Protective mechanism of salvianolic acid B on blood vessels / 中国中药杂志

Salvianolic acid B(Sal B) is the main water-soluble component of Salvia miltiorrhiza Bunge. Studies have found that Sal B has a good protective effect on blood vessels. Sal B can protect endothelial cells by anti-oxidative stress, inducing autophagy, inhibiting endoplasmic reticulum stress(ERS), inhibiting endothelial inflammation and adhesion molecule expression, inhibiting endothelial cell permeability, anti-thrombosis, and other ways. In addition, Sal B can alleviate endothelial cell damage caused by high glucose(HG). For vascular smooth muscle cell(VSMC), Sal B can reduce the synthesis and secretion of inflammatory factors by inhibiting cyclooxygenase. It can also play a vasodilatory role by inhibiting Ca~(2+) influx. In addition, Sal B can inhibit VSMC proliferation and migration, thereby alleviating vascular stenosis. Sal B also inhibits lipid deposition in the subendothelium, inhibits macrophage conversion to foam cells, and reduces macrophage apoptosis, thereby reducing the volume of subendothelial lipid plaques. For some atherosclerosis(AS) complications, such as peripheral artery disease(PAD), Sal B can promote angiogenesis, thereby improving ischemia. It should be pointed out that the conclusions obtained from different experiments are not completely consistent, which needs further research. In addition, previous pharmacokinetics showed that Sal B was poorly absorbed by oral administration, and it was unstable in the stomach, with a large first-pass effect in the liver. Sal B had fast distribution and metabolism in vivo and short drug action time. These affect the bioavailability and biological effects of Sal B, and the development of clinically valuable Sal B non-injectable delivery systems remains a great challenge.

Attenuation of Oxidative Stress-Induced Cell Apoptosis and Pyroptosis in RSC96 Cells by Salvianolic Acid B / 中国结合医学杂志

OBJECTIVE@#To determine whether salvianolic acid B (Sal B) exerts protective effects on diabetic peripheral neuropathy by attenuating apoptosis and pyroptosis.@*METHODS@#RSC96 cells were primarily cultured with DMEM (5.6 mmol/L glucose), hyperglycemia (HG, 125 mmol/L glucose) and Sal B (0.1, 1, and 10 µ mol/L). Cells proliferation was measured by 3-(4, 5-cimethylthiazol-2-yl)-2, 5-dilphenyltetrazolium bromide assay. Reactive oxygen species (ROS) generation and apoptosis rate were detected by flow cytometry analysis. Western blot was performed to analyze the expressions of poly ADP-ribose polymerase (PARP), cleaved-caspase 3, cleaved-caspase 9, Bcl-2, Bax, NLRP3, ASC, and interleukin (IL)-1β.@*RESULTS@#Treatment with HG at a concentration of 125 mmol/L attenuated cellular proliferation, while Sal B alleviated this injury (P<0.05). In addition, Sal B inhibited HG-induced ROS production and apoptosis rate (P<0.05). Furthermore, treatment with Sal B down-regulated HG-induced PARP, cleaved-caspase 3, cleaved-caspase 9, Bax, NLRP3, ASC, and IL-1β expression, but mitigated HG-mediated down-regulation of Bcl-2 expression (P<0.05).@*CONCLUSION@#Sal B may protect RSC96 cells against HG-induced cellular injury via the inhibition of apoptosis and pyroptosis activated by ROS.

Neuroprotective Effect of Isobenzofuranones on Hydrogen Peroxide-Mediated Redox Imbalance in Primary Cultures of Hippocampal Neurons

Abstract In live organisms, there is a balance between the production of reactive oxygen species (ROS) and their neutralization. The increased level of these species leads to a condition called redox imbalance. The aim of this study was to evaluate the protective action of isobenzofuranones in primary cultures of hippocampal neurons subjected to redox imbalance. To accomplish this, MTT and LIVE/DEAD assays were initially performed. In the cultures pretreated with isobenzofuranones 1 and 2, there was a higher number of live cells when compared to that in the untreated ones. Regarding redox imbalance, there was a significant increase in the intracellular levels of ROS. The cultures pretreated with isobenzofuranones showed a reduction in ROS levels. Lipid peroxidation caused by oxidative damage was significantly reduced in the cultures pretreated with isobenzofuranones 1 and 2. Taken together, these data show the ability of isobenzofuranones 1 and 2 to significantly minimize cytotoxicity, cell death, intracellular levels of ROS and lipid peroxidation induced by redox imbalance. These results suggest that isobenzofuranones 1 and 2 represent a possible alternative therapy for the neurodegenerative disturbances that are triggered by ROS production increases.

Isolation of dihydrobenzofuran derivatives from ethnomedicinal species Polygonum barbatum as anticancer compounds

BACKGROUND: Ethnomedicinally, the family Polygonaceae is famous for the management of cancer. Various species of this family have been reported with anticancer potentials. This study was designed to isolate anticancer compounds from ethnomedicinally important species Polygonum barbatum. METHODS: The column chromatography was used for the isolation of compounds from the solvent fraction of P. barbatum. The characterization of isolated compounds was performed by various spectroscopic techniques like UV, IR, mass spectrometry and 1D-2D NMR spectroscopy. Keeping in view the ethnomedicinal importance of the family, genus and species of P barbatum, the isolated compounds (1-3) were screened for anticancer potentials against oral cancer (CAL-27) and lungs cancer (NCI H460) cell lines using MTT assay. Active compound was further investigated for apoptosis by using morphological changes and flow cytometry analysis. In vivo anti-angiogenic study of the isolated compounds was also carried using chorioallantoic membrane assay. Docking studies were carried out to explore the mechanism of anticancer activity. RESULTS: Three dihydrobenzofuran derivatives (1-3) have been isolated from the ethyl acetate fraction of P. barbatum. The structures of isolated compounds were elucidated as methyl (2S,3S)-2-(3,4-dimethoxyphenyl)-4-((E)-3-ethoxy-3-oxoprop-1-en-1-yl)-7-methoxy-2,3-dihydrobenzo-furan-3-carboxylate (1), (E)-3-((2S,3S)-2-(3,4-dimethoxyphenyl)-7-methoxy-3-(methoxy carbonyl)-2,3-dihydrobenzofuran-4-yl)acrylic acid (2) and (2S,3 S)-4-((E)-2-carboxyvinyl)-2-(3,4-dimethoxyphenyl)-7-hydroxy-2,3-dihydrobenzofuran-3-carboxylic acid (3). The compound 1 was found to be more potent with IC50 of 48.52 ± 0.95 and 53.24 ± 1.49 against oral cancer cells as compared to standard drug (IC50 = 97.76 ± 3.44 µM). Both compound also inhibited lung cancer cells but at higher concentrations. Morphological and flow cytometry analysis further confirms that compound 1 induces apoptosis after 24 to 48 h treatment. In antiangiogenesis assay, compounds 1, 2 and 3 exhibited IC50 values of 8.2 ± 1.1,13.4 ± 1.1 and 57.7 ± 0.3 µM respectively. The docking studies revealed that the compounds under study have the potential to target the DNA and thymidylate synthase (TS). CONCLUSION: Based on its overwhelming potency against the tested cell lines and in angiogenesis assay, compound 1 can be further evaluated mechanistically and can be developed as anticancer drug candidate.

N-Myristoyltransferases as antileishmanial targets: a piggyback approach with benzoheterocyclic analogues

Leishmaniasis is one of the neglected diseases that remain in need for pharmacological alternatives. In this context, N-Myristoyltransferases (NMT) arise as interesting targets to explore since they are involved in the co/post-translational processing of peptides which are responsible for host cell invasion. Studies that consider these enzymes as targets point out the potential of benzoheterocyclic compounds as inhibitors of Candida albicans's N-myristoyltransferase. Here we applied a combination of comparative binding site analysis and molecular docking studies based on a Piggyback approach in the search for new Leishmania major NMT ligands. Our results revealed that NMT enzymes from both pathogens present enough structural similarity to allow extrapolation of the knowledge available from C. albicans studies to develop new L. major NMT inhibitors. Molecular docking studies with benzoheterocyclic analogues indicate the potential of benzothiazole derivatives as L. major NMT ligands, giving rise to a completely new class of chemical compounds to be explored in the development of antileishmanial drugs.

Antifungal activity against colletotrichum acutatum and colletotrichum gloeosporioides of the major constituents from wood sawdust of platymiscium gracile benth / Actividad antifúngica contra colletotrichum acutatum y colletotrichum gloeosporioides de los constituyentes mayoritarios del aserrín de madera de platymiscium gracile benth

The tree tomato (Solanum betaceum Cav., Solanaceae) anthracnose, caused by the fungi Colletotrichum acutatum and Colletotrichum gloeosporioides, is the most important disease of this crop in Colombia for its wide distribution and the losses it causes. In the present work, the in vitro antifungal activity of the soluble fractions in n-hexane, dichloromethane, and ethyl acetate, and their major constituents from the sawdust of timber specie Platymiscium gracile Benth. (Fabaceae) against both fungi was evaluated. The n-hexane-soluble fraction exhibited the greatest inhibitory effect. The metabolites homopterocarpin (a pterocarpan, 0.39 percent dry weight), calycosin (an isoflavone, 2.01 percent) and scoparone (a coumarin, 1.48 percent) were isolated for the first time from wood sawdust of P. gracile. The structure of these compounds was determined by 1H and 13C NMR analyses. The three compounds tested showed significant antifungal activity.

La antracnosis del tomate de árbol (Solanum betaceum Cav., Solanaceae), ocasionada por los hongos Colletotrichum acutatum y Colletotrichum gloeosporioides, es la enfermedad más importante de este cultivo en Colombia por su amplia distribución y las pérdidas que ocasiona. En el presente trabajo se evaluó la actividad antifúngica in vitro de las fracciones solubles en n-hexano, diclorometano y acetato de etilo, y sus componentes mayoritarios, del aserrín de la especie maderable Platymiscium gracile Benth. (Fabaceae), contra ambos hongos. La fracción en n-hexano exhibió el mayor efecto inhibitorio. Los metabolitos homopterocarpina (un pterocarpano; 0.39 por ciento del peso seco de aserrín), calicosin (una isoflavona; 2.01 por ciento) y escoparona (una cumarina; 1.48 por ciento) se aislaron por primera vez desde el aserrín de madera de P. gracile empleando técnicas cromatográficas. La estructura de los compuestos se determinó por análisis de RMN de 1H y 13C. Los tres metabolitos mostraron una actividad antifúngica significativa contra ambos hongos.

Attenuation of renal ischemic reperfusion injury by salvianolic acid B via suppressing oxidative stress and inflammation through PI3K/Akt signaling pathway

Salvianolic acid B (SAB) is one the major phytocomponents of Radix Salvia miltiorrhiza and exhibit numerous health promoting properties. The objective of the current study was to examine whether SAB exerts a renoprotective effect by attenuating oxidative stress and inflammatory response through activating phosphatidylinositol 3-kinase/serine-threonine kinase B (PI3K/Akt) signaling pathway in a renal ischemic reperfusion rat model. Forty Sprague-Dawley male rats (250–300 g) were obtained and split into four groups with ten rats in each group. The right kidney of all rats was removed (nephrectomy). The rats of the Control group received only saline (occlusion) and served as a sham control group, whereas rats subjected to ischemic reperfusion (IR) insult by clamping the left renal artery served as a postitive control group. The other 2 groups of rats were pretreated with SAB (20 and 40 mg·kg-1·day-1) for 7 days prior IR induction and served as treatment groups (SAB 20+IR; SAB 40+IR). Renal markers creatinine (Cr) and blood urea nitrogen (BUN) were significantly lower in the groups that received SAB. Pretreatment with SAB appears to attenuate oxidative stress by suppressing the production of lipid peroxidation products like malondialdehyde as well as elevating antioxidant activity. The concentration of inflammatory markers and neutrophil infiltration (myeloperoxidase) were significantly decreased. Meanwhile, PI3K protein expression and pAkt/Akt ratio were significantly upregulated upon supplementation with SAB, indicating its renoprotective activity. Taken together, these results indicate that SAB can therapeutically alleviate oxidative stress and inflammatory process via modulating PI3K/Akt signaling pathway and probably ameliorate renal function and thus act as a renoprotective agent.

Effects of the encapsulation of usnic acid into liposomes and interactions with antituberculous agents against multidrug-resistant tuberculosis clinical isolates

Mycobacterium tuberculosis (Mtb) has acquired resistance and consequently the antibiotic therapeutic options available against this microorganism are limited. In this scenario, the use of usnic acid (UA), a natural compound, encapsulated into liposomes is proposed as a new approach in multidrug-resistant tuberculosis (MDR-TB) therapy. Thus the aim of this study was to evaluate the effect of the encapsulation of UA into liposomes, as well as its combination with antituberculous agents such as rifampicin (RIF) and isoniazid (INH) against MDR-TB clinical isolates. The in vitro antimycobacterial activity of UA-loaded liposomes (UA-Lipo) against MDR-TB was assessed by the microdilution method. The in vitro interaction of UA with antituberculous agents was carried out using checkerboard method. Minimal inhibitory concentration values were 31.25 and 0.98 µg/mL for UA and UA-Lipo, respectively. The results exhibited a synergistic interaction between RIF and UA [fractional inhibitory concentration index (FICI) = 0.31] or UA-Lipo (FICI = 0.28). Regarding INH, the combination of UA or UA-Lipo revealed no marked effect (FICI = 1.30-2.50). The UA-Lipo may be used as a dosage form to improve the antimycobacterial activity of RIF, a first-line drug for the treatment of infections caused by Mtb.

Protection against neurotoxicity by an autophagic mechanism

The objective of the present study was to investigate the effects of 3-n-butylphthalide (NBP) on a 1-methyl-4-phenylpyridinium (MPP+)-induced cellular model of Parkinson’s disease (PD) and to illustrate the potential mechanism of autophagy in this process. For this purpose, rat PC12 pheochromocytoma cells were treated with MPP+ (1 mM) for 24 h following pretreatment with NBP (0.1 mM). Cell metabolic viability was determined by the MTT assay and cell ultrastructure was examined by transmission electron microscopy. The intracellular distribution and expression of α-synuclein and microtubule-associated protein light chain 3 (LC3) were detected by immunocytochemistry and Western blotting. Our results demonstrated that: 1) NBP prevented MPP+-induced cytotoxicity in PC12 cells by promoting metabolic viability. 2) NBP induced the accumulation of autophagosomes in MPP+-treated PC12 cells. 3) Further study of the molecular mechanism demonstrated that NBP enhanced the colocalization of α-synuclein and LC3 and up-regulated the protein level of LC3-II. These results demonstrate that NBP protects PC12 cells against MPP+-induced neurotoxicity by activating autophagy-mediated α-synuclein degradation, implying that it may be a potential effective therapeutic agent for the treatment of PD.

Does usnic acid affect microtubules in human cancer cells? / O ácido úsnico pode afetar microtúbulos em células cancerosas humanas?

Usnic acid, a lichen metabolite, is known to exert antimitotic and antiproliferative activities against normal and malignant human cells. Many chemotherapy agents exert their activities by blocking cell cycle progression, inducing cell death through apoptosis. Microtubules, protein structure involved in the segregation of chromosomes during mitosis, serve as chemotherapeutical targets due to their key role in cellular division as well as apoptosis. The aim of this work was to investigate whether usnic acid affects the formation and/or stabilisation of microtubules by visualising microtubules and determining mitotic indices after treatment. The breast cancer cell line MCF7 and the lung cancer cell line H1299 were treated with usnic acid 29 µM for 24 hours and two positive controls: vincristine (which prevents the formation of microtubules) or taxol (which stabilizes microtubules). Treatment of MCF7 and H1299 cells with usnic acid did not result in any morphological changes in microtubules or increase in the mitotic index. These results suggest that the antineoplastic activity of usnic acid is not related to alterations in the formation and/or stabilisation of microtubules.

O ácido úsnico, um metabólito de liquens, é conhecido por sua atividade antimitótica e antiproliferativa em células humanas normais e malignas. Muitos quimioterápicos exercem suas atividades bloqueando a progressão do ciclo celular e induzindo morte celular por apoptose. Os microtúbulos, estruturas protéicas envolvidas na segregação dos cromossomos durante a mitose, servem como alvo quimioterapêutico devido ao seu importante papel tanto na divisão celular quanto nos mecanismos de morte celular por apoptose. O objetivo deste trabalho foi investigar se o ácido úsnico afeta a formação e/ou estabilização dos microtúbulos, a partir da visualização de microtúbulos e determinação de índices mitóticos após o tratamento. Células de câncer de mama MCF7 e de câncer de pulmão H1299 foram tratadas por 24 horas com 29 µM de ácido úsnico e dois controles positivos: vincristina (que impede a formação de microtúbulos) e taxol (que estabiliza microtúbulos). O tratamento das células MCF7 e H1299 com o ácido úsnico não resultou em aumento do índice mitótico. Os resultados sugerem que a atividade antineoplásica do ácido úsnico não está relacionada a alterações na formação e/ou estabilização de microtúbulos.

Sulfuretin protects against cytokine-induced beta-cell damage and prevents streptozotocin-induced diabetes

NF-kappaB activation has been implicated as a key signaling mechanism for pancreatic beta-cell damage. Sulfuretin is one of the main flavonoids produced by Rhus verniciflua, which is reported to inhibit the inflammatory response by suppressing the NF-kappaB pathway. Therefore, we isolated sulfuretin from Rhus verniciflua and evaluated if sulfuretin could inhibit cytokine- or streptozotocin-induced beta-cell damage. Rat insulinoma RINm5F cells and isolated rat islets were treated with IL-1beta and IFN-gamma to induce cytotoxicity. Incubation of cells and islets with sulfuretin resulted in a significant reduction of cytokine-induced NF-kappaB activation and its downstream events, iNOS expression, and nitric oxide production. The cytotoxic effects of cytokines were completely abolished when cells or islets were pretreated with sulfuretin. The protective effect of sulfuretin was further demonstrated by normal insulin secretion of cytokine-treated islets in response to glucose. Treatment of mice with streptozotocin resulted in hyperglycemia and hypoinsulinemia, which was further evidenced by immunohistochemical staining of islets. However, the diabetogenic effects of streptozotocin were completely prevented when mice were pretreated with sulfuretin. The anti-diabetogenic effects of sulfuretin were also mediated by suppression of NF-kappaB activation. Collectively, these results indicate that sulfuretin may have therapeutic value in preventing beta-cell damage.

Study of the anti-inflammatory and analgesic effects of novel rigid benzofuran-3, 4-dihydroxy chalcone by formalin, hot-plate and carrageenan tests in mice

It is reported that dihydroxy chalcones have analgesic and anti-inflammatory effects. Study of the structure activity relationship [SAR] shows that benzofuran-3-one derivatives may be more effective in this respect. In this study, a new [Z]-2-[3,4-dihydroxybenzylidene]-5-methoxybenzofuran-3[2H]-one [compound 5] was synthesized and its analgesic and anti-inflammatory effects were evaluated by formalin, carrageenan and hot-Plate methods in mice. The results showed that, compound 5 induced significant antinociceptive and anti-inflammatory effect [P< 0.01]. Maximum analgesia [42.6%] was obtained at dose of 25 mg/kg in the first phase of formalin test. The effect of compound 5 was higher [87.7%] in chronic phase of inflammation induced by formalin [P< 0.01]. Administration of 25 mg/kg of compound 5 inhibited the inflammation induced by carrageenan, 32.8% and 41.7%, 1 and 3 hour after carrageenan injection, respectively. In addition, this dose of compound 5, induces significant analgesia [20.2%] in hot plate test 45 minutes after injection [P<0.01]. Therefore it seems that compound 5 has potential for discovery of a compound with potent anti-inflammatory and analgesic effects and its scaffold could be use for further structural modifications

Effects of cyclo-oxygenase and thromboxane synthetase inhibitors on right atrial prostaglandins.

OBJECTIVES: The aim of this study was to find out the effects of cyclo-oxygenase and thromboxane synthetase inhibitors on right atrial prostacyclin and thromboxane A2 levels. METHODS: The study consisted of a total of 50 patients subjected to coronary bypass surgery. These patients were divided into two groups, Group I and Group II each consisting of 25 patients. In Group I patients, the right atrial tissues were studied for effects of indomethacin and U63557A on the prostaglandin levels. In Group II patients, the right atrial tissues were studied for effects of Aspirin and U63557A on the prostaglandin levels. RESULTS: In Group I patients, the atrial tissues pretreated with indomethacin showed a fall in the levels of 6 keto PGF1 alpha from 153.5 +/- 28.4 pg/0.1 mg to 59.7 +/- 11.6 pg/0.1 mg and of TXB2 from 41.6 +/- 1.2 pg/0.1 mg to 17.2 +/- 3.2 pg/0.1 mg. In the atrial tissues of Group I treated with U63557A the levels of 6 keto PGF1 alpha fell to 145.4 +/- 26.8 pg/0.1 mg and the levels of TXB2 fell to 14.7 +/- 2.8 pg/0.1 mg. In Group II patients, the atrial tissues pretreated with aspirin, showed a fall in the levels of 6 keto PGF1 alpha from 142.1 +/- 2.8 pg/0.1 mg to 17.5 +/- 0.8 pg/0.1 mg. In the atrial tissues pretreated with U63557A, the levels of 6 keto PGF1 alpha fell to 131.2 +/- 2.9 pg/0.1 mg and the levels of TXB2 fell to 14.4 +/- 0.7 pg/0.1 mg. CONCLUSIONS: The study showed that human right atrial tissues are capable of producing TXA2 in addition to prostacyclin. Indomethacin and aspirin by inhibiting generation of cyclic endoperoxides inhibited synthesis of both prostacyclin and TXA2. In contrast a thromboxane synthethase inhibitor U63557A selectively inhibited TXA2 without significant effects on prostacyclin synthesis.

Aspectos farmacoclínicos de la amiodarona / Pharmacoclinical aspects of the amiodarone

Se indican los aspectos farmacoclínicos de la amiodarona y se revisan algunos aspectos que tienen vigencia en la práctica clínica diaria. Se informa el uso de la amiodarona como uno de los fármacos antiarrítmicos más importantes de la última década y los beneficios e inconvenientes que puede obtener un paciente con su uso