Farnesyl protein transferase inhibitory components of Polygonum multiflorum

Emodin-8-O-β-D-glucopyranoside-induced hepatotoxicity and gender differences in zebrafish as revealed by integration of metabolomics and transcriptomics

BACKGROUND

Emodin-8-O-β-D-glucopyranoside (Em8G) is an active ingredient of traditional Chinese medicine Rhei Radix et Rhizoma and Polygonum multiflorum Thunb.. And it caused hepatotoxicity, while the underlying mechanism was not clear yet.

PURPOSE

We aimed to explore the detrimental effects of Em8G on the zebrafish liver through the metabolome and transcriptome integrated analysis.

STUDY DESIGN AND METHODS

In this study, zebrafish larvae were used in acute toxicity tests to reveal the hepatotoxicity of Em8G. Adult zebrafish were then used to evaluate the gender differences in hepatotoxicity induced by Em8G. Integration of transcriptomic and metabolomic analysis was used further to explore the molecular mechanisms underlying gender differences in hepatotoxicity.

RESULTS

Our results showed that under non-lethal concentration exposure conditions, hepatotoxicity was observed in Em8G-treated zebrafish larvae, including changes in liver transmittance, liver area, hepatocyte apoptosis and hepatocyte vacuolation. Male adult zebrafish displayed a higher Em8G-induced hepatotoxicity than female zebrafish, as demonstrated by the higher mortality and histopathological alterations. The results of transcriptomics combined with metabolomics showed that Em8G mainly affected carbohydrate metabolism (such as TCA cycle) in male zebrafish and amino acid metabolism (such as arginine and proline metabolism) in females, suggesting that the difference of energy metabolism disorder may be the potential mechanism of male and female liver toxicity induced by Em8G.

CONCLUSIONS

This study provided the direct evidence for the hepatotoxicity of Em8G to zebrafish models in vivo, and brought a new insight into the molecular mechanisms of Em8G hepatotoxicity, which can guide the rational application of this phytotoxin. In addition, our findings revealed gender differences in the hepatotoxicity of Em8G to zebrafish, which is related to energy metabolism and provided a methodological reference for evaluating hepatotoxic drugs with gender differences.

Molecular identification and functional characterization of two glycosyltransferases genes from Fallopia multiflora

The traditional Chinese medicine plant Fallopia multiflora (Thunb.) Harald. contains various pharmacodynamically active glycosides, such as stilbene glycosides, anthraquinone (AQ) glycosides, and flavonoid glycosides. Glycosylation is an important reaction in plant metabolism that is generally completed by glycosyltransferase in the last step of the secondary metabolite biosynthesis pathway, and it can improve the beneficial properties of many natural products. In this study, based on the transcriptome data of F. multiflora, we cloned two Uridine-diphosphate-dependent glycosyltransferases (UGTs) from the cDNA of F. multiflora (FmUGT1 and FmUGT2). Their full-length sequences were 1602 and 1449 bp, encoding 533 and 482 amino acids, respectively. In vitro enzymatic reaction results showed that FmUGT1 and FmUGT2 were promiscuous and could catalyze the glycosylation of 12 compounds, including stilbenes, anthraquinones, flavonoids, phloretin, and curcumin, and we also obtained and structurally identified 13 glycosylated products from both of them. Further experiments on the in vivo function of FmUGT1 and FmUGT2 showed that 2, 3, 5, 4'- tetrahydroxy stilbene-2-O-β-d-glucoside (THSG) content in hairy roots was elevated significantly when FmUGT1 and FmUGT2 were overexpressed and decreased accordingly in the RNA interference (RNAi) groups. These results indicate that FmUGT1 and FmUGT2 were able to glycosylate a total of 12 structurally diverse types of acceptors and to generate O-glycosides. In addition, FmUGT1 and FmUGT2 efficiently catalyzed the biosynthesis of THSG, and promoted the production of AQs in transgenic hairy roots.

A comprehensive review of traditional uses, phytochemistry and pharmacology of Reynoutria genus

Objectives

The genus Reynoutria belonging to the family Polygonaceae is widely distributed in the north temperate zone and used in folk medicine. It is administered as a sedative, tonic and digestive, also as a treatment for canities and alopecia. Herein, we reported a review on traditional uses, phytochemistry and pharmacology reported from 1985 up to early 2022. All the information and studies concerning Reynoutria plants were summarized from the library and digital databases (e.g. ScienceDirect, SciFinder, Medline PubMed, Google Scholar, and CNKI).

Key findings

A total of 185 articles on the genus Reynoutria have been collected. The phytochemical investigations of Reynoutria species revealed the presence of more than 277 chemical components, including stilbenoids, quinones, flavonoids, phenylpropanoids, phospholipids, lactones, phenolics and phenolic acids. Moreover, the compounds isolated from the genus Reynoutria possess a wide spectrum of pharmacology such as anti-atherosclerosis, anti-inflammatory, antioxidative, anticancer, neuroprotective, anti-virus and heart protection.

Summary

In this paper, the traditional uses, phytochemistry and pharmacology of genus Reynoutria were reviewed. As a source of traditional folk medicine, the Reynoutria genus have high medicinal value and they are widely used in medicine. Therefore, we hope our review can help genus Reynoutria get better development and utilization.

Pharmacokinetics, Tissue Distribution, and Excretion Characteristics of a Radix Polygoni Multiflori Extract in Rats

Although progress has been achieved in the pharmacological activity and toxicity of Radix Polygoni Multiflori (RPM), the chemical basis of its toxicity is still unclear. Here, we performed a multicompound pharmacokinetic analysis and investigated the tissue distribution and excretion characteristics of RPM components after oral administration in rats. The findings demonstrated that the active ingredients of the RPM extract were quickly absorbed after oral administration, with high exposure levels of emodin, 2,3,5,4′-teterahydroxystilbene-2-O-β-D-glucoside (TSG), citreorosein, torachrysone-8-O-glucoside (TG), emodin-8-O-β-D-glucoside (EG), and physcion-8-O-β-D-glucoside (PG). The tissue distributions of emodin, TSG, TG, EG, and PG were high in the liver and kidney. These components were the key contributors to the effectiveness and toxicity of RPM on the liver and kidney. Most of the active ingredients were mainly excreted through feces and bile, while a few were converted into other products in the body and excreted through urine and feces.

Polygonum multiflorum: Recent updates on newly isolated compounds, potential hepatotoxic compounds and their mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum multiflorum Thunb.(PM), (known as Heshouwu () in China) is one of the most important and well mentioned Chinese medicinal herbs in the literature for its use in blackening hair, nourishing liver and kidney, anti-aging, anti-hyperlipidemia, antioxidant, anti-inflammatory, anticancer, hepatoprotection, cardio-protection and improving age-related cognitive dysfunction. The purpose of this review is to give a comprehensive and recent update on PM: new compounds or isolated for the first time, potential hepatotoxic compounds and their mechanisms. Moreover, future perspectives and challenges in the future study of this plant are conversed which will make a new base for further study on PM.

MATERIALS AND METHODS

A comprehensive review of relevant published literature on PM using the scientific databases SCOPUS, PubMed, and Science Direct was done.

RESULTS

PM is broadly produced in many provinces of China and well known in other Eastern Asian Countries for its ethno-medical uses. Previous phytochemical investigation of PM had led to the isolation of more than 175 compounds including recently isolated 70 new compounds. Most of the new compounds isolated after 2015 are majorly dianthrone glycosides and stilbene glycosides. Processing has also a significant effect on chemical composition, pharmacological activities, and toxicity of PM. PM-induced liver injury is increasing after the first report in Hong Kong in 1996. Hepatotoxicity of PM was constantly reported in Japan, Korea, China, Australia, Britain, Italy, and other countries although its toxicity is related to idiosyncratic hepatotoxicity. More interestingly, although there is indispensable interest to predict idiosyncratic hepatotoxicity of PM and understand its mechanisms, the responsible hepatotoxic compounds and mechanisms of liver damage induced by PM are still not clear. There is a big controversy on the identification of the most responsible constituent. Anthraquinone and stilbene compounds in PM, mainly emodine and TSG are mentioned in the literature to be the main responsible hepatotoxic compounds. However, comparing the two compounds, which one is the more critical toxic agent for PM-induced hepatotoxicity is not well answered. Affecting different physiological and metabolic pathways such as oxidative phosphorylation and TCA cycle pathway, metabolic pathways, bile acid excretion pathway and genetic polymorphisms are among the mechanisms of hepatotoxicity of PM.

CONCLUSION

Deeper and effective high throughput experimental studies are still research hotspots to know the most responsible constituent and the mechanism of PM-induced hepatotoxicity.

Simultaneous Determination of 13 Constituents of Radix Polygoni Multiflori in Rat Plasma and Its Application in a Pharmacokinetic Study

Radix Polygoni Multiflori (RPM) has been widely used to treat various diseases in Asian countries for many centuries. Although, stilbenes and anthraquinones, two major components of RPM, show various bioactive effects, it has been speculated that the idiosyncratic hepatotoxicity induced by RPM may be related to these constituents. However, information on the pharmacokinetics of stilbenes and anthraquinones at a subtoxic dose of RPM is limited. A simple and sensitive UPLC-MS/MS bioanalytical method for the simultaneous determination of 13 ingredients of RPM, including chrysophanol, emodin, aloe-emodin, rhein, physcion, questin, citreorosein, questinol, 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside, torachrysone-8-O-glucoside, chrysophanol-8-O-β-D-glucoside, emodin-8-O-β-D-glucoside, and physcion-8-O-β-D-glucoside, in rat plasma was established. Acetonitrile was employed to precipitate the plasma with appropriate sensitivity and acceptable matrix effects. Chromatographic separation was performed using a waters HSS C18 column with a gradient elution using water and acetonitrile both containing 0.025% formic acid within a run time of 9 min. The constituents were detected in negative ionization mode using multiple reaction monitoring. The method was fully validated in terms of selectivity, linearity, accuracy, precision, recovery, matrix effects, and stability. The lower limit of quantitation of the analytes was 0.1–1 ng/mL. The intrabatch and interbatch accuracies were 87.1–109%, and the precision was within the acceptable limits. The method was applied to a pharmacokinetic study after oral administration of RPM extract to rats at a subtoxic dose of 36 g/kg.

Nuclear Factor Kappa B Activation and Peroxisome Proliferator-activated Receptor Transactivational Effects of Chemical Components of the Roots of Polygonum multiflorum

BACKGROUND

Polygonum multiflorum is well-known as "Heshouwu" in traditional Chinese herbal medicine. In Northeast Asia, it is often used as a tonic to prevent premature aging of the kidney and liver, tendons, and bones and strengthening of the lower back and knees.

OBJECTIVE

To research the anti-inflammatory activities of components from P. multiflorum.

MATERIALS AND METHODS

The compounds were isolated by a combination of silica gel and YMC R-18 column chromatography, and their structures were identified by analysis of spectroscopic data (1D, 2D-nuclear magnetic resonance, and mass spectrometry). The anti-inflammatory activities of the isolated compounds 1-15 were evaluated by luciferase reporter gene assays.

RESULTS

Fifteen compounds (1-15) were isolated from the roots of P. multiflorum. Compounds 1-5 and 14-15 significantly inhibited tumor necrosis factor-α-induced nuclear factor kappa B-luciferase activity, with IC50 values of 24.16-37.56 μM. Compounds 1-5 also greatly enhanced peroxisome proliferator-activated receptors transcriptional activity with EC50 values of 18.26-31.45 μM.

CONCLUSION

The anthraquinone derivatives were the active components from the roots of P. multiflorum as an inhibitor on inflammation-related factors in human hepatoma cells. Therefore, we suggest that the roots of P. multiflorum can be used to treat natural inflammatory diseases.

SUMMARY

This study presented that fifteen compounds (1-15) isolated from the roots of Polygonum multiflrum exert signifiant anti inflmmatory effects by inhibiting TNF α induced NF κB activation and PPARs transcription. Abbreviation used: NF κB: Nuclear factor kappa B, PPARs: Peroxisome proliferator activated receptors, PPREs: Peroxisome proliferator response elements, TNF α: Tumor necrosis factor α, ESI-MS: Electrospray ionization mass spectrometry, HepG2: Human hepatoma cells.

Review of clinical studies of Polygonum multiflorum Thunb. and its isolated bioactive compounds

Polygonum multiflorum Thunb. (PMT), officially listed in the Chinese Pharmacopoeia, is one of the most popular perennial Chinese traditional medicines known as He shou wu in China and East Asia, and as Fo-ti in North America. Mounting pharmacological studies have stressed out its key benefice for the treatment of various diseases and medical conditions such as liver injury, cancer, diabetes, alopecia, atherosclerosis, and neurodegenerative diseases as well. International databases such as PubMed/Medline, Science citation Index and Google Scholar were searched for clinical studies recently published on P. multiflorum. Various clinical studies published articles were retrieved, providing information relevant to pharmacokinetics-pharmacodynamics analysis, sleep disorders, dyslipidemia treatment, and neurodegenerative diseases. This review is an effort to update the clinical picture of investigations ever carried on PMT and/or its isolated bio-compounds and to enlighten its therapeutic assessment.

Promotion effect of constituents from the root of Polygonum multiflorum on hair growth

Two new compounds, gallic acid ester of torachrysone-8-O-β-D-glucoside (1) and (E)-2,3,5,4'-tetrahydroxystilbene-2-O-β-D-xyloside (4), along with eight known compounds (2, 3, 5-10) were isolated from a 70% ethanol extract of Polygonum multiflorum roots. The structures were determined by (1)H and (13)C NMR, HMQC, and HMBC spectrometry. Extracts of P. multiflorum have been reported to promote hair growth in vivo. This study was carried out to evaluate the effects of isolated compounds from P. multiflorum on promoting hair growth using dermal papilla cells (DPCs), which play an important role in hair growth. When DPCs were treated with compounds (1-10) from P. multiflorum, compounds 1, 2, 3, 6, and 10 increased the proliferation of DPCs compared with the control. Specifically, compound 2 (10 and 20 μM) induced a greater increase in the proliferation of DPCs than minoxidil (10 μM). Additionally, treatment of vibrissa follicles with compound 2 for 21 days increased hair-fiber length significantly. On the basis of this result, further investigation and optimization of these derivatives might help in the development of therapeutic agents for the treatment of alopecia.

Novel derivatives of aclacinomycin A block cancer cell migration through inhibition of farnesyl transferase

In the course of screening for an inhibitor of farnesyl transferase (FTase), we identified two compounds, N-benzyl-aclacinomycin A (ACM) and N-allyl-ACM, which are new derivatives of ACM. N-benzyl-ACM and N-allyl-ACM inhibited FTase activity with IC50 values of 0.86 and 2.93 μM, respectively. Not only ACM but also C-10 epimers of each ACM derivative failed to inhibit FTase. The inhibition of FTase by N-benzyl-ACM and N-allyl-ACM seems to be specific, because these two compounds did not inhibit geranylgeranyltransferase or geranylgeranyl pyrophosphate (GGPP) synthase up to 100 μM. In cultured A431 cells, N-benzyl-ACM and N-allyl-ACM also blocked both the membrane localization of H-Ras and activation of the H-Ras-dependent PI3K/Akt pathway. In addition, they inhibited epidermal growth factor (EGF)-induced migration of A431 cells. Thus, N-benzyl-ACM and N-allyl-ACM inhibited EGF-induced migration of A431 cells by inhibiting the farnesylation of H-Ras and subsequent H-Ras-dependent activation of the PI3K/Akt pathway.

Pharmacokinetics and tissue distribution of 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside from traditional Chinese medicine Polygonum multiflorum following oral administration to rats

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum multiflorum is an important traditional Chinese medicine used for health promotion and disease treatment. One major bioactive compound in P. multiflorum is a stilbene glycoside (2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside, PM-SG), which possesses antioxidative, anti-inflammatory and endothelial-protective activities.

MATERIALS AND METHODS

The purpose of the present study was to investigate in vivo pharmacokinetics and tissue distribution of PM-SG after oral administration of Polygonum multiflorum extract to rats by using a reversed-phase high-performance liquid chromatography coupled with liquid-liquid phase extraction. The pharmacokinetic parameters were determined using both compartmental and non-compartmental analyses.

RESULTS

All calibration curves for PM-SG in rat plasma and tissues were linear (all r(2)>0.99) over the range of 0.27-185.00 μg/ml. The intra- and inter-day variations were less than 3% at concentration range of 8.7-131.2 μg/ml and good overall recoveries (97.7-101.5%) were obtained at the same range. The maximum concentration (C(max)) and the time to reach this concentration (T(max)) of PM-SG were 31.9 μg/ml and 40.0 min, respectively. The pharmacokinetic profiles estimated by fitting two-compartment and non-compartment models revealed that PM-SG was rapidly absorbed into the body fluids and widely distributed throughout the body, with great efficiency of utility, followed by quick elimination. The highest PM-SG levels were detected in liver and lungs (90.3 ± 20.8 μg/g and 86.8 ± 9.0 μg/g, respectively) whereas little in brain and testes, indicating PM-SG can hardly penetrate the blood-brain and blood-testicle barriers.

CONCLUSIONS

This was the first report on the favorable pharmacokinetic profiles of PM-SG in rat plasma and tissues after oral administration. It may provide a meaningful basis for clinical application of such a bioactive compound of herbal medicines.