Simultaneous determination of loganin, morroniside, catalpol and acteoside in normal and chronic kidney disease rat plasma by UPLC-MS for investigating the pharmacokinetics of Rehmannia glutinosa and Cornus officinalis Sieb drug pair extract

Multifaceted therapeutic potentials of catalpol, an iridoid glycoside: an updated comprehensive review

Catalpol, classified as an iridoid glucoside, is recognized for its significant role in medicine, particularly in the treatment of various conditions such as diabetes mellitus, neuronal disorders, and inflammatory diseases. This review aims to evaluate the biological implications of catalpol and the mechanisms underlying its diverse pharmacological effects. A thorough exploration of existing literature was conducted utilizing the keyword "Catalpol" across prominent public domains like Google Scholar, PubMed, and EKB. Catalpol has demonstrated a diverse array of pharmacological effects in experimental models, showcasing its anti-diabetic, cardiovascular-protective, neuroprotective, anticancer, hepatoprotective, anti-inflammatory, and antioxidant properties. In summary, catalpol manifests a spectrum of biological effects through a myriad of mechanisms, prominently featuring its anti-inflammatory and antioxidant capabilities. Its diverse pharmacological profile underscores its potential for therapeutic applications across a range of conditions. Further research is warranted to fully elucidate the clinical implications of catalpol and optimize its use in medical practice.

An RGD-Conjugated Prodrug Nanoparticle with Blood-Brain-Barrier Penetrability for Neuroprotection Against Cerebral Ischemia-Reperfusion Injury

Cerebral ischemia-reperfusion injury significantly contributes to global morbidity and mortality. Loganin is a natural product with various neuroprotective effects; however, it lacks targeted specificity for particular cells or receptors, which may result in reduced therapeutic efficacy and an increased risk of side effects. To address the limitations of loganin, we developed LA-1, a novel compound incorporating an Arg-Gly-Asp (RGD) peptide to target integrin receptor αvβ3, enhancing brain-targeting efficacy. LA-1 exhibited optimal nanoscale properties, significantly improved cell viability, reduced ROS production, and enhanced survival rates in vitro. In vivo, LA-1 decreased infarct sizes, improved neurological function, and reduced oxidative stress and neuroinflammation. Proteomic analysis showed LA-1 modulates PI3K/Akt and Nrf2/HO-1 pathways, providing targeted neuroprotection. These findings suggest LA-1's potential for clinical applications in treating cerebral ischemia-reperfusion injury.

Bioactivities of morroniside: A comprehensive review of pharmacological properties and molecular mechanisms

Morroniside (MOR) is an iridoid glycoside and the main active principle of the medicinal plant, Cornus officinalis Sieb. This phytochemical is associated with numerous health benefits due to its antioxidant properties. The primary objective of the present study was to assess the pharmacological effects and underlying mechanisms of MOR, utilizing published data obtained from literature databases. Data collection involved accessing various sources, including PubMed/Medline, Scopus, Science Direct, Google Scholar, Web of Science, and SpringerLink. Our findings demonstrate that MOR can be utilized for the treatment of several diseases and disorders, as numerous studies have revealed its significant therapeutic activities. These activities encompass anti-inflammatory, antidiabetic, lipid-lowering capability, anticancer, trichogenic, hepatoprotective, gastroprotective, osteoprotective, renoprotective, and cardioprotective effects. MOR has also shown promising benefits against various neurological ailments, including Alzheimer's disease, Parkinson's disease, spinal cord injury, cerebral ischemia, and neuropathic pain. Considering these therapeutic features, MOR holds promise as a lead compound for the treatment of various ailments and disorders. However, further comprehensive preclinical and clinical trials are required to establish MOR as an effective and reliable therapeutic agent.

Iridoids modulate inflammation in diabetic kidney disease: A review

In recent years, preclinical research on diabetic kidney disease (DKD) has surged to the forefront of scientific and clinical attention. DKD has become a pervasive complication of type 2 diabetes. Given the complexity of its etiology and pathological mechanisms, current interventions, including drugs, dietary modifications, exercise, hypoglycemic treatments and lipid-lowering methods, often fall short in achieving desired therapeutic outcomes. Iridoids, primarily derived from the potent components of traditional herbs, have been the subject of long-standing research. Preclinical data suggest that iridoids possess notable renal protective properties; however, there has been no summary of the research on their efficacy in the management and treatment of DKD. This article consolidates findings from in vivo and in vitro research on iridoids in the context of DKD and highlights their shared anti-inflammatory activities in treating this condition. Additionally, it explores how certain iridoid components modify their chemical structures through the regulation of intestinal flora, potentially bolstering their therapeutic effects. This review provides a focused examination of the mechanisms through which iridoids may prevent or treat DKD, offering valuable insights for future research endeavors. Please cite this article as: Zhou TY, Tian N, Li L, Yu R. Iridoids modulate inflammation in diabetic kidney disease: A review. J Integr Med. 2024; 22(3): 210-222.

Development and validation of a simple and rapid UPLC-MS/MS method for loganin and its application in pharmacokinetic and tissue distribution studies

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis Sieb. et Zucc. is a medicinal and edible homolog in traditional Chinese medicine. Loganin, an iridoid glycoside, is one of the main active components of Cornus officinalis Sieb. et Zucc. Loganin has been demonstrated to improve depression-like behavior and may be a potential antidepressant candidate. However, the pharmacokinetic characteristics and tissue distribution of loganin, especially in the brain region, are still unclear.

AIM OF THE STUDY

This study aims to investigate the pharmacokinetic characteristics and tissue distribution after oral administration of loganin in rats.

MATERIALS AND METHODS

A simple, rapid and reproducible UPLC-MS/MS method was developed and validated for the determination of loganin in rat plasma and tissues. The samples were prepared by acetonitrile precipitation with chloramphenicol as internal standard (IS). Loganin was separated by gradient elution on ACQUITY UPLC®BEH C18 (2.1 × 50 mm, 1.7 μm) using multiple reactions monitoring (MRM) mode. Concentration-time data was subjected to pharmacokinetic analysis. The pharmacokinetic parameters of loganin in rat plasma were analyzed by compartment model using DAS 2.0 software.

RESULTS

The established UPLC-MS/MS method was accurate and reliable with a good linearity (R2 > 0.99) in the respective concentration range, satisfying the quantitative requirements. This method was successfully used to study the pharmacokinetics and tissue distribution after oral administration of loganin in rats. The peak time (Tmax) of oral administration was about 40 min, and the half-life (t1/2) was about 50 min, indicating that loganin was quickly absorbed and eliminated in rats. Oral bioavailability was 5.50%. The dose correlation results showed that AUC had a poor correlation with dose, while Cmax had a good correlation with dose. In tissues, loganin (35 mg/kg) was highly distributed in the stomach, small intestine, kidney, liver and lung. When the dose was 70 mg/kg, loganin had significant distribution in the cortex.

CONCLUSION

In this study, a simple and sensitive UPLC-MS/MS method was developed and validated for the determination of loganin in rat plasma and tissues. Loganin was absorbed quickly, eliminated quickly, and had low bioavailability. The distribution of loganin in the cortex was higher than that in the hippocampus. We hope that our results can provide a reference for loganin to become a new antidepressant.

Magnetic molecularly-imprinted microspheres with a core-shell structure for the extraction of catalpol from both Rehmannia glutinosa Libosch and biological samples

We report on the successful development of a magnetic molecularly imprinted polymer (MMIP) for the separation and detection of catalpol in Rehmannia glutinosa extract and biological samples. Catalpol was used as the template molecule for the MMIPs, which were synthesized using the reverse prediction approach and differential UV-visible spectra to optimize the synthesis conditions. The resulting MMIPs were characterized using techniques including scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry, which confirmed their excellent nuclear shell construction and simple rapid magnetic separation. Static and dynamic adsorption experiments were performed to assess the sensitivity, repeatability, and adsorption capacity of the MMIPs. Adsorption capacity was found to be high (59.09 µg/mg). The MMIPs also exhibited strong identification specificity for catalpol analogs (IF = 2.41). Magnetic solid phase extraction (MSPE) was optimized to establish an MSPE-HPLC approach based on the MMIPs. Under ideal conditions, the new method showed excellent determination coefficient (R2 > 0.99) in the ranges of 0.1-1.0 mg/mL and 0.03-0.18 mg/mL for R. glutinosa extract and biological material, respectively, with limits of detection of 5.4 ng/mL and 1.7 ng/mL. The novelty of this research lies in the preparation of magnetic surface MMIPs using a magnetic carrier. These MMIPs exhibit excellent magnetic properties and possess specific adsorption capability for catalpol, enabling rapid separation. They offer advantages such as low cost, high specificity, chemical stability, physical robustness, and recyclability (97.09%-106.53%, 91.32%-100.99%). The application of these polymers in the pretreatment method for determining the catalpol content in R. glutinosa extract and biological samples enhances the extraction efficiency and detection accuracy for catalpol. It eliminates interference and influences from other components in catalpol determination while exhibiting high sensitivity, good enrichment effects, excellent reusability, and a high recovery rate.

Serum Pharmacochemistry and Pharmacokinetics of Major Components after Oral Administration Luhong Recipe in Rats by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

Luhong recipe (LHR) is an empirical prescription for the treatment of chronic heart failure for a long time, with safety, reliability and significant efficacy. However, its pharmacokinetics have not been studied. This study was to establish a UHPLC-MS/MS method for the simultaneous analysis of epimedin A, epimedin B, epimedin C, icariin, psoralen, isopsoralen in rat plasma, and apply it to the pharmacokinetic study of LHR after oral administration. These six analytes were ionized by electrospray positive ionization (ESI⁺ ). The MS/MS transitions used for monitoring is successively converted to m/z 839.3→369.1, m/z 809.2→369.1, m/z 823.3→369.1, m/z 677.2→205.2, m/z 187.1→115.2 and m/z 230→120.9. The linearity, precision, accuracy, stability, matrix effect and recovery of the established method were within the acceptable range. It was suitable for the determination of six analytes after oral administration LHR. The pharmacokinetic results showed the time to reach the peak concentration (T_max ) was 0.17-13.5h, the peak concentration (C_max ) was 109.23-980 ng/mL, the area under the concentration time curve (AUC_(0-t) ) was 65.48-8846.08 ng·h/mL, and the apparent distribution volume (Vd) was 24772-896132 mL/kg. These results provided a meaningful basis for formulating the clinical dose regimen of LHR.

Catalpol Exerts Antidepressant-Like Effects by Enhancing Anti-oxidation and Neurotrophy and Inhibiting Neuroinflammation via Activation of HO-1

Catalpol is an iridoid glycoside with rich content, rich nutrition, and numerous biological activities in Rehmanniae Radix contained in classic antidepressant prescriptions in Chinese clinical medicine. Catalpol has been confirmed previously its exact antidepressant-like effect involved heme oxygenase (HO)-1, but its antidepressant molecular targets and mechanism are still unclear. Here, catalpol's antidepressant-like molecular target was diagnosed and confirmed by ZnPP intervention [the antagonist of HO-1, (10 μg/rat), intracerebroventricular] for the first time, and its molecule mechanism network was determined through HO-1 related pathway and molecules in the hippocampus. Results showed that ZnPP significantly abolished catalpol's (10 mg/kg) reversal on depressive-like behaviors of chronic unpredictable mild stress rats, abolished catalpol's up-regulation on the phosphorylation level of extracellular regulated protein kinases (ERK)1/2 and brain-derived neurotrophic factor (BDNF)'s receptor tropomyosin-related kinase B (TrkB), the nuclear expression level of nuclear factor E 2-related factor 2 (Nrf2), the levels of anti-oxidant factors (such as HO-1, SOD, GPX, GST, GSH) and BDNF, and abolished catalpol's down-regulation on the levels of peroxide and neuroinflammation factors [cyclooxygenase-2 (COX-2), induced nitrogen monoxide synthase (iNOS), nitric oxide (NO)]. Thus, HO-1 could serve as an important potential molecular target for catalpol's antidepressant-like process, and the antidepressant-like mechanism of catalpol could at least involve the activation of HO-1 triggering the up-regulation of the ERK1/2/Nrf2/HO-1 pathway-related factors to enhance the anti-oxidant defense, triggering the down-regulation of the COX-2/iNOS/NO pathway-related factors to inhibit neuroinflammation, and triggering the up-regulation of the BDNF/TrkB pathway to enhance neurotrophy.

Phytochemistry, synthesis, analytical methods, pharmacological activity, and pharmacokinetics of loganin: A comprehensive review

Iridoid glycosides (IGs) are found in many medicinal and edible plants, such as Gardenia jasminoides, Cistanche tubulosa, Eucommia ulmoides, Rehmanniae Radix, Lonicera japonica, and Cornus officinalis. Loganin, an IG, is one of the main active ingredient of Cornus officinalis Sieb. et Zucc., which approved as a medicinal and edible plant in China. Loganin has been widely concerned due to its extensive pharmacological effects, including anti-diabetic, antiinflammatory, neuroprotective, and anti-tumor activities, etc. Studies have shown that these underlying mechanisms include anti-oxidation, antiinflammation and anti-apoptosis by regulating a variety of signaling pathways, such as STAT3/NF-κB, JAK/STAT3, TLR4/NF-κB, PI3K/Akt, MCP-1/CCR2, and RAGE/Nox4/p65 NF-κB signaling pathways. In order to better understand the research status of loganin and promote its application in human health, this paper systematically summarized the phytochemistry, analysis methods, synthesis, pharmacological properties and related mechanisms, and pharmacokinetics based on the research in the past decades.

Corni Fructus Alleviates UUO-Induced Renal Fibrosis via TGF-β/Smad Signaling

Renal fibrosis is a type of chronic kidney disease (CKD) induced by infiltration of inflammatory cells, myofibroblast accumulation, and ECM production in the kidney. From a long time ago, Corni Fructus (CF) is known to supplement the liver and kidney with its tepid properties. In this study, we investigated the renal protective mechanism of CF, which is known to supplement the kidney, in rat model of unilateral ureteral obstruction (UUO). After inducing UUO through surgery, the group was separated ( $n=8$ ) and the drug was administered for 2 weeks; normal rats (normal), water-treated UUO rats (control), CF 100 mg/kg-treated UUO rats (CF100), and CF 200 mg/kg-treated UUO rats (CF200). As a result of histopathological examination of kidney tissue with H&E, MT, and PAS staining, it was confirmed that the infiltration of inflammatory cells and the erosion of collagen were relatively decreased in the kidneys treated with CF. Also, CF significantly reduced the levels of MDA and BUN in serum. As a result of confirming the expression of the factors through western blotting, CF treatment significantly reduced the expression of NADPH oxidase and significantly regulated the AMPK/LKB1/NF-κB pathway associated with inflammation. In addition, it downregulated the expression of major fibrotic signaling factors, such as α-SMA, collagen I, MMP-2, and TIMP-1, and significantly regulated the TGF-β1/Smad pathway, which is known as a major regulator of renal fibrosis. Taken together, these findings indicate that CF can alleviate renal fibrosis by regulating the TGF-β1/Smad pathway through inhibition of oxidative stress in UUO.

UPLC-MS/MS method for the determination of the herb composition of Tangshen formula and the in vivo pharmacokinetics of its metabolites in rat plasma

INTRODUCTION

Tangshen formula (TSF) is a traditional Chinese medicine composed of seven medicinal herbs including Astragalus membranaceus, Rehmannia glutinosa Libosch, Citrus aurantium L., etc. which is used to treat diabetic nephropathy III, IV qi and yin deficiency and stasis syndrome. Most of the studies on TSF are pharmacological and pharmacodynamic experiments. There are few basic studies on its chemical substances, and the effective constituents are not clear.

OBJECTIVE

To analyse the main chemical components of TSF and the absorbed components in rat plasma following oral administration based on liquid chromatography tandem mass spectrometry (LC-MS/MS). Moreover, providing a rapid and valid analytical strategy for simultaneous determination of six components in rat plasma and use it in pharmacokinetic studies.

RESULTS

A total of 132 components were identified in TSF, and 44 components were identified in rat plasma after oral TSF, 35 of which were prototype components and nine were metabolic components. A sensitive and reliable LC-MS/MS method was developed for simultaneous determination of six components in rat plasma. The intra-day and inter-day precision relative standard deviation (RSD) was lower than 15%; the accuracy of low, medium and high concentrations ranged from 80% to 120%. The recovery met the requirements and the RSD of the recoveries was less than 15%.

CONCLUSION

A total of 132 components were identified in TSF. The LC-MS/MS quantitative method for the simultaneous determination of morroniside, loganin, notoginsenoside R₁ , ginsenoside Re, ginsenoside Rb₁ and astragaloside IV in rat plasma was established for the first time. The pharmacokinetic parameters are clarified, which can guide the clinical medication of TSF.

Drug-interaction between paclitaxel and goshajinkigan extract and its constituents

Paclitaxel, a standard chemotherapeutic agent for several types of cancer, including ovarian, breast, and non-small-cell lung cancer, causes peripheral neuropathy as an adverse effect in 60–70% of the patients. The utility of combination therapy with paclitaxel and goshajinkigan, a traditional Japanese Kampo medicine, in managing paclitaxel-induced neuropathy during chemotherapy has been explored. Paclitaxel is predominantly metabolized in the liver by cytochrome P450 (CYP) 2C8 to produce 6α-hydroxypaclitaxel and by CYP3A4 to produce 3′-p-hydroxypaclitaxel. In this study, we evaluated the inhibitory or inducing effects of goshajinkigan extract (GJG) and its representative and bioavailable constituents, geniposidic acid, plantagoguanidinic acid, paeoniflorin, catalpol, loganin, and neoline, on the metabolism of paclitaxel via CYP2C8 and CYP3A4 using pooled human liver microsomes and cultured human cryopreserved hepatocytes to provide the drug information about the pharmacokinetic interaction of this combination therapy. GJG significantly inhibited the production of 3’-p-hydroxypaclitaxel and 6α-hydroxypaclitaxel in vitro in a concentration-dependent manner. The half maximal inhibitory concentration (IC₅₀) values of GJG were 4.5 and 7.8 mg/ml, respectively, for 3′-p-hydroxypaclitaxel and 6α-hydroxypaclitaxel productions. Neoline inhibited the production of 3′-p-hydroxypaclitaxel at 50 μM, but not at lower concentrations. Apart from neoline, other GJG constituents (at concentrations up to 50 or 10 μM of all test substances) did not exhibit inhibitory or inducing effects. Since GJG showed the inhibitory effect on the metabolism of paclitaxel at much higher concentrations than those used clinically, it can be concluded that GJG product does not exhibit any pharmacokinetic interaction with paclitaxel in clinical practice.

Loganin Inhibits Angiotensin II-Induced Cardiac Hypertrophy Through the JAK2/STAT3 and NF-κB Signaling Pathways

Loganin is an iridoid glycoside extracted from Cornus officinalis, which is a traditional oriental medicine, and many biological properties of loganin have been reported. Nevertheless, it is not clear whether loganin has therapeutic effect on cardiovascular diseases. Hence, the aim of the present study was to investigate the effect of loganin on Ang II-induced cardiac hypertrophy. In the present study, we reported for the first time that loganin inhibits Ang II-provoked cardiac hypertrophy and cardiac damages in H9C2 cells and in mice. Furthermore, loganin can achieve cardioprotective effects through attenuating cardiac fibrosis, decreasing pro-inflammatory cytokine secretion, and suppressing the phosphorylation of critical proteins such as JAK2, STAT3, p65, and IκBα. Besides, the outstanding findings of the present study were to prove that loganin has no significant toxicity or side effects on normal cells and organs. Based on these results, we conclude that loganin mitigates Ang II-induced cardiac hypertrophy at least partially through inhibiting the JAK2/STAT3 and NF-κB signaling pathways. Accordingly, the natural product, loganin, might be a novel effective agent for the treatment of cardiac hypertrophy and heart failure.

Morroniside suppresses hydrogen peroxide-stimulated autophagy and apoptosis in rat ovarian granulosa cells through the PI3K/AKT/mTOR pathway

Previous evidences have indicated that granulosa cells play a critical role in follicular growth. Hydrogen peroxide (H2O2)-induced oxidative stress has been associated with ovarian granulosa cell apoptosis and ovarian function. Recently, a study highlighted the protective role of morroniside against H2O2-induced damage. In this study, we aimed to investigate the effects of morroniside on H2O2-stimulated rat ovarian granulosa cells and its underlying molecular mechanisms. Our results showed that H2O2 treatment suppressed cell survival and increased apoptosis in rat granulosa cells, while treatment with morroniside markedly increased H2O2-induced granulosa cell survival in a dose-dependent manner (0, 10, 50 and 100 µM). Moreover, treatment with 50 µM morroniside impeded H2O2-induced cell apoptosis. An elevation in intracellular ROS, MDA, SOD, GSH-Px, and CAT level was observed in H2O2-induced granulosa cells; however, this effect was abrogated by morroniside treatment. Further studies suggested that administration of morroniside inhibited H2O2-induced granulosa cell apoptosis and caspase-3 activity. In addition, after morroniside treatment of H2O2-stimulated granulosa cells, autophagy-related protein (LC3-II/LC3-I ratio) and beclin-1 expression was decreased and p62 level was increased. Interestingly, we found that morroniside treatment activated the PI3K/AKT/mTOR pathway in H2O2-stimulated granulosa cells. Finally, we showed that treatment with PI3K and mTOR inhibitors reversed the protective effects of morroniside on H2O2-induced granulosa cells. Taken together, our data suggest that treatment with morroniside decreased apoptosis, autophagy, and oxidative stress in rat granulosa cells through the PI3K/AKT/mTOR pathway.

Determination and Pharmacokinetic Profiles of Four Active Components From Scrophularia ningpoensis Hemsl. in Rats

Acteoside, angoroside C, harpagoside, and cinnamic acid, which are the main bioactive ingredients of Scrophularia ningpoensis Hemsl., have wide clinical use with various biological effects. A new and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established with taxifolin as the internal standard (IS) in this study and was successfully used to study the pharmacokinetic profiles of four active components from S. ningpoensis Hemsl. in rats after sublingual intravenous administration. After protein precipitation with acetonitrile, the mobile phase (consisting of acetonitrile and 0.1% formic acid) was used to separate the analytes on an Acquity UPLC BEH C18 chromatography column (2.1 × 50 mm, 1.7 μm) under gradient elution. The precursor-to-product ion transitions of 623.4 → 161.3 m/z for acteoside, 783.5 → 175.0 m/z for angoroside C, 493.3 → 345.2 m/z for harpagoside and 147.2 → 103.4 m/z for cinnamic acid were monitored by mass spectrometry with negative electrospray ionization in the multiple reaction monitoring (MRM) mode. The concentration range of 10–1,000 ng/ml could be detected by this method with a lower limit of quantification (LLOQ) of 10 ng/ml for each analyte. The intra- and inter-day precision (RSD%) of the method ranged from 2.6 to 9.9% and 2.7–11.5%, respectively. Meanwhile, the accuracy (RE%) was −9.6–10.7% in this developed method. The mean recoveries of four active components from S. ningpoensis Hemsl. were more than 76.7% with negligible matrix effects. The four active components from S. ningpoensis Hemsl. were stable under multiple storage and process conditions. A new, sensitive and simple analytical method had been established and was successfully applied to the pharmacokinetic profiles of four active components from S. ningpoensis Hemsl. in rats after sublingual intravenous administration.

A review on the structure and pharmacological activity of phenylethanoid glycosides

Phenylethanoid glycosides (PhGs) are compounds made of phenylethyl alcohol, caffeic acid and glycosyl moieties. The first published references about phenylethanoid glycosides concerned the isolation of echinacoside from Echinaceu ungustifolia (Asteraceae) in 1950 and verbascoside from Verbascum sinuatum (Scrophulariaceae) in 1963. Over the past 60 years, many compounds with these structural characteristics have been isolated from natural sources, and most of these compounds possess significant bioactivities, including antibacterial, antitumor, antiviral, anti-inflammatory, neuro-protective, antioxidant, hepatoprotective, and immunomodulatory activities, among others. In this review, we will summarize the phenylethanoid glycosides described in recent papers and list all the compounds that have been isolated over the past few decades. We will also attempt to present and assess recent studies about the separation, extraction, determination, and pharmacological activity of the excellent natural components, phenylethanoid glycosides.

Characterization of the intestinal absorption of morroniside from Cornus officinalis Sieb. et Zucc via a Caco-2 cell monolayer model

Morroniside is a biologically active polyphenol found in Cornus officinalis Sieb. et Zucc (CO) that exhibits a broad spectrum of pharmacological activities, such as protecting nerves, and preventing diabetic liver damage and renal damage. However, little data are available regarding the mechanism of its intestinal absorption. Here, an in vitro human intestinal epithelial cell model of cultured Caco-2 cells was applied to study the absorption and transport of morroniside. The effects of donor concentration, pH and inhibitors were investigated. The bidirectional permeability of morroniside from the apical (AP) to the basolateral (BL) side and in the reverse direction was studied. When administered at three tested concentrations (5, 25 and 100 μM), the apparent permeability coefficient (Papp) values in the AP-to-BL direction ranged from 1.59 × 10-6 to 2.66 × 10-6 cm/s. In the reverse direction, BL-to-AP, the value was ranged from 2.67 × 10-6 to 4.10 × 10-6 cm/s. The data indicated that morroniside transport was pH-dependent. The permeability of morroniside was affected by treatment with various inhibitors, such as multidrug resistance protein inhibitors MK571 and indomethacin, as well as the breast cancer resistance protein inhibitor apigenin. The mechanisms of the intestinal absorption of morroniside may involve multiple transport pathways, such as the passive diffusion and efflux protein-mediated active transport especially involving multidrug resistance protein 2 and breast cancer resistance protein. After the addition of CO, the Papp values in the AP-to-BL direction increased significantly, therefore, it can be assumed that some ingredients in the CO promote morroniside absorption in the small intestine.

Protective effects of iridoid glycosides on acute colitis via inhibition of the inflammatory response mediated by the STAT3/NF-кB pathway

Morroniside and loganin are iridoid glycosides extracted from Cornus officinalis, a plant species widely used in traditional Chinese medicine. However, the anti-inflammatory effects of morroniside and loganin in colitis are barely understood. The aim of the present study was to explore the effects of morroniside and loganin on the dextran sodium sulfate (DSS)-induced murine model of colitis and an LPS-induced colorectal cancer (CRC) cell inflammation model, and to clarify the underlying mechanisms. We found that morroniside and loganin were able to ameliorate clinical features, including disease activity index (DAI), histological inflammation score and periodic acid-Schiff staining (PAS). In the mouse model, morroniside and loganin treatment increased expression of tight junction proteins (TJs) and decreased pro-inflammatory cytokine production. Moreover, our findings showed that the expression of p-STAT3 and p-p65 were suppressed compared to the disease group. In in vitro experiments, treatment with morroniside and loganin had no obvious effects on proliferative activity in HCT116 cells and HIEC-6 cells. Expression of pro-inflammatory cytokines was inhibited by morroniside and loganin treatment in comparison with the LPS-treated group. Taken together, morroniside and loganin have beneficial effects on colitis in vivo and are anti-inflammatory in vitro. Possible mechanisms of the anti-inflammatory response may include blockade of the STAT3/NF-κB pathway.

"Quantity-effect" research strategy for comparison of antioxidant activity and quality of Rehmanniae Radix and Rehmannia Radix Praeparata by on-line HPLC-UV-ABTS assay

Background

Quantitation analysis and chromatographic fingerprint of multi-components are frequently used to evaluate quality of herbal medicines but fail to reveal activity of the components. It is necessary to develop a rational approach of chromatography coupled with activity detection for quality assessment of herbal medicines.

Methods

An on-line HPLC-ultraviolet detection-2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging (HPLC-UV-ABTS) method was developed to obtain the chromatographic fingerprints and ABTS^+• inhibition profiles (active fingerprints) of Rehmanniae Radix (Dihuang) and Rehmannia Radix Praeparata (Shu Dihuang). Eighteen compounds showing ABTS^+• inhibition activity were identified by HPLC-fourier-transform mass spectrometry (HPLC-FTMS). Verbascoside was used as a positive control to evaluate the total activities of the samples and the contribution rate of each compound. The similarities of the chromatographic and active fingerprints were estimated by the vectorial angle cosine method.

Results

The results showed that the HPLC-UV-ABTS method could efficiently detect antioxidant activity of the herbal medicine samples. The antioxidants were different between the two herbs and several new antioxidants were identified in Shu Dihuang. A function equation was generated in terms of the negative peak area (x) and the concentrations of verbascoside (y, μg/mL), y = 2E-07 × ⁴ - 8E-05 × ³ + 0.0079 × ² + 0.5755x + 1.4754, R² = 1. Iridoid glycosides were identified as main antioxidants and showed their higher contributions to the total activity of the samples. The total contributions of the three main active components in the Dihuang and Shu Dihuang samples to the total activity, such as echinacoside, verbascoside and an unknown compound, were 39.2–58.1% and 55.9–69.4%, respectively. The potencies of the main active components in the Shu Dihuang samples were two to ten times those in the Dihuang samples. Similarity values for S12 in the chromatographic fingerprints and S03, S12 and P03 in the active fingerprints were less than 0.9. The three batches of samples might show their different quality with the other samples.

Conclusions

The results suggested that the combination of “quantity-effect” research strategy and the HPLC-UV-ABTS analysis method could comprehensively evaluate the active components and quality of Dihuang and Shu Dhuang.

Multiple Biological Effects of an Iridoid Glucoside, Catalpol and Its Underlying Molecular Mechanisms

Catalpol, an iridoid glucoside, is widely distributed in many plant families and is primarily obtained from the root of Rehmanniaglutinosa Libosch. Rehmanniaglutinosa is a plant very commonly used in Chinese and Korean traditional medicine for various disorders, including diabetes mellitus, neuronal disorders, and inflammation. Catalpol has been studied extensively for its biological properties both in vitro and in vivo. This review aims to appraise the biological effects of catalpol and their underlying mechanisms. An extensive literature search was conducted using the keyword "Catalpol" in the public domains of Google scholar, PubMed, and Scifinder. Catalpol exhibits anti-diabetic, cardiovascular protective, neuroprotective, anticancer, hepatoprotective, anti-inflammatory, and anti-oxidant effects in experimental studies. Anti-inflammatory and antioxidant properties are mostly related for its biological effect. However, some specific mechanisms are also elucidated. Elevated serotonin and BDNF level by catalpol significantly protect against depression and neurodegeneration. Catalpol demonstrated an increased mitochondrial biogenesis and activation of PI3K/Akt pathway for insulin sensitizing effect. Further, its cardiovascular protective effect was linked to PI3K/Akt, apelin/APJ and Jak-Stat pathway. Catalpol produced a significant reduction in cell proliferation and an increase in apoptosis in different cancer conditions. Overall, catalpol demonstrated multiple biological effects due to its numerous mechanisms including anti-inflammatory and antioxidant effects.

Catalpol alleviates adriamycin-induced nephropathy by activating the SIRT1 signalling pathway in vivo and in vitro

BACKGROUND AND PURPOSE

Catalpol, a water-soluble active ingredient isolated from Rehmannia glutinosa, exhibits multiple pharmacological activities. However, the mechanism(s) underlying protection against renal injury by catalpol remains unknown.

EXPERIMENTAL APPROACH

Adriamycin-induced kidney injury models associated with podocyte damage were employed to investigate the nephroprotective effects of catalpol. In vivo, TUNEL and haematoxylin-eosin staining was used to evaluate the effect of catalpol on kidney injury in mice. In vitro, effects of catalpol on podocyte damage induced by adriamycin was determined by elisa kit, flow cytometry, Hoechst 33342, and TUNEL staining. The mechanism was investigated by siRNA, EX527, and docking simulations.

KEY RESULTS

In vivo, catalpol treatment significantly improved adriamycin-induced kidney pathological changes and decreased the number of apoptotic cells. In vitro, catalpol markedly decreased the intracellular accumulation of adriamycin and reduced the calcium ion level in podocytes and then attenuated apoptosis. Importantly, the regulatory effects of catalpol on sirtuin 1 (SIRT1), multidrug resistance-associated protein 2 (MRP2), and the TRPC6 channel were mostly abolished after incubation with SIRT1 siRNA or the SIRT1-specific inhibitor EX527. Furthermore, docking simulations showed that catalpol efficiently oriented itself in the active site of SIRT1, indicating a higher total binding affinity score than that of other SIRT1 activators, such as resveratrol, SRT2104, and quercetin.

CONCLUSION AND IMPLICATIONS

Taken together, our results suggest that catalpol exhibits strong protective effects against adriamycin-induced nephropathy by inducing SIRT1-mediated inhibition of TRPC6 expression and enhancing MRP2 expression.

Recent Advances on Drug Analyses Using Ultra Performance Liquid Chromatographic Techniques and their Application to the Biological Samples

Introduction:

Ultra-Performance Liquid Chromatographic (UPLC) method enables analyst to establish an analysis at higher pressure than High Performance Liquid Chromatographic (HPLC) method towards liquid chromatographic methods. UPLC method provides the opportunity to study a higher pressure compared to HPLC, and therefore smaller column in terms of particle size and internal diameter are generally used in drug analysis. The UPLC method has attracted gradually due to its advantages such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. In this review, the recent selected studies related to the UPLC method and its method validation are summarized. The drug analyses and the results of the studies which were investigated by UPLC method, with certain parameters from literature are presented.

Background:

Quantitative determination of drug active substances by High-Performance Liquid Chromatography (HPLC) from Liquid Chromatography (LC) methods has been carried out since the 1970's with the use of standard analytical LC methods. In today's conditions, rapid and very fast even ultra-fast, flow rates are achieved compared to conventional HPLC due to shortening analysis times, increasing method efficiency and resolution, reducing sample volume (and hence injection volume), reducing waste mobile phase. Using smaller particles, the speed and peak capacity are expanding to new limit and this technology is named as Ultra Performance Liquid Chromatography. In recent years, as a general trend in liquid chromatography, ultra-performance liquid chromatography has taken the place of HPLC methods. The time of analysis was for several minutes, now with a total analysis time of around 1-2 minutes. The benefits of transferring HPLC to UPLC are much better understood when considering the thousands of analyzes performed for each active substance, in order to reduce the cost of analytical laboratories where relevant analysis of drug active substances are performed without lowering the cost of research and development activities.

Methods:

The German Chemist Friedrich Ferdinand Runge, proposed the use of reactive impregnated filter paper for the identification of dyestuffs in 1855 and at that time the first chromatographic method in which a liquid mobile phase was used, was reviewed. Christian Friedrich Chönbein, who reported that the substances were dragged at different speeds in the filter paper due to capillary effect, was followed by the Russian botanist Mikhail S. Tswet, who planted studies on color pigment in 1906. Tswet observes the color separations of many plant pigments, such as chlorophyll and xanthophyll when he passes the plant pigment extract isolated from plant through the powder CaCO3 that he filled in the glass column. This method based on color separation gives the name of "chromatographie" chromatography by using the words "chroma" meaning "Latin" and "graphein" meaning writing.

Results and Conclusion:

Because the UPLC method can be run smoothly at higher pressures than the HPLC method, it offers the possibility of analyzing using much smaller column sizes and column diameters. Moreover, UPLC method has advantages, such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. The use of the UPLC method especially analyses in biological samples such as human plasma, brain sample, rat plasma, etc. increasingly time-consuming due to the fact that the analysis time is very short compared to the HPLC, because of the small amount of waste analytes and the considerable savings in their cost.

Loganetin protects against rhabdomyolysis-induced acute kidney injury by modulating the toll-like receptor 4 signalling pathway

BACKGROUND AND PURPOSE

Acute kidney injury (AKI) is a rapid renal dysfunctional disease, for which no effective drugs or therapies are available to improve prognosis. Loganetin is a natural product with unknown bioactivities. Here, we identified a new protective effect and mechanism of Loganetin in a mouse model of AKI induced by rhabdomyolysis.

EXPERIMENTAL APPROACH

AKI was induced using glycerol by i.m. injection in mice models. Thirty minutes and 24 and 48 hr after injection of glycerol, the mice received 2 and 18 mg·kg^-1 of Loganetin i.p. respectively. Then mice blood and kidney were collected for various biochemical and histopathological studies. Mechanistic studies on modulation of AKI by Loganetin were performed using HK-2 cells and Toll-like receptor 4 (TLR4) knockout mice.

KEY RESULTS

In the Loganetin treated group, kidney damage and mortality rate were declined, and blood urea nitrogen and serum creatinine were much lower. Loganetin prevented damage to the tubular structures induced by glycerol and decreased apoptotic cells at the corticomedullary junction. In HK-2 cells, Loganetin could inhibit NF-κB pathway and pro-apoptotic genes expression. However, TLR4 was silenced by a specific shRNA, and the inhibitory effect of Loganetin in HK-2 cells vanished. Loganetin also down-regulated the expression of inflammation factors by suppressing TLR4 activity.

CONCLUSION AND IMPLICATIONS

All the results suggested that TLR4 plays a critical role in AKI development, and Loganetin ameliorates AKI by inhibiting TLR4 activity and blocking the JNK/p38 pathway, which provides a new strategy for AKI treatment.

A Novel Integrative Processing Technology for the Preparation of Rehmanniae Radix Slices

The traditional processing method for the slices preparation of Rehmanniae roots is time- and energy-consuming and is prone to result in loss of active components during twice water-treatment (once for wash and the other for softening) and drying steps. In this study, we firstly explored an integrative processing technique for Rehmanniae Radix by 2x3 factorial experiment based on the contents of catalpol and verbascoside as measured by HPLC. The potential differences between the traditional stepwise processing technique and the integrative processing technique for catalpol and verbascoside in the prepared slices were investigated. To further confirm the effectiveness of drugs using the integrative processing technique, some pharmacological variables, such as rectal temperature, hematologic parameters (RBC, HGB, HCT, and blood viscosity), and coagulation parameters (TT, APTT, PT and FIB), were detected in a blood-heat and hemorrhage syndrome rat model. Two-way ANOVA analysis showed that drying for 18 h at 50°C was considered as the best combination of process conditions. The mean catalpol and verbascoside contents in the integrative method-processed samples (4.30% and 0.33%, respectively) were higher than those in the traditional method-processed samples (2.61% and 0.21%, respectively). Significant increases in rectal temperature, and hematologic parameters, TT, APTT, and FIB, were observed in the model group rats, compared to the blank group animals (P<0.01). Both in the integrative groups and traditional groups, the extracts caused significant decreases in rectal temperature, RBC, HGB, and HCT with increased concentration compared to the model group animals. All coagulation parameters tested were shortened in model rats received two kind prepared slices. There were no significant therapeutic differences between the integrative and the traditional method-processed slices on the hemostasis and hemorheological parameters in this blood-heat and hemorrhage syndrome rat model, indicating that our integrative method may be a feasible technique for processing Rehmanniae Radix slices.

Elucidation of the Intestinal Absorption Mechanism of Loganin in the Human Intestinal Caco-2 Cell Model

Loganin, iridoid glycosides, is the main bioactive ingredients in the plant Strychnos nux-vomica L. and demonstrates various pharmacological effects, though poor oral bioavailability in rats. In this study, the intestinal absorption mechanism of loganin was investigated using the human intestinal Caco-2 cell monolayer model in both the apical-to-basolateral (A-B) and the basolateral-to-apical (B-A) direction; additionally, transport characteristics were systematically investigated at different concentrations, pHs, temperatures, and potential transporters. The absorption permeability (PappAB) of loganin, which ranged from 12.17 to 14.78 × 10-6cm/s, was high at four tested concentrations (5, 20, 40, and 80μM), while the major permeation mechanism of loganin was found to be passive diffusion with active efflux mediated by multidrug resistance-associated protein (MRP) and breast cancer resistance protein (BCRP). In addition, it was found that loganin was not the substrate of efflux transporter P-glycoprotein (P-gp) since the selective inhibitor (verapamil) of the efflux transporter exhibited little effects on the transport of loganin in the human intestinal Caco-2 cells. Meanwhile, transport from the apical to the basolateral side increased 2.09-fold after addition of a MRP inhibitor and 2.32-fold after addition of a BCRP inhibitor. In summary, our results clearly demonstrate, for the first time, a good permeability of loganin in the human intestinal Caco-2 cell model and elucidate, in detail, the intestinal absorption mechanism and the effects of transporters on iridoid glycosides compounds.

Morroniside regulates hair growth and cycle transition via activation of the Wnt/β-catenin signaling pathway

Hair loss is characterized by a shortened hair anagen phase and hair follicles (HF) miniaturization. Morroniside is the most abundant iridoid glycoside extracted from Cornus officinalis and has various bioactivities in different cell functions and tissue regeneration. In this study, we investigated the effects and the underlying mechanism of morroniside on hair growth and regulation of HF cycle transition. Morroniside treatment significantly enhanced outer root sheath cell (ORSC) proliferation and migration in vitro. Additionally, morroniside upregulated Wnt10b, β-catenin and lef1. The enhanced ORSC proliferation and migration due to morroniside treatment were partly rescued by a Wnt/β-catenin signaling inhibitor, DKK1. Furthermore, in a hair-induced mouse model, morroniside injection accelerated the onset of anagen and delayed HF catagen, as shown by histological examination. Immunohistochemical analyses revealed that Wnt/β-catenin signaling pathway expression was upregulated in the HFs. These findings suggest that morroniside regulates HF growth and development partly through the Wnt/β-catenin signaling pathway and may be a potential treatment for hair loss.

Pharmacokinetic Comparisons of Multiple Triterpenic Acids from Jujubae Fructus Extract Following Oral Delivery in Normal and Acute Liver Injury Rats

Jujubae Fructus, the dried fruit of Ziziphus jujuba, has been used as Chinese medicine and food for centuries. Triterpenic acids have been found to be the major bioactive constituents in Jujubae Fructus responsible for their hepatoprotective activity in previous phytochemical and biological studies, while few pharmacokinetic studies have been conducted. To reveal the kinetics of the triterpenic acids under the pathological liver injury state, an established ultra-performance liquid chromatography coupled with a mass spectrometry method was applied for the simultaneous quantitation of seven triterpenic acids (ceanothic acid, epiceanothic acid, pomonic acid, alphitolic acid, maslinic acid, betulinic acid, and betulonic acid) in plasma samples of normal and acute liver injury rats induced by CCl₄. The results showed that there were significant differences (p < 0.05) in the pharmacokinetic parameters of seven triterpenic acids between model and normal groups. The AUC_0–t and AUC_0–∞ of epiceanothic acid (5227 ± 334 μg&sdot;h/L vs. 1478 ± 255 μg ⋅ h/L and 6127 ± 423 μg ⋅ h/L vs. 1482 ± 255 μg ⋅ h/L, respectively) and pomonic acid (4654 ± 349 μg ⋅ h/L vs. 1834 ± 225 μg ⋅ h/L and 4776 ± 322 μg ⋅ h/L vs. 1859 ± 230 μg ⋅ h/L, respectively) in model rats were significantly higher than those in normal rats, and the CLz/F of them were significantly decreased (0.28 ± 0.02 L/h/kg vs. 1.36 ± 0.18 L/h/kg and 19.96 ± 1.30 L/h/kg vs. 53.15 ± 5.60 L/h/kg, respectively). In contrast, the above parameters for alphitolic acid, betulinic acid and betulonic acid exhibited the quite different trend. This pharmacokinetic research might provide useful information for the clinical usage of triterpenic acids from Jujubae Fructus.

Ethnopharmacology, phytochemistry, and pharmacology of Cornus officinalis Sieb. et Zucc

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis (Cornaceae), known in Chinese as "Shanzhuyu," is a frequently used traditional Chinese medicine. It tastes sour and is astringent and slightly warm in nature. Its fruits have long been used to treat kidney deficiency, high blood pressure, waist and knee pain, dizziness, tinnitus, impotence, spermatorrhea, menorrhagia, and other diseases in China. The main distribution areas are Shanxi and Gansu.

AIM OF THE STUDY

This review focused on the ethnopharmacological uses of the herb. We also focus on the phytochemical, pharmacological, and toxicological studies on C. officinalis. The recent analytical methods developed for the quality control of the herb's constituents are also reviewed. Additionally, future trends and prospects in the study of this herb are proposed.

MATERIALS AND METHODS

Information on C. officinalis was gathered by searching the internet (PubMed, ScienceDirect, Wiley, ACS, CNKI, Scifinder, Web of Science, Google Scholar, and Baidu Scholar) and libraries.

RESULTS

This review compiled the ethnopharmacological uses, including the classic prescriptions and historical applications. Approximately 300 chemical compounds have been isolated and identified from C. officinalis. The major active components of the plant are organic acids and iridoids, among which morroniside and loganin have been extensively investigated. The fruit of the plant has been used in treating many diseases in traditional medicine. Scientific studies indicated the herb's wide range of pharmacological activities, such as hepatic and renal protection, antidiabetes activity, cardioprotection, antioxidation, neuroprotection, antitumor activity, anti-inflammation, analgesic effects, antiaging activity, antiamnesia, antiosteoporosis, and immunoregulation. The analytical methods developed for the quantitative and qualitative determination of various compounds in the herb were further reviewed.

CONCLUSIONS

In this paper, we reviewed various studies conducted on C. officinalis, especially in areas of its ethnopharmacological use, as well as on its phytochemistry, pharmacology, and modern analytical methods used. Some of the herb's ethnomedical indications have been confirmed by the herb's pharmacological effects, such as its hepatic and renal protection and the antidiabetic effects. In particular, the crude extract and its chemical composition have exerted good therapeutic effect in diabetic treatment. C. officinalis entails additional attention on its pharmacological effects and drug development to expand its effective use clinically. Many advanced technologies are used for quality testing, but the detection component is exceedingly scarce for synthetically evaluating the quality of C. officinalis herbs. Thus, further research is necessary to investigate the quality control and toxicology of the plant, to further elucidate its clinical use, and to control herbal quality.

Comparative pharmacokinetics of four active components on normal and diabetic rats after oral administration of Gandi capsules

The Gandi capsule, a famous traditional Chinese medicine (TCM), is a hospital preparation that has been widely used in China for decades for the treatment of diabetes.

Liuwei Dihuang soft capsules attenuates endothelial cell apoptosis to prevent atherosclerosis through GPR30-mediated regulation in ovariectomized ApoE-deficient mice

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang (LWDH), a classical traditional Chinese medicine prescription, has been widely used to prevent and to treat various diseases with symptoms of 'Kidney-Yin' deficiency syndrome for over 1000 years in China. It is commonly used to treat functional decline associated with senile disease and menopausal syndrome, especially memory decline, insomnia, diabetes and osteoporosis. Modern experimental pharmacological studies indicated that the mechanism of LWDH treatment of menopausal syndrome may be associated with enhanced estrogenic effects. However, little attention has been paid to the potential impact of LWDH on atherosclerosis (AS) associated with female menopause. The aim of this study was to evaluate the preventive effects of LWDH intake on an animal model of female menopause AS and to explore the underlying molecular mechanism.

MATERIALS AND METHODS

ApoE^-/- mice were randomly divided into 4 groups, with C57BN/L6 mice as the control group. All ApoE^-/- mice were ovariectomized (Ovx) one week prior to oral administration and initiation of high-fat diet. C57BL/6 mice were given sham operation and maintained on normal diet. The three administered groups were given simvastatin (4mg/kg via i.g.) and LWDH (4.5, 9.0g/kg via i.g.) every day for 14 weeks. Atherosclerotic lesions in the aortic root were determined by oil red O staining and hematoxylin-eosin staining. α-Actin and CD68 in atherosclerotic lesions were detected by immunohistological assay. Serum lipids and homocysteine (Hcy) levels were measured in the 14th week. The cleaved caspase-3, C/EBP homologous protein (CHOP) and G protein coupled estrogen receptor 30 (GPR30) expressions in the aortic arch endothelium were determined by immunohistochemistry and Western blot. The inhibitory effect of LWDH-medicated (20%, 12h) on Hcy (20%, 24h)-induced apoptosis of human umbilical vein endothelial cells (HUVECs) was examined by flow cytometry and Hoechst 33258 staining. Intracellular ROS production, nitric oxide release, and endothelial NO synthase (eNOS) activity were measured with or without LWDH-medicated serum pretreatment. In addition, CHOP, glucose-regulated protein GPR30, 78 (Grp78), Bcl-2, Bax and cleaved caspase-3 were analyzed by Western blot. Finally, the influence of G15, a specific antagonist of GPR30, on the protective effect of LWDH on endothelial cells was investigated.

RESULTS

In vivo administration of LWDH prevented plaque formation and reduced plasma lipid and Hcy levels. LWDH inhibited CHOP and cleaved caspase-3 expression in vivo and in vitro while maintaining GPR30 expression. In vitro study showed that Hcy-induced HUVECs apoptosis was weakened by LWDH-medicated serum pretreatment. Treatment with LWDH-medicated serum significantly upregulated NO release and eNOS activity in HUVECs. In addition, LWDH-medicated serum treatment optimized the balance between Bax and Bcl-2, and attenuated intracellular ROS production. G15 reversed the protective effect of LWDH on endothelial cells and the changes of apoptosis-related proteins.

CONCLUSIONS

LWDH treatment can significantly reduce plaque formation in an animal model of menopausal AS. The mechanism may be inhibition of Hcy-induced endothelial cell apoptosis by modulating GPR30. Hence, LWDH can potentially be used to prevent AS-related vascular disease in menopausal women.

Blocking Smad2 signalling with loganin attenuates SW10 cell cycle arrest induced by TNF-α

The activity of Schwann cells (SWCs) is very important in trauma-induced nerve repair, and tumour necrosis factor-α (TNF-α) produced during tissue injury inhibits the viability of SWCs, which delays the repair of peripheral nerves. Loganin is an iridoid glycoside that has been shown to alleviate a variety of cytotoxic effects. In the current study, we evaluated the potential efficacy and the mechanism of action of loganin in TNF-α-induced cytotoxicity in SW10 cells. The experimental results indicated that loganin blocked TNF-α-mediated Smad2 activation, downregulated the expression of the G1 phase cell cycle inhibitor p15IN4KB, and upregulated the expression of the G1 phase cell cycle activator cyclin D1-CDK4/6, which upregulated E2F-1-dependent survivin expression and relieved TNF-α-induced apoptosis in SW10 cells. The protective effect of loganin on SWCs has potential medicinal value in the promotion of peripheral nerve repair and is significant for studies in the field of tissue regeneration.

p-JAK2 plays a key role in catalpol-induced protection against rat intestinal ischemia/reperfusion injury

Catalpol attenuated rat intestinal I/R injury by decreasing mitochondria-mediated apoptosis through blocking the JAK2/STAT3 signaling pathwayviaselective inhibition of p-JAK2.

Echinacoside and Cistanche tubulosa (Schenk) R. wight ameliorate bisphenol A-induced testicular and sperm damage in rats through gonad axis regulated steroidogenic enzymes

ETHNOPHARMACOLOGICAL RELEVANCE

Male infertility has been increasing over the last decades and being a pressing health problem nowadays. Cistanche tubulosa (CT) is a traditional Chinese medicine used to boost male sexual function. Echinacoside (ECH) is one of the major compounds exist in CT and might be a potential agent to protect testis and sperm injury.

AIM OF THE STUDY

To investigate the mechanisms behind the possible protective effects of CT and ECH against testicular and sperm toxicity.

MATERIALS AND METHODS

CT was identified by 5.8s gene sequencing. The major compositions (echinacoside and acteoside) of CT were quantified by HPLC method. The adult male Sprague-Dawley rats were exposed to BPA, CT or ECH for 42 consecutive days. The sperm parameters were observed by dark-field microscope; serum hormone levels (FSH, LH and testosterone) were tested by radio immunosorbent; LDH-x activity were evaluated using commercial kits; the expressions of the key steroidogenic enzymes were evaluated by qRT-PCR, heat map, immunofluorescence and western blot.

RESULTS

The CT and ECH treatments against BPA-induced testicular and sperm toxicity showed that CT and ECH have reversed BPA-induced abnormality in sperm characteristics, testicular structure and normalized serum testosterone. This was concomitant with the increased expression of LDH-x as well as the key steroidogenic enzymes including StAR, CYP11A1, 3β-HSD, 17β-HSD and CYP17A1, suggesting that CT and ECH enhanced testosterone biosynthesis.

CONCLUSIONS

CT and ECH attenuated poor sperm quality and testicular toxicity in rats through up-regulation steroidogenesis enzymes and ECH is the active compound of CT as a potential natural reproductive agent.

Simultaneous Determination of Catalpol, Aucubin, and Geniposidic Acid in Different Developmental Stages of Rehmannia glutinosa Leaves by High Performance Liquid Chromatography

Although R. glutinosa roots are currently the only organ source in clinics, its leaves are a potential supplement for the roots especially in extraction of some important bioactive compounds. Our early work found that the contents of catalpol and total iridoid glycosides varied among different developmental stages of R. glutinosa leaves. Aucubin and geniposidic acid, the abundant major bioactive compounds in Eucommia ulmoides and Gardenia jasminoides, respectively, were found present in R. glutinosa roots, however, and have not been analyzed in its leaves. In this paper, we aimed to determine contents of these three iridoid glycosides in different developmental stages of R. glutinosa leaves using the optimized HPLC-UV conditions. Our results showed that aucubin and GPA in R. glutinosa leaves were much lower than catalpol and showed the increasing trend with the leaf development, which was different from catalpol. This work provided the important information for future exploitation of R. glutinosa leaves as a potential supplement for its roots in extraction of some important bioactive compounds and studying the relationship of aucubin and catalpol metabolism.