Total glucosides of paeony attenuate renal tubulointerstitial injury in STZ-induced diabetic rats: role of Toll-like receptor 2

Paeoniflorin: a review of its pharmacology, pharmacokinetics and toxicity in diabetes

The escalating global prevalence of diabetes underscores the urgency of addressing its treatment and associated complications. Paeoniflorin, a monoterpenoid glycoside compound, has garnered substantial attention in recent years owing to its potential therapeutic efficacy in diabetes management. Thus, this study aims to systematically overview the pharmacological effects, pharmacokinetics and toxicity of paeoniflorin in diabetes. Plenty of evidences have verified that paeoniflorin improves diabetes and its complication through reducing blood sugar, enhancing insulin sensitivity, regulating gut microbiota and autophagy, restoration of mitochondrial function, regulation of lipid metabolism, anti-inflammation, anti-oxidative stress, inhibition of apoptosis, immune regulation and so on. Paeoniflorin possess the characteristics of rapid absorption, wide distribution, rapid metabolism and renal excretion. Meanwhile, toxicity studies have suggested that paeoniflorin has low acute toxicity, minimal subacute and chronic toxicity, and no genotoxic or mutational toxic effects. In conclusion, this paper systematically elucidates the potential therapeutic application and safety profile of paeoniflorin in diabetes management.

Therapeutic effect of total glucosides of paeony on IgA vasculitis nephritis: progress and prospects

IgA vasculitis nephritis (IgAVN), a type of immune system disease characterized by the deposition of IgA in the mesangial area of the glomerulus, is most common in children. Corticosteroids and immunosuppressants agents are commonly prescribed for the clinical management of IgAVN; however, these therapies are associated with numerous adverse reactions. This necessitates the discovery of alternative, potential therapeutic agents that can offer a safer treatment option. Natural plants contain abundant total glucosides of paeony (TGP), which represent one of the most prevalent secondary metabolites found within these organisms. TGP has been proven to be a safe and desirable natural medicine, with the most central ingredient being polyphenolic. TGP, a naturally occurring and cost-effective compound, exerts its therapeutic influence on IgAVN via diverse pathways and targets, with minimal side effects. Its substantial clinical potential underscores the importance of delving deeper into its pharmacological mechanisms, which hold great promise for novel drug development. This review examines the multifaceted therapeutic mechanisms of TGP in IgAVN encompassing modulation of Wnt/β-catenin pathways and programmed cell death pathways, antioxidant and anti-inflammatory effects, and enhancement of vascular repair. Additionally, we provide an overview of recent advancements in enhancing the bioavailability of TGP and highlight crucial considerations that may inform future research endeavors.

Visualizing temporal dynamics and research trends of macrophage-related diabetes studies between 2000 and 2022: a bibliometric analysis

Background

Macrophages are considered an essential source of inflammatory cytokines, which play a pivotal role in the development of diabetes and its sequent complications. Therefore, a better understanding of the intersection between the development of diabetes and macrophage is of massive importance.

Objectives

In this study, we performed an informative bibliometric analysis to enlighten relevant research directions, provide valuable metrics for financing decisions, and help academics to gain a quick understanding of the current macrophage-related diabetes studies knowledge domain.

Methods

The Web of Science Core Collection database was used for literature retrieval and dataset export. Bibliometrix R-package was performed to conduct raw data screening, calculating, and visualizing.

Results

Between 2000 and 2022, the annual publication and citation trends steadily increased. Wu Yonggui was the scholar with the most published papers in this field. The institute with the highest number of published papers was the University of Michigan. The most robust academic collaboration was observed between China and the United States of America. Diabetologia was the journal that published the most relevant publications. The author's keywords with the highest occurrences were "inflammation", "diabetic nephropathy", and "obesity". In addition, "Macrophage polarization" was the current motor topic with potential research prospects.

Conclusions

These comprehensive and visualized bibliometric results summarized the significant findings in macrophage-related diabetes studies over the past 20 years. It would enlighten subsequent studies from a macro viewpoint and is also expected to strengthen investment policies in future macrophage-related diabetes studies.

Total Glucosides of Paeony Inhibited Autophagy and Improved Acute Kidney Injury Induced by Ischemia-Reperfusion via the lncRNA TUG1/miR-29a/PTEN Axis

Objective

Total glucosides of paeony (TGP) has been proven to affect anti-inflammatory, immunomodulatory and hypoxia tolerance. This study investigates the effect of TGP on autophagy in acute kidney injury (AKI) induced by ischemia-reperfusion (I/R).

Methods

Rat model of AKI induced by I/R was established. Rats were administered with TGP at different doses by oral gavage. The contents of BUN, creatinine, NGAL, Kim-1 and IL-18 were detected. The levels of inflammatory factors (TNF-α, IL-1β and IL-6) and autophagy were measured. The expressions of lncRNA TUG1, miR-29a and PTEN were detected and their binding relationships were verified. I/R rat model with overexpressed TUG1 was established to explore the effect of TGP on kidney injury and autophagy. The hypoxia/reoxygenation (HR) model of HK-2 cells and the HR model of HK-2 cells overexpressing TUG1 and low-expressing PTEN were established.

Results

TGP decreased the contents of BUN, creatinine, NGAL, Kim-1 and IL-18, and reduced the levels of inflammatory factors. LncRNA TUG1 and PTEN were downregulated, and miR-29a was upregulated in kidney tissues. The binding relationships between lncRNA TUG1 and miR-29a, and miR-29a and PTEN were confirmed. TGP suppressed PTEN expression via the lncRNA TUG1/miR-29a axis. Overexpressing lncRNA TUG1 attenuated the protective effect of TGP on AKI and autophagy in HK-2 cells. TGP improved cell viability and inhibited the autophagy in HR model of HK-2 cells via lncRNA TUG1/miR-29a/PTEN axis.

Conclusion

TGP inhibited autophagy and improved AKI induced by I/R via the lncRNA TUG1/miR-29a/PTEN axis.

Umbelliferone ameliorates renal function in diabetic nephropathy rats through regulating inflammation and TLR/NF-κB pathway

Diabetic nephropathy (DN) is a leading cause of renal failure, contributing to severe morbidity and mortality in diabetic patients. Umbelliferae (Umb) has been well characterized to exert protective effects in diabetes. However, the action and mechanism of Umb in DN remains unclear. In this work, we studied the effect of Umb in a streptozotocin (STZ)-induced DN rat model and explore its underlying mechanism. DN rats were treated withUmb (20, 40 mg·kg^-1) orirbesartan (15 mg·kg^-1) for 4 weeks. Levels of serum glucose, insulin, blood uric acid, creatinine, triglycerides (TG) and total cholesterol (TC) were measured bycommercial assay kits, respectively. Histopathological changes andinflammatory cytokine levels including IL-6, IL-1β and TNF-α in the kidney were also evaluated. Alterations in the expression of podocin, CD2AP and TLR/NF-κB were assessed by western blotting. Our results showed that Umb reduced renal injury in DN rat model, as evidenced by the decrease in blood glucose, 24 h urinary protein, serum creatinine, and blood uric acid. Umb also significantly ameliorated the renal histopathological alteration, and down-regulated the expression of epithelial-to-mesenchymal transition-related molecular markers podocin and CD2AP. Moreover, Umb inhibited TLR2, TLR4, MyD88 expressions, NF-κB activation and considerably reduced levels of other downstream inflammatory molecules (TNF-α, IL-6, IL-1β). These findings indicated that Umb improved renal function through regulating inflammation and TLR/NF-κB pathway, suggesting the potential efficacy of Umb in DN treatment.

Anti-inflammatory and immunoregulatory effects of paeoniflorin and total glucosides of paeony

As a Traditional Chinese Medicine, Paeonia lactiflora Pallas has been used to treat pain, inflammation and immune disorders for more than 1000 years in China. Total glycoside of paeony (TGP) is extracted from the dried root of Paeonia lactiflora Pallas. Paeoniflorin (Pae) is the major active component of TGP. Our research group has done a lot of work in the pharmacological mechanisms of Pae and found that Pae possessed extensive anti-inflammatory and immune regulatory effects. Pae could inhibit inflammation in the animal models of autoimmune diseases, such as experimental arthritis, psoriatic mice and experimental autoimmune encephalomyelitis, and so on. Pae modulates the functions and activation of immune cells, decreases inflammatory medium production, and restores abnormal signal pathway. Pae could balance the subsets of immune cells through inhibiting abnormal activated cell subsets and restoring regulatory cell subsets. Pae could regulate signaling pathways (GPCR pathway, MAPKs /NF-κB patway, PI3K /Akt /mTOR pathway, JAK2 /STAT3 pathway, TGFβ /Smads, and etc.). TGP is composed of Pae, hydroxyl-paeoniflorin, paeonin, albiflorin and benzoylpaeoniflorin etc. Pae accounts for more than 40% of TGP. Like Pae, TGP has anti-inflammatory and immune regulatory effects. TGP has been widely used to treat autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis, allergic contact dermatitis, and etc. in China. Furthermore, TGP has some superior features with immune regulation, gentle effect, many indications and few adverse drug reactions. These findings suggest that TGP may be a promising anti-inflammatory and immune drug with soft regulation and has more superiority in the treatment of AIDs. Currently, TGP is used for the treatment of RA, SLE and other AIDs in more than 1000 hospitals in China, which obtained great social and economic benefits.

Tlr1-13, Nod1/2 and antimicrobial gene expression in the epididymis and testis of rats with alloxan-induced diabetes

Pattern recognition receptors (PRRs) such as toll-like receptors (TLRs) and nuclear oligomerization domain (NOD) receptors along with antimicrobial proteins and peptides (AMPs) are crucial for innate immunity. The pathology of insulin-dependent diabetes mellitus is associated with the disrupted expression of TLRs, NODs and AMPs in the kidney, lungs and other organs. However, such a relation in the male reproductive tract is not yet investigated. In this study, we analysed the expression pattern of Tlr1-13, Nod1/2 receptors and AMPs (β-defensins and defensin-like proteins of the Sperm-Associated Antigen 11 (Spag11) family) in the male reproductive tissues (caput, cauda and testis) obtained from diabetic or insulin-treated diabetic or untreated control rats. Alterations in the expression pattern of Tlr1-13, Nod 1/ 2, Defb1, 2, 21, 24, 27, 30 and Spag11a/ c/ t were observed under diabetic conditions. Administration of insulin to diabetic rats could modulate the expression pattern of only some these genes. Results of our study indicate perturbed gene expression profile of Tlrs, Nod1/2, Defbs and Spag11 isoforms in the epididymis and testis of diabetic rats, and this could be one of the important reasons for the increased risk of infections in the male genital tract.

The Regulatory Effects of Paeoniflorin and Its Derivative Paeoniflorin-6'-O-Benzene Sulfonate CP-25 on Inflammation and Immune Diseases

The plant extract "total glucosides of peony" (TGP) constitutes a mixture of glycosides that is isolated from the roots of the well-known traditional Chinese herb Paeonia lactiflora Pall. Paeoniflorin (Pae) is the most abundant component and the main biologically active ingredient of TGP. Pharmacologically, Pae exhibits powerful anti-inflammatory and immune regulatory effects in some animal models of autoimmune diseases including Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE). Recently, we modified Pae with an addition of benzene sulfonate to achieve better bioavailability and higher anti-inflammatory immune regulatory effects. This review summarizes the pharmacological activities of Pae and the novel anti-inflammatory and immunomodulatory agent Paeoniflorin-6'-O-benzenesulfonate (CP-25) in various chronic inflammatory and autoimmune disorders. The regulatory effects of Pae and CP-25 make them promising agents for other related diseases, which require extensive investigation in the future.

Duhuo Jisheng Decoction inhibits SDF-1-induced inflammation and matrix degradation in human degenerative nucleus pulposus cells in vitro through the CXCR4/NF-κB pathway

Lower back pain (LBP) is the most common disease in orthopedic clinics world-wide. A classic Fangji of traditional Chinese medicine, Duhuo Jisheng Decoction (DHJSD), has been proven clinically effective for LBP but its therapeutic mechanisms remain unclear. We hypothesized that DHJSD might relieve LBP through inhibiting the exaggerated proinflammatory cytokines and extracellular matrix (ECM) degradation. Thus, we studied the effects of DHJSD on stromal cell-derived factor-1 (SDF-1)-induced inflammation and ECM degradation in human nucleus pulposus cells (hNPCs). The primary hNPCs were isolated from either degenerated human intervertebral disc (HID) of LBP patients or normal HID of lumbar vertebral fracture patients, and cultured in vitro. The cells were treated with SDF-1 (10 ng/mL) and subsequently with different concentrations (100-500 μg/mL) of DHJSD for 24 h, respectively. We found that application of DHJSD significantly antagonized the SDF-1-induced production of proinflammatory cytokines and reduction of aggrecan and type II collagen in the hNPCs. DHJSD also markedly reduced the SDF-1-induced increase of CXCR4 and p-p65 and inhibited the nuclear translocation of p65 in the hNPCs. DHJSD, CXCR4-siRNA, and NF-κB inhibitor (BAY11-7082) caused the same inhibition of exaggerated proinflammatory cytokines in the SDF-1-treated hNPCs. These results provided compelling evidence that DHJSD may inhibit the generation of proinflammatory mediators and ECM degradation of HID through an orchestrated targeting at multiple molecules in the SDF-1/CXCR4/NF-κB pathway, thus offered novel mechanistic insights into the clinical effectiveness of DHJSD on LBP.

Tripterygium wilfordii mitigates hyperglycemia-induced upregulated Wnt/β-catenin expression and kidney injury in diabetic rats

Aberrant activation of the Wnt/β-catenin pathway contributes to the development of diabetic nephropathy (DN); however, treatment with Tripterygium wilfordii (TW) may be beneficial for patients with DN. The aim of the present study was to evaluate the effect of TW on Wnt/β-catenin expression in the kidneys of diabetic rats. Male Sprague-Dawley rats were randomly injected with vehicle (control) or streptozotocin to induce diabetes. Diabetic rats were then randomly treated with vehicle (sodium carboxymethyl cellulose; SCC), TW combined with SCC (8 or 16 mg/kg) or irbesartan (50 mg/kg) daily for 8 weeks. Metabolic parameter levels and renal pathological changes were examined. mRNA and protein expression of Wnt-1, glycogen synthase kinase (GSK)-3β, β-catenin, nuclear factor (NF)-κB and transforming growth factor (TGF)-β1 in the kidneys of rats from all groups were measured. Compared with the DM group, metabolic parameters and morphological parameters, apart from blood glucose levels, were significantly improved in TW-treated rats (all P<0.01). Furthermore, levels of Wnt-1, β-catenin, NF-κB-p65 and TGF-β1 mRNA and protein were significantly reduced in the kidneys of TW-treated rats compared with DM rats, whereas levels of GSK-3β mRNA and protein did not differ significantly between any of the groups; however, the expression of P-GSK-3β protein was significantly decreased in the kidneys of TW-treated rats compared with the DM group. The protective effects of TW tended to be dose-dependent and were an improvement compared with irbesartan treatment in diabetic rats. Therefore, the results of the present study indicated that treatment with TW mitigated hyperglycemia-induced upregulated Wnt-1 and β-catenin expression in kidney tissues and ameliorated diabetes-induced kidney injury in rats.

Paeoniflorin attenuates incipient diabetic nephropathy in streptozotocin-induced mice by the suppression of the Toll-like receptor-2 signaling pathway

Toll-like receptors (TLRs) may be involved in diabetic nephropathy (DN). Paeoniflorin (PF) is an effective Chinese traditional medicine with anti-inflammatory and immunoregulatory effects that may inhibit the TLR2 signaling pathway. In this study, we investigated the effects of PF on the kidneys of mice with streptozotocin-induced type 1 diabetes mellitus using TLR2 knockout mice (TLR2^−/−) and wild-type littermates (C57BL/6J-WT). After 12 weeks of intraperitoneal injection of PF at doses of 25, 50, and 100 mg/kg once a day, diabetic mice had significantly reduced albuminuria and attenuated renal histopathology. These changes were associated with substantially alleviated macrophage infiltration and decreased expression of TLR2 signaling pathway biomarkers. These data support a role of TLR2 in promoting inflammation and indicate that the effect of PF is associated with the inhibition of the TLR2 pathway in the kidneys of diabetic mice. PF thus shows therapeutic potential for the prevention and treatment of DN.

Radix Puerariae and Fructus Crataegi mixture inhibits renal injury in type 2 diabetes via decreasing of AKT/PI3K

Background

Radix puerariae (RP) is a herbal medicines for diabetes, mainly because of anti-oxidative, insulin resistance and hypoglycemic effect. Fructus crataegi (FC) also possesses strong antioxidant activity in vitro. This study focused on the effects of herbal mixture of RP and FC (RPFC) on renal protection through a diabetic rat model.

Methods

Type 2 Diabetic model was established with high fat diet followed by injecting rats a low dose of STZ (25 mg/kg body weight). Rats were randomly divided into five groups: normal, high fat diet, diabetes mellitus, high fat diet plus RPFC prevention, and RPFC prevention before diabetes mellitus. RPFC was given to rats daily by intragastric gavage. The blood bio-chemical index and renal pathological changes were examined. The later includes hematoxylin and eosin staining, periodic acid schiff staining, and Masson trichrome staining. Protein levels of were determined by Western blot and immunohistochemical staining. mRNA levels were detected by RT-PCR.

Results

Rats prevented with RPFC resulted in decreasing blood glucose with corresponding vehicle treated rats. Glomerulus mesangial matrix expansion, renal capsule constriction, and renal tubular epithelial cell edema were less severe following RPFC prevention. Moreover, RPFC prevention reduced protein levels of PI3K, AKT, α-SMA and collagen IV in the kidney of diabetic rats.

Conclusion

Combined prevention with RPFC may inhibit the PI3K/AKT pathway in the kidney, thereby prevent renal injury in diabetic rats.

Treatment effects and mechanisms of Yujin Powder on rat model of large intestine dampness-heat syndrome

ETHNOPHARMACOLOGICAL RELEVANCE

Yujin Powder (YJP), an old prescription, is one of the most classical prescription for treating the large intestine dampness-heat syndrome (LIDHS). However, its potential modern pharmacological mechanisms remain unclear.

AIM OF THE STUDY

The present study was designed to explore the essence of LIDHS and treatment mechanisms of the YJP on the LIDHS.

METHODS

The rat model of LIDHS was established by such complex factors as high-sugar and high-fat diet, improper diet, high temperature and humidity environment (HTHE), drinking and intraperitoneal injection of Escherichia coli., which imitated the inducing conditions of LIDHS. Then the clinical symptoms and signs, blood routine, blood biochemistry, whole blood viscosity (WBV), serum inflammatory cytokines levels and the histopathological changes of main organs were detected and observed, respectively.

RESULTS

The results showed that the clinical symptoms and signs of the model rats were consistent with the diagnostic criteria of LIDHS, moreover, there were obvious systemic inflammatory response and extensive congestion. And after treatment with YJP in different dosages, the clinical symptoms and signs of the rats with LIDHS were improved; the indexes of blood routine and blood biochemistry and inflammatory cytokines levels tended to be normal; the WBV decreased and histopathological changes of major organs were alleviated or returned to normal. There was an obvious dose-effect relationship, and the high dose of YJP (HD-YJP) had the best treatment effects.

CONCLUSIONS

These results suggested that in LIDHS, diarrhea was the major clinical manifestation; the large intestine was the main lesion area; mucosa injury, inflammation and congestion of the large intestine with systemic inflammatory response and congestion were the most typical pathological characteristics. Meanwhile, YJP exhibited the comprehensive effects of anti-diarrhea, anti-inflammation, lowering blood lipid, relieving blood stasis, repairing intestinal mucosa and regulation and protection of multiple organs on LIDHS. These findings provided not only important information for understanding the essence of LIDHS but also the theoretical basis for developing new-drugs for treating dampness-heat type of diarrheal diseases.

Toll-like receptor 7 involves the injury in acute kidney ischemia/reperfusion of STZ-induced diabetic rats

PURPOSE

To determine whether Toll-like receptor 7 (TLR7) is the potential targets of prevention or progression in the renal ischemia/reperfusion (I/R) injury of STZ-induced diabetic rats.

METHODS

Thirty six Sprague-Dawley rats were randomly arranged to the nondiabetic (ND) or diabetic group (DM), with each group further divided into sham (no I/R injury), I/R (ischemia-reperfusion) and CD (given by Chloroquine) group. Preoperatively, Chloroquine (40 mg/kg, intraperitoneal injection.) was administrated 6 days for treatment group. I/R animals were subjected to 25 min of bilateral renal ischemia. Renal function, histology, apoptosis, cytokines, expression of TLR7, MyD88 and NF-κB were detected.

RESULTS

The serum levels of blood urea nitrogen, creatinine, IL-6 and TNF-α, apoptotic tubular epithelial cells, expression of TLR7, MyD88 and NF-κB were significantly increased in DM+I/R group, compared with ND+I/R group (p<0.05). All these changes were further improved by TLR7 inhibition Chloroquine except Paller scores (p<0.05).

CONCLUSION

Toll-like receptor 7 inhibition attenuates the acute renal ischemia/reperfusion injury of STZ-induced diabetic in SD rats.

Paeoniflorin inhibits high glucose-induced macrophage activation through TLR2-dependent signal pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Paeoniflorin(PF), extracted from the root peeled of Paeonia lactiflora Pall(Family: Ranunculaceae), has therapeutic potential in many animal models of inflammatory diseases.

AIM OF THE STUDY

Although the anti-inflammatory efficacy of PF has been well illustrated in several animal models, whether it could attenuate diabetic nephropathy and detailed mechanisms are still obscure. Till now, accumulating evidence has proposed the pivotal role of toll-like receptors (TLRs) in renal inflammation in diabetic patients. In this setting, the current study aimed to investigate the effects and underlying mechanism of PF on high glucose-induced activation of toll like-receptor 2 (TLR2) signaling in macrophages.

MATERIALS AND METHODS

Bone marrow-derived macrophages (BMDM) were isolated from male Tlr2^tm1kir (TLR2-/-) mice and wild-type littermates (C57BL/6JWT). The level of TLR2 and activation of downstream signaling were evaluated in response to 30mmol/L high glucose (HG)-containing medium. Macrophages behaviors, which include cell viability, migration and inflammatory cytokines production, were also determined.

RESULTS

PF suppressed HG-induced production of TLR2, activation of downstream signaling and synthesis of inducible nitric oxide synthase (iNOS). PF could further inhibit MyD88-dependent pathway in HG-induced models in which TLR2 was knocked out. Moreover, deletion of TLR2 inhibited the HG-induced activation of MyD88-dependent pathway, but not TIR domain containing adapter inducing interferon-β (Trif) signal pathway in BMDMs. As HG stimulation polarizes macrophages into M1 phenotype, treatment of PF or knockout of TLR2 significantly reduces M1 markers on the membrane of macrophages. Additionally, levels of inflammatory cytokines and iNOS were remarkably reduced in response to PF or TLR2 deficiency.

CONCLUSION

Collectively, these data demonstrated that HG activated macrophages primarily through TLR2-dependent mechanisms which aggravated the severity of renal inflammation and eventually contributed to DN. Additionally, PF might be applied as a potential therapeutic agent in the battle against progressive DN.

Simultaneous determination of paeoniflorin from total glucosides of paeony in Sprague-Dawley rats and spontaneously hypertensive rats by high-performance liquid chromatography-tandem mass spectrometry: in vivo and in vitro studies

Paeoniflorin is a well-known monoterpene glucoside in the herbal drug that exhibits a number of biological activities. The pharmacokinetic characteristics of paeoniflorin from total glucosides of paeony in spontaneously hypertensive rats (SHR) are still unclear. It is essential to investigate the in vivo and in vitro pharmacokinetic differences of paeoniflorin from total glucosides of paeony in Sprague-Dawley (SD) and SHR. The in vivo pharmacokinetic data were analyzed using DAS 2.0 software and the in vitro metabolic characteristics were measured using rat hepatic microsomes. The concentration of paeoniflorin in biological samples was determined using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry method, which showed good precision and stability. The plasma concentration-time profiles of paeoniflorin following oral administration of total glucosides of paeony showed a single peak and there were significant differences in the mean values of AUC_(0-t) , AUC_(0-∞) , CL_z /F and T_max between SD and SHR (p < 0.05). The metabolic rate of paeoniflorin from total glucosides of paeony was slower in SHR than in SD rats (p < 0.05). The results might be useful in further applications of paeoniflorin and total glucosides of paeony. Copyright © 2016 John Wiley & Sons, Ltd.

Simultaneous determination of paeoniflorin-6′-O-benzene sulfonate (CP-25) and its active paeoniflorin (Pae) metabolite in rat plasma using UPLC-MS/MS: an application for pharmacokinetic studies

Paeoniflorin (Pae), a water-soluble monoterpene glucoside, is the main effective component of total glucoside of paeony (TGP) paeoniflorin-6′-O-benzene sulfonate (CP-25), an acylated derivative of Pae, was synthesized via esterification.

Target-mediated pharmacokinetic/pharmacodynamic model based meta-analysis and dosing regimen optimization of a long-acting release formulation of exenatide in patients with type 2 diabetes mellitus

A hybrid pharmacokinetic/pharmacodynamic (PK/PD) model with extended-release (ER) process and target mediated drug disposition (TMDD) was developed for exenatide ER to account for its complex absorption process and glucagon-like peptide 1 receptor (GLP-1R)-mediated non-linear PK behaviors along with its influences to fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c). Using hybrid PK/PD model, simulations were done to explore the potential dosing regimens which could achieve likelihood of more pharmacodynamic exposure with respect to FPG and HbA1c over a much shorter period compared with the currently used treatment protocol. The mean PK/PD data about exenatide ER for type 2 diabetes mellitus (T2DM) were digitized from the publications, and the hybrid PK/PD model was performed using the Monolix 4.3 program. The plasma concentration-time and FPG/HbA1c-time profiles for exenatide ER subcutaneously administrated to patients with T2DM were well described by this hybrid model. Monte Carlo simulation was applied to mimic the PK profiles when higher loading dose 7.5 and 5.0 mg exenatide ER were subcutaneously administrated with different dosing intervals at the first 3 weeks of 30-week treatment. Two potentially optimizing schedules could improve the likelihood of achieving much more FPG and HbA1c exposures than currently used clinical treatment protocol.

Curcumin ameliorates renal fibrosis by inhibiting local fibroblast proliferation and extracellular matrix deposition

Renal fibrosis is mainly characterized by activation and proliferation of interstitial fibroblasts and by excessive synthesis and accumulation of extracellular matrix (ECM) components, including fibronectin (FN) and collagen. This study investigated the effects of curcumin on proliferation of renal interstitial fibroblasts and their underlying mechanisms in vivo and in vitro. ECM components were visualized by Sirius red and immunohistochemistry staining and quantified by western blot analysis in mice with unilateral ureteral obstruction (UUO). Duplex staining for proliferating cell nuclear antigen and α-smooth muscle actin (α-SMA), as well as MTT and flow cytometry assays, were performed to measure fibroblast proliferation. Protein expression of phosphorylated Smad2/3 (p-Smad2/3) and peroxisome proliferator-activated receptor-γ (PPAR-γ) were assessed by western blotting. Curcumin treatment decreased the accumulation of type I collagen and FN in the kidney of animals with UUO. Activation of rat renal interstitial fibroblasts (NRK-49F) was induced by TGF-β1. Curcumin treatment inhibited fibroblast proliferation and the cell cycle was arrested in the G1 phase. Curcumin treatment upregulated the expression of PPAR-γ and downregulated the expression of p-Smad2/3. These results suggest that curcumin treatment ameliorates renal fibrosis by reducing fibroblast proliferation and ECM accumulation mediated by PPAR-γ and Smad-dependent TGF-β1 signaling.