Morroniside promotes skin wound re-epithelialization by facilitating epidermal stem cell proliferation through GLP-1R-mediated upregulation of ß-catenin expression.

Epidermal stem cells (EpSCs) play a vital role in skin wound healing through re-epithelialization. Identifying chemicals that can promote EpSC proliferation is helpful for treating skin wounds. This study investigates the effect of morroniside on cutaneous wound healing in mice and explores the underlying mechanisms. Application of 10‒50 µg/mL of morroniside to the skin wound promotes wound healing in mice. In vitro studies demonstrate that morroniside stimulates the proliferation of mouse and human EpSCs in a time- and dose-dependent manner. Mechanistic studies reveal that morroniside promotes the proliferation of EpSCs by facilitating the cell cycle transition from the G1 to S phase. Morroniside increases the expression of ß-catenin via the glucagon-like peptide-1 receptor (GLP-1R)-mediated PKA, PKA/PI3K/AKT and PKA/ERK signaling pathways, resulting in an increase in cyclin D1 and cyclin E1 expression, either directly or by upregulating c-Myc expression. This process ultimately leads to EpSC proliferation. Administration of morroniside to mouse skin wounds increases the phosphorylation of AKT and ERK, the expressions of ß-catenin, c-Myc, cyclin D1, and cyclin E1, as well as the proliferation of EpSCs, in periwound skin tissue, and accelerates wound re-epithelialization. These effects of morroniside are mediated by the GLP-1R. Overall, these results indicate that morroniside promotes skin wound healing by stimulating the proliferation of EpSCs via increasing ß-catenin expression and subsequently upregulating c-Myc, cyclin D1, and cyclin E1 expressions through GLP-1R signaling pathways. Morroniside has clinical potential for treating skin wounds.

Morroniside ameliorates lipopolysaccharide-induced inflammatory damage in iris pigment epithelial cells through inhibition of TLR4/JAK2/STAT3 pathway.

AIM: To investigate the effect of morroniside (Mor) on lipopolysaccharide (LPS)-treated iris pigment epithelial cells (IPE). METHODS: IPE cells were induced by LPS and treated with Mor. Cell proliferation was detected by cell counting kit (CCK) -8, apoptosis was detected by flow cytometry, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-8 were measured by enzyme-linked immunosorbent assay (ELISA) kits, and the protein expression of TLR4, JAK2, p-JAK2, STAT3, and p-STAT3 was analyzed by Western blotting. In addition, overexpression of TLR4 and Mor treatment of LPS-stimulated IPE cells were also tested for the above indices. RESULTS: Mor effectively promoted the proliferation and inhibited the apoptosis of LPS-treated IPE cells. In addition, Mor significantly reduced the levels of TNF-α, IL-6, and IL-8 and significantly inhibited the expression of TLR4, p-JAK2, and p-STAT3 in LPS-treated IPE cells. The effect of Mor on LPS-treated IPE cells was markedly attenuated after overexpression of TLR4. CONCLUSION: These findings suggest that Mor may ameliorate LPS-induced inflammatory damage and apoptosis in IPE through inhibition of TLR4/JAK2/STAT3 pathway.

Morroniside alleviates lipopolysaccharide-induced inflammatory and oxidative stress in inflammatory bowel disease by inhibiting NLRP3 and NF-κB signaling pathways.

OBJECTIVE: To investigate the effects of morroniside on inflammatory and oxidative stress in lipopolysaccharide (LPS)-induced inflammatory bowel disease (IBD) cell model. METHODS: NCM460 cells were treated with 2-, 5-, or 10-µg/mL LPS for 24 h to develop an IBD cell model. MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) colorimetric assay was performed to uncover the role of morroniside on the viability of LPS-treated NCM460 cells. Flow cytometry and immunoblot assays were performed to confirm the effects of morroniside on the apoptosis of LPS-treated NCM460 cells. Quantitative polymerase chain reaction and enzyme-linked-immunosorbent serologic assays were performed to confirm the effects of morroniside on inflammatory and oxidative stress by measuring the levels of tumor necrosis factor-α, interleukin-1ß, IL-6, superoxide dismutase, malondialdehyde, total antioxidant capacity, and myeloperoxidase. In addition, immunoblot and immunofluorescence assays were performed to detect the effects of morroniside on NLRP3 and NF-κB pathways. RESULTS: Monosine attenuated LPS-induced injury of NCM460 cells. Monosine reduced LPS-induced inflammation in NCM460 cells. In addition, morroniside reduced LPS-induced oxidative stress in NCM460 cells. Mechanically, morroniside suppressed NLRP3 and NF-κB pathways, and alleviated LPS-induced inflammatory and oxidative stress in IBD. CONCLUSION: Morroniside could serve as a promising drug for treating IBD.

Morroniside attenuates nucleus pulposus cell senescence to alleviate intervertebral disc degeneration via inhibiting ROS-Hippo-p53 pathway.

Intervertebral disc (IVD) degeneration (IVDD) which is highly prevalent within the elderly population, is a leading cause of chronic low back pain and disability. Nucleus pulposus (NP) cell senescence plays an indispensable role in the pathogenesis of IVDD. Morroniside is a major iridoid glycoside and one of the quality control metrics of Cornus officinalis Siebold & Zucc (CO). An increasing body of evidence suggests that morroniside and CO-containing formulae share many similar biological effects, including anti-inflammatory, anti-oxidative, and anti-apoptotic properties. In a previous study, we reported that Liuwei Dihuang Decoction, a CO-containing formula, is effective for treating IVDD by targeting p53 expression; however, the therapeutic role of morroniside on IVDD remains obscure. In this study, we assessed the pharmacological effects of morroniside on NP cell senescence and IVDD pathogenesis using a lumbar spine instability surgery-induced mouse IVDD model and an in vitro H2O2-induced NP cell senescence model. Our results demonstrated that morroniside administration could significantly ameliorate mouse IVDD progression, concomitant with substantial improvement in extracellular matrix metabolism and histological grading score. Importantly, in vivo and in vitro experiments revealed that morroniside could significantly reduce the increase in SA-ß-gal activities and the expression of p53 and p21, which are the most widely used indicators of senescence. Mechanistically, morroniside suppressed ROS-induced aberrant activation of Hippo signaling by inhibiting Mst1/2 and Lats1/2 phosphorylation and reversing Yap/Taz reduction, whereas blockade of Hippo signaling by Yap/Taz inhibitor-1 or Yap/Taz siRNAs could antagonize the anti-senescence effect of morroniside on H2O2-induced NP cell senescence model by increasing p53 expression and activity. Moreover, the inhibition of Hippo signaling in the IVD tissues by morroniside was further verified in mouse IVDD model. Taken together, our findings suggest that morroniside protects against NP cell senescence to alleviate IVDD progression by inhibiting the ROS-Hippo-p53 pathway, providing a potential novel therapeutic approach for IVDD.

[Effects and mechanism of morroniside on osteogenic differentiation and proliferation of mouse MC3T3-E1 cells].

Objective: To study the effects of morroniside (MOR) on the proliferation and osteogenic differentiation of mouse MC3T3-E1 cells. Methods: The 4th generation MC3T3-E1 cells were randomly divided into 6 groups: control group (group A), MOR low dose group (10 µmol/L, group B), MOR medium-low dose group (20 µmol/L, group C), MOR medium dose group (40 µmol/L, group D), MOR medium-high dose group (80 µmol/L, group E), and MOR high dose group (100 µmol/L, group F). The proliferation activity of each group was detected by cell counting kit 8 (CCK-8) assay; the bone differentiation and mineralized nodule formation of each group were detected by alizarin red staining; real-time fluorescence quantitative PCR (RT-qPCR) was performed to detect cyclin-dependent kinase inhibitor 1A (P21), recombinant Cyclin D1 (CCND1), proliferating cell nuclear antigen (PCNA), alkaline phosphatase (ALP), collagen type Ⅰ (COL-1), bone morphogenetic protein 2 (BMP-2), and adenosine A2A receptor (A2AR) mRNA expressions; Western blot was used to detecte the expressions of osteopontin (OPN), Runt-related transcription factor 2 (RUNX2), and adenosine A2AR protein. Results: The CCK-8 assay showed that the absorbance ( A) values of groups B to F were significantly higher than that of group A at 24 hours of culture, with group C significantly higher than the rest of the groups ( P<0.05). The MOR concentration (20 µmol/L) of group C was selected for the subsequent CCK-8 assay; the results showed that the A values of group C were significantly higher than those of group A at 24, 48, and 72 hours of culture ( P<0.05). Alizarin red staining showed that orange-red mineralized nodules were visible in all groups and the number of mineralized nodules was significantly higher in groups B and C than in group A ( P<0.05). RT-qPCR showed that the relative expressions of P21, CCND1, and PCNA mRNAs were significantly higher in group C than in group A ( P<0.05). The expressions of ALP, BMP-2, COL-1, and adenosine A2AR mRNAs in groups B to E were significantly higher than those in group A, with the expressions of ALP, BMP-2, COL-1 mRNAs in group C significantly higher than the rest of the groups ( P<0.05). Compared with group A, the expressions of OPN and RUNX2 proteins in groups B and C were significantly increased, while those in group D and E were significantly inhibited ( P<0.05). There was no significant difference between groups B and C and between groups D and E ( P>0.05). The relative expression of adenosine A2AR protein in groups B to E was significantly higher than that in group A, with group C significantly higher than the rest of the groups ( P<0.05). Conclusion: MOR can promote the proliferation and osteogenic differentiation of MC3T3-E1 cells; the mechanism of MOR may be achieved by interacting with adenosine A2AR.

Morroniside, a novel GATA3 binding molecule, inhibits hepatic stellate cells activation by enhancing lysosomal acid lipase expression.

BACKGROUND: Liver fibrosis can be easily developed into irreversible liver cirrhosis or even liver cancer. Lysosomal acid lipase (LAL), encoded by the lipase A (Lipa) gene, is a critical enzyme involved in liver fibrosis development. Morroniside, an iridoid glycoside isolated from Cornus officinalis Sieb. et Zucc., exerts hepatic protective effects. However, the mechanism of action underling the anti-liver fibrosis effects of morroniside have not been fully elucidated. PURPOSE: To explore whether Lipa served as a biomarker for liver fibrosis and investigate the anti-liver fibrosis effects of morroniside and the underlying action mechanism in liver fibrosis cell models. METHODS: LAL expression was examined in the liver tissues of CCl4 and high-fat diet (HFD)-induced liver fibrosis animal models. α-smooth muscle actin (α-SMA) level, collagen and GATA family expressions were analyzed by Real-time PCR and Western blot. Putative transcription factor binding sites in the DNA sequences of Lipa was identified by PROMO-ALGGEN v8.3 online software and ENCODE ChIP-Seq Significance Tool. MD simulation was performed to explore the protein-ligand interaction. RESULTS: We found that the expression of hepatic LAL is lower in the liver fibrosis animal models than the control models. The reduced LAL expression is associated with HSCs activation, suggesting LAL is novel liver fibrosis biomarker. More importantly, our data showed that morroniside exerts anti-liver fibrosis effects in vitro. Mechanistic studies reveal that it binds to the hydrophobic sites of GATA3 and also reduces GATA3 expression, which increases LAL expression. CONCLUSIONS: This study, for the first time, suggests LAL is a novel biomarker for liver fibrosis. Besides, morroniside exerts its anti-liver fibrosis effects by targeting GATA3 and LAL and hence inhibits HSC activation. These findings provide strong scientific evidence to support the development of morroniside as novel alternative or complementary therapeutics for liver injury prevention and treatment.

Protective effect and mechanism of loganin and morroniside on acute lung injury and pulmonary fibrosis.

BACKGROUND: Loganin and morroniside are two iridoid glycosides with anti-inflammatory, antioxidant and anti-tumor effects. Whether they have effect on acute lung injury and pulmonary fibrosis are still unknown. PURPOSE: To explore the potential effects of loganin and morroniside against acute lung cancer and pulmonary fibrosis, and the underlying molecular mechanism. STUDY DESIGN AND METHODS: Cell and animal models of acute lung injury were established by the induction of LPS. After intervention with loganin and morroniside, the pathological symptom of lung tissue was assessed, pro-inflammatory factors in cells and lung tissues were detected, NF- κB/STAT3 signaling pathway related proteins were detected by western blotting. Mice pulmonary fibrosis model was induced by bleomycin, pathological symptom was assessed by HE and Masson staining. Fibrosis related indicators were detected by qPCR or western blot. CD4+/CD8+ was detected by flow cytometry. RESULTS: Loganin and morroniside relieved the pathological symptom of lung tissue in acute lung injury, pro-inflammatory factors such as IL-6, IL-1ß, TNF-α mRNA were inhibited. Expression of p-p65 and STAT3 in lung tissues were also downregulated. In addition, loganin and morroniside downregulated the expression of collagen fiber, hydroxyproline and TGF-ß1, collagen I and α-SMA mRNA in lung tissues of pulmonary fibrosis model. This study proved that loganin and morroniside have protective effect on acute lung injury and pulmonary fibrosis, and may provide theoretical basis for the development of new clinical drugs.

Morroniside protects OLN-93 cells against H2O2-induced injury through the PI3K/Akt pathway-mediated antioxidative stress and antiapoptotic activities.

Neurodegenerative disorders, including spinal cord injury (SCI), result in oxidative stress-induced cell damage. Morroniside (MR), a major active ingredient of the Chinese herb Shan Zhu Yu, has been shown to ameliorate oxidative stress and inflammatory response. Our previous study also confirmed that morroniside protects SK-N-SH cell line (human neuroblastoma cells) against oxidative impairment. However, it remains unclear whether MR also plays a protective role for oligodendrocytes that are damaged following SCI. The present study investigated the protective effects of MR against hydrogen peroxide (H2O2)-induced cell death in OLN-93 cells. MR protected OLN-93 cells from H2O2-induced injury, attenuated H2O2-induced increase in reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and blocked the reduction of mitochondrial membrane potential (MMP) induced by H2O2. MR enhanced the activity of the antioxidant enzyme superoxide dismutase (SOD) and suppressed H2O2-induced downregulation of the antiapoptotic protein Bcl-2 and activation of the proapoptotic protein caspase-3. Finally, we found that LY294002, a specific inhibitor of the PI3K/Akt pathway, inhibited the protective effect of MR against H2O2-induced OLN-93 cell injury in the MTT and TUNEL assays. LY294002 also inhibited the expression of SOD and Bcl-2, and increased the expression of iNOS and c-caspase-3 induced by MR treatment. MR exerts protective effects against H2O2-induced OLN-93 cell injury through the PI3K/Akt signaling pathway-mediated antioxidative stress and antiapoptotic activities. MR may provide a potential strategy for SCI treatment or other related neurodegeneration.

Morroniside promotes the osteogenesis by activating PI3K/Akt/mTOR signaling.

Morroniside exerts a proosteogenic effect, which can prevent bone loss. However, the detailed mechanism underlying Morroniside-regulated bone formation is unclear. Morroniside can maintain cell homeostasis by promoting PI3K/Akt/mTOR signaling. The purpose of this study is to explore the significance of PI3K/Akt/mTOR signaling in Morroniside-regulated osteogenesis. The results showed that Morroniside promoted the activities of PI3K, Akt, and mTOR in osteoblast precursor MC3T3-E1. The differentiation of MC3T3-E1 to mature osteoblasts promoted by Morroniside can be reversed by the pharmacological inhibition of PI3K or mTOR. Importantly, in the presence of Morroniside, the osteoblast differentiation suppressed by PI3K inhibitor was reversed by mTOR overexpression. In vivo assays showed that in bone tissue of ovariectomized mice, Morroniside-enhanced osteoblast formation was reversed by the pharmacological inhibition of PI3K or mTOR. In conclusion, Morroniside can promote the osteogenesis through PI3K/Akt/mTOR signaling, which provides a novel clue for the strategy of Morroniside in treating osteoporosis.

Morroniside suppresses hydrogen peroxide-stimulated autophagy and apoptosis in rat ovarian granulosa cells through the PI3K/AKT/mTOR pathway.

Previous evidences have indicated that granulosa cells play a critical role in follicular growth. Hydrogen peroxide (H2O2)-induced oxidative stress has been associated with ovarian granulosa cell apoptosis and ovarian function. Recently, a study highlighted the protective role of morroniside against H2O2-induced damage. In this study, we aimed to investigate the effects of morroniside on H2O2-stimulated rat ovarian granulosa cells and its underlying molecular mechanisms. Our results showed that H2O2 treatment suppressed cell survival and increased apoptosis in rat granulosa cells, while treatment with morroniside markedly increased H2O2-induced granulosa cell survival in a dose-dependent manner (0, 10, 50 and 100 µM). Moreover, treatment with 50 µM morroniside impeded H2O2-induced cell apoptosis. An elevation in intracellular ROS, MDA, SOD, GSH-Px, and CAT level was observed in H2O2-induced granulosa cells; however, this effect was abrogated by morroniside treatment. Further studies suggested that administration of morroniside inhibited H2O2-induced granulosa cell apoptosis and caspase-3 activity. In addition, after morroniside treatment of H2O2-stimulated granulosa cells, autophagy-related protein (LC3-II/LC3-I ratio) and beclin-1 expression was decreased and p62 level was increased. Interestingly, we found that morroniside treatment activated the PI3K/AKT/mTOR pathway in H2O2-stimulated granulosa cells. Finally, we showed that treatment with PI3K and mTOR inhibitors reversed the protective effects of morroniside on H2O2-induced granulosa cells. Taken together, our data suggest that treatment with morroniside decreased apoptosis, autophagy, and oxidative stress in rat granulosa cells through the PI3K/AKT/mTOR pathway.

Morroniside attenuates high glucose-induced BMSC dysfunction by regulating the Glo1/AGE/RAGE axis.

OBJECTIVES: High glucose (HG)-mediated bone marrow mesenchymal stem cell (BMSC) dysfunction plays a key role in impaired bone formation induced by type 1 diabetes mellitus (T1DM). Morroniside is an iridoid glycoside derived from the Chinese herb Cornus officinalis, and it has abundant biological activities associated with cell metabolism and tissue regeneration. However, the effects and underlying mechanisms of morroniside on HG-induced BMSC dysfunction remain poorly understood. MATERIALS AND METHODS: Alkaline phosphatase (ALP) staining, ALP activity and Alizarin Red staining were performed to assess the osteogenesis of BMSCs. Quantitative real-time PCR and Western blot (WB) were used to investigate the osteo-specific markers, receptor for advanced glycation end product (RAGE) signalling and glyoxalase-1 (Glo1). Additionally, a T1DM rat model was used to assess the protective effect of morroniside in vivo. RESULTS: Morroniside treatment reverses the HG-impaired osteogenic differentiation of BMSCs in vitro. Morroniside suppressed advanced glycation end product (AGEs) formation and RAGE expression by triggering Glo1. Moreover, the enhanced osteogenesis due to morroniside treatment was partially blocked by the Glo1 inhibitor, BBGCP2. Furthermore, in vivo, morroniside attenuated bone loss and improved bone microarchitecture accompanied by Glo1 upregulation and RAGE downregulation. CONCLUSIONS: These findings suggest that morroniside attenuates HG-mediated BMSC dysfunction partly through the inhibition of AGE-RAGE signalling and activation of Glo1 and may be a potential treatment for diabetic osteoporosis.

Morroniside enhances angiogenesis and improves cardiac function following acute myocardial infarction in rats.

Angiogenesis is critical for re-establishing blood supply to the ischemic myocardium after acute myocardial infarction (AMI). This study aimed to investigate the effects of morroniside on angiogenesis after AMI and explored associated proangiogenic mechanisms. A rat model of AMI was established by ligation of the left anterior descending coronary artery followed by administration of three doses of morroniside. Immunofluorescence staining was performed to identify newly generated endothelial cells and arterioles. The protein expression levels associated with angiogenesis were examined by western blots. Echocardiography was used to examine cardiac function. Our data revealed that morroniside promoted angiogenesis and improved cardiac function in rats with AMI. The proangiogenic effect of morroniside might be mediated by the VEGFA/VEGF receptor 2 signaling pathway.

Effects of Morroniside on the Viability of Random Skin Flaps in Rats.

Objective: The purpose of our experiment was to determine whether morroniside can improve the survival of ischemic skin flaps in rats. Methodology: A total of 40 male Sprague-Dawley rats were randomly divided into two groups (control group and treatment group). Modified McFarlane flaps were performed (causally based, 9 cm × 3 cm). The percentage of survival of each flap was calculated. Flap blood flows were measured by Laser-Doppler flowmeter. Flap vasculature was assessed by angiography after Lead oxide-gelatin injection. Vascular endothelial growth factor (VEGF) was evaluated by immunochemistry. Superoxide Dismutase (SOD) level and malondiadehyde (MDA) content were determined using assay kits. Results: At the seventh postoperative day, the morroniside-treated rats showed a higher percentage of flap survival than the control rats. Flap perfusion and the level of vascular endothelial growth factor were significantly elevated in the morroniside-treated group. In the treatment group, the distal section of the flap was nearly saturated with contrast agent, while in the control group, the contrast agent perfused only half of the flap. In the treatment group, morroniside administration significantly increased SOD level and reduced MDA content. Conclusion: Morroniside can enhance ischemic flap survival.

Morroniside protects against chronic atrophic gastritis in rat via inhibiting inflammation and apoptosis.

The aim of our study was to investigate the therapeutic efficacy of Morroniside (MR) in a chronic atrophic gastritis (CAG) rat model and its underlying mechanisms. Male Wistar rats were employed to induce CAG model. All animals were divided into six groups: control, model (CAG), positive (Vitacoenzyme tablets), MR low, middle and high three doses groups. Histopathology observation of gastric tissues was detected by hematoxylin and eosin (H&E) staining. The levels of gastrointestinal hormones and inflammatory factors in serum were measured by Enzyme-linked immunosorbent assay (ELISA). Apoptosis of gastric mucosa cell was detected using Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) assay. Protein expressions were evaluated by Western blotting. Obvious pathological injury and in the CAG model group were observed, which was improved after treatment with MR. The contents of serum gastrin (GAS) was increased whereas motilin (MTL) was decreased in a dose-dependent manner after MR treatment. MR markedly attenuated the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-1 beta (IL-1ß). Moreover, MR inhibited apoptosis of gastric mucosal cell as presented by TUNEL, coupled with an upregulation in Bcl-2 expression and a downregulation in Bax, cleaved caspase-3 and cleaved caspase-9 expression. Furthermore, the expression levels of phospho-NF-κB p65 (p-NF-κB p65) and p-IKKα/ß proteins were reduced accompanied by an increase in IκB-α expression in the MR-treated groups. The study demonstrated that MR is able to protect against CAG via inhibiting inflammation and apoptosis, which might provide a stronger theoretical basis for the treatment of CAG.

Morroniside protects against cerebral ischemia/reperfusion injury by inhibiting neuron apoptosis and MMP2/9 expression.

The aim of the present study was to investigate the effect of morroniside against matrix metalloproteinase (MMP)2/9 and focal cerebral ischemia/reperfusion (I/R) injury in rats. A rat model of focal cerebral I/R injury rats was established and rats were administered with 30, 90 or 270 mg/kg/day morroniside for 7 days. The expression of MMP2/9 and neuronal apoptosis were assessed. In addition, the expression of active caspase-3, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were measured. The results revealed that MMP2 and MMP9 expression was upregulated and the percentage of apoptotic neurons was increased in rats with focal cerebral I/R injury compared with the control. However, treatment with morroniside significantly inhibited I/R-induced MMP2/9 expression and neuron apoptosis compared with the untreated I/R injury group. Morroniside administration also decreased the expression of active caspase-3 and increased the Bcl-2/Bax ratio compared with untreated rats with focal cerebral I/R injury. The inhibitory effect of morroniside on MMP2/9 expression and neuron apoptosis was dose dependent. In summary, the results of the present study suggest that morroniside is able to protect against cerebral I/R injury in the brain and may have potential as a therapeutic treatment for patients who have suffered a stroke.

Morroniside prevents H2O2 or Aß1-42-induced apoptosis via attenuating JNK and p38 MAPK phosphorylation.

Amyloid-ß peptide (Aß) plays a causal role in the development and progression of Alzheimer's disease (AD). Oxidative stress and activation of mitogen-activated protein kinase (MAPK) are involved in Aß-induced neurotoxicity. Morroniside, one active monomer of dry ripe sarcocarp of Cornus officinalis, has shown antioxidant properties in several cell lines. The present study investigated the protective actions of morroniside against the cytotoxicity produced by exposure to H2O2 or Aß1-42 in rat pheochromocytoma (PC12) cells. Exposure of PC12 cells to 150 µM H2O2 or 20 µM Aß1-42 down-regulated anti-apoptotic protein expression (Bcl-2), up-regulated pro-apoptotic protein expression (Bax, cytochrome C, and cleaved caspase-3), increased JNK and p38 MAPK phosphorylation and finally caused significant cell death. This effect was reversed by pretreatment with morroniside in a dose-dependent manner. Among the selective inhibitors of MAPKs, the JNK inhibitor (SP600125) and p38 MAPK inhibitor (SB203580) showed steady preventive effect against H2O2 or Aß1-42-induced apoptosis. The results suggest that different from the selective inhibitors of MAPKs, morroniside can inhibit H2O2 or Aß1-42-induced apoptotic pathway activation through suppressing its upstream signaling components of JNK and p38 MAPK phosphorylation simultaneously.

Ethnopharmacology, phytochemistry, and pharmacology of Cornus officinalis Sieb. et Zucc.

ETHNOPHARMACOLOGICAL RELEVANCE: Cornus officinalis (Cornaceae), known in Chinese as "Shanzhuyu," is a frequently used traditional Chinese medicine. It tastes sour and is astringent and slightly warm in nature. Its fruits have long been used to treat kidney deficiency, high blood pressure, waist and knee pain, dizziness, tinnitus, impotence, spermatorrhea, menorrhagia, and other diseases in China. The main distribution areas are Shanxi and Gansu. AIM OF THE STUDY: This review focused on the ethnopharmacological uses of the herb. We also focus on the phytochemical, pharmacological, and toxicological studies on C. officinalis. The recent analytical methods developed for the quality control of the herb's constituents are also reviewed. Additionally, future trends and prospects in the study of this herb are proposed. MATERIALS AND METHODS: Information on C. officinalis was gathered by searching the internet (PubMed, ScienceDirect, Wiley, ACS, CNKI, Scifinder, Web of Science, Google Scholar, and Baidu Scholar) and libraries. RESULTS: This review compiled the ethnopharmacological uses, including the classic prescriptions and historical applications. Approximately 300 chemical compounds have been isolated and identified from C. officinalis. The major active components of the plant are organic acids and iridoids, among which morroniside and loganin have been extensively investigated. The fruit of the plant has been used in treating many diseases in traditional medicine. Scientific studies indicated the herb's wide range of pharmacological activities, such as hepatic and renal protection, antidiabetes activity, cardioprotection, antioxidation, neuroprotection, antitumor activity, anti-inflammation, analgesic effects, antiaging activity, antiamnesia, antiosteoporosis, and immunoregulation. The analytical methods developed for the quantitative and qualitative determination of various compounds in the herb were further reviewed. CONCLUSIONS: In this paper, we reviewed various studies conducted on C. officinalis, especially in areas of its ethnopharmacological use, as well as on its phytochemistry, pharmacology, and modern analytical methods used. Some of the herb's ethnomedical indications have been confirmed by the herb's pharmacological effects, such as its hepatic and renal protection and the antidiabetic effects. In particular, the crude extract and its chemical composition have exerted good therapeutic effect in diabetic treatment. C. officinalis entails additional attention on its pharmacological effects and drug development to expand its effective use clinically. Many advanced technologies are used for quality testing, but the detection component is exceedingly scarce for synthetically evaluating the quality of C. officinalis herbs. Thus, further research is necessary to investigate the quality control and toxicology of the plant, to further elucidate its clinical use, and to control herbal quality.

Morroniside promotes angiogenesis and further improves microvascular circulation after focal cerebral ischemia/reperfusion.

Preservation of cerebral microvascular functional integrity is crucial for protecting and repairing the brain after stroke. Our previous study demonstrated that morroniside promoted angiogenesis 7days after stroke. The current study aimed to further evaluate the long-term effects of morroniside on angiogenesis and to examine whether angiogenesis induced by morroniside could improve blood flow velocity. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO), and morroniside was then administered once per day at a dose of 270mg/kg. New vessel formation and the expression of ephrinB2/VEGFR2 signaling pathway components were examined 14days after MCAO to examine angiogenesis and the associated mechanisms. The dynamics of regional cerebral blood flow (rCBF) and the number of vessels of the leptomeningeal anastomoses were analyzed to characterize microvascular circulation 3days after MCAO. We demonstrated that morroniside promoted angiogenesis by regulating the ephrinB2/VEGFR2 signaling pathway 14days post-ischemia. By 3days post-ischemia, morroniside improved rCBF and increased the number of vessels of the leptomeningeal anastomoses. Moreover, morroniside decreased the infarct volume and improved neurological function 14days after MCAO. Our findings suggest that morroniside promoted long-term angiogenesis, thereby improving microvascular circulation and neurological function. It suggested that the angiogenic mechanism of morroniside might be mediated by the ephrinB2/VEGFR2 signaling pathway.

The effect of Liuwei Dihuang decoction on PI3K/Akt signaling pathway in liver of type 2 diabetes mellitus (T2DM) rats with insulin resistance.

ETHNOPHARMACOLOGICAL RELEVANCE: Liuwei Dihaung decoction (LWDHT) is a well-known classic traditional Chinese medicine formula, consists of six herbs including Rehmannia glutinosa Libosch.(family: Scrophulariaceae), Cornus officinalis Sieb.(family: Cornaceae), Dioscorea opposite Thunb.(family: Dioscoreaceae), Alisma orientale(G. Samuelsson) Juz (family: Alismataceae), Poria cocos (Schw.) Wolf (family: Polyporaceae) and Paeonia suffruticosa Andrews (family: Paeoniaceae). It has been used in the treatment of many types of diseases with signs of deficiency of Yin in the kidneys in China clinically. This study is aimed at investigating the effect of Liuwei dihuang decoction on PI3K/Akt signaling pathway in liver of T2DM rats with insulin resistance. MATERIALS AND METHODS: T2DM model was induced in male Sprague-Dawley (SD) rats by high sugar and high fat diets combined with small dose of streptozocin (STZ) injection. The successful T2DM rats were randomly allocated three group--vehicle group, positive control group and Liuwei Dihuang decoction group. After 12-weeks treatment with distilled water, rosiglitazone and LWDHT by intragastric administration respectively, the rats were put to death in batches. The variance of fasting blood glucose (FBG) and fasting insulin (FINS) in serum were determined, the pathological changes of each rats' liver were observed by hematoxylin-eosin (HE) staining, the expression of insulin receptor substrate 2(IRS2), phosphatidylinositol 3-kinase (PI3K) and protein kinas B (Akt) involving the canonical PI3K/Akt signaling pathway were detected by Real-time fluorescent quantitative PCR (RT-PCR), and the expression level of IRS2, PI3K, Akt protein and phosphorylated IRS2, PI3K, Akt protein were evaluated by Western Blot. All the data were analyzed by SPSS 17.0. RESULTS: Four weeks of treatment with LWDHT could significantly decrease the level of FBG and FINS in serum, improve the cellular morphology of liver, kidney, pancreas tissue, and the expression of IRS2, PI3K, Akt mRNA and phosphorylated IRS2, PI3K, Akt protein involved in the canonical PI3K/Akt signaling pathway of T2DM rats in liver were significantly up-regulated, while the total IRS2, PI3K, and Akt protein had no obvious changes. CONCLUSIONS: The results suggest that Liuwei Dihuang decoction could intervene insulin resistance of T2DM, in part, through regulation of canonical PI3K/Akt signaling pathway of T2DM rats in liver.

Morroniside-Induced PP2A Activation Antagonizes Tau Hyperphosphorylation in a Cellular Model of Neurodegeneration.

BACKGROUND: An accumulation of hyperphosphorylated tau in the brain is a hallmark of Alzheimer's disease (AD). Deficits in protein phosphatase 2A (PP2A) are associated with tau hyperphosphorylation in AD. OBJECTIVE: To investigate the effects of morroniside (MOR), isolated from Cornus officinalis, on tau hyperphosphorylation and its underlying mechanisms related to PP2A. METHODS: SK-N-SH cells were pretreated with 50-200 µM MOR for 24 h followed by 20 nM okadaic acid (OA) for 6 h. PP2Ac siRNA was transfected into HEK293 cells to determine the direct interaction of MOR with PP2A. Western blotting was used to measure the expression of proteins and enzymes. PP2A activity was measured by molybdenum blue spectrophotometry. RESULTS: Pretreatment with MOR improved the cellular morphological damage and inhibited tau hyperphosphorylation in SK-N-SH cells induced by OA, a PP2A inhibitor. Moreover, MOR increased PP2A activity, concurrent with a decrease in the expression of demethylated PP2A at Leu309 and phosphorylated PP2A at Tyr307. MOR decreased protein phosphatase methylesterase 1 (PME-1) expression and the ratio of PME-1/leucine carboxyl methyltransferase 1 (LCMT-1). Furthermore, MOR treatment decreased the phosphorylation of Src at Tyr416, which regulates the phosphorylation of PP2A. MOR had no effect on PP2Ac expression and tau hyperphosphorylation in PP2Ac siRNA-transfected cells. CONCLUSION: MOR attenuated OA-induced tau hyperphosphorylation via PP2A activation, and its mechanism might be related to the regulation of PP2Ac post-translational modification and upstream enzymes such as Src and PME-1.