Comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats and microarray analysis of drug-metabolizing genes

Rhein induces bone regeneration via alleviating inflammation in murine periodontitis model

OBJECTIVE

To evaluate the effect of rhein on eliminating the inflammation and promoting bone regeneration of periodontitis after local administration.

MATERIALS AND METHODS

In vivo, periodontitis model was established in murine mandibular first molar by using ligature for 7 days, followed by ligature removal and local administration of rhein/vehicle for 7 consecutive days. In vitro, periodontal ligament fibroblasts were treated by LPS, along with the applications of rhein/vehicle. Histology and molecular biology approaches were applied for analysis.

RESULTS

In vivo, rhein alleviated periodontitis inflammation through downregulating the inflammatory index and promoted the osteogenic potential of PDL fibroblasts in a dosage-dependent manner. The result of micro-CT validated this phenomenon. In vitro, rhein administration inhibited the phosphorylation and nuclear translocation of P65, along with the arose runx2 level of PDL fibroblasts with the stimulus of LPS in mimicking periodontitis.

CONCLUSION

Rhein played its inhibitory role on inflammation via curbing the activation of P65 but uprising the activities of Runx2 in PDL fibroblasts in periodontitis microenvironment. These data suggested that rhein could be an effective and potential clinical choice for the treatment of periodontitis.

Probiotic potential of Lacticaseibacillus rhamnosus VHProbi M15 on sucralfate-induced constipation in mice

The main objective of this study was to investigate the potential probiotic properties of Lacticaseibacillus rhamnosus VHProbi®M15 (M15). This study examined the effects of M15 on sucralfate-induced constipation in a mouse model. The BALB/c mice were randomly divided into four groups: the normal group (NOR) was without any treatment, while the constipation (CON), phenolphthalein (PHE), and probiotic (PRO) treatment groups were fed with sucralfate until the appearance of constipation symptoms. Afterward, the NOR and CON groups were given 1 ml saline orally every day until the end of the experiment; the PHE and PRO groups were given phenolphthalein or M15 suspension in 1 ml orally, respectively. Compared with the CON group, the fecal water content and intestinal peristalsis improved in the PRO group. Here, intake of M15 effectively attenuated sucralfate-induced constipation, recuperated colonic epithelial integrity, and increased serum levels of gastrointestinal excitatory neurotransmitters (motilin, gastrin, substance P). Analysis of the intestinal microbiota of mice by 16S rRNA metagenomic revealed an increase in the relative abundance of Bacteroides and a decrease in Sclerotinia, Verrucosa and Proteus in the PRO group. Compared with the CON group, the constipation-induced intestinal microecological changes were partially recovered in the PHE and PRO groups. These results demonstrate that M15 enhanced gastrointestinal transit and alleviated in mice with sucralfate-induced constipation.

Sanhuang Xiexin Decoction Ameliorates TNBC By Modulating JAK2-STAT3 and Lipid Metabolism

OBJECTIVE

To investigate the therapeutic effect of Sanhuang Xiexin Decoction (SXD) on triple-negative breast cancer (TNBC) in mice and its underlying mechanism.

METHODS

The high-performance liquid chromatography (HPLC) was used to quantitate and qualify SXD. A total of 15 female BALB/c mice were inoculated subcutaneously on the right hypogastrium with 3×105 of 4T1-Luc cells to establish TNBC mouse model. All mice were divided randomly into 3 groups, including phosphate buffered solution (PBS), SXD and doxorubicin (DOX) groups (positive drug). Additionally, tumor growth, pathological changes, serum lipid profiles, expression of Janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) signaling pathway and its key targets including inflammatory factors, cell cycle and epithelial-mesenchymal transition (EMT) markers were investigated. Besides, the biosafety of SXD was also evaluated in mice.

RESULTS

Rhein, coptisine, berberine hydrochloride and baicalin were all found in SXD, and the concentrations of these 4 components were 0.57, 2.61, 2.93, and 46.04 mg/g, respectively. The mouse experiment showed that SXD could notably suppress the development of tumors and reduce the density of tumor cells (P<0.01). The serum lipid analysis and Oil-Red-O staining both showed the differences, SXD group exhibited higher serum adiponectin and HDL-C levels with lower TC and LDL-C levels compared to the PBS and DOX groups (P<0.05 or P<0.01), respectively. SXD also decreased the levels of phospho-JAK2 (p-JAK2), phospho-STAT3 (p-STAT3) expressions and its downstream factors, including mostly inflammatory cytokine, EMT markers, S phase of tumor cells and vascular endothelial growth factor (VEGF) expression (P<0.05 or P<0.01), respectively. The biosafety assessment of SXD revealed low levels of toxicity in mice.

CONCLUSION

SXD could inhibit TNBC by suppressing JAK2-STAT3 phosphorylation which may be associated with modulation of lipid metabolism.

RP-HPLC METHOD DEVELOPMENT, VALIDATION, AND ITS PHARMACOKINETIC APPLICABILITY IN PRECLINICAL EVALUATION OF RHEIN TREATED WITH NOVEL DIACEREIN EUTECTICS

The current study represents the bio-analytical method for the estimation of Rhein (Rh, an active metabolite of Diacerein (DIA)) in rats treated with novel DIA eutectics to investigate the pharmacokinetics of DIA. A simple protein precipitation technique was used to extract Rh and internal standard (IS), p-aminobenzoic acid, and injected into a Phenomenex Gemini C18 column. The separation was achieved by gradient elution comprising of ammonium acetate (10 mM; pH 3.0) and acetonitrile in 18 min of run time at a flow rate of 0.8 mL/min with the retention time of 11.8 min (Rh) and 5.9 min (IS). The results revealed that the proposed method was linear over the range of 200-20,000 ng/mL (r² > 0.9988) of Rh and proved to be precise and accurate. The method was fully validated as per the USFDA guideline and the pharmacokinetic study in rats was performed for Rh following oral administration of the pure DIA and newly developed eutectics. Therefore, the present method could be used to estimate DIA to illustrate the comparative pharmacokinetic analysis. This can be also applied to its related multi-component formulations for future study.

The Metabolism and Pharmacokinetics of Rhein and Aurantio-Obtusin

BACKGROUND

Anthraquinones, rhein and aurantio-obtusin were isolated from the herb Duhaldea nervosa for the first time by our group, which were also found in plants that belong to the plant family Compositae. Anthraquinone compounds have a range of pharmacological activities such as anti-inflammatory, anti-cancer, antioxidation, anti-diabetes, etc. and can be used as a laxative, for liver protection, treatment of chronic renal failure, etc. However, in recent years, anthraquinones have been reported to be cytotoxic to the liver and kidneys. Therefore, it is very important to study the pharmacokinetics and metabolism of rhein and aurantio-obtusin, which are common ingredients in many traditional Chinese medicines (TCM). According to our research, the pharmacokinetics and metabolism of rhein and aurantio-obtusin are comprehensively summarized in the paper for the first time.

OBJECTIVE

The study provides comprehensive information on pharmacokinetics and metabolism of rhein and aurantio- obtusin in different Species; meanwhile, the aim of this review is also to provide a reference for a reasonable application of TCM enriched with these two ingredients.

METHODS

The metabolism and pharmacokinetics of rhein and aurantio-obtusin were searched by the Web of Science, PubMed, Google scholar and some Chinese literature databases.

RESULTS

Rhein and aurantio-obtusin exist mainly in the form of metabolites in the body. Rhein and aurantio-obtusin and its metabolites might be responsible for pharmacological effects in the body. Therefore, the significance of studying the in vivo metabolites of rhein and aurantio-obtusin is not only essential to clarify their pharmacological mechanism, but also to find new active compound ingredients. The metabolism of rhein is different in different species, so the toxicity effects of rhein may also be different after oral administration in different species; however, the metabolic profiles of aurantio-obtusin in the liver microsomes of different species are similar.

CONCLUSION

This paper not only provides detail regarding the pharmacokinetics of rhein and aurantio-obtusin, but it is anticipated that it will also facilitate further study on the metabolism of rhein and aurantio-obtusin.

Electroacupuncture via chronically implanted electrodes improves gastrointestinal motility by balancing sympathovagal activities in a rat model of constipation

Electroacupuncture (EA) has been reported for treating constipation in clinical studies. However, little is known of the possible mechanisms involved in the prokinetic effect of EA. The aim of this study was to investigate the effects and underlying autonomic mechanisms of EA via chronically implanted electrodes for constipation in rat induced by Loperamide (Lop). Lop was given to regular rats to induce constipation. EA was performed via a pair of electrodes chronically implanted at bilateral acupoint ST-36. Feces characteristics, gastric emptying, small intestinal transit, distal colon transit time (dCTT), and whole gut transit time (WGTT) were measured in various sessions with EA or sham EA in rats with constipation induced by Lop. Heart rate variability (HRV) derived from the electrocardiogram was analyzed to evaluate autonomic functions. The number of fecal pellets was reduced by 27% with Lop (P < 0.01) and normalized by 7-day EA. Similar results were also observed in pellet weight. In normal rats compared with sham EA, EA shortened dCTT by 74% (P < 0.05 vs. sham EA), increased small intestinal transit by 28% (P < 0.01) and gastric emptying by 27% (P < 0.05), and accelerated whole gut transit by 14% (P < 0.05). In Lop-treated rats, the dCTT and WGTT were prolonged by Lop and normalized by EA. Lop significantly decreased vagal activity and increased sympathetic nerve activity; however, EA reversed these effects. EA at ST-36 via chronically implanted electrodes improves Lop-induced constipation by enhancing GI motility via the autonomic mechanisms. NEW & NOTEWORTHY The findings of the present study suggest that the proposed electroacupuncture (EA) may have great therapeutic potential for treating patients with opioid-induced constipation. It was demonstrated that EA at ST-36 improved transit of every organ along the gut mediated via the autonomic mechanisms in normal rats and rats with Lop-induced constipation. It is advised to administrate EA daily instead of two or three times weekly as reported in most of the clinical studies.

Probiotics decrease depressive behaviors induced by constipation via activating the AKT signaling pathway

Chronic constipation is often accompanied by emotional disorders such as depression and anxiety. The aim of this study was to determine whether administration of a multispecies probiotic can decrease depressive behaviors through the gut-brain axis and identify any underlying mechanisms. A mouse model of constipation induced by loperamide (5 mg·kg^-1,i.p.) was used. For that purpose, 36 ICR male mice were divided into three groups: control, constipation and probiotic groups. The probiotic group received treatment with a probiotic once per day for 14 days via a gavage. All other groups were given an equal volume of normal saline. The fecal parameters and intestinal transit ratio were recorded. The forced swimming test and tail suspension test were used to detect changes in depressive behaviors. Total superoxide dismutase (T-SOD) activity and malondialdehyde (MDA) levels were measured by assay kits. We also detected neuronal survival, as well as phosphorylated Ser/Thr protein kinase (p-AKT), Bcl-2, Bcl-2 associated X protein (Bax) and cleaved caspase-3 levels in the hippocampus. The results showed that administration of a probiotic could ameliorate depressive behaviors and relieve neuronal cell injury in the hippocampal CA3 regions. Moreover, probiotic treatment decreased MDA levels and increased SOD activity. Furthermore, probiotic administration increased p-AKT and Bcl-2 levels in the hippocampus of the constipated mice, while decreasing the concentrations of Bax and cleaved caspase-3, so as to inhibit the neural apoptosis. In the present study, we confirm that probiotics can alleviate depression induced by constipation through protecting neuronal health via activation of the AKT signaling pathway.

[Current Status of Translational Research on Constipation]

Constipation is one of the most common gastrointestinal disorders with a prevalence up to 16.5% in the general population. It is frequently multifactorial and the pathophysiologic mechanism of constipation is not fully understood. Many preclinical studies of constipation have used animal models. Translational research using these animal models is essential to the investigation of neurogenic and myogenic mechanisms of colon, and to the estimation of the clinical efficacy of new drugs. In this review, we discuss some of the current translational research projects on constipation using animal models.