新型硫化氢供体GYY4137对脂多糖诱导的小鼠急性肺损伤的保护作用

目的:急性肺损伤是临床上常见的危重病,发病急,死亡率高,目前仍缺乏有效的治疗手段,新型的外源性硫化氢供体GYY4137具有抗炎、抗休克、抗癌及抗血栓等作用,本研究探讨其对脂多糖诱导的小鼠急性肺损伤的保护作用及其机制。方法:将BALB/c小鼠(18-20 g)随机分为3组:正常对照组(20只),脂多糖组(20只),治疗组(20只),然后复制小鼠脂多糖诱导的急性肺损伤模型:给予小鼠腹腔注射脂多糖(10 mg/kg)复制小鼠急性肺损伤模型模型,治疗组注射脂多糖1小时后给予腹腔注射GYY4137(50 mg/kg),在给予脂多糖8小时后将小鼠处死,留取血清与组织标本。检测小鼠血清中的炎症因子肿瘤坏死因子α、白介素6及白介素10的表达,检测小鼠血清中H2S的含量,测得肺脏湿/干比,检测肺组织中的髓过氧化物酶活性,并测得肺组织中与氧化应激相关的H2O2、·OH与SOD因子的含量。结果:脂多糖引起了严重的肺损伤,GYY4137对脂多糖导致的肺水肿、炎症反应及氧化应激损伤有不同程度的改善,保护了脂多糖造成的肺损伤,降低了脂多糖诱导的小鼠肺脏氧化应激损伤。其保护作用于抗炎、抗氧化有关。结论:GYY4137可能通过抗炎、抗氧化作用途径保护了脂多糖造成的急性肺损伤,可能在炎症疾病模型中也发挥相同作用,并且为未来临床使用缓释硫化氢供体提供了基础资料。     

Dual Effects of Hydrogen Sulfide Donor on Meiosis and Cumulus Expansion of Porcine Cumulus-Oocyte Complexes

Hydrogen sulfide (H₂S) has been revealed to be a signal molecule with second messenger action in the somatic cells of many tissues, including the reproductive tract. The aim of this study was to address how exogenous H₂S acts on the meiotic maturation of porcine oocytes, including key maturation factors such as MPF and MAPK, and cumulus expansion intensity of cumulus-oocyte complexes. We observed that the H₂S donor, Na₂S, accelerated oocyte in vitro maturation in a dose-dependent manner, following an increase of MPF activity around germinal vesicle breakdown. Concurrently, the H₂S donor affected cumulus expansion, monitored by hyaluronic acid production. Our results suggest that the H₂S donor influences oocyte maturation and thus also participates in the regulation of cumulus expansion. The exogenous H₂S donor apparently affects key signal pathways of oocyte maturation and cumulus expansion, resulting in faster oocyte maturation with little need of cumulus expansion.     

内源性气体硫化氢在中枢神经系统中的作用

内源性硫化氢(H2S)可以刺激神经细胞cAMP水平增加,提高NMDA受体介导的突触后兴奋性电位,提高诱导海马长时程增强。H2S不仅具有神经调节剂的功能,还有神经保护剂的功能。H2S自身并不能将细胞从氧化应激中解救出来,但是它能通过提高胞内有效的抗氧化剂——还原型谷胱苷肽的含量而起到保护神经元的作用。对H2S的研究刚刚起步,对其在神经系统中的作用机制开展研究将有助于了解其在神经元保护方面所起的作用。     

Effect of Hydrogen Sulfide Donor on Antioxidant State of Wheat Plants and Their Resistance to Soil Drought

Russian Journal of Plant Physiology - Effects of plant treatment with a donor of hydrogen sulfide—sodium hydrosulfide—on the state of antioxidative and osmoprotective systems of young...     

Nanoemulsion for Solubilization,Stabilization, and In Vitro Release of Pterostilbene for Oral Delivery

Pterostilbene, being extracted from many plants, has significant biological activities in preventing cancer, diabetes, and cardiovascular diseases so as to have great potential applications in pharmaceutical fields. But the poor solubility and stability of pterostilbene strictly restrained its applications. As a good protection and oral delivery system, an optimal nanoemulsion for pterostilbene was developed by using low-energy emulsification method. Systematic pseudo-ternary phase diagrams have been studied in optimization of nanoemulsion formulations. The prepared pterostilbene nanoemulsion was characterized by transmission electron microscope, Fourier transform Raman spectrum, and laser droplet size analyzer. Nanoemulsion droplets are circular with smooth margin, and the mean size is 55.8 ± 10.5 nm. The results illustrated that the nanoemulsion as oral delivery system dramatically improved the stability and solubility of pterostilbene, and in vitro release of pterostilbene was significantly improved (96.5% in pH 3.6 buffer; 13.2% in pH 7.4 buffer) in comparison to the pterostilbene suspension (lower than 21.4% in pH 3.6 buffer; 2.6% in pH 7.4 buffer).KEY WORDS: 3,5-dimethoxyl-4′-hydroxystilbene, nanoemulsion, pseudo-ternary phase diagram, pterostilbene, release study     

Hydrogen Sulfide Donor Protects Porcine Oocytes against Aging and Improves the Developmental Potential of Aged Porcine Oocytes

Porcine oocytes that have matured in in vitro conditions undergo the process of aging during prolonged cultivation, which is manifested by spontaneous parthenogenetic activation, lysis or fragmentation of aged oocytes. This study focused on the role of hydrogen sulfide (H₂S) in the process of porcine oocyte aging. H₂S is a gaseous signaling molecule and is produced endogenously by the enzymes cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (MPST). We demonstrated that H₂S-producing enzymes are active in porcine oocytes and that a statistically significant decline in endogenous H₂S production occurs during the first day of aging. Inhibition of these enzymes accelerates signs of aging in oocytes and significantly increases the ratio of fragmented oocytes. The presence of exogenous H₂S from a donor (Na₂S.9H₂O) significantly suppressed the manifestations of aging, reversed the effects of inhibitors and resulted in the complete suppression of oocyte fragmentation. Cultivation of aging oocytes in the presence of H₂S donor positively affected their subsequent embryonic development following parthenogenetic activation. Although no unambiguous effects of exogenous H₂S on MPF and MAPK activities were detected and the intracellular mechanism underlying H₂S activity remains unclear, our study clearly demonstrates the role of H₂S in the regulation of porcine oocyte aging.     

An Oral-Controlled Release Drug Delivery System for Liquid and Semisolid Drug Formulations

A novel oral drug delivery system for the controlled release of liquid drugs, drug solutions, and semisolid drug preparations is presented that is utilizing the constant vapor pressure of liquefied gas. The system is equipped with a capillary as an element determining the drug delivery rate and contains a liquefied propellant with a suitable boiling point below human body temperature. In the dissolution studies, polyacrylate gels of different viscosities containing paracetamol as model drug were used. Zero-order release kinetics was obtained. The release rates were dependent on the gel viscosity. Besides, by gel viscosity, the drug release rates could also be modified by changing the propellant type and the capillary parameters such as length or diameter. Accordingly, the new system enables a wide range of drug delivery kinetics which can be modified in a case-by-case basis in order to match the desired drug delivery characteristics.     

Selective Medium for Hydrogen Sulfide Production by Salmonellae

Triple Sugar Iron Agar does not reveal hydrogen sulfide production by all Salmonella organisms nor does it permit clear-cut separation of those nonsalmonellae which produce H(2)S. Numerous media with varied combinations of nutrients, inhibitors, selective agents, pH levels, and metal salts were tested for H(2)S production of cultures of Salmonella, Citrobacter, Edwardsiella, Arizona, Proteus, Providencia, Klebsiella, and Enterobacter. An agar medium has been devised which promotes growth and H(2)S production (generally within 6 hr) by Salmonella, Arizona, and Edwardsiella but which inhibits hydrogen sulfide production or growth of all other gram-negative organisms tested (including Citrobacter) or inhibits both. The use of this medium should facilitate the selection and identification of Salmonella.     

Redox Biochemistry of Hydrogen Sulfide

H₂S, the most recently discovered gasotransmitter, might in fact be the evolutionary matriarch of this family, being both ancient and highly reduced. Disruption of γ-cystathionase in mice leads to cardiovascular dysfunction and marked hypertension, suggesting a key role for this enzyme in H₂S production in the vasculature. However, patients with inherited deficiency in γ-cystathionase apparently do not present vascular pathology. A mitochondrial pathway disposes sulfide and couples it to oxidative phosphorylation while also exposing cytochrome c oxidase to this metabolic poison. This report focuses on the biochemistry of H₂S biogenesis and clearance, on the molecular mechanisms of its action, and on its varied biological effects.     

Stress-Protective Responses of Wheat and Rye Seedlings Whose Chilling Resistance Was Induced with a Donor of Hydrogen Sulfide

Russian Journal of Plant Physiology - The effect of sodium hydrosulfide (NaHS) as a donor of hydrogen sulfide on the resistance to subzero temperatures was investigated in the seedlings of winter...     

Hydrogen Sulfide Donor NaHS Protects Mesenchymal Stem and Melanoma Cells from the Negative Effects of Infrared Laser Irradiation

Molecular Biology - We have established earlier that 835-nm infrared laser irradiation results in a dose-dependent growth inhibition of human mesenchymal stem and melanoma cells and is able to...     

Bimatoprost-Loaded Ocular Inserts as Sustained Release Drug Delivery Systems for Glaucoma Treatment: In Vitro and In Vivo Evaluation

The purpose of the present study was to develop and assess a novel sustained-release drug delivery system of Bimatoprost (BIM). Chitosan polymeric inserts were prepared using the solvent casting method and characterized by swelling studies, infrared spectroscopy, differential scanning calorimetry, drug content, scanning electron microscopy and in vitro drug release. Biodistribution of ^99mTc-BIM eye drops and ^99mTc-BIM-loaded inserts, after ocular administration in Wistar rats, was accessed by ex vivo radiation counting. The inserts were evaluated for their therapeutic efficacy in glaucomatous Wistar rats. Glaucoma was induced by weekly intracameral injection of hyaluronic acid. BIM-loaded inserts (equivalent to 9.0 µg BIM) were administered once into conjunctival sac, after ocular hypertension confirmation. BIM eye drop was topically instilled in a second group of glaucomatous rats for 15 days days, while placebo inserts were administered once in a third group. An untreated glaucomatous group was used as control. Intraocular pressure (IOP) was monitored for four consecutive weeks after treatment began. At the end of the experiment, retinal ganglion cells and optic nerve head cupping were evaluated in the histological eye sections. Characterization results revealed that the drug physically interacted, but did not chemically react with the polymeric matrix. Inserts sustainedly released BIM in vitro during 8 hours. Biodistribution studies showed that the amount of ^99mTc-BIM that remained in the eye was significantly lower after eye drop instillation than after chitosan insert implantation. BIM-loaded inserts lowered IOP for 4 weeks, after one application, while IOP values remained significantly high for the placebo and untreated groups. Eye drops were only effective during the daily treatment period. IOP results were reflected in RGC counting and optic nerve head cupping damage. BIM-loaded inserts provided sustained release of BIM and seem to be a promising system for glaucoma management.     

Functional Interaction of ROS and Nitric Oxide during Induction of Heat Resistance of Wheat Seedlings by Hydrogen Sulfide Donor

Russian Journal of Plant Physiology - The participation of reactive oxygen species (ROS) and nitric oxide (NO), and also enzymatic systems generating them, in the development of heat resistance of...     

Homocysteine to Hydrogen Sulfide or Hypertension

Hyperhomocysteinemia, an increased level of plasma homocysteine, is an independent risk factor for the development of premature arterial fibrosis with peripheral and cerebro-vascular, neurogenic and hypertensive heart disease, coronary occlusion and myocardial infarction, as well as venous thromboembolism. It is reported that hyperhomocysteinemia causes vascular dysfunction by two major routes: (1) increasing blood pressure and, (2) impairing the vasorelaxation activity of endothelial-derived nitric oxide. The homocysteine activates metalloproteinases and induces collagen synthesis and causes imbalances of elastin/collagen ratio which compromise vascular elastance. The metabolites from hyperhomocysteinemic endothelium could modify components of the underlying muscle cells, leading to vascular dysfunction and hypertension. Homocysteine metabolizes in the body to produce H₂S, which is a strong antioxidant and vasorelaxation factor. At an elevated level, homocysteine inactivates proteins by homocysteinylation including its endogenous metabolizing enzyme, cystathionine γ-lyase. Thus, reduced production of H₂S during hyperhomocysteinemia exemplifies hypertension and vascular diseases. In light of the present information, this review focuses on the mechanism of hyperhomocysteinemia-associated hypertension and highlights the novel modulatory role of H₂S to ameliorate hypertension.     

Lyophilized Sustained Release Mucoadhesive Chitosan Sponges for Buccal Buspirone Hydrochloride Delivery: Formulation and In Vitro Evaluation

This work aims to prepare sustained release buccal mucoadhesive lyophilized chitosan sponges of buspirone hydrochloride (BH) to improve its systemic bioavailability. Chitosan sponges were prepared using simple casting/freeze-drying technique according to 3² factorial design where chitosan grade was set at three levels (low, medium, and high molecular weight), and concentration of chitosan solution at three levels (0.5, 1, and 2%). Mucoadhesion force, ex vivo mucoadhesion time, percent BH released after 8 h (Q8h), and time for release of 50% BH (T_50%) were chosen as dependent variables. Additional BH cup and core buccal chitosan sponge were prepared to achieve uni-directional BH release toward the buccal mucosa. Sponges were evaluated in terms of drug content, surface pH, scanning electron microscopy, swelling index, mucoadhesion strength, ex vivo mucoadhesion time, and in vitro drug release. Cup and core sponge (HCH 0.5E) were able to adhere to the buccal mucosa for 8 h. It showed Q8h of 68.89% and exhibited a uni-directional drug release profile following Higuchi diffusion model.KEY WORDS: buspirone HCL, casting/freeze-drying technique, chitosan, cup and core sponge, mucoadhesive buccal sponges     

Liquid Crystalline Systems for Transdermal Delivery of Celecoxib: In Vitro Drug Release and Skin Permeation Studies

Liquid crystalline systems of monoolein/water could be a promising approach for the delivery of celecoxib (CXB) to the skin because these systems can sustain drug release, improve drug penetration into the skin layers and minimize side effects. This study evaluated the potential of these systems for the delivery of CXB into the skin based on in vitro drug release and skin permeation studies. The amount of CXB that permeated into and/or was retained in the skin was assayed using an HPLC method. Polarizing light microscopy studies showed that liquid crystalline systems of monoolein/water were formed in the presence of CXB, without any changes in the mesophases. The liquid crystalline systems decreased drug release when compared to control solution. Drug release was independent of the initial water content of the systems and CXB was released from cubic phase systems, irrespective of the initial water content. The systems released the CXB following zero-order release kinetics. In vitro drug permeation studies showed that cubic phase systems allowed drug permeation and retention in the skin layers. Cubic phase systems of monoolein/water may be promising vehicles for the delivery of CXB in/through the skin because it improved CXB skin permeation compared with the control solution.KEY WORDS: celecoxib, drug delivery systems, liquid crystalline system, monoolein, skin permeation     

Production of Hydrogen Sulfide by Streptomyces odorifer

By use of various trapping systems, as well as lead acetate papers, Streptomyces odorifer was shown to produce hydrogen sulfide. Other sulfur-containing compounds may be produced by S. odorifer, but the amounts obtained were too small for detailed analysis. It was suggested that hydrogen sulfide might be a part of the earthy-odor complex produced by S. odorifer.     

his-Linked Hydrogen Sulfide Locus in Salmonella typhimurium

Investigation of strains of Salmonella typhimurium having extended his deletion mutations indicates that a genetic site (or sites) affecting H₂S production is located in the region of the chromosome adjacent to the operator end of the his operon. This site is co-transducible with the his genes. Experimental data indicate that the site is also present on an F'his factor derived from S. typhimurium, FS401. Evidence is presented for the existence of another site affecting H₂S production which is not linked to his.