Pharmacological evaluation of insulin mimetic novel suppressors of PEPCK gene transcription from Paeoniae Rubra Radix

Paeoniflorin Induces ER Stress-Mediated Apoptotic Cell Death by Generating Nox4-Derived ROS under Radiation in Gastric Cancer

Gastric cancer is one of the most prevalent cancer types worldwide, and its resistance to cancer therapies, such as chemotherapy and radiotherapy, has made treating it a major challenge. Paeoniflorin (PF) is one potential pharmacological treatment derived from paeony root. However, in cancer, the molecular mechanisms and biological functions of PF are still unclear. In the present study, we found that PF exerts anti-tumor effects in vivo and in vitro and induces apoptotic cell death through ER stress, calcium (Ca2+), and reactive oxygen species (ROS) release in gastric cancer cells. However, ROS inhibition by DPI and NAC blocks cell death and the PERK signaling pathway via the reduction of Nox4. Moreover, PF triggers a synergistic inhibitory effect of the epithelial-mesenchymal transition (EMT) process under radiation exposure in radiation-resistant gastric cancer cells. These findings indicate that PF-induced Ca2+ and ROS release overcomes radioresistance via ER stress and induces cell death under radiation in gastric cancer cells. Therefore, PF, in combination with radiation, may be a powerful strategy for gastric cancer therapy.

In vitro, in vivo, and in silico evaluation of the glucocorticoid receptor antagonist activity of 3,6-dibromocarbazole

3,6-Dibromocarbazole is a novel environmental contaminant which is currently detected in several environmental media worldwide. This work aims to investigate the anti-glucocorticoid potency and endocrine disrupting effects of 3,6-dibromocarbazole. In vitro experiments indicated that 3,6-dibromocarbazole possessed glucocorticoid receptor (GR) antagonistic activity and inhibited dexamethasone-induced GR nuclear translocation. 3,6-Dibromocarbazole reduced the expression levels of glucocorticoid responsive genes including glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), fatty acid synthase (FAS), and tyrosine aminotransferase (TAT), and further disrupted the protein expression of two key enzymes PEPCK and FAS in gluconeogenesis. In vivo experiments showed that 3,6-dibromocarbazole induced abnormal development of zebrafish embryos and disrupted the major neurohormones involved in activation of hypothalamic-pituitary-adrenocortical (HPA) axis in zebrafish larvae. The results of molecular docking and molecular dynamics simulation contributed to explain the antagonistic effect of 3,6-dibromocarbazole. Taken together, this work identified 3,6-dibromocarbazole as a GR antagonist, which might exert endocrine disrupting effects by interfering the pathway of gluconeogenesis.

1,2,3,4,6-Penta-O-galloyl-d-glucose Interrupts the Early Adipocyte Lifecycle and Attenuates Adiposity and Hepatic Steatosis in Mice with Diet-Induced Obesity

Phytochemicals that interrupt adipocyte lifecycle can provide anti-obesity effects. 1,2,3,4,6-penta-O-galloyl-d-glucose (PGG) is a tannin with two isomers that occurs widely in plants and exhibits various pharmacological activities. The aim of the investigation is to comprehensively examine effects of PGG isomer(s) on adipocyte lifecycle and diet-induced obesity. Human mesenchymal stem cells (hMSC), 3T3-L1 fibroblasts, and H4IIE hepatoma cells were used to determine the effects of PGG isomers on cell viability and adipogenesis. Mice with diet-induced obesity were generated from male C57/BL6 mice fed with a 45% high fat diet. Oral administration of β-PGG (0.1 and 5 mg/kg) lasted for 14 weeks. Viability was reduced by repeated PGG treatment in hMSC, preadipocytes, and cells under differentiation. PGG mainly induces apoptosis, and this effect is independent of its insulin mimetic action. In vivo, administration of β-PGG attenuated shortening of the colon, hyperlipidaemia, fat cells and islet hypertrophy in DIO mice. Hepatic steatosis and related gene expression were improved along with glucose intolerance. Increased serum adiponectin, leptin, and glucagon-like peptide-1 levels were also observed. In conclusion, repeated PGG treatment interrupts the adipocyte lifecycle. PGG administration reduces adiposity and fatty liver development in DIO mice, and therefore, PGG could aid in clinical management of obesity.

The long winding road to the safer glucocorticoid receptor (GR) targeting therapies

Glucocorticoids (Gcs) are widely used to treat inflammatory diseases and hematological malignancies, and despite the introduction of novel anti-inflammatory and anti-cancer biologics, the use of inexpensive and effective Gcs is expected to grow. Unfortunately, chronic treatment with Gcs results in multiple atrophic and metabolic side effects. Thus, the search for safer glucocorticoid receptor (GR)-targeted therapies that preserve therapeutic potential of Gcs but result in fewer adverse effects remains highly relevant. Development of selective GR agonists/modulators (SEGRAM) with reduced side effects, based on the concept of dissociation of GR transactivation and transrepression functions, resulted in limited success, and currently focus has shifted towards partial GR agonists. Additional approach is the identification and inhibition of genes associated with Gcs specific side effects. Others and we recently identified GR target genes REDD1 and FKBP51 as key mediators of Gcs-induced atrophy, and selected and validated candidate molecules for REDD1 blockage including PI3K/Akt/mTOR inhibitors. In this review, we summarized classic and contemporary approaches to safer GR-mediated therapies including unique concept of Gcs combination with REDD1 inhibitors. We discussed protective effects of REDD1 inhibitors against Gcs–induced atrophy in skin and bone and underlined the translational potential of this combination for further development of safer and effective Gcs-based therapies.

Genus Paeonia: A comprehensive review on traditional uses, phytochemistry, pharmacological activities, clinical application, and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Paeonia, which comprises approximately 52 shrubs or herbaceous perennials around the world, is the only genus of the Paeoniaceae and is pervasively distributed in Asia, southern Europe, and North America. Many species of the genus Paeonia have been used for centuries in ethnomedical medical systems.

AIM OF THE REVIEW

The present study aims to summarize the traditional uses, clinical applications, and toxicology of the genus Paeonia, to critically evaluate the state-of-the-art phytochemical and pharmacological studies of this genus published between 2011 and 2020, and to suggest directions for further in-depth research on Paeonia medicinal resources.

MATERIALS AND METHODS

Popular and widely used databases such as PubMed, Scopus, Science Direct, and Google Scholar were searched using the various search strings; from these searches, a number of citations related to the traditional uses, phytochemistry, biological activities, clinical application, and toxicology of the genus Paeonia were retrieved.

RESULTS

The use of 21 species, 2 subspecies, and 7 varieties of the genus Paeonia as traditional herbal remedies has been reported, and many ethnomedicinal uses, such as the treatment of hematemesis, blood stasis, dysmenorrhea, amenorrhea, epilepsy, spasms, and gastritis, have been recorded. The roots and root bark are the most frequently reported parts of the plants used in medicinal applications. In phytochemical investigations, 451 compounds have been isolated from Paeonia plants to date, which contains monoterpenoid glucosides, flavonoids, tannins, stilbenes, triterpenoids and steroids, and phenols. Studies of their pharmacological activities have revealed the antioxidant, anti-inflammatory, antitumour, antibacterial, antiviral, cardiovascular protective, and neuroprotective properties of the genus Paeonia. In particular, some bioactive extracts and compounds (total glucosides of peony (TGP), paeonol, and paeoniflorin) have been used as therapeutic drugs or tested in clinical trials. In addition to the "incompatibility" of the combined use of "shaoyao" and Veratrum nigrum L. roots in traditional Chinese medicine theory, Paeonia was considered to have no obvious toxicity based on the available toxicological tests.

CONCLUSION

A large number of phytochemical and pharmacological reports have indicated that Paeonia is an important medicinal herb resource, and some of its traditional uses including the treatment of inflammation and cardiovascular diseases and its use as a neuroprotective agent, have been partially confirmed through modern pharmacological studies. Monoterpenoid glucosides are the main active constituents. Although many compounds have been isolated from Paeonia plants, the biological activities of only a few of these compounds (paeoniflorin, paeonol, and TGP) have been extensively investigated. Some paeoniflorin structural analogues and resveratrol oligomers have been preliminarily studied. With the exception of several species (P. suffruticosa, P. ostii, P. lactiflora, and P. emodi) that are commonly used in folk medicine, many medicinal species within the genus do not receive adequate attention. Conducting phytochemical and pharmacological experiments on these species can provide new clues that may lead to the discovery of medicinal resources. It is necessary to identify the effective phytoconstituents of crude extracts of Paeonia that displayed pharmacological activities by bioactivity-guided isolation. In addition, comprehensive plant quality control, and toxicology and pharmacokinetic studies are needed in the future studies.

Regulation of CAR and PXR Expression in Health and Disease

Pregnane X receptor (PXR, NR1I2) and constitutive androstane receptor (CAR, NR1I3) are members of the nuclear receptor superfamily that mainly act as ligand-activated transcription factors. Their functions have long been associated with the regulation of drug metabolism and disposition, and it is now well established that they are implicated in physiological and pathological conditions. Considerable efforts have been made to understand the regulation of their activity by their cognate ligand; however, additional regulatory mechanisms, among which the regulation of their expression, modulate their pleiotropic effects. This review summarizes the current knowledge on CAR and PXR expression during development and adult life; tissue distribution; spatial, temporal, and metabolic regulations; as well as in pathological situations, including chronic diseases and cancers. The expression of CAR and PXR is modulated by complex regulatory mechanisms that involve the interplay of transcription factors and also post-transcriptional and epigenetic modifications. Moreover, many environmental stimuli affect CAR and PXR expression through mechanisms that have not been elucidated.

Anti-inflammatory and anti-apoptotic effects of the combination of Ligusticum chuanxiong and Radix Paeoniae against focal cerebral ischaemia via TLR4/MyD88/MAPK/NF-κB signalling pathway in MCAO rats

Objective

This study was performed to assess the anti-inflammatory and anti-apoptotic effects of the combination of Ligusticum chuanxiong and Radix Paeoniae (XS) on focal cerebral ischaemic stroke.

Methods

MCAO rats were used to evaluate the effect of XS on stroke. Cerebral water content was measured, and the levels of IFN-γ, IL-1β, IL-6 and IL-12 in serum and brain were assessed by ELISA kits. Protein expressions including p-p38, p-38, TLR-4, p-ERK, ERK, TLR-5, NF-κBp65, Myd88, Caspase-3 and Caspase-12 were examined by WB and IHC. Q-PCR was applied to examine IL-1β and IL-6 mRNA levels in the rat brain of each group.

Key findings

XS treatment remarkedly decreased the levels of IFN-γ, IL-1β, IL-6 and IL-12 in serum and brain tissues of MCAO rats. In the ischaemic brain, the expressions of TLR-4, TLR-5, p-p38, p-ERK, Myd88, NF-κBp65, Caspase-3 and Caspase-12 were increased significantly, while the treatment attenuated the activated expressions by MCAO. XS also downregulated Caspase-3 and Caspase-12 expressions. IL-1β and IL-6 mRNA levels in MCAO brain tissue were decreased by XS treatment.

Conclusions

XS could protect MCAO rats by anti-inflammation and anti-apoptosis through TLR4/MyD88/MAPK/NF-κB signalling pathway. Furthermore, the combination has a more meaningful improvement on focal cerebral ischaemic stroke.

Moutan Cortex and Paeoniae Radix Rubra reverse high-fat-diet-induced metabolic disorder and restore gut microbiota homeostasis

The present study was designed to investigate the therapeutic effcts of Moutan Cortex (CM, root bark of Paeonia suffruticosa Andr) and Paeoniae Radix Rubra (PR, root of Paeonia veitchii Lynch) on metabolic disorders, focusing on the infuence of CM and PR on the obesity-related gut microbiota homeostasis. The diet-induced obese (DIO) mouse model was used to test the therapeutic effects of CM and PR. The mice were orally administered with CM and PR for 6 weeks, and oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were performed to evaluate the insulin sensitivity of the mice. Sterol-regulatory element binding proteins (SREBPs) and their target genes were measured by quantitative RT-PCR. High-throughput 16S ribosomal RNA (16S rRNA) gene sequencing technology was used to determine the composition of gut microbiota, and the metabolites in serum were analyzed by GC-MS. Our results indicated that CM and PR combination alleviated obese and insulin resistance in the DIO mice, leading to increased glucose uptake and gene expression in muscle and liver, and down-regulated SREBPs and their target genes in liver. Interesting, neither the CM-PR extracts, nor the major components of CM and PR did not affect SREBPs activity in cultured cells. Meanwhile, CM and PR significantly modulated the gut microbiota of the high-fat diet (HFD) treated mice, similar to metformin, and CM-PR reversed the overall microbiota composition similar to the normal chow diet (NCD) treated mice. In conclusion, our results provide novel mechanisms of action for the effects of CM and PR in treating DIO-induced dysregulation of sugar and lipid metabolism.

Evaluation of the In Vivo Therapeutic Effects of Radix Paeoniae Rubra Ethanol Extract with the Hypoglycemic Activities Measured from Multiple Cell-Based Assays

Background. Radix Paeoniae Rubra (Chi Shao) contains several phytochemicals with hypoglycemic actions. Current research aims to explore potential insulinotropic effects and long-term therapeutic efficacy of such herb against type 2 diabetes. Methods. Composition analysis for the ethanol extract (PRExt) was executed by high performance liquid chromatography. Polyphenol-enriched fraction was characterized by high pressure size exclusion chromatography. Multiple cell platforms were employed to evaluate hypoglycemic bioactivities. In animal experiments, blood glucose, the homeostasis model assessment (HOMA)-index assessment, glucose tolerance test, and in vivo glucose uptake were all measured. Additional effects of PRExt on obesity and hepatic steatosis were evaluated by serum and histological analysis. Results. PRExt provides multiple hypoglycemic effects including the enhancement of glucose-mediated insulin secretion. Pentagalloylglucose and polyphenol-enriched fraction are two insulinotropic constituents. Moreover, PRExt intraperitoneal injection causes acute hypoglycemic effects on fasted db/db mice. Oral administration of PRExt (200 mg/kg b.w.) gradually reduces blood glucose in db/db mice to the level similar to that in C57J/B6 mice after 30 days. The improvement of glucose intolerance, HOMA-index, and in vivo glucose uptake is evident in addition to the weight loss effect and attenuation of hepatic steatosis. Conclusion. PRExt is an effective antidiabetic herbal extract with multiple hypoglycemic bioactivities.

Combination of Ligusticum chuanxiong and Radix Paeoniae ameliorate focal cerebral ischemic in MCAO rats via endoplasmic reticulum stress-dependent apoptotic signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Combination of Ligusticum chuanxiong and Radix Paeoniae (XS) is highly effective in the treatment for focal cerebral ischemic, but the underlying mechanism is not clear. This study was conducted to evaluate the combinative effects of XS on MCAO rats and explore the underlying mechanisms.

MATERIALS AND METHODS

MCAO rats were used to evaluate the protective effect of Ligusticum chuanxiong (CX), Radix Paeoniae Rubra (CS) and their combination (XS) on ameliorating focal cerebral ischemic. Cerebral ischemia deficits and infarct size were performed by 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin (H-E) staining. Activities of SOD, CAT and GSH-Px, as well as levels of LPO and MDA were detected by commercial kits while ELISA kits for the content of plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator (PA). Immunohistochemistry (IHC) and western blot analysis (WB) were carried out to examine the protein expressions including PKR-like endoplasmic reticulum kinase (PERK), cytoplasmic of glucose regulated protein 78 (GRP78), X box-binding protein-1 (XBP-1), activating transcription factor-6 (ATF-6), C/EBP-homologous protein (CHOP), metalloprotease-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), Bcl-2 associated X protein (Bax), and porcineB-cellleukemia/lymphoma-2 (Bcl-2) in brain tissues. Reverse transcription polymerase chain reaction (RT-PCR) and Quantitative PCR (Q-PCR) were applied to examine vascular endothelial growth factor (VEGF) and N-methyl-d-aspartate receptors (NMDAR1) mRNA levels.

RESULTS

CX, CS and their combination (XS) could reduce cerebral ischemia deficits and infarct size of MCAO rats. They increased SOD, CAT and GSH-Px activities, and reduced MDA and LPO levels in serum, markedly. A significant decrease of endoplasmic reticulum stress-related factors PERK, XBP-1, ATF-6 and CHOP protein expression levels while an increase of GRP78 and MVD expression by the treatment of CX, CS and XS. It could also be observed that their treatment could reduce apoptotic damage of brain tissues by up-regulating Bax level and down-regulating Bcl-2 level. Furthermore, the levels of MMP-9 and PAI-1 in serum and tissues of rats were down-regulated remarkably while TIMP-1 and PA levels were up-regulated. VEGF mRNA level was up-regulated dramatically whereas NMDAR1 was reduced. Importantly, the combination of CX and CS, namely XS, has a more meaningful improvement on focal cerebral ischemic than CX or CS alone.

CONCLUSION

All these revealed that the combined XS exerted more remarkable protective effects than alone. XS could inhibit neuronal apoptosis by attenuating ER-stress-dependent apoptotic signaling and protected the blood-brain barrier. These findings might supply beneficial hints for the synergy of CX and CS, and provide the basis for rationality of XS preparation and deserve further clinical investigations.

Anti-tumor effect of Radix Paeoniae Rubra extract on mice bladder tumors using intravesical therapy

Radix Paeoniae Rubra (RPR) is the dried root of Paeonia lactiflora Pallas and Paeonia veitchii Lynch, and is a herbal medicine that is widely used in traditional Chinese medicine for the treatment of blood-heat and blood-stasis syndrome, similarly to Cortex Moutan. The present study identified the same three components in RPR and Cortex Moutan extracts. In addition, it has been reported that RPR has an anti-cancer effect. Bladder cancer is the seventh most common type of cancer worldwide. Due to the high recurrence rate, identifying novel drugs for bladder cancer therapy is essential. In the present study, RPR extract was evaluated as a bladder cancer therapy in vitro and in vivo. The present results revealed that RPR extract reduced the cell viability of bladder cancer cells with a half maximal inhibitory concentration of 1-3 mg/ml, and had an extremely low cytotoxic effect on normal urothelial cells. Additionally, RPR decreased certain cell cycle populations, predominantly cells in the G1 phase, and caused a clear sub-G increase. In a mouse orthotopic bladder tumor model, intravesical application of RPR extract decreased the bladder tumor size without altering the blood biochemical parameters of the mice. In summary, the present results demonstrate the anti-proliferative properties of RPR extract on bladder cancer cells, and its anti-bladder tumor effect in vivo. Compared to Cortex Moutan extract, RPR extract may provide a more effective alternative therapeutic strategy for the intravesical therapy of superficial bladder cancer.

Monoterpene derivatives with anti-allergic activity from red peony root, the root of Paeonia lactiflora

The methanolic extract and its subfractions from red peony root, the dried roots of Paeonia lactiflora Pallas showed potent antiallergic effects, as inhibition of immunoglobulin E (IgE)-mediated degranulation in rat basophil leukemia (RBL)-2H3 cells. Bioassay-guided fractionation led to the isolation of 16 monoterpene derivatives, including 3 new compounds, paeoniflorol (1), 4'-hydroxypaeoniflorigenone (2) and 4-epi-albiflorin (3), together with 13 known ones (4-16). The chemical structures of the new compounds were elucidated on the basis of spectroscopic and chemical evidences. Among the isolated monoterpene derivatives, nine compounds showed potent anti-allergic effects and compound 1 was the most effective. A primary structure-activity relationship of monoterpene derivatives was discussed.

Evaluation of the medicinal herb Graptopetalum paraguayense as a treatment for liver cancer

Background

Hepatocellular carcinoma (HCC) is the fifth most common malignancy and the third most common cause of cancer-related death worldwide. Sorafenib is the only drug for patients with advanced-stage hepatocellular carcinoma (HCC) that has been shown to confer a survival benefit to patients with HCC; however, it has many side effects. Thus, alternate therapeutic strategies with improved safety and therapeutic efficacy for the management of HCC should be developed.

Methods and Findings

We demonstrate that an extract of Graptopetalum paraguayense (GP) down-regulated the expression levels of several onco-proteins, including AURKA, AURKB, and FLJ10540, in HCC cells. To isolate the active components in the GP extracts, we prepared extracts fractions and assessed their effects on the expression of onco-proteins in HCC cells. The fraction designated HH-F3 was enriched in active ingredients, exhibited cytotoxic effects, and suppressed the expression of the onco-proteins in HCC cells. The structure of the main active compound in HH-F3 was found to be similar to that of the proanthocyanidin compounds derived from Rhodiola rosea. In addition, a distinct new compound rich in 3, 4, 5-trihydroxy benzylic moieties was identified in the HH-F3 preparations. Mechanistic studies indicated that HH-F3 induced apoptosis in HCC cells by promoting the loss of mitochondrial membrane potential and the production of reactive oxygen species. HH-F3 also enhanced PTEN expression and decreased AKT phosphorylation at Ser473 in a concentration-dependent manner in HCC cells. Moreover combination of GP or HH-F3 and sorafenib synergistically inhibits the proliferation of Huh7 cells. The treatment of a rat model with diethylnitrosamine (DEN)-induced liver cancer with extracts of GP and HH-F3 decreased hepatic collagen contents and inhibited tumor growth.

Conclusions

These results indicate that GP extracts and HH-F3 can protect the liver by suppressing tumor growth; consequently, these compounds could be considered for the treatment of HCC.

Botanical compounds and their regulation of nuclear receptor action: the case of traditional Chinese medicine

Nuclear receptors (NRs) are major pharmacological targets that allow an access to the mechanisms controlling gene regulation. As such, some NRs were identified as biological targets of active compounds contained in herbal remedies found in traditional medicines. We aim here to review this expanding literature by focusing on the informative articles regarding the mechanisms of action of traditional Chinese medicines (TCMs). We exemplified well-characterized TCM action mediated by NR such as steroid receptors (ER, GR, AR), metabolic receptors (PPAR, LXR, FXR, PXR, CAR) and RXR. We also provided, when possible, examples from other traditional medicines. From these, we draw a parallel between TCMs and phytoestrogens or endocrine disrupting chemicals also acting via NR. We define common principle of action and highlight the potential and limits of those compounds. TCMs, by finely tuning physiological reactions in positive and negative manners, could act, in a subtle but efficient way, on NR sensors and their transcriptional network.