Comparative pharmacokinetics and tissue distribution of polydatin, resveratrol, and emodin after oral administration of Huzhang and Huzhang-Guizhi herb-pair extracts to rats

ETHNOPHARMACOLOGICAL RELEVANCE

Huzhang-Guizhi herb pair (HGHP), composed of Polygonum cuspidatum (Huzhang [HZ] in Chinese, the root of Polygonum cuspidatum Sieb. & Zucc.) and Ramulus Cinnamomi (Guizhi [GZ] in Chinese, the dried twig of Cinnamomum cassia Presl.), is a popular herb pair commonly used to treat arthritis and involved in many Chinese prescriptions. In order to reveal the influence of GZ on HZ on bioavailability, the pharmacokinetic behaviors and tissue distribution variations of the three analytes from HZ were detected between oral administration of HZ and HGHP extracts to rats.

MATERIALS AND METHODS

Male Sprague-Dawley rats were randomly assigned to two groups for pharmacokinetics study and eight groups for tissues distribution research with the equivalent dose of 18 g crude HZ/kg. Assays for analytes from HZ (polydatin, resveratrol, emodin) were developed and validated using high performance liquid chromatography with ultraviolet detection (HPLC-UV).

RESULTS

Part pharmacokinetic parameters including area under the concentration-time curve (AUC), the maximum plasma concentration (Cmax), biological half-life (t1/2), mean residence time (MRT), time to peak concentration (Tmax), clearance rate/bioavailability (CL/F) and volume of distribution/bioavailability (Vd/F) showed significant difference (P < 0.05) after oral administration of HGHP, as compared to those of HZ. The three analytes could be detected in heart, liver, spleen, lung, kidney and brain. Compared with the HZ group, AUC0-t of polydatin in heart, liver and kidney increased significantly (p < 0.05) while that in spleen decreased significantly (p < 0.05); AUC0-t of resveratrol in all detected tissues increased conspicuously (p < 0.05) in the HGHP group; AUC0-t of emodin in heart, liver, spleen, lung, and kidney increased conspicuously (p < 0.05), and decreased obviously (p < 0.05) in brain in the HGHP group.

CONCLUSIONS

GZ could strongly influence the pharmacokinetic parameters and tissue distribution characteristics of polydatin, resveratrol and emodin in rats when administrated with HZ or HGHP extracts. It might provide a reference for further explanation of the compatibility mechanism and the clinical application of HGHP.

Targeting TRPV1 and TRPA1: A feasible strategy for natural herbal medicines to combat postoperative ileus

Under physiological or pathological conditions, transient receptor potential (TRP) channel vanilloid type 1 (TRPV1) and TRP ankyrin 1 (TRPA1) possess the ability to detect a vast array of stimuli and execute diverse functions. Interestingly, increasing works have reported that activation of TRPV1 and TRPA1 could also be beneficial for ameliorating postoperative ileus (POI). Increasing research has revealed that the gastrointestinal (GI) tract is rich in TRPV1/TRPA1, which can be stimulated by capsaicin, allicin and other compounds. This activation stimulates a variety of neurotransmitters, leading to increased intestinal motility and providing protective effects against GI injury. POI is the most common emergent complication following abdominal and pelvic surgery, and is characterized by postoperative bowel dysfunction, pain, and inflammatory responses. It is noteworthy that natural herbs are gradually gaining recognition as a potential therapeutic option for POI due to the lack of effective pharmacological interventions. Therefore, the focus of this paper is on the TRPV1/TRPA1 channel, and an analysis and summary of the processes and mechanism by which natural herbs activate TRPV1/TRPA1 to enhance GI motility and relieve pain are provided, which will lay the foundation for the development of natural herb treatments for this disease.

Shouhui Tongbian Capsules induce regression of inflammation to improve intestinal barrier in mice with constipation by targeted binding to Prkaa1: With no obvious toxicity

Constipation arising from the poor bowel movement is a rife enteric health problem. Shouhui Tongbian Capsule (SHTB) is a traditional Chinese medicine (TCM) which effectively improve the symptoms of constipation. However, the mechanism has not been fully evaluated. The purpose of this study was to evaluate the effect of SHTB on the symptoms and intestinal barrier of mice with constipation. Our data showed that SHTB effectively improved the constipation induced by diphenoxylate, which was confirmed by shorter first defecation time, higher internal propulsion rate and fecal water content. Additionally, SHTB improved the intestinal barrier function, which was manifested by inhibiting the leakage of Evans blue in intestinal tissues and increasing the expression of occludin and ZO-1. SHTB inhibited NLRP3 inflammasome signaling pathway and TLR4/NF-κB signaling pathway, reduced the number of proinflammatory cell subsets and increased the number of immunosuppressive cell subsets to relieve inflammation. The photochemically induced reaction coupling system combined with cellular thermal shift assay and central carbon metabolomics technology confirmed that SHTB activated AMPKα through targeted binding to Prkaa1 to regulate Glycolysis/Gluconeogenesis and Pentose Phosphate Pathway, and finally inhibited intestinal inflammation. Finally, no obvious toxicity related to SHTB was found in a repeated drug administration toxicity test for consecutive 13 weeks. Collectively, we reported SHTB as a TCM targeting Prkaa1 for anti-inflammation to improve intestinal barrier in mice with constipation. These findings broaden our knowledge of Prkaa1 as a druggable target protein for inflammation inhibition, and open a new avenue to novel therapy strategy for constipation injury.

The isomers, aloe-emodin and emodin, possess differential inhibitory activities against CYP1B1 enzyme

Aloe-emodin, known as a 3-hydroxymethyl-chrysazin, is one of anthraquinones mainly found in Rheum officinale Baill, Rheum palmatum L and Rheum tanguticum Maxim. Ex BALF. In recent studies, aloe-emodin possesses many pharmacological effects, including antitumor, antibacterial, antiviral, anti-inflammatory, cardiovascular protection, liver protection, immune regulation, estrogenic activity as a phytoestrogen, and so on. Cytochrome P450 (CYP) 1B1 (CYP1B1), as a major estrogen metabolizing enzyme, can metabolize 17β-estradiol (E2) to 4-hydroxy-E2 (4-OH-E2), which cause DNA damage and lead to tumor. Few studies have found that anthraquinones possess inhibitory activity against CYP1B1 enzyme. In this study, compared with emodin (3-Hydroxy-6-methyl-chrysazin, C₁₅H₁₀O₅), the inhibition of aloe-emodin (3-hydroxymethyl-chrysazin, C₁₅H₁₀O₅) on the activity of CYP1B1 was studied. The molecular mechanism of inhibition and the structure-activity relationship were also discussed. Although isomeric, the IC50 values of aloe-emodin and emodin were 0.192 ± 0.015 nM and 0.067 ± 0.003 µM, indicating the inhibition of aloe-emodin was about 350times stronger than that of emodin. Through structure-activity relationship analyses, it revealed the difference of inhibitory activity only due to different hydroxyl positions. When the hydroxyl group is transferred from the chrysazin skeleton to the methyl group, the hydrogen bond formed by this structure with the CYP1B1 protein can change the protein conformation, which may interfere with the binding of the substrate to CYP1B1 protein active site pocket and inhibit the catalytic activity of the CYP1B1 protein. Although the hydroxyl position changed, the inhibition mechanism did not change, all of which were mixed inhibition. This study reveals an anti-tumor mechanism of the anthraquinone compound aloe-emodin.

Regulatory roles of phytochemicals on circular RNAs in cancer and other chronic diseases

As novel non-coding RNAs (ncRNAs), circular RNAs (circRNAs) play an essential role in the pathogenesis of many chronic diseases, and the regulation of these functional molecules has become a research hotspot gradually. Within the past decade, phytochemicals were reported to regulate the expression of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in various chronic diseases, and more recently, most studies focus on the regulatory roles of phytochemicals on circRNAs. Abnormal expression of circRNAs has been identified in chronic diseases like cancer, heart failure, depression and atherosclerosis, and numerous studies have revealed the modulation of circRNAs by phytochemicals including berberine, celastrol, cinnamaldehyde, curcumin, et al. The expression of circRNAs, such as circSATB2 and circFOXM1, were modulated by phytochemicals, and these regulations further affected cell proliferation, apoptosis, migration, invasion, autophagy, chemosensitivity, radiosensitivity and other biological processes. Mechanismly, the circRNAs mainly functioned as miRNA sponge, subsequently affecting miRNA-mediated regulation of target genes and related cell signaling pathways. In this review, we summarized the impact of phytochemicals on circRNAs expression and biological function, and discussed the mechanisms underlying phytochemicals regulating circRNAs in cancer and other chronic diseases.

Effect of Qizhitongluo capsule on lower limb rehabilitation after stroke: A randomized clinical trial

BACKGROUND

An individual's level of lower limb motor function is associated with his or her disability level after stroke, and motor improvement may lead to a better prognosis and quality of life. Data from animal models show that Qizhitongluo (QZTL) capsule facilitates recovery after focal brain injury. We aimed to validate the efficacy and safety of the QZTL capsule for promoting lower limb motor recovery in poststroke patients.

METHODS

In this randomized, multicenter, double-blind, placebo- and active-controlled trial from 13 sites in China, participants with ischemic stroke and Fugl-Meyer motor scale (FMMS) scores of <95 were eligible for inclusion. Patients were randomly assigned in a 2:1:1 ratio to the QZTL group, Naoxintong (NXT) group or placebo group for 12 weeks at 15-28 days after the onset of stroke. The primary outcome was the change in the Lower Limb FMMS (FMMS-LL) score from baseline over the 12-week intervention period.

RESULTS

622 participants were randomly assigned to the QZTL group (309), NXT group (159), or placebo group (154). The FMMS-LL score increased by 4.81 points (95 % CI, 4.27-5.35) in the QZTL group, by 3.77 points (95 % CI, 3.03-4.51) in the NXT group and by 3.00 points (95 % CI, 3.03-4.51) in the placebo group at week 12. The QZTL group showed significantly larger improvements compared with the placebo group at each interview from weeks 4-12 (difference, 0.89 [0.30,1.49] at week 4, P = 0.0032; difference, 1.83[1.01,2.66] at 90 days poststroke, P < 0.0001; difference, 1.81[0.88,2.74] at week 12, P = 0.0001).

CONCLUSION

The QZTL capsule is an effective treatment for lower limb motor impairment. The finding indicates that the QZTL capsule may be used as a potential new strategy for stroke rehabilitation.

Natural product derived phytochemicals in managing acute lung injury by multiple mechanisms

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) as common life-threatening lung diseases with high mortality rates are mostly associated with acute and severe inflammation in lungs. With increasing in-depth studies of ALI/ARDS, significant breakthroughs have been made, however, there are still no effective pharmacological therapies for treatment of ALI/ARDS. Especially, the novel coronavirus pneumonia (COVID-19) is ravaging the globe, and causes severe respiratory distress syndrome. Therefore, developing new drugs for therapy of ALI/ARDS is in great demand, which might also be helpful for treatment of COVID-19. Natural compounds have always inspired drug development, and numerous natural products have shown potential therapeutic effects on ALI/ARDS. Therefore, this review focuses on the potential therapeutic effects of natural compounds on ALI and the underlying mechanisms. Overall, the review discusses 159 compounds and summarizes more than 400 references to present the protective effects of natural compounds against ALI and the underlying mechanism.

Sirt3 is a novel target to treat sepsis induced myocardial dysfunction by acetylated modulation of critical enzymes within cardiac tricarboxylic acid cycle

Sepsis induced myocardial dysfunction (SIMD) results in high morbidity and mortality. However, the effective therapeutic strategies for SIMD treatment remain limited. Sirt3 is the main mitochondrial Sirtuin member and is a key modulator of mitochondrial metabolism and function. In this study, we aimed to investigate the effect and mechanism of Sirt3 on SIMD. SIMD was induced by 20 mg/kg Lipopolysaccharides (LPS) injection for 6 h in mice. Sepsis could induce the reduction of cardiac Sirt3 expression and global deficiency of Sirt3 exacerbated cardiac function. Quantitative acetyl-proteomics and cardiac metabolomics analysis revealed that loss of Sirt3 led to hyper-acetylation of critical enzymes within cardiac tricarboxylic acid (TCA) cycle and generation of lactate and NADH, subsequently promotion of cardiac dysfunction after sepsis. Additionally, to evaluate whether Emodin could be utilized as a potential Sirt3 modulator to treat SIMD, male wild type mice (WT mice) or global Sirt3 deficient mice (Sirt3^-/- mice) were intraperitoneally injected with 40 mg/kg Emodin for 5 days followed by 20 mg/kg LPS administration for another 6 h and observed that exogenous administration of Emodin could attenuate myocardial dysfunction in septic WT mice. However, septic Sirt3^-/- mice can not gain benefit on cardiac performance from Emodin infusion. In conclusion, this study presented the protective role of Sirt3 targeting SIMD, which may provide a potential novel approach to maintain normal cardiac performance after sepsis.

Qingchangligan formula attenuates the inflammatory response to protect the liver from acute failure induced by d-galactosamine/lipopolysaccharide in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The Qingchangligan formula, a traditional Chinese medicine comprising five herbs, is useful for treatment of patients with liver failure; however, its protective and regulatory mechanisms remain elusive.

AIM OF THE STUDY

To test the hypothesis that the Qingchangligan formula protects mice against acute liver failure by inhibiting liver inflammation.

MATERIALS AND METHODS

Acute liver failure (ALF) was induced by intraperitoneal injection of D-GalN (700mg/kg) plus LPS (10μg/kg). The Qingchangligan formula was administered to mice in three doses of 50mg/kg (on day 1, day 2, and day 3) prior to D-GalN/LPS injection by intragastric administration. The mice in different groups were sacrificed at 6h after D-GalN/LPS injection, and liver samples and blood were collected for analysis.

RESULTS

Administration of the Qingchangligan formula not only ameliorated liver injury, as evidenced by reduced transaminase levels and well-preserved liver architecture, but also decreased the lethality in ALF mice. Moreover, in the ALF model, pretreatment with the Qingchangligan formula alleviated liver inflammation and decreased hepatocyte apoptosis. Further demonstrating the protective effects of the Qingchangligan formula, we found that pretreatment with the Qingchangligan formula reduced the expression of inflammatory cytokines by decreasing the expression of components of the mitogen-activated protein kinase (MAPK) pathway and promoting autophagy in vitro and in vivo.

CONCLUSIONS

Our findings demonstrated that the Qingchangligan formula exerts a protective effect against the pathophysiology of ALF, especially in regulating liver inflammation, and provide a rationale for using the Qingchangligan formula as a potential therapeutic strategy to ameliorate ALF.

Ethnobotanical investigations on plants used in folk medicine in the regions of Constantine and Mila (North-East of Algeria)

ETHNO-PHARMACOLOGICAL RELEVANCE

Constantine and Mila regions have been investigated in an ethnobotanical study for the first time. A total of 102 medicinal plants have been cited to treat human ailments. Twenty-eight new species of 31 common plants with 151 new therapeutic applications and 12 new cited species including one endemic specie Zygophyllum cornutum Coss were found as compared to other Algerian regions. In addition, to the best of our knowledge, 369 new medicinal uses of 75 known plants, were reported for the first time in the Mediterranean basin.

AIM OF THE STUDY

This study is aimed at contributing to safeguard world cultural heritage and document ethnomedicinal uses of plants in Algeria and the Mediterranean basin; data on the national and global uses in the world were obtained to extract new potential species for further phytochemical and clinical investigations.

MATERIALS AND METHODS

The survey was carried out in two cities in the northeast of Algeria: Constantine and Mila. It was based on semi-structured interviews of 79 local informants. Data were analyzed using quantitative indices, namely, informant consensus factor, fidelity level (FL), use value (UV), and relative frequency citation (RFC), to evaluate the reliability and richness of herbal knowledge in the region.

RESULTS

The interviewed persons used 102 plant species belonging to 90 genera and distributed among 53 families, represented mainly by Lamiaceae, Apiaceae, and Asteraceae (30%, 13%, and 10%, respectively), which were used to treat 14 ailment categories. The category of most frequent ailments (16%) was digestive disorders (diarrhea, constipation, and stomach bloating). The highest RFC was found for Origanum glandulosum Desf. With regard to the fidelity level, a higher FL was found for Tilia cordata Mill. (100%), followed by Artemisia herba alba Asso. with an FL of 95.74% and Punica granatum L. with an FL of 93.09%) to treat gastrointestinal system diseases, and Aloe sp. L. with an FL of 96.67% for skin diseases. The highest UV was found for Origanum glandulosum Desf. (2.280). Moreover, new medicinal uses were recorded for the first time in Algeria and Mediterranean regions.

CONCLUSION

The present study has highlighted the rich herbal knowledge about newfound medicinal plants and their new uses in the Mediterranean region, which could be useful not only in facilitating other studies such as phytochemical and pharmacological investigations and upgrading the sources of biomolecules beneficial to people but also in reopening discussion on pharmacovigilance in herbal medicine as an imperative requirement for local authorities.

Zhikang Capsule ameliorates dextran sodium sulfate-induced colitis by inhibition of inflammation, apoptosis, oxidative stress and MyD88-dependent TLR4 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Zhikang Capsule (ZKC) is a traditional Chinese medicine (TCM) modified from classic formulas Qi-Li-San (an ancient formula dating to Qing Dynasty) and Fu-Jin-Sheng-Ji-San (written into The Golden Mirror of Medicine). ZKC contains 14 kinds of materials and has been widely used for the clinical therapy of inflammatory bowel diseases (IBD) for a long time. However, the therapeutic mechanisms of ZKC are still unclear.

AIM OF THE STUDY

To determine the protective effect of ZKC on dextran sodium sulfate (DSS)-induced colitis and explore the underlying mechanisms.

MATERIALS AND METHODS

C57BL/6 mice were fed with 3% DSS in drinking water for one week to induce experimental colitis. They were randomly assigned to six groups according to the treatment conditions. The histological changes of colon tissues were observed by hematoxylin and eosin (H&E) staining. The serum concentration of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β, and IL-12) and anti-inflammatory mediators (IL-4 and IL-10) was detected by enzyme-linked immune sorbent assays (ELISAs). The production of MPO, SOD, MDA, NO, and caspase-3 was assessed by biochemical assay kits. The expression of iNOS, ICAM-1, and NF-ΚB was evaluated by immunohistochemistry staining. The levels of TLR4, MyD88, and TRAF6 were determined by western blot.

RESULTS

Histologic analysis exhibited that ZKC alleviated the inflammation, loss of goblet cells, and submucosal edema induced by DSS. ZKC significantly suppressed the pro-inflammatory cytokines and promoted the anti-inflammatory mediators. The antioxidation of ZKC was indicated by increased activity of SOD and reduced production of MDA, NO, and iNOS in ZKC-treated mice. Furthermore, ZKC repressed the colonic expression of caspase-3 and the activity of the MyD88-dependent TLR4 signaling pathway.

CONCLUSIONS

This research demonstrated the protective effect of ZKC on DSS-induced colitis. For the first time, we identified four therapeutic mechanisms of ZKC, including effective inhibition of the inflammatory responses, significant alleviation of intestinal epithelium apoptosis, considerable prevention of oxidative stress, and selective down-regulation of the MyD88-dependent TLR4 signaling pathway. With high therapeutic effects and low toxic effects, ZKC exhibits great superiority over western medicines in IBD treatment.

Pharmacological safety evaluation of a traditional herbal medicine "Zereshk-e-Saghir" and assessment of its hepatoprotective effects on carbon tetrachloride induced hepatic damage in rats

ETHNOPHARMACOLOGICAL RELEVANCE

"Zereshk-e-Saghir" (ZES), one of the traditional herbal medicines in old manuscripts of Persian hakims, has been used for the treatment of liver disorders. This current study is aimed to evaluate ZES effects on animal model to investigate its safety and hepatoprotective activity.

MATERIALS AND METHODS

ZES was prepared according to a traditional method by blending aqueous extracts of Berberis vulgaris L., with fine particles of other plants including Rosa damascene Mill, Cichorium intybus L., Cucumis sativus L., Portulaca oleracea L., Rheum palmatum L., and Nardostachys jatamansi DC.. The lethality of ZES was determined in male NMRI mice. Acute organ toxicity of ZES (750 and 1500mg/kg for 15 days, orally) was evaluated by measuring the cell blood count, liver marker enzymes, creatinine, antioxidant status and histopathological examinations in rats. CCl4-induced liver toxicity was used to examine the hepatoprotective effects of the preparation. The rats were pretreated with 250, 500, 750 and 1500mg/kg ZES by gavage for 15 days. At day 16, the rats were intraperitoneally injected 1ml/kg CCl4 in olive oil. Forty-eight hours after CCl4 injection, the animals were sacrificed and their liver samples and blood were collected for determination of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase (ALT, AST, and ALP), histopathological examinations and antioxidant status.

RESULTS

Treatment of the mice with a single dose of ZES up to 2g/kg did not cause mortality. Treatment of the rats with doses of 750 and 1500mg/kg for 15 days showed no significant hematotoxicity and hepatotoxicity. Treatment of the rats with ZES reduced the increased serum levels of ALT, AST, and ALP induced by CCl4 at the doses of 250, 500, and 750mg/kg. This was almost confirmed by histopathological examinations. Pretreatment with ZES also decreased lipid peroxidation and maintained the levels of glutathione and total antioxidant capacity.

CONCLUSIONS

The present in vivo study revealed that the long term usage of ZES was safe for organs in laboratory animals. Meanwhile, prescribing the traditionally-recommended dose of ZES can be probably used against the liver injuries induced by xenobiotics. Further studies in other models of liver injuries are recommended for finding the exact hepatoprotective mechanism of ZES.

Traditional Chinese medicine formulas for the treatment of osteoporosis: Implication for antiosteoporotic drug discovery

ETHNOPHARMACOLOGICAL RELEVANCE

Osteoporosis is a chronic epidemic which can leads to enhanced bone fragility and consequent an increase in fracture risk. Traditional Chinese medicine (TCM) formulas have a long history of use in the prevention and treatment of osteoporosis. Antiosteoporotic TCM formulas have conspicuous advantage over single drugs. Systematic data mining of the existing antiosteoporotic TCM formulas database can certainly help the drug discovery processes and help the identification of safe candidates with synergistic formulations. In this review, the authors summarize the clinical use and animal experiments of TCM formulas and their mechanism of action, and discuss the potential antiosteoporotic activity and the active constituents of commonly used herbs in TCM formulas for the therapy of osteoporosis.

MATERIALS AND METHODS

The literature was searched from Medline, Pubmed, ScienceDirect, Spring Link, Web of Science, CNKI and VIP database from 1989 to 2015, and also collected from Chinese traditional books and Chinese Pharmacopoeia with key words such as osteoporosis, osteoblast, osteoclast, traditional Chinese medicine formulas to identify studies on the antiosteoporotic effects of TCM formulas, herbs and chemical constituents, and also their possible mechanisms.

RESULTS

Thirty-three TCM formulas were commonly used to treat osteoporosis, and showed significant antiosteoporotic effects in human and animal. The herb medicines and their chemical constituents in TCM formulas were summarized, the pharmacological effects and chemical constituents of commonly used herbs in TCM formulas were described in detail. The action mechanisms of TCM formulas and their chemical constituents were described. Finally, the implication for the discovery of antiosteoporotic leads and combinatory ingredients from TCM formulas were prospectively discussed.

CONCLUSIONS

Clinical practice and animal experiments indicate that TCM formulas provide a definite therapeutic effect on osteoporosis. The active constituents in TCM formulas are diverse in chemical structure, and include flavonoids, lignans, saponins and iridoid glycosides. Antiosteoporotic mechanism of TCM formulas and herbs involves multi regulatory pathways, such as Wnt/β-catenin, BMP/Smad, MAPK pathway and RANKL/OPG system. Phytochemicals from TCM formulas and their compositional herb medicines offer great potential for the development of novel antiosteoporotic drugs. The active ingredients in TCM formulas can be developed in combination as potent drugs, which may exhibit better antiosteoporotic effects compared to the individual compound.

Synergistic effects of rhubarb-gardenia herb pair in cholestatic rats at pharmacodynamic and pharmacokinetic levels

ETHNOPHARMACOLOGICAL RELEVANCE

Herb pair serves as the basic building block of a traditional Chinese medicine (TCM) formula. The rhubarb-gardenia herb pair (RGHP), composed of rhubarb and gardenia, has meaningful clinical effects to cure cholestasis diseases. This study was designed to confirm the expected synergistic effects of RGHP at pharmacodynamic and pharmacokinetic levels.

MATERIALS AND METHODS

Thirty male Sprague-Dawley rats were divided into control, model and drug-treated groups. After intragastrically administrated with α-naphthylisothiocyanate (ANIT) to induce cholestasis, rats were treated with rhubarb, gardenia or RGHP. For pharmacodynamic study, biochemical and histopathological tests were performed to assess the hepatoprotective effects. While for pharmacokinetic study, a LC-MS method was developed for determination of five main chemical markers, namely genipin, rhein, aloe emodin, emodin and chrysophanol in rat plasma.

RESULTS

The biochemical and histopathological tests suggested that RGHP exerted enhanced hepatoprotective effects against the ANIT-induced cholestasis compared with single herbs. The pharmacokinetic study indicated RGHP could significantly elevate systemic exposure level and prolong retention time of five markers in comparison with rhubarb or gardenia alone.

CONCLUSIONS

The present study demonstrated the synergistic effects of RGHP in ANIT-induced cholestatic rats at pharmacodynamic and pharmacokinetic levels, and has significant enlightenments for the rational use of the related TCM formulas containing RGHP.

One-pot β-cyclodextrin-assisted extraction of active ingredients from Xue-Zhi-Ning basing its encapsulated ability

Xue-Zhi-Ning (XZN) is a traditional Chinese medicine formula, containing active ingredients with poor solubility in water, which has been demonstrated to be helpful for patients with hyperlipidemia. One-pot β-cyclodextrin (β-CD)-assisted extraction of active ingredients from XZN has been carried out to develop an efficient and eco-friendly extraction process. Five active compounds--rubrofusarin gentiobioside, 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside, emodin, nuciferine and quercetin--were identified by UPLC/DAD/MS and used as indexes to evaluate the process optimized by an orthogonal test. The results showed that addition of β-CD significantly enhanced the extraction ratios of all five components. The enhancement of extraction ratios was positively correlated with the apparent formation constants between β-CD and the compounds. The study also showed that the stabilities and dissolution rates of the active ingredients were improved in the presence of β-CD. This one-pot β-cyclodextrin-assisted extraction has the potential to be applied in pharmaceutical preparations directly.

Hepatotoxic assessment of Polygoni Multiflori Radix extract and toxicokinetic study of stilbene glucoside and anthraquinones in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Polygoni Multiflori Radix (PMR) has been traditionally used as a tonic and an anti-aging remedy for centuries; however, hepatic lesions linked to PMR have been frequently reported.

AIM OF THE STUDY

This work attempted to investigate the hepatotoxic potential of PMR extract and the toxicokinetics of stilbene glucoside and anthraquinones in PMR extract following repeated administration.

MATERIALS AND METHODS

Histopathological and biochemical tests were performed to assess the hepatotoxicity of PMR extract. A rapid and sensitive liquid chromatography-mass spectrometry (LC-MS) assay was developed for toxicokinetic analysis of the main constituents of PMR extract, including 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG), emodin-8-O-β-D-glucoside and emodin.

RESULTS

The histopathological and biochemical tests indicated that repeated administration of high-dose PMR extract (20 g/kg) for 3 weeks could cause hepatic lesions, while the low-dose treatment (1 g/kg) was safe. Necrosis and steatosis of hepatic cells, inflammatory cell infiltration and mild fibrosis were the main toxicity symptoms caused by high-dose PMR extract in rat liver. The aspartate aminotransferase (AST) levels increased by approximately 17%, from 110.80±0.84 to 129.75±10.83 IU/L, in the high-dose group compared with the control group. The proposed LC-MS method was proven to be suitable for the simultaneous quantification of these three constituents by affording desirable linearity (r(2)>0.998) and satisfactory precision (error less than 10%). The toxicokinetic study showed that emodin could not be detected in the low-dose group, but the AUC and Cmax of emodin displayed a gradual increase with repeated treatments in the high-dose group. The toxicokinetics of TSG in the low- and high-dose groups exhibited similar trends after repeated administration.

CONCLUSIONS

Consideration needs to be given to the rational application of PMR in the clinic to balance its benefits and risks. The increased emodin exposure in vivo provided a putative explanation for the observed hepatic lesions induced by PMR extract, although further studies to confirm the potentially causal link between emodin exposure and hepatic lesions are still necessary.

Protection of vascular endothelial cells from high glucose-induced cytotoxicity by emodin

Induction of endothelial cytotoxicity by hyperglycemia in diabetes has been widely accepted. Emodin is a natural anthraquinone in rhubarb used for treatment of diabetes, but its mechanism of action is not fully understood. This study aimed to examine the potential beneficial effects of emodin on endothelial cytotoxicity caused by high glucose milieu. Culture of human umbilical vein endothelial cells (HUVECs) with high concentrations of glucose resulted in damage to the cells, leading to decreased formazan products by 14-27%, reduced DNA contents by 12-19%, and increased hypodiploid apoptosis by 40-109%. These adverse effects of high glucose could be prevented to a large extent by co-culture with 3 μM of emodin which per se did not affect HUVECs viability. In addition, CCL5 expression of HUVECs cultured in high glucose medium was significantly elevated at both mRNA and protein levels, an effect abolished after treatment with emodin. Moreover, the enhanced adhesion of monocytes to HUVECs (2.1-2.2 fold over control) and elevated chemotaxis activities (2.3-2.4 fold over control) in HUVECs cultured in high glucose medium were completely reversed by emodin. Emodin also suppressed activation of p38 MAPK and ERK1/2 due to high glucose. Our data demonstrated that endothelial cytotoxicity occurred clearly when HUVECs were exposed to high glucose milieu and emodin was able to alleviate the impairments. The protective effects of emodin might be related to the inhibition of CCL5 expression and subsequent cell stress/inflammatory events possibly mediated by activation of MAPK signaling pathways.

Investigation on the spectrum-effect relationships of Da-Huang-Fu-Zi-Tang in rats by UHPLC-ESI-Q-TOF-MS method

ETHNOPHARMACOLOGICAL RELEVANCE

Da-Huang-Fu-Zi-Tang (DHFZT) is a crucial TCM formula commonly used for the treatment of acute pancreatitis in Chinese clinical application. Our previous work found that DHFZT could act against pancreatic injury in rats with severe acute pancreatitis (SAP). The goal of this paper was to study the underlying correlations between the chemical spectra and the protective effect of DHFZT on pancreatic acinar cell to reveal the real bioactive compounds in DHFZT.

MATERIALS AND METHODS

The fingerprint chromatograms of rat serum after oral administration of DHFZT were established by UHPLC-ESI-Q-TOF-MS technique. At the same time, the model of anti-acute pancreatitis on cells was established by adding 10(-7) mol/L cerulein to AR42J cell line, and the protective effects of the serum on pancreatic acinar cell from injury was evaluated by detecting the efficacy of amylase. Then, the spectrum-effect relationships between UHPLC fingerprints and anti-acute pancreatitis activities were evaluated using canonical correlation analysis (CCA) statistical method. The chromatogram separation was performed on a C18 reversed phase UHPLC column (2.1 mm × 100 mm, 3.5 μm, Agilent), the column temperature was set at 35°C. The mobile phase consisted of 0.1% formic acid and acetonitrile with gradient elution. The serum samples were analyzed both in negative and positive ion mode. The mother and productive ions were scanned within the mass range of m/z 100-1200 and 50-1200, respectively. A thorough analysis of a great deal of information of the constituents in the rat serum was undertaken. The structure identification of the detected compounds was achieved by using high resolution MS values as well as the MS/MS fragments.

RESULTS

Eighteen peaks in rat serum after oral administration of DHFZT were detected within only 30 min recorded chromatograms. The structure of the 18 compounds were then given out, of which 10 were the original form of compounds absorbed from DHFZT, 8 were the metabolites of the compounds existed in rat serum. According to the CCA results, talatisamine, rhein glucoside, rhein isomer methylation, hypaconine, hydroxyl-chrysophanol, emodin glucuronide conjugation, and chrysophanol glucuronide conjugation were finally found to be the main anti-acute pancreatitis components in DHFZT.

CONCLUSIONS

The model presented in this paper successfully discovered the spectrum-effect relationships of DHFZT, which showed a representative way to discover the primary active ingredients from the complicated herbal drugs.

Aloe-emodin from rhubarb (Rheum rhabarbarum) inhibits lipopolysaccharide-induced inflammatory responses in RAW264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Rheum rhabarbarum (rhubarb) has long been used for the treatment of inflammation in China and other Asian countries. However, the mechanism underlying the anti-inflammatory activity of this medicinal plant is not fully understood. The present study was designed to investigate the anti-inflammatory effects of anthraquinones, the major constituents in rhubarb, and the molecular mechanism involved in their anti-inflammatory effects.

MATERIALS AND METHODS

RAW264.7 cells were stimulated by lipopolysaccharide (LPS) in the presence or absence of the compounds examined. The proliferation of RAW264.7 cells was assayed by the Alamar-Blue method. The quantity of nitric oxide (NO) was determined by Griess assay. The expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR. Inducible nitric oxide synthase (iNOS), inhibitor of nuclear factor κBα (IκBα), extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), c-Jun NH2-terminal kinase (JNK), and Akt/phosphoinositide 3-kinase (PI3K) protein expression levels were determined by Western blotting.

RESULTS

Aloe-emodin markedly suppressed the production of NO, interleukin-6 (IL-6), and interleukin-1β (IL-1β) in LPS-stimulated RAW264.7 cells with no apparent cytotoxicity. The mRNA expression levels of iNOS, IL-6, and IL-1β genes were also significantly inhibited by aloe-emodin. Western blot analysis showed that aloe-emodin suppressed LPS-induced iNOS protein expression, IκBα degradation, and the phosphorylation of ERK, p38, JNK, and Akt.

CONCLUSIONS

These results demonstrate that aloe-emodin is the bioactive component of rhubarb that confers an anti-inflammatory effect through a likely mechanism involving a decrease in pro-inflammatory cytokine production in LPS-induced RAW264.7 macrophages via inhibition of NF-κB, MAPK, and PI3K pathways.

Interaction of five anthraquinones from rhubarb with human organic anion transporter 1 (SLC22A6) and 3 (SLC22A8) and drug-drug interaction in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Rhubarb is a well-known traditional Chinese medicine and has been used in China for thousands of years. Anthraquinone derivatives including rhein, emodin, aloe-emodin, chrysophanol and physcion are the important components in rhubarb.

MATERIALS AND METHODS

Here we studied the interaction of five anthraquinone derivatives with human renal organic anion transporter 1 (hOAT1) and hOAT3 stably expressed in cells, and interaction of rhein or rhubarb extract (RE) with furosemide (FS, substrate of OATs) in rats.

RESULTS

Uptake of 6-carboxyl fluorescein via hOAT1 and fluorescein via hOAT3 were markedly inhibited by rhein, emodin and aloe-emodin, and slightly inhibited by chrysophanol and physcion. The estimated IC₅₀ values for rhein, emodin, aloe-emodin and probenecid (typical inhibitor of hOAT1 and hOAT3) were 0.23, 0.61, 2.29 and 18.34 μM for hOAT1, and 0.08, 1.22, 5.37 and 5.83 μM for hOAT3, respectively. Furthermore, the data from the cellular accumulation assay indicated that these five compounds were not substrates of hOAT1 or hOAT3. Pharmacokinetic interaction between rhein and FS in rats showed that area under the curve (AUC₀-t) for FS was increased by 65% when coadministrated with rhein. RE was also used to interact with FS in rats and results showed that AUC₀-t of FS was increased by 32% and by 52% when coadministrated with single-dose or multiple-dose of RE, respectively.

CONCLUSIONS

These findings suggested that five anthraquinones inhibited hOAT1 and hOAT3, but these compounds were not transported by hOAT1 or hOAT3. Furthermore, rhein or RE, might cause drug-drug interaction when coadministrated with substrates of OAT1 or OAT3 in vivo.

Purgative components in rhubarbs: adrenergic receptor inhibitors linked with glucose carriers

Rhubarbs and their extractives have been used as cathartic for many years. There have been numerous breakthroughs in the pharmacological research of the drug. However, as the key point of the mechanism, the targets of the effective components still remain unclear. In this paper, with an in vitro system of isolated intestine, we found that both the rhubarb extractives and the anthraquinone derivatives can antagonize the adrenaline effectively. Furthermore, computer based docking provided the binding model of the anthraquinone derivatives and adrenergic receptor. Then, based on the results of the small intestinal promotion and purgative effect experiments in vivo, we built an "inhibitor-carrier" hypothesis to elucidate the mechanism of rhubarb. This work provided key massages for the pharmacological research of rhubarb, such a common and active medicinal plant, and might be of help for the development of new purgative drugs.