VASODILATATION INDUCED BY SINOMENINE LOWERS BLOOD PRESSURE IN SPONTANEOUSLY HYPERTENSIVE RATS

Sinomenine accelerate wound healing in rats by augmentation of antioxidant, anti-inflammatory, immunuhistochemical pathways

Sinomenine (SN) is a well-documented unique plant alkaloid extracted from many herbal medicines. The present study evaluates the wound healing potentials of SN on dorsal neck injury in rats. A uniform cut was created on Sprague Dawley rats (24) which were arbitrarily aligned into 4 groups receiving two daily topical treatments for 14 days as follows: A, rats had gum acacia; B, rats addressed with intrasite gel; C and D, rats had 30 and 60 mg/ml of SN, respectively. The acute toxicity trial revealed the absence of any toxic signs in rats after two weeks of ingestion of 30 and 300 mg/kg of SN. SN-treated rats showed smaller wound areas and higher wound closure percentages compared to vehicle rats after 5, 10, and 15 days of skin excision. Histological evaluation of recovered wound tissues showed increased collagen deposition, fibroblast content, and decreased inflammatory cells in granulated tissues in SN-addressed rats, which were statistically different from that of gum acacia-treated rats. SN treatment caused positive augmentation of Transforming Growth Factor Beta 1 (angiogenetic factor) in wound tissues, denoting a higher conversion rate of fibroblast into myofibroblast (angiogenesis) that results in faster wound healing action. Increased antioxidant enzymes (SOD and CAT), as well as decreased MDA contents in recovered wound tissues of SN-treated rats, suggest the antioxidant potentials of SN that aid in faster wound recovery. Wound tissue homogenates showed higher hydroxyproline amino acid (collagen content) values in SN-treated rats than in vehicle rats. SN treatment suppressed the production of pro-inflammatory cytokines and increased anti-inflammatory cytokines in the serum of wounded rats. The outcomes present SN as a viable pharmaceutical agent for wound healing evidenced by its positive modulation of the antioxidant, immunohistochemically proteins, hydroxyproline, and anti-inflammatory cytokines.

Chemistry and biology of ent-morphinan alkaloids

Morphinan alkaloids have attracted constant attention since the isolation of morphine by Sertürner in 1805. However, a group of 45 compounds possessing a complete ent-morphinan backbone can also be found in the literature. These compounds are related to the morphinandienone subgroup and display a substitution pattern which is different from the morphinans. In particular, these alkaloids could be substituted at position C-2 and C-8 either by a hydroxy function or a methoxy moiety. Four groups of ent-morphinan alkaloids can be proposed, the salutaridine, pallidine, cephasugine and erromangine series. Interestingly, the botanical distribution of the ent-morphinans is more widespread than for the morphinans and includes the Annonaceae, Berberidaceae, Euphorbiaceae, Fumariaceae, Hernandiaceae, Lauraceae, Menispermaceae, Monimiaceae, Papaveraceae, and Ranunculaceae families. To date, their exact mode of production remains elusive and their interplay with the biosynthetic pathway of other classes of benzyltetrahydroisoquinoline alkaloids, in particular aporphines, should be confirmed. Exploration of the biological and therapeutic potential of these compounds is limited to some areas, namely central nervous system (CNS), inflammation, cancer, malaria and viruses. Further studies should be conducted to identify the cellular/molecular targets in view of promoting these compounds as new scaffolds in medicinal chemistry.

Sinomenine Confers Protection Against Myocardial Ischemia Reperfusion Injury by Preventing Oxidative Stress, Cellular Apoptosis, and Inflammation

Sinomenine (SIN), an alkaloid extracted from the root of S. acutum. sinomenine, has been shown to have antiarrhythmic, antioxidant, and anti-inflammatory effects in myocardial ischemia-reperfusion injury (MIRI) ex vivo. In this study, we investigated the cardioprotective effects of SIN in an in vivo mouse model of MIRI. Adult male C57BL/6J mice received SIN (80 mg/kg) for 5 days and underwent 30 min of percutaneous occlusion of the left anterior descending artery (LAD) followed by 24 h of reperfusion. Results showed that pretreatment with SIN significantly reduced myocardial infarct size and concentrations of markers of cardiac injury and improved left ventricular ejection fraction (EF) and shortening fraction (FS) in MIRI mice. The SIN pretreatment prevented the MIRI-induced decrease in the expression levels of Bcl-2, increase in the expression levels of caspase-3, caspase-9, and Bax, and increase in the number of TUNEL-positive cells in ischemic heart tissue. It was also found that pretreatment with SIN prevented the MIRI-induced oxidative stress imbalance in ischemic heart tissue, as shown by the increase in total antioxidant capacity (T-AOC) and glutathione (GSH) and the decrease in malondialdehyde (MDA), reactive oxygen species (ROS), and dihydroethidium (DHE) density. Further studies showed that the stimulus of cardiac ischemia/reperfusion caused a remarkable increase in the expression levels of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) mRNA in ischemic heart tissue, which was effectively prevented by pretreatment with SIN. These results demonstrate that SIN can attenuate MIRI-induced cardiac injury in vivo by preventing oxidative stress, inflammation, and apoptosis.

Sinomenine in Cardio-Cerebrovascular Diseases: Potential Therapeutic Effects and Pharmacological Evidences

Cardio-cerebrovascular diseases, as a major cause of health loss all over the world, contribute to an important part of the global burden of disease. A large number of traditional Chinese medicines have been proved effective both clinically and in pharmacological investigations, with the acceleration of the modernization of Chinese medicine. Sinomenine is the main active constituent of sinomenium acutum and has been generally used in therapies of rheumatoid arthritis and neuralgia. Varieties of pharmacological effects of sinomenine in cardio-cerebrovascular system have been discovered recently, suggesting an inspiring application prospect of sinomenine in cardio-cerebrovascular diseases. Sinomenine may retard the progression of atherosclerosis by attenuating endothelial inflammation, regulating immune cells function, and inhibiting the proliferation of vascular smooth muscle cells. Sinomenine also alleviates chronic cardiac allograft rejection relying on its anti-inflammatory and anti-hyperplastic activities and suppresses autoimmune myocarditis by immunosuppression. Prevention of myocardial or cerebral ischemia-reperfusion injury by sinomenine is associated with its modulation of cardiomyocyte death, inflammation, calcium overload, and oxidative stress. The regulatory effects on vasodilation and electrophysiology make sinomenine a promising drug to treat hypertension and arrhythmia. Here, in this review, we will illustrate the pharmacological activities of sinomenine in cardio-cerebrovascular system and elaborate the underlying mechanisms, as well as give an overview of the potential therapeutic roles of sinomenine in cardio-cerebrovascular diseases, trying to provide clues and bases for its clinical usage.

Chemo Proling and Simultaneous Analysis of Different Combinations of Sinomenii Caulis and Ramulus Cinnamomi Using UHPLC-Q-TOF-MS, GC-MS and HPLC Methods

OBJECTIVE

Sinomenii Caulis (QingFengTeng) and Ramulus Cinnamomi (GuiZhi) are traditional Chinese drugs that have been used for anti-inflammation. In this study, the team plans to find out the material basis of a Chinese herb combination composed of the two herbs with different ratios.

METHODS

The extracts of the herbal compound with various ratios obtained from ethanol extraction were analyzed by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) and gas chromatography coupled mass spectrometry to identify the basic chemical compounds. Simultaneously, the contents of the eight main components (sinomenine, magnoflorine, laurifoline, dauricine, coumarin, cinnamyl alcohol, cinnamic acid and cinnamaldehyde) from herb formula were determined by gradient elution by high-performance liquid chromatography. Furthermore, the content of sinomenine and cinnamaldehyde were determined by isocratic elution, respectively.

RESULTS

Eighteen compounds in the herb formula were identified by UHPLC-Q-TOF-MS. The components in the GuiZhi are mostly volatile oils and the kinds of compounds isolated from the formula in the ratio of 4:1 were the most. Wherein eight compounds were identified as the main detection targets in the content determination.

CONCLUSION

The extraction rate of sinomenine in QingFengTeng was related to the proportion of GuiZhi in the drug pairs. Synchronously, the addition of sinomenine in different proportions also had some influence on the extraction of cinnamaldehyde in GuiZhi. Furthermore, the series of methods was successfully applied to the simultaneous determination of chemical compounds in different samples of QingFengTeng-GuiZhi decoction.

Review of Natural Resources With Vasodilation: Traditional Medicinal Plants, Natural Products, and Their Mechanism and Clinical Efficacy

For decades, chronic diseases including cardiovascular and cerebrovascular diseases (CCVDs) have plagued the world. Meanwhile, we have noticed a close association between CCVDs and vascular lesions, such as hypertension. More focus has been placed on TMPs and natural products with vasodilation and hypotension. TMPs with vasodilatory and hypotensive activities are mainly from Compositae, Lamiaceae, and Orchidaceae (such as V. amygdalina Del., T. procuinbens L., M. glomerata Spreng., K. galanga L., etc.) whereas natural products eliciting vasorelaxant potentials were primarily from flavonoids, phenolic acids and alkaloids (such as apigenin, puerarin, curcumin, sinomenine, etc.). Furthermore, the data analysis showed that the vasodilatory function of TMPs was mainly concerned with the activation of eNOS, while the natural products were primarily correlated with the blockage of calcium channel. Thus, TMPs will be used as alternative drugs and nutritional supplements, while natural products will be considered as potential therapies for CCVDs in the future. This study provides comprehensive and valuable references for the prevention and treatment of hypertension and CCVDs and sheds light on the further studies in this regard. However, since most studies are in vitro and preclinical, there is a need for more in-depth researches and clinical trials to understand the potential of these substances.

Investigation of morin-induced insulin secretion in cultured pancreatic cells

Morin is a flavonoid contained in guava that is known to reduce hyperglycemia in diabetes. Insulin secretion has been demonstrated to increase following the administration of morin. The present study is designed to investigate the potential mechanism(s) of morin-induced insulin secretion in the MIN6 cell line. First, we identified that morin induced a dose-dependent increase in insulin secretion and intracellular calcium content in MIN6 cells. Morin potentiated glucose-stimulated insulin secretion (GSIS). Additionally, we used siRNA for the ablation of imidazoline receptor protein (NISCH) expression in MIN6 cells. Interestingly, the effects of increased insulin secretion by morin and canavanine were markedly reduced in Si-NISCH cells. Moreover, we used KU14R to block imidazoline I₃ receptor (I-3R) that is known to enhance insulin release from the pancreatic β-cells. Without influence on the basal insulin secretion, KU14R dose-dependently inhibited the increased insulin secretion induced by morin or efaroxan in MIN6 cells. Additionally, effects of increased insulin secretion by morin or efaroxan were reduced by diazoxide at the dose sufficient to open K_ATP channels and attenuated by nifedipine at the dose used to inhibit L-type calcium channels. Otherwise, phospholipase C (PLC) is introduced to couple with imidazoline receptor (I-R). The PLC inhibitor dose-dependently inhibited the effects of morin in MIN6 cells. Similar blockade was also observed in protein kinase C (PKC) inhibitor-treated cells. Taken together, we found that morin increases insulin secretion via the activation of I-R in pancreatic cells. Therefore, morin would be useful to develop in the research and treatment of diabetic disorders.

Diosmin, a Citrus Nutrient, Activates Imidazoline Receptors to Alleviate Blood Glucose and Lipids in Type 1-Like Diabetic Rats

Diosmin is a nutrient that is widely contained in citrus and that has been indicated to improve glucose metabolism in diabetic disorders. Recently, we demonstrated that diosmin induces β-endorphin to lower hyperglycemia in diabetic rats. However, the mechanisms of diosmin in opioid secretion were unclear. Therefore, we focused on the secretion of opioids from isolated adrenal glands induced by diosmin. The changes in the released β-endorphin-like immunoreactivity (BER) were determined using ELISA. Diosmin increased the BER level in a dose-dependent manner, and this effect was markedly reduced in the absence of calcium ions. Activation of the imidazoline I-2 receptor (I-2R) has been introduced to induce opioid secretion. Interestingly, we observed that diosmin activates CHO cells expressing I-R. Additionally, diosmin-increased BER was inhibited by the blockade of I-2R in isolated adrenal glands. Additionally, an antagonist of I-2R blocked diosmin-induced effects, including the reduction in hyperglycemia and the increase in plasma BER in streptozotocin-induced diabetic rats (STZ-diabetic rats). Repeated treatment of STZ-diabetic rats with diosmin for one week induced changes in hepatic glycogen, lipid levels, and the expression of phosphoenolpyruvate carboxykinase (PEPCK). Furthermore, an antagonist of I-2R blocked the diosmin-induced changes. Additionally, plasma lipids modified by diosmin were also reversed by the blockade of I-2R in STZ-diabetic rats. Taken together, we suggest that diosmin may activate I-2R to enhance the secretion of β-endorphin from adrenal glands and to influence metabolic homeostasis, resulting in alleviation of blood glucose and lipids in STZ-diabetic rats.

Therapeutic Effect Analysis of Sinomenine on Rat Cerebral Ischemia-Reperfusion Injury

OBJECTIVE

The objective of this study is to investigate the therapeutic effect of sinomenine (SIN) on rat cerebral ischemia-reperfusion (IR) injury and the molecular mechanism.

METHODS

One hundred thirty-five rats were equally randomized into sham-operated group, middle cerebral artery occlusion (MCAO) group, and SIN group, and reversible rat MCAO model was made according to the Longa method for the MCAO and SIN groups. Then, 15 rats from each group were decapitated at 6, 12, and 24 hours after reperfusion to obtain brain tissue samples. Rats in the SIN group were injected with sinomenine by tail vein (90 mg/kg) 1 hour before ischemia; rats in the MCAO and sham-operated groups were administrated with the same volume of saline. Neurological severity score (NSS), infarction volume, ischemic brain water content, and blood-brain barrier (BBB) permeability were determined at corresponding time points. Acid-sensing ion channel (ASIC) 1a mRNA level was determined by quantitative real-time polymerase chain reaction; ischemic brain contents of lactic acid (LD), lactic dehydrogenase (LDH), ATPase, and inflammatory factors were determined by spectrophotometric method.

RESULTS

At 12 hours after reperfusion and since then, NSS in the SIN group decreased obviously; infarction volume, brain water content, and BBB permeability in the SIN group were lower than those in the MCAO group (P < .05). IR injury resulted in the upregulation of the contents of ASIC1a mRNA, LD, LDH, and inflammatory factors and the downregulation of the contents of ATPase, while SIN could reverse the upregulation/downregulation effect induced by IR injury (P < .05).

CONCLUSION

Through its anti-inflammation effect, which alleviates acidosis, improves energy metabolism, and inhibits ASIC1a level, SIN protects ischemic rat brain against cerebral IR injury.

Canavanine induces insulin release via activation of imidazoline I3 receptors

The aim of the present study was to identify the effect of canavanine on the imidazoline receptor because canavanine is a guanidinium derivative that has a similar structure to imidazoline receptor ligands. Transfected Chinese hamster ovary-K1 cells expressing imidazoline receptors (nischarin (NISCH)-CHO-K1 cells) were used to elucidate the direct effects of canavanine on imidazoline receptors. In addition, the imidazoline I3 receptor has been implicated in stimulation of insulin secretion from pancreatic β-cells. Wistar rats were used to investigate the effects of canavanine (0.1, 1 and 2.5 mg/kg, i.v.) on insulin secretion. In addition the a specific I3 receptor antagonist KU14R (4 or 8 mg/kg, i.v.) was used to block I3 receptors. Canavanine decreased blood glucose by increasing plasma insulin in rats. In addition, canavanine increased calcium influx into NISCH-CHO-K1 cells in a manner similar to agmatine, the endogenous ligand of imidazoline receptors. Moreover, KU12R dose-dependently attenuated canavanine-induced insulin secretion in HIT-T15 pancreatic β-cells and in the plasma of rats. The data suggest that canavanine is an agonist of I3 receptors both in vivo and in vitro. Thus, canavanine would be a useful tool in imidazoline receptor research.

Characterization of musclin as a new target for treatment of hypertension

Musclin is a novel skeletal muscle-derived factor found in the signal sequence trap of mouse skeletal muscle cDNAs. Recently, it has been demonstrated that musclin is involved in the pathogenesis of spontaneously hypertensive rats (SHRs). However, it is known as a genetic hypertension model. In the present study, we aim to investigate the role of musclin in another animal model of hypertension and characterize the direct effect of musclin on vascular contraction. The results show that expression of musclin was increased in arterial tissues isolated from DOCA-salt induced hypertensive rats or the normal rats received repeated vasoconstriction with phenylephrine. Additionally, direct incubation with phenylephrine did not modify the expression of musclin in the in vitro studies. Also, the direct effect of musclin on the increase of intracellular calcium was observed in a concentration-dependent manner. These results provide the evidence to support that musclin is involved in hypertension. Thus, musclin is suitable to be considered as a novel target for treatment of hypertension.

Role of musclin in the pathogenesis of hypertension in rat

Musclin is a novel skeletal muscle-derived secretory factor found in the signal sequence trap of mouse skeletal muscle cDNAs. Musclin possesses a region homologous to the natriuretic peptide family. Thus, musclin is found to bind with the natriuretic peptide clearance receptors. However, the role of musclin in vascular regulation remains unclear. In this study, we aim to investigate the direct effect of musclin on vascular tone and to analyze its role in hypertension using the spontaneously hypertensive rats (SHR). In aortic strips isolated from SHR, musclin induced contractions in a dose-dependent manner. We found that the musclin-induced vasoconstriction was more marked in SHR than in normal rats (WKY). Moreover, this contraction was reduced by blockade of natriuretic peptide receptor C using the ab14355 antibody. Therefore, mediation of the natriuretic peptide receptor in musclin-induced vasoconstriction can be considered. In addition, similar to the natriuretic peptide receptor, expression of the musclin gene in blood vessels was higher in SHR than in WKY. Injection of musclin markedly increased the blood pressure in rats that can be inhibited by anti-musclin antibodies. Musclin-induced vasoconstriction was more pronounced in SHR than in WKY as in its expression. Taken together, these results suggest that musclin is involved in blood pressure regulation. The higher expression of musclin in hypertension indicates that musclin could be used as a new target for the treatment of hypertension in the future.

Characterization of preptin-induced insulin secretion in pancreatic β-cells

We aimed to characterize the effects of preptin on insulin secretion at the single-cell level, as well as the mechanisms underlying these changes, with respect to regulation by intracellular Ca(2+) [Ca(2+)](i) mobilization. This study assessed the effect of preptin on insulin secretion and investigated the link between preptin and the phospholipase C (PLC)/protein kinase C (PKC) pathway at the cellular level using fura-2 pentakis(acetoxymethyl) ester-loaded insulin-producing cells (Min 6 cells). Our results demonstrate that preptin promotes insulin secretion in a concentration-dependent manner. Using a PLC inhibitor (chelerythrine) or a PKC inhibitor (U73122) resulted in a concentration-dependent decrease in insulin secretion. Also, preptin mixed with IGF2 receptor (IGF2R) antibodies suppressed insulin secretion in a dose-dependent manner, which indicates that activation of IGF2R is mediated probably because preptin is a type of proIGF2. In addition, preptin stimulated insulin secretion to a similar level as did glibenclamide. The activation of PKC/PLC by preptin stimulation is highly relevant to the potential mechanisms for increase in insulin secretion. Our results provide new insight into the insulin secretion of preptin, a secreted proIGF2-derived peptide that can induce greater efficacy of signal transduction resulting from PLC and PKC activation through the IGF2R.

Sinomenium acutum: a review of chemistry, pharmacology, pharmacokinetics, and clinical use

CONTEXT

Sinomenium acutum (Thumb.) Rehd. et Wils. (Menispermaceae, SA) has been used as a traditional Chinese medicine in the treatment of various diseases for hundreds of years; it possesses favorable effects against autoimmune diseases, especially rheumatoid arthritis (RA). A great number of investigations have been done on SA in the last decade, but they are usually scattered across various publications.

OBJECTIVE

The purpose of this article is to summarize and review the published scientific information about the chemical constituents, pharmacological effects, pharmacokinetics, and clinic applications of this plant since 2000.

RESULTS

The information for 89 cases included in this review was compiled. The SA contains alkaloids, sterols, phospholipids, and some other components. A great deal of pharmacological and clinic research has been done on sinomenine, a main compound from SA, which mainly focuses on the immune system, cardiovascular system, and nervous system.

CONCLUSION

Previous studies strongly support its potential as an effective adaptogenic herbal remedy. There is no doubt that SA is being widely used now and will have extraordinary potential for the future.