podocytes. ISO activated the AMPK/Nrf2 pathway. Attenuating AMPK diminished the protective effect of ISO on HUVECs and podocytes, curbed cell proliferation, intensified apoptosis and oxidative stress, and dampened autophagy. In-vivo experiments also displayed that ISO reduced histopathological damage, lowered serum creatinine, urea nitrogen and urinary ACR levels, and eased kidney damage in DN mice.

CONCLUSION

ISO attenuates HG-induced oxidative stress and activates autophagy by motivating the AMPK/Nrf2 pathway, exerting a protective effect on HUVECs and podocytes and reducing renal injury in DN mice.

Doxorubicin-Induced TrkAIII Activation: A Selection Mechanism for Resistant Dormant Neuroblastoma Cells

Patients with advanced neuroblastoma (NB) receive multimodal clinical therapy, including the potent anthracycline chemotherapy drug doxorubicin (Dox). The acquisition of Dox resistance, however, is a major barrier to a sustained response and leads to a poor prognosis in advanced disease states, reinforcing the need to identify and inhibit Dox resistance mechanisms. In this context, we report on the identification and inhibition of a novel Dox resistance mechanism. This mechanism is characterized by the Dox-induced activation of the oncogenic TrkAIII alternative splice variant, resulting in increased Dox resistance, and is blocked by lestaurtinib, entrectinib, and crizotinib tyrosine kinase and LY294002 IP3-K inhibitors. Using time lapse live cell imaging, conventional and co-immunoprecipitation Western blots, RT-PCR, and inhibitor studies, we report that the Dox-induced TrkAIII activation correlates with proliferation inhibition and is CDK1- and Ca²⁺-uniporter-independent. It is mediated by ryanodine receptors; involves Ca²⁺-dependent interactions between TrkAIII, calmodulin and Hsp90; requires oxygen and oxidation; occurs within assembled ERGICs; and does not occur with fully spliced TrkA. The inhibitory effects of lestaurtinib, entrectinib, crizotinib, and LY294002 on the Dox-induced TrkAIII and Akt phosphorylation and resistance confirm roles for TrkAIII and IP3-K consistent with Dox-induced, TrkAIII-mediated pro-survival IP3K/Akt signaling. This mechanism has the potential to select resistant dormant TrkAIII-expressing NB cells, supporting the use of Trk inhibitors during Dox therapy in TrkAIII-expressing NBs.

Isorhapontigenin Modulates SOX9/TOLLIP Expression to Attenuate Cell Apoptosis and Oxidative Stress in Paraquat-Induced Acute Kidney Injury

Paraquat (PQ) is a widely used herbicide but can be lethal to humans. The kidney is vital for PQ elimination; therefore, explorations for therapeutic approaches for PQ-induced acute kidney injury (AKI) are of great significance. Here, the effects of a natural bioactive polyphenol isorhapontigenin (ISO) on PQ-AKI were investigated. In vitro experiments carried out in PQ-intoxicated rat renal tubular epithelial cells (NRK-52E) showed that ISO treatment inhibited PQ-induced cell apoptosis and oxidative stress, which was evidenced by the decreased proapoptotic proteins [cleaved caspase 3/9 and poly (ADP-ribose) polymerase (PARP)], the reduced oxidative stress indicators [reactive oxygen species (ROS), malondialdehyde (MDA), and lactate dehydrogenase (LDH) leakage], and the increased antioxidants [superoxide dismutase (SOD), nuclear factor E2-related factor 2 (NRF2), and oxygenase-1 (HO-1)]. Furthermore, 50 mg/kg ISO pretreatment before PQ administration significantly attenuated PQ-AKI in rats, as manifested by the improved renal tubule damage, the reduced serum and urine markers of kidney injury, and the inhibited cell apoptosis and oxidative stress in the renal cortex. Furthermore, expression of sex-determining region Y box 9 (SOX9) and Toll-interacting protein (TOLLIP) in NRK-52E cells and the renal cortex was significantly upregulated after ISO treatment. Overexpression of SOX9 increased TOLLIP transcription and attenuated PQ-induced apoptosis and oxidative stress, whereas knockdown of SOX9 impaired the protective effects of ISO on NRK-52E cells against PQ toxicity. In conclusion, the present study demonstrated that ISO modulated SOX9/TOLLIP expression to attenuate cell apoptosis and oxidative stress in PQ-AKI, suggesting the potential of ISO in treating PQ-poisoned patients.

Induction of p27 contributes to inhibitory effect of isorhapontigenin (ISO) on malignant transformation of human urothelial cells

Bladder cancer (BC) is the most expensive cancer to manage on a per-patient basis, costing about $4 billion in total healthcare expenditure per annum in America alone. Therefore, identifying a natural compound for prevention of BC is of tremendous importance for managing this disease. Previous studies have identified isorhapontigenin (ISO) as having an 85% preventive effect against invasive BC formation induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). The results showed here that ISO treatment inhibited EGF-induced cell transformation of human urothelial cells through induction of tumor suppressor p27 transcription secondary to activation of an E2F1-dependentpathway.ISOtreatmentrenderedcellsresistanttoEGF-induced anchorage-independent growth concurrent with p27 protein induction in both UROtsa and SV-HUC-1 cells. ISO inhibition of EGF-induced cell transformation could be completely reversed by knockdown of p27, indicating that this protein was essential for the noted ISO inhibitory action. Mechanistic studies revealed that ISO treatment resulted in increased expression of E2F1, which in turn bound to its binding site in p27 promoter and initiated p27 transcription. The E2F1 induction was due to the elevation of its translation caused by ISO-induced miR-205 downregulation. Consistently, miR-205 was found to be overexpressed in human BCs, and ectopic expression of miR-205 mitigated ISO inhibitory effects against EGF-induced outcomes. Collectively, the results here demonstrate that ISO exhibits its preventive effect on EGF-induced human urothelial cell transformation by induction of p27 through a miR-205/E2F1 axis. This is distinct from what has been described for the therapeutic effects of ISO on human BC cells.

Biological Synthesis of Bioactive Gold Nanoparticles from Inonotus obliquus for Dual Chemo-Photothermal Effects against Human Brain Cancer Cells

The possibility for an ecologically friendly and simple production of gold nanoparticles (AuNPs) with Chaga mushroom (Inonotus obliquus) (Ch-AuNPs) is presented in this study. Chaga extract’s reducing potential was evaluated at varied concentrations and temperatures. The nanoparticles synthesized were all under 20 nm in size, as measured by TEM, which is a commendable result for a spontaneous synthesis method utilizing a biological source. The Ch-AuNPs showed anti-cancer chemotherapeutic effects on human brain cancer cells which is attributed to the biofunctionalization of the AuNPs with Chaga bioactive components during the synthesis process. Further, the photothermal ablation capability of the as-prepared gold nanoparticles on human brain cancer cells was investigated. It was found that the NIR-laser induced thermal ablation of cancer cells was effective in eliminating over 80% of the cells. This research projects the Ch-AuNPs as promising, dual modal (chemo-photothermal) therapeutic candidates for anti-cancer applications.

Isorhapontigenin alleviates cerebral ischemia/reperfusion injuries in rats and modulated the PI3K/Akt signaling pathway

Isorhapontigenin (ISO) is one of the main bioactive components of Gnetum cleistostachyum and was shown to possess antioxidant and antitumor functions. Herein, we hope to examine the neuroprotection impacts of ISO in rats subjected to transient middle cerebral artery occlusion/reperfusion (MCAO/R, 2/24 h) injuries. ISO was injected intraperitoneally into the rats immediately after cerebral ischemia. After 24 h of the reperfusion, infarct volume, brain water contents, neurological deficit, and cerebral blood flow were assessed. Hippocampus histopathology change was detected by H&E and TUNEL staining. The expressions of cleaved caspase-3, Bax and Bcl-2, and phospho-Akt (p-Akt) were investigated by real-time RT-PCR or western blot analysis. We found that ISO significantly suppressed the infarct volumes, brain water contents, and neurological deficit, increased CBF, and relieved histopathologic change in a dose-dependent manner. Reduced malondialdehyde (MDA) and elevated activities of superoxide dismutase (SOD) and GSH and glutathione peroxidase (GSH-PX) were observed in ISO group. ISO remarkably decreased caspase-3 and Bax and increased levels of Bcl-2. Additionally, ISO upregulated p-Akt expression. Blocking of PI3K activities by wortmannin can abolish the ISO-caused decrease in infarct volumes and neurologic deficit scores and abrogate the promotion of p-Akt. The data indicated that ISO played neuroprotective impacts against focal I/R injuries, possibly related to the activating of PI3K/Akt signaling.

A Stilbenoid Isorhapontigenin as a Potential Anti-Cancer Agent against Breast Cancer through Inhibiting Sphingosine Kinases/Tubulin Stabilization

Isorhapontigenin (ISO), a tetrahydroxylated stilbenoid, is an analog of resveratrol (Rsv). The various biological activities of Rsv and its derivatives have been previously reported in the context of both cancer and inflammation. However, the anti-cancer effect of ISO against breast cancer has not been well established, despite being an orally bioavailable dietary polyphenol. In this study, we determine the anti-cancer effects of ISO against breast cancer using MCF7, T47D, and MDA-MB-231 cell lines. We observed that ISO induces breast cancer cell death, cell cycle arrest, oxidative stress, and the inhibition of cell proliferation. Additionally, sphingosine kinase inhibition by ISO controlled tubulin polymerization and cancer cell growth by regulating MAPK/PI3K-mediated cell cycle arrest in MCF7 cells. Interestingly, SPHK1/2 gene silencing increased oxidative stress, cell death, and tubulin destabilization in MCF7 cells. This suggests that the anti-cancer effect of ISO can be regulated by SPHK/tubulin destabilization pathways. Overall, ISO successfully induced breast cancer cell death and cell growth arrest, suggesting this phytochemical is a better alternative for breast cancer treatment. Further studies in animal models could confirm the potency and usability of ISO over Rsv for targeting breast cancer, potentially posing an alternative candidate for improved therapy in the near future.

Plasma pharmacokinetics of isorhapontigenin, a novel derivative of stilbenes, in mice by LC-MS/MS method

Isorhapontigenin (ISO), a novel derivative of stilbene compound, possessess good pharmacological activities such as antiviral, antioxidant, and anticancer. The purpose of this study is to investigate the pharmacokinetic of ISO in mice plasma, after oral administration of three doses (40, 80, and 160 mg/kg). Isorhapontigenin was detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and a reliable LC-MS/MS assay for ISO in mice plasma was developed. The method was linear over a concentration range of 5-2000 ng/ml, and the lower limit of quantification was 5 ng/ml. The results indicated that there was a linear relationship between AUC_(0-t), AUC_(0-∞), and C_max of ISO and dosages. ISO underwent quick absorption and elimination in mice.

Isorhapontigenin, a resveratrol analogue selectively inhibits ADP-stimulated platelet activation

Isorhapontigenin is a polyphenolic compound found in Chinese herbs and grapes. It is a methoxylated analogue of a stilbenoid, resveratrol, which is well-known for its various beneficial effects including anti-platelet activity. Isorhapontigenin possesses greater oral bioavailability than resveratrol and has also been identified to possess anti-cancer and anti-inflammatory properties. However, its effects on platelet function have not been reported previously. In this study, we report the effects of isorhapontigenin on the modulation of platelet function. Isorhapontigenin was found to selectively inhibit ADP-induced platelet aggregation with an IC₅₀ of 1.85 μM although it displayed marginal inhibition on platelet aggregation induced by other platelet agonists at 100 μM. However, resveratrol exhibited weaker inhibition on ADP-induced platelet aggregation (IC₅₀ > 100 μM) but inhibited collagen induced platelet aggregation at 50 μM and 100 μM. Isorhapontigenin also inhibited integrin αIIbβ3 mediated inside-out and outside-in signalling and dense granule secretion in ADP-induced platelet activation but interestingly, no effect was observed on α-granule secretion. Isorhapontigenin did not exert any cytotoxicity on platelets at the concentrations of up to 100 μM. Furthermore, it did not affect haemostasis in mice at the IC₅₀ concentration (1.85 μM). In addition, the mechanistic studies demonstrated that isorhapontigenin increased cAMP levels and VASP phosphorylation at Ser157 and decreased Akt phosphorylation. This suggests that isorhapontigenin may interfere with cAMP and PI3K signalling pathways that are associated with the P2Y₁₂ receptor. Molecular docking studies emphasised that isorhapontigenin has greater binding affinity to P2Y₁₂ receptor than resveratrol. Our results demonstrate that isorhapontigenin has selective inhibitory effects on ADP-stimulated platelet activation possibly via P2Y₁₂ receptor.

Pre-clinical Pharmacokinetic and Metabolomic Analyses of Isorhapontigenin, a Dietary Resveratrol Derivative

Background: Isorhapontigenin (trans-3,5,4'-trihydroxy-3'-methoxystilbene, ISO), a dietary resveratrol (trans-3,5,4'-trihydroxystilbene) derivative, possesses various health-promoting activities. To further evaluate its medicinal potentials, the pharmacokinetic and metabolomic profiles of ISO were examined in Sprague-Dawley rats. Methods: The plasma pharmacokinetics and metabolomics were monitored by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. Results: Upon intravenous injection (90 μmol/kg), ISO exhibited a fairly rapid clearance (CL) and short mean residence time (MRT). After a single oral administration (100 μmol/kg), ISO was rapidly absorbed and showed a long residence in the systemic circulation. Dose escalation to 200 μmol/kg resulted in higher dose-normalized maximal plasma concentrations (C_max/Dose), dose-normalized plasma exposures (AUC/Dose), and oral bioavailability (F). One-week repeated daily dosing of ISO did not alter its major oral pharmacokinetic parameters. Pharmacokinetic comparisons clearly indicated that ISO displayed pharmacokinetic profiles superior to resveratrol as its C_max/Dose, AUC/Dose, and F were approximately two to three folds greater than resveratrol. Metabolomic investigation revealed that 1-week ISO administration significantly reduced plasma concentrations of arachidonic acid, cholesterol, fructose, allantoin, and cadaverine but increased tryptamine levels, indicating its impact on metabolic pathways related to health-promoting effects. Conclusion: ISO displayed favorable pharmacokinetic profiles and may be a promising nutraceutical in view of its health-promoting properties.

Isorhapontigenin induced cell growth inhibition and apoptosis by targeting EGFR-related pathways in prostate cancer

Isorhapontigenin (ISO), a naturally phytopolyphenol compound existing in Chinese herb, apples, and various vegetables, has attracted extensive interest in recent years for its diverse pharmacological characteristics. Increasing evidences reveal that ISO can inhibit cancer cell growth by induced apoptosis, however, the molecular mechanisms is not fully understood. In this study, we found for the first time that ISO apparently induced cell growth inhibition and apoptosis by targeting EGFR and its downstream signal pathways in prostate cancer (PCa) cells both in vitro and in vivo, whereas no obviously effect on normal prostate cells. From the results, we found that ISO competitively targeted EGFR with EGF and inhibited EGFR auto-phosphorylation, and then decreased the levels of p-Erk1/2, p-PI3 K, and p-AKT, and further induced down-regulation of p-FOXO1 and promoted FOXO1 nuclear translocation; and finally resulted in a significantly up-regulation of Bim/p21/27/Bax/cleaved Caspase-3/cleaved PARP-1 and a markedly down-regulation of Sp1/Bcl-2/XIAP/Cyclin D1. Moreover, our experimental data demonstrated that treatment of ISO decreased protein level of AR via both inhibiting the expression of AR gene and promoting the ubiquitination/degradation of AR proteins in proteasome. In vivo, we also found that ISO inhibited the growth of subcutaneous xenotransplanted tumor in nude mice by inducing PCa cell growth inhibition and apoptosis. Taken together, all findings here clearly implicated that EGFR-related signal pathways, including EGFR-PI3K-Akt and EGFR-Erk1/2 pathways, were involved in ISO-induced cell growth inhibition and apoptosis in PCa cells, providing a more solid theoretical basis for the application of ISO to treat patients with prostate cancer in clinic.

A Theoretical Study on the Antioxidant Activity of Piceatannol and Isorhapontigenin Scavenging Nitric Oxide and Nitrogen Dioxide Radicals

The antioxidant activity of naturally occurring stilbene compounds piceatannol (PIC) and isorhapontigenin (ISO) scavenging two free radicals (NO and NO₂) were studied using density functional theory (DFT) method. Four reaction mechanisms have been considered: hydrogen atom transfer (HAT), radical adduct formation (RAF), single electron transfer (SET), and sequential proton loss electron transfer (SPLET). The reaction channels in water solution were traced independently, and the respective thermodynamic and kinetic parameters were obtained. We found PIC and ISO scavenge NO mainly through RAF mechanism, and scavenge NO₂ through HAT mechanism. The capacity of PIC scavenging NO₂ is much higher than ISO, but the reactivity of scavenging NO is lower than ISO.

Belamcanda chinensis (L.) DC-An ethnopharmacological, phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Belamcanda chinensis (L.) DC is the sole species in the genus Belamcanda Adans. (Iridaceae), found mainly in Northeast Asia. Bombus chinensis has long been used in traditional Chinese medicine for its multiple therapeutic uses in the form of antipyretic agents, antidote, expectorant, antiphlogistic and analgesic.

AIM OF THE REVIEW

This manuscript comprehensively summarizes the various studies published in recent years on the botany, ethnopharmacology, phytochemistry, biological activity and toxicology of B. chinensis. We hope to provide a foundation for future studies on the mechanism of action and development of better therapeutic agents based on B. chinensis.

MATERIAL AND METHODS

All information available on B. chinensis was collected using electronic search engines, such as PubMed, SciFinder Scholar, CNKI, TPL (www.theplantlist.org), Google Scholar and Web of Science.

RESULTS

The analysis shown that ethno-medical uses of B. chinensis have been recorded in China, Japan and Korea since a long time. Based on a phytochemical investigation, this plant contains flavonoids, terpenoids, quinones, phenolic compounds, ketones, organic acids, etc. Crude extracts and pure compounds isolated from B. chinensis exhibited various biological effects.

CONCLUSIONS

In light of its long traditional use and the modern phytochemical and pharmacological studies summarized here, B. chinensis is known to be a promising medicinal plant with the isolated extracts and chemical components showing a wide range of biological activities. Thus, it is imperative that the necessary programs and value assessment of B. chinensis be established for further studies. It is also important that the synergistic or antagonistic effects of this traditional herbal medicine are investigated in depth to identify more bioactive components by bioactivity-guided isolation strategies, and to illustrate the mechanisms of action targeting on ethnomedical uses. Future clinical studies can also focus on the main therapeutic aspects, toxicity and adverse effects of B. chinensis.

Administration of Piceatannol Complexed with α-Cyclodextrin Improves Its Absorption in Rats

Piceatannol is polyphenolic antioxidant found in passion fruit (Passiflora edulis) seeds. The aim of this study was to improve the absorption of piceatannol using α-cyclodextrin (αCD). The solubility of piceatannol in neutral and acidic solutions increased in an αCD concentration-dependent manner. The maximum plasma concentration of intact piceatannol and the time-to-maximum plasma concentration of O-methylated piceatannol metabolites increased in rats administered αCD-piceatannol inclusion complexes (PICs). Administering the αCD inclusion complexes significantly increased the area under the concentration-time curve of total stilbene derivatives (0-3 h) in terms of the total amount of intact piceatannol, O-methylated piceatannol, conjugated piceatannol, and isorhapontigenin. Gastrointestinal ligation experiments demonstrated that substantially higher levels of piceatannol metabolites were present in the lower intestine (the ileum) at 1 h postintragastric αCD-PICs administration as compared to those observed following piceatannol administration only. These results suggested that αCD enhanced piceatannol movement and absorption in the small intestine.

Quantum Chemical Study on the Antioxidation Mechanism of Piceatannol and Isorhapontigenin toward Hydroxyl and Hydroperoxyl Radicals

A systematic study of the antioxidation mechanisms behind hydroxyl (•OH) and hydroperoxyl (•OOH) radical scavenging activity of piceatannol (PIC) and isorhapontigenin (ISO) was carried out using density functional theory (DFT) method. Two reaction mechanisms, abstraction (ABS) and radical adduct formation (RAF), were discussed. A total of 24 reaction pathways of scavenging •OH and •OOH with PIC and ISO were investigated in the gas phase and solution. The thermodynamic and kinetic properties of all pathways were calculated. Based on these results, we evaluated the antioxidant activity of every active site of PIC and ISO and compared the abilities of PIC and ISO to scavenge radicals. According to our results, PIC and ISO may act as effective •OH and •OOH scavengers in organism. A4-hydroxyl group is a very important active site for PIC and ISO to scavenge radicals. The introducing of -OH or -OCH₃ group to the ortho-position of A4-hydroxyl group would increase its antioxidant activity. Meanwhile, the conformational effect was researched, the results suggest that the presence and pattern of intramolecular hydrogen bond (IHB) are considerable in determining the antioxidant activity of PIC and ISO.

Absorption and metabolism of piceatannol in rats

Piceatannol (trans-3,3',4,5'-tetrahydroxystilbene), a natural analogue of resveratrol, has multiple biological functions. Nevertheless, piceatannol's biological fate is yet to be determined. In this study, we evaluated the absorption and metabolism of piceatannol in rats. Furthermore, the area under the plasma concentration curves (AUC) and metabolic pathway of piceatannol were compared with those of resveratrol. We determined the plasma concentrations of piceatannol, resveratrol, and their respective metabolites following their intragastric administration. Resveratrol metabolites were only conjugates, whereas piceatannol metabolites were piceatannol conjugates, O-methyl piceatannol, and its conjugates. The AUC for piceatannol, resveratrol, and their metabolites increased in a dose-dependent manner (90-360 μmol/kg). The AUC for total piceatannol was less than that for total resveratrol, whereas the AUC for piceatannol (8.6 μmol·h/L) after piceatannol and resveratrol coadministration was 2.1 times greater than that for resveratrol (4.1 μmol·h/L). The greater AUC for piceatannol was a result of its higher metabolic stability.

Progress on understanding the anticancer mechanisms of medicinal mushroom: inonotus obliquus

Cancer is a leading cause of death worldwide. Recently, the demand for more effective and safer therapeutic agents for the chemoprevention of human cancer has increased. As a white rot fungus, Inonotus obliquus is valued as an edible and medicinal resource. Chemical investigations have shown that I. obliquus produces a diverse range of secondary metabolites, including phenolic compounds, melanins, and lanostane-type triterpenoids. Among these are active components for antioxidant, antitumoral, and antiviral activities and for improving human immunity against infection of pathogenic microbes. Importantly, their anticancer activities have become a hot recently, but with relatively little knowledge of their modes of action. Some compounds extracted from I. obliquus arrest cancer cells in the G0/G1 phase and then induce cell apoptosis or differentiation, whereas some examples directly participate in the cell apoptosis pathway. In other cases, polysaccharides from I. obliquus can indirectly be involved in anticancer processes mainly via stimulating the immune system. Furthermore, the antioxidative ability of I. obliquus extracts can prevent generation of cancer cells. In this review, we highlight recent findings regarding mechanisms underlying the anticancer influence of I. obliquus, to provide a comprehensive landscape view of the actions of this mushroom in preventing cancer.

Extraction of antioxidants from spruce (Picea abies) bark using eco-friendly solvents

INTRODUCTION

Antioxidants are known to avert oxidation processes and they are found in trees and other plant materials. Tree bark is a major waste product from paper pulp industries; hence it is worthwhile to develop an extraction technique to extract the antioxidants.

OBJECTIVE

To develop a fast and environmentally sustainable extraction technique for the extraction of antioxidants from bark of spruce (Picea abies) and also to identify the extracted antioxidants that are abundant in spruce bark.

METHODOLOGY

A screening experiment that involved three different techniques was conducted to determine the best technique to extract antioxidants. The antioxidant capacity of the extracts was determined with DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Pressurised fluid extraction (PFE) turned out to be the best technique and a response surface design was therefore utilised to optimise PFE. Furthermore, NMR and HPLC-DAD-MS/MS were applied to identify the extracted antioxidants.

RESULTS

PFE using water and ethanol as solvent at 160 and 180°C, respectively, gave extracts of the highest antioxidant capacity. Stilbene glucosides such as isorhapontin, piceid and astringin were identified in the extracts.

CONCLUSION

The study has shown that PFE is a fast and environmentally sustainable technique, using water and ethanol as solvent for the extraction of antioxidants from spruce bark.

Preparative isolation and purification of seven isoflavones from Belamcanda chinensis

INTRODUCTION

Isoflavonoids from Belamcanda chinensis are known to have a number of physiological benefits including anti-inflammatory, anti-angiogenic and anti-mutagenic properties. However, there have been no reports on the effective isolation and purification of isoflavonoids from B. chinensis.

OBJECTIVE

To develop an efficient method for the preparative isolation and purification of isoflavones from B. chinensis by high-speed counter-current chromatography (HSCCC).

METHODOLOGY

A two-step HSCCC isolation method was developed using solvent system of n-hexane-ethyl acetate-2-propanol-methanol-water (5:6:2:3.5:6, v/v) and of ethyl acetate-methanol-water (10:2:9, v/v). FLASH purification system (45% methanol, isocratic) was also used for further purification. The purities and chemical structures of the isolated compounds were determined by high-performance liquid chromatography-photodiode array detection (HPLC-PDA), electrospray ionisation-mass spectrometry (ESI-MS), ¹H- and ¹³C-nuclear magnetic resonance spectrometry (NMR) and nuclear overhauser enhancement (NOE).

RESULTS

HSCCC was successfully used for the preparative separation and purification of seven isoflavones, including tectoridin (145.4 mg, 97.5%), iridin (77.9 mg, 94.0%), irilin D (42.0 mg, 92.0%), tectorigenin (294.1 mg, 98.6%), iristectorigenin A (86.8 mg, 93.4%), irigenin (141.8 mg, 95.8%) and irisflorentin (73.4 mg, 94.7%) from the rhizomes of B. chinensis.

CONCLUSION

Two isoflavone glycosides and five isoflavone derivatives were successfully isolated and purified from the crude methanol extract of dried rhizomes of the B. chinensis by HSCCC.

Responses of ultra-weak chemiluminescence and secretory IgA in saliva to the induction of angry and depressive moods

Oxidative damage to tissues and cells contributes to disease processes. We used ultra-weak chemiluminescence (uwCL) as an indicator of oxidative activity to examine the effects of psychological challenges on oxidative responses. We also examined the association of underlying psychological characteristics with oxidative and immune responses. Eighteen healthy men and women with a mean age of 24.1 were recruited. Anger and depressive symptoms were evaluated using the State-Trait Anger Expression Inventory and the Center for Epidemiological Studies Depression Scale, respectively. Following a baseline period, participants were required to complete two separate speech tasks where they were asked to recall life events that made them feel angry (AT) or depressed (DT). The tasks were separated by a 30-min recovery period and the order was randomized between participants using a counterbalanced design. Saliva was sampled and assayed for uwCL and secretory immunoglobulin A (sIgA). The level of uwCL was significantly increased in response to both tasks (p<.05), whereas sIgA concentrations decreased significantly in response to DT (p<.05). At 30 min after each task, uwCL values were positively related to anger-in (p<.005), anger expression (p<.05) and trait anger (p<.05) post-AT, and sIgA concentrations were positively related to anger-out (p<.05) post-AT and -DT, after controlling for covariates. The present study suggests that induction of angry and depressive moods can increase oxidative activity and transiently weaken immunity indicated by salivary sIgA concentrations. In addition, anger personality traits may modify these responses.

Isorhapontigenin and resveratrol suppress oxLDL-induced proliferation and activation of ERK1/2 mitogen-activated protein kinases of bovine aortic smooth muscle cells

The objective of our study was to compare the inhibitory effect of isorhapontigenin (ISO) and resveratrol, two natural antioxidants, on oxidized low-density lipoprotein (oxLDL)-induced proliferation of bovine aortic smooth muscle cells (BASMCs) and its relation to reactive oxygen species (ROS) generation and extracellular signal-regulated kinase 1/2 activation. The results showed that stimulation of oxLDL (50-150 microg/mL) for 48 hr induced a dose-dependent increase in cell number and incorporation of [3H]thymidine into DNA of BASMCs. Western blot analysis demonstrated that oxLDL (150 microg/mL) stimulated an evident phosphorylation of p42/44 MAP kinases in BASMCs. Incubation of BASMCs with oxLDL induced significant increase in ROS detected by using an oxidant-sensitive fluorescent probe of 2',7'-dichlorofluorescin diacetate. The level of H2O2 in the medium of cultured BASMCs also increased markedly. Preincubation of BASMCs with ISO and resveratrol significantly inhibited oxLDL-induced cell proliferation and incorporation of [3H]thymidine, and the phosphorylation of p42/44 MAP kinases in BASMCs as well. Furthermore, preincubation of BASMCs with ISO and resveratrol attenuated oxLDL-induced increases in ROS and H2O2 levels. The results suggested that oxLDL-induced acute formation of ROS and subsequent activation of redox-sensitive extracellular signal-regulated kinase 1/2 MAPK pathways, which might be important for mitogenic signaling of oxLDL in vascular smooth muscle cells. The inhibitory effect of ISO and resveratrol on oxLDL-induced mitogenesis of BASMCs might be taken through blocking the generation of ROS and activation of the ERKs pathway.

Effect of isorhapontigenin on respiratory burst of rat neutrophils

The effect of Isorhapontigenin (Iso) isolated from Belamcanda chinensis on respiratory burst of rat neutrophils was investigated. Iso (1, 10, 100 mmol/l) showed an inhibitory effect on superoxide anion and hydrogen peroxide production in phorbol myristate acetate (PMA) activated rat neutrophils in a concentration-dependent manner. Scanning electron microscopy detected that Iso (100 mmol/l) protected against surface changes in rat neutrophils stimulated with PMA. Also, 100 mmol/l Iso inhibited the release of beta-glucuronidase from the activated neutrophils. Electron-spin resonance (ESR) detected that Iso scavenged oxygen free radicals generated in the PMA activated Neutrophils. These results suggest that Iso inhibits respiratory burst of PMA-activated rat neutrophils by scavenging oxygen free radicals.