NaHS Solution Research Articles

Dissolving sodium hydrosulfide in drinking water is not a good source of hydrogen sulfide for animal studies

Hydrogen sulfide (H2S) has many physiological and pathological roles in the human body. Sodium hydrosulfide (NaHS) is widely used as a pharmacological tool for assessing H2S effects in biological experiments. Although H2S loss from NaHS solution is a matter of minutes, some animal studies use NaHS in solution as an H2S-donating compound in drinking water. This study addresses whether 30 μM NaHS in drinking water prepared in rat/mouse water bottles remains stable for at least 12–24 h, as presumed by some authors. NaHS solutions (30 μM) were prepared in drinking water and immediately transferred to rat/mice water bottles. Samples were obtained from the tip of water bottles and from inside of the bottles at 0, 1, 2, 3, 4, 5, 6, 12, and 24 h for sulfide measurement using the methylene blue method. Furthermore, NaHS (30 μM) was administered to male and female rats for two weeks, and serum sulfide concentrations were measured every other day in the first week and at the end of the second week. NaHS solution was unstable in the samples obtained from the tip of water bottles; it declined by 72% and 75% after 12 and 24 h, respectively. In the samples obtained from the inside of the water bottles, the decline in the NaHS was not significant until 2 h; however, it decreased by 47% and 72% after 12 and 24 h, respectively. NaHS administration did not affect serum sulfide levels in male and female rats. In conclusion, NaHS solution prepared in drinking water can not be used for H2S donation as the solution is unstable. This route of administration exposes animals to variable and lower-than-expected amounts of NaHS.

Abstract 538: Local Hydrogen Sulfide Therapy Augments Angiogenesis And Ischemic Wound Healing

Introduction: Hydrogen sulfide (H 2 S) is an important signaling molecule in cellular O 2 sensing, wound healing and angiogenesis. Low H 2 S levels have been shown in diabetes and cardiovascular disease and H 2 S impairment may play a role in chronic non-healing ischemic wounds. H 2 S promotes angiogenesis in cell culture but in vivo data are lacking. We utilized a novel local H 2 S delivery method to investigate the effects of H 2 S therapy in rodents. Methods: Sprague Dawley rats (n=6-10/group) underwent dorsal myocutaneous ischemic flap wound creation under anesthesia. NaHS solution (100 μM) was delivered locally to the wound every 12 hours via implanted microtubing externalized and attached to a fluid delivery vest. Sham rats received saline solution while a third group received H 2 S blocker DL-propargylglycine (PAG). Laser speckle contrast images (LSCI) were recorded over 14 days. Flap tissue was collected for histologic analysis of tissue viability and degree of ischemic insult. Neovascularization was quantified by CD31 immunohistochemistry (IHC). VEGF protein expression was quantified by Western blot. Results: H 2 S treated flaps reperfused at a two-fold greater rate compared to sham and PAG treated flaps by LSCI (mean 12.9 flux/day vs. 6.9 flux/day, P=0.02). IHC mean microvascularity in sham flaps was 18 vessels/mm 2 compared to 47 vessels/mm 2 in H 2 S treated flaps (P=0.0092). Panniculus carnosis muscle thickness (408 μm vs. 234 μm) and myofibril count (56 vs. 38/100k μm 2 ) were preserved in H 2 S treated flaps (P=0.02, 0.04). H 2 S treatment upregulated VEGF while PAG was associated with decreased expression. Conclusion: H 2 S treated flaps have improved wound revascularization, tissue healing and angiogenic signaling. Blockade of H 2 S results in poor revascularization and decreased angiogenic protein expression. H 2 S pathways may play a critical role in the pathogenesis of impaired wound healing and could represent a potential therapeutic target for ischemic wounds.

Programmable Drug Release from a Dual-Stimuli Responsive Magnetic Metal–Organic Framework

Along with the increasing incidence of cancer and drawbacks of traditional drug delivery systems (DDSs), developing novel nanocarriers for sustained targeted-drug release has become urgent. In this regard, metal–organic frameworks (MOFs) have emerged as potential candidates due to their structural flexibility, defined porosity, lower toxicity, and biodegradability. Herein, a FeMn-based ferromagnetic MOF was synthesized from a preassembled Fe2Mn(μ3-O) cluster. The introduction of the Mn provided the ferromagnetic character to FeMn-MIL-88B. 5-Fluoruracil (5-FU) was encapsulated as a model drug in the MOFs, and its pH and H2S dual-stimuli responsive controlled release was realized. FeMn-MIL-88B presented a higher 5-FU loading capacity of 43.8 wt % and rapid drug release behavior in a tumor microenvironment (TME) simulated medium. The carriers can rapidly release loaded drug of 70% and 26% in PBS solution (pH = 5.4) and NaHS solution (500 μM) within 24 h. The application of mathematical release models indicated 5-FU release from carriers can be precisely fitted to the first-order, second-order, and Higuchi models of release. Moreover, the cytotoxicity profile of the carrier against human embryonic kidney cells (HEK293T) suggests no adverse effects up to 100 μg/mL. The lesser toxic effect on cell viability can be attributed to the low toxicity values [LD50 (Fe) = 30 g·kg–1, (Mn) = 1.5 g·kg–1, and (terephthalic acid) = 5 g·kg–1] of the MOFs structural components. Together with dual-stimuli responsiveness, ferromagnetic nature, and low toxicity, FeMn-MIL-88B MOFs can emerge as promising carriers for drug delivery applications.

The effect of hydrogen sulfide on ischemi̇a /reperfusion injury in an experimental testicular torsion model

Testicular torsion is an acute pediatric surgical emergency requiring rapid diagnosis to prevent the permanent ischaemic damage of the testicles. Hydrogen Sulfide (H2S) have shown to cure tissue damage and has a role in the prevention of I/R damage. We aimed to evaluate the effect of H2S in testicular torsion. Eighteen male, Wistar albino rats were divided into 3 groups. The sham group which is applied surgical stress. The ischemia/reperfusion group (I/R) which detorsion performed 1h later than testicular torsion application. I/R+NaHS treatment group, NaHS solution was injected intraperitoneally for 1 week. On the 7th day of the detorsion all left testes were fixed in Bouin solution and sent to Pathology Department for histopathological examination. All right testes were washed with normal saline, dried in a sterile way and stored in - 80°C deepfreeze up to the date of biochemical processes. Testicular tissues were obtained for the detection of myeloperoxidase (MPO), malondialdehyde (MDA), AOPP (advanced oxidation protein product) for oxidant markers and ferric reducing antioxidant power (FRAP) levels, superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) activities for antioxidant markers and histopathological exploration. The effects of NaHs administration on oxidation were evaluated by determination of testicular MPO, MDA and AOPP levels. Increased testicular MPO (58.6%) activity was observed in the I/R group compared to the sham group. Following NaHS treatment, MPO (26.7%) activity was significantly decreased in rats exposed to I/R injury (Figure1). MDA levels did not alter. Increases in AOPP (20.9%) levels were observed in the I/R group. NaHS treatment resulted in significant decreases in AOPP (25.1%) levels in testes tissues of rats exposed to I/R injury. The effects of NaHS treatment on antioxidant system FRAP, SOD, GSH and GSH-Px activities were evaluated. GSH levels were significantly increased in the IR+NaHS group compared to the I/R group. In histopathological examination degeneration of seminiferous tubules and spermatogenic cells were observed in the I/R group. After NaHS treatment, normal spermatogenic activity with many spermatozoa in the lumen of most seminiferous tubules were observed in the I/R injured rats. According to Johnsen's scoring (JS), the I/R group was significantly decreased compared to the sham group. JS values for the I/R+NaHS group were significantly increased compared to the I/R group. Our study supports that ischemia/reperfusion injury plays an important role in the testicular torsion injury, and it is a pioneer study showing that H₂S may have a potential for therapeutic effect. The limitation of this work is this is an experimental study with limited number of animals. According to the results of our study, hydrogen sulfide treatment has beneficial effects on biochemical and histopathological results of testicular injury in testic torsion.

Simultaneous biological nitrification and desulfurization treatment of ammonium and sulfide-rich wastewater: Effectiveness of a sequential batch operation.

Sulfide inhibition to nitrifying bacteria has prevented the integration of digestate nitrification and biogas desulfurization to simplify anaerobic digestion systems. In this study, liquid digestate with NaHS solution was treated using nitrifying sludge in a sequential-batch reactor with a long fill period, with an ammonium loading rate of 293mg-N L-1d-1 and a stepwise increase in the sulfide loading rate from 0 to 32, 64, 128, and 256mg-S L-1d-1. Batch bioassays and microbial community analysis were also conducted with reactor sludge under each sulfide loading rate to quantify the microbial acclimatization to sulfide. In the reactor, sulfide was completely removed. Complete nitrification was maintained up to a sulfide load of 128mg-S L-1d-1, which is higher than that in previous reports and sufficient for biogas treatment. In the batch bioassays, the sulfide tolerance of NH4+ oxidizing activity (the 50% inhibitory sulfide concentration) increased fourfold over time with the compositional shift of nitrifying bacteria to Nitrosomonas nitrosa and Nitrobacter spp. However, the sulfur removal rate of the sludge slightly decreased, although the abundance of the sulfur-oxidizing bacteria Hyphomicrobium increased by 30%. Therefore, nitrifying sludge was probably acclimatized to sulfide not by the increasing sulfide removal rate but rather by the increasing nitrifying bacteria, which have high sulfide tolerance. Successful simultaneous nitrification and desulfurization were achieved using a sequential-batch reactor with a long fill period, which was effective in facilitating the present acclimatization.

An experimental study on metal precipitation driven by fluid mixing: implications for genesis of carbonate-hosted lead–zinc ore deposits

A type of carbonate-hosted lead–zinc (Pb–Zn) ore deposits, known as Mississippi Valley Type (MVT) deposits, constitutes an important category of lead–zinc ore deposits. Previous studies proposed a fluid-mixing model to account for metal precipitation mechanism of the MVT ore deposits, in which fluids with metal-chloride complexes happen to mix with fluids with reduced sulfur, producing metal sulfide deposition. In this hypothesis, however, the detailed chemical kinetic process of mixing reactions, and especially the controlling factors on the metal precipitation are not yet clearly stated. In this paper, a series of mixing experiments under ambient temperature and pressure conditions were conducted to simulate the fluid mixing process, by titrating the metal-chloride solutions, doping with or without dolomite, and using NaHS solution. Experimental results, combined with the thermodynamic calculations, suggest that H2S, rather than HS− or S2−, dominated the reactions of Pb and/or Zn precipitation during the fluid mixing process, in which metal precipitation was influenced by the stability of metal complexes and the pH. Given the constant concentrations of metal and total S in fluids, the pH was a primary factor controlling the Pb and/or Zn metal precipitation. This is because neutralizing or neutralized processes for the ore-forming fluids can cause instabilities of Pb and/or Zn chloride complexes and re-distribution of sulfur species, and thus can facilitate the hydrolysis of Pb and Zn ions and precipitation of sulfides. Therefore, a weakly acidic to neutral fluid environment is most favorable for the precipitation of Pb and Zn sulfides associated with the carbonate-hosted Pb–Zn deposits.

Effects of hydrogen sulfide on storage quality, water mobility and cell wall metabolism of strawberry fruit

The effects of hydrogen sulfide (H2S) on storage quality, cellular water distribution, and cell wall metabolism of strawberry fruit after subjected to shelf or cold storage were investigated. Fruit were fumigated with a range of aqueous NaHS solution (0.4-3.2 mmol/L), then stored at 20°C for 3 d or 0°C for 9 d. H2S-treated fruit significantly maintained higher fruit firmness (FF) and titratable acidity (TA) as well as lower decay compared to the control fruit. Furthermore, H2S inhibited the loss in extractable juice (EJ) and improved storage quality that not only resulted from the suppressing of respiration rate, but also from the modification of water mobility and cell wall metabolism. High FF and EJ in H2S-treated fruit were closely associated with lower exchanges of free water between vacuole and cytoplasm/free space or cell wall, water-soluble polysaccharides (WSP), and activities of cell wall-modifying enzymes. Therefore, a potential benefit of H2S on retarding softening was that the H2S can reinforce the hydrogen bonding in polysaccharides and reduce activities of cell wall-modifying enzymes, causing a stabilization of cell wall structure. Although approval of the use of H2S on foods has not yet been granted, an alternative reducing agent gas based on H2S tended to be more effective in improving strawberry quality. Keywords: hydrogen sulfide, strawberry, softening, water mobility, cell wall metabolism DOI: 10.25165/j.ijabe.20181106.4074 Citation: Zhi H H, Liu Q Q, Dong Y. Effects of hydrogen sulfide on storage quality, water mobility and cell wall metabolism of strawberry fruit. Int J Agric & Biol Eng, 2018; 11(6): 201–207.

Effects of hydrogen sulfide on root architecture, leaf reactive oxygen and photosynthetic characteristics of Malus hupehensis under waterlogging.

The root architecture, leaf reactive oxygen species and photosynthetic characteristics of potted Malus hupehensis seedlings were investigated after 10 days of waterlogging under five concentrations of hydrogen sulfide (H2S) donor sodium hydrosulfide (NaSH, 0, 0.02, 0.05, 0.1, 0.2 mmol·L-1) and NaSH with scavenger hypotaurine (HT). The results showed that the root length, root surface area, root volume, root diameter, root top number, fractal dimension, first lateral roots and root activity all increased, the leaf superoxide anion (O2-·) accumulation and hydrogen pero-xide (H2O2) content both decreased, the leaf Pn, Tr, gs, WUE and CUE all raised, the plant height and biomass both increased when the 0.02-0.1 mmol·L-1 NaHS were added to the waterlogging environment. Adding 0.1 mmol·L-1 NaHS showed the best effects. All these parameters dropped back to the level of waterlogging alone when NaHS concentration was 0.2 mmol·L-1 or HT was added to the 0.1 mmol·L-1 NaHS solution. These suggested that applying an appropriate amount of H2S could effectively alleviate the inhibition of soil waterlogging on the root growth of M. hupehensis and relieve the effects of waterlogging stress on photosynthesis and plant growth by reducing the production of reactive oxygen species and increasing CUE.

Effect of hydrogen sulfide on inducible nitric oxide synthase in kidneys of Type 1 diabetic rats

To investigate effects of hydrogen sulfide (H2S) on inducible nitric oxide synthase (iNOS) in kidneys of Type 1 diabetic rats. Methods: Thirty-two male SD rats were randomly divided into four groups: A normal control (NC) group, a diabetes mellitus (DM) group, a NaHS (NaHS+DM) group, and a NaHS control (NaHS) group (n=8 per group). Type 1 diabetes was induced by a single intraperitoneal injection of streptozotocin (55 mg/kg). After successful establishment of models, the rats in NaHS+DM and NaHS groups were injected with NaHS solution (56 μmol/kg) intraperitoneally. Eight weeks later, the activities of total nitric oxide synthase (T-NOS) and iNOS, as well as the level of nitric oxide (NO) were detected in serum and renal tissues, respectively. The activity of glutathione peroxidase (GSH-Px) was determined in renal tissues. The ultrastructures of renal tissues were observed by transmission electron microscope. The protein expression of iNOS in renal tissues was detected by Western blot. Results: Compared with the NC group, there was no significant difference in the various indexes in the NaHS group (P>0.05). However, in the DM group, the activities of T-NOS and iNOS, and the level of NO were all increased significantly in serum and renal tissues, while the activity of GSH-Px was decreased in renal tissues. Under the electronic microscope, the thickening of the glomerular capillary basement membrane, the proliferation of mesangial matrix, and the foot fusion were observed. The protein expression of iNOS was increased obviously in renal tissues in the DM group (P<0.01). Compared with the DM group, the activities of T-NOS and iNOS and the level of NO were all decreased in serum and renal tissues, while the activity of GSH-Px was increased in renal tissues in the NaHS+DM group (P<0.01). The renal ultrastructural damages were ameliorated obviously. The protein expression of iNOS was decreased significantly (P<0.01). Conclusion: H2S exerts a protective effect on kidney injury in type 1 diabetic rats. The mechanism might be related to inhibition of iNOS activity and protein expression, in turn leading to reduction of NO content in renal tissues.

Effects of hydrogen sulfide on NO content and iNOS activity in diaphragm from type 1 diabetic rats

To investigate the effects of hydrogen sulfide (H2S) on nitric oxide (NO) content and inducible nitric oxide syn-thase (iNOS) activity in diaphragm from type 1 diabetic rats. Thirty-two male SD rats were randomly divided into four groups:nor-mal control group (NC), diabetes mellitus group (DM), DM treatment group (DM + NaHS) and NaHS control group (NaHS) (n=8). Rats were treated with streptozotocin 55 mg/kg by intraperitoneal injection to establish type 1 diabetic rat model. The fourth week after the model-ing, the rats in the DM + NaHS and NaHS groups were treated with 14μmol/kg NaHS solution by intraperitoneally injected. After treatment for 5 weeks, fasting blood glucose (FBG) and diaphragm weight (DW)/body weight (BW) were measured. The pathological changes of draphrag-matic tissues were observed by HE staining. The activity of iNOS was analyzed by spectrophotometric method, while the content of NO was measured by nitric acid reductase method. The iNOS expressions at mRNA and protein levels in diaphragmatic tissues were detected by RT-PCR and Western blot respectively. Compared with the NC group, there was no significant difference in the various indexes in the NaHS group. While FBG was increased significantly, DW/BW was decreased obviously in the DM group. HE staining revealed obvious changes in diaphragmatic tissues. The activity of iNOS and the content of NO were increased. The levels of iNOS mRNA and protein were in-creased significantly. Compared with the DM group, DW/BW and pathological damages were improved in the DM + NaHS group. The activity of iNOS and NO content were decreased significantly. The levels of iNOS mRNA and protein were decreased obviously. Exoge-nous H2S can suppress iNOS activity and expression to decrease the content of NO, which improving the capacity of diaphragm in type 1 diabet-ic rats.

Foliar application of sodium hydrosulfide (NaHS), a hydrogen sulfide (H2S) donor, can protect seedlings against heat stress in wheat (Triticum aestivum L.)

Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide (H2S) has been proven to function in physiological responses to various stresses. The present study evaluated the effect of foliar application of wheat seedlings with a H2S donor, sodium hydrosulfide (NaHS), on the response to acute heat stress. The results showed that pretreatment with NaHS could promote heat tolerance of wheat seedlings in a dose-dependent manner. Again, it was verified that H2S, rather than other sulfur-containing components or sodion derived from NaHS solution, should contribute to the positive role in promoting wheat seedlings against heat stress. To further study antioxidant mechanisms of NaHS-induced heat tolerance, superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11) activities, and H2S, hydrogen peroxide (H2O2), malonaldehyde (MDA), and soluble sugar contents in wheat seedlings were determined. The results showed that, under heat stress, the activities of SOD, CAT, and APX, H2S, H2O2, MDA, and soluble sugar contents in NaHS-pretreated seedlings and its control all increased. Meanwhile, NaHS-pretreated seedlings showed higher antioxidant enzymes activities and gene expression levels as well as the H2S and soluble sugar levels, and lower H2O2, MDA contents induced by heat stress. While little effect was detected in antioxidant enzymes activities and soluble substances contents in pretreated wheat seedlings compared with its control under normal culture conditions (data not shown). All of our results suggested that exogenous NaHS could alleviate oxidative damage and improve heat tolerance by regulating the antioxidant system in wheat seedlings under heat stress.

Effects of hydrogen sulfide on contraction capacity of diaphragm from type 1 diabetic rats

To investigate the effects of hydrogen sulfide (H2S) on contraction capacity of diaphragm in type 1 diabetic rats. Thirty-two male SD rats were randomly divided into a normal group (NC), a diabetic group (DM), a NaHS treatment group (DM+NaHS) and a NaHS group (NaHS) (n=8). Intraperitoneal injection of streptozotocin was utilized to establish diabetic rat model. After the modeling, the rats in the DM+NaHS and the NaHS groups were intraperitoneally injected with 28 μmol/kg NaHS solution. 8 weeks later, the diaphragm contractility was assessed by isolated draphragm strips perfusion. The peak twitch tension (Pt), maximum tetanic tension (Po) and maximal rates of contraction/relaxation (±dT/dtmax) were determined. The alterations in diaphragm ultrastructure were observed under electron microscopy. The diaphragm weight/body weight (DW/BW) was measured. The activities of succinic dehydrogenase (SDH), lactate dehydrogenase (LDH) and sarcoplasmic reticulum Ca2+ ATPase (SERCA) were analyzed by spectrophotometric method. The mRNA levels of SERCA and prospholamban (PLB) in diaphragm were detected by RT-PCR. Compared with the NC group, there was no significant change in all measured index in the NaHS group (P>0.05), while Pt, Po and ±dT/dtmax were significantly decreased in the DM group (P<0.05). Transmission electron microscopy revealed obvious ultrastructural changes in the diaphragm. The DW/BW ratio and the activities of SDH, LDH and SERCA were decreased. The SERCA mRNA was decreased, while PLB mRNA was increased. Compared with the DM group, the diaphragm contractility and ultrastructure damage were improved in the DM+NaHS group. The DW/BW ratio and the activities of SDH, LDH and SERCA were increased. The SERCA mRNA was increased, while PLB mRNA was decreased (all P<0.05). H(2)S can enhance the contraction capacity of diaphragm in type 1 diabetic rats, which is involved in regulating the activities of biological enzymes and the gene expressions of calcium regulatory proteins.

Effect of hydrogen sulfide on cardiac myosin light chain kinase expression in diabetic rats

To investigate the effect of hydrogen sulfide (H2S) on cardiac myosin light chain kinase (MLCK) expression in diabetic rats. A total of 32 male SD rats were randomly divided into a normal control group (NC group), a diabetic control group (DM), a NaHS treatment group (DM+NaHS) and a NaHS group (NaHS) (n=8 in each group). Intraperitoneal injection of streptozotocin was utilized to establish Type 1 diabetic rat model. The diabetic rats in the DM+NaHS and NaHS groups were intraperitoneally injected with 28 μmol/kg NaHS solution. Eight weeks later, the ventricular hemodynamic parameters, the ratio of heart weight/body weight (HW/BW ratio), the levels of lactate dehydrogenase (LDH) and creatine kinase MB isozyme (CK-MB) in serum were determined. The ultrastructures of myocardium were observed under electron microscopy. The expressions of MLCK mRNA and protein level in myocardium were detected by RT-PCR and Western blot, respectively. Compared with the NC group, there was no significant difference in the various indexes in the NaHS group (all P>0.05). The function of left ventricular contract and relaxation were decreased obviously in diabetic rats, while the HW/BW ratio was increased (all P<0.01). The levels of LDH and CK-MB were increased (both P<0.01) in serum, while the levels of MLCK mRNA and protein were decreased significantly (both P<0.01) in myocardial tissues. Compared with the DM group, the left ventricular hemodynamic parameters and myocardial ultrastructure damage were improved in the DM+NaHS group, while the HW/BW ratio was decreased (all P<0.05). The levels of LDH and CK-MB were decreased (both P<0.01), while the levels of MLCK mRNA and protein were increased significantly (both P<0.01). H2S can protect myocardium in diabetic rats, which may be associated with upregulation of cardiac MLCK.

Protective effect of hydrogen sulfide on kidneys of type 1 diabetic rats

To explore the protective effects of hydrogen sulfide (H2S) on kidneys of type 1 diabetic rats and its underlying mechanism. Thirty-two male SD rats were randomly divided into four groups:normal control (NC) group, diabetes mellitus (DM) group, DM treatment (NaHS+DM) group and NaHS control (NaHS) group. The rats from DM group and NaHS+DM group were injected intraperitoneally with Streptozotocin 55 mg/kg to induce type 1 diabetes mellitus (n=8). After modeling, rats in NaHS+DM group and NaHS group were intraperitoneally injected with NaHS solution at the dosage of 56 μmol/kg. After 8 weeks, urinary protein content was detected in urine samples collected for 24 h. and the ratio of kidney weight/body weight (renal index) was determined in isolated kidneys. Besides, the levels of fasting blood glucose (FBG), blood urea nitrogen (BUN) and serum creatinine (Scr) were measured biochemically. The morphological changes of renal tissue were observed by HE staining. The content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and Caspase-3 in renal tissue were determined by spectrophotometry. The protein expression levels of Bcl-2 and Bax in renal tissue were detected using Western blot. There was no significant difference in the respective measured indexes in rats between NC group and NaHS group. However, in DM group, the levels of 24 h urinary protein, FBG, BUN, Scr and renal index were increased significantly; HE staining showed that the basement membrane was thickened and the amount of glomerular mesangial matrix was increased; MDA content, Caspase-3 activity and Bax expression levels were increased, while SOD activity and Bcl-2 expression were decreased. Compared with those in DM group, the morphological changes of renal tissue and its function were improved; MDA content, Caspase-3 activity and Bax expression were decreased significantly, while SOD activity and Bcl-2 expression were increased obviously in NaHS+DM group. H2S can protect the kidneys of type 1 diabetic rats, which is related to suppressing oxidative stress and cell apoptosis.

Protective effects of hydrogen sulfide on diaphragmatic muscle of Type 1 diabetic rats and its anti-apoptotic mechanisms

To explore the protective effects of hydrogen sulfide (H2S) on diaphragmatic muscle of Type 1 diabetic rats and its anti-apoptotic mechanism. Thirty male Sprague Dawley rats were randomly divided into a control group, a diabetes group and a treatment group (n=10 per group). Streptozotocin (i.p.) was utilized to establish a rat model of Type 1 diabetes mellitus (DM). The DM rats were treated with NaHS solution (i.p.). After 8 weeks, the diaphragmatic muscle contractility was assessed by isolated diaphragmatic strips experiments. The peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxation time (1/2RT) and maximal rates of contraction/relaxation (±dT/dtmax) were measured. The alterations of diaphragmtic ultrastructure were observed by electron microscopy. The content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and caspase-3 were analyzed by spectrophotometric method. The expressions levels of Bcl-2 and Bax mRNA in diaphragmatic muscle were detected by RT-PCR. Compared with the control group, in the diabetic group, the Pt, Po and ±dT/dtmax were significantly reduced (all P<0.01), while CT and 1/2RT were significantly increased (both P<0.01); ultrastructure in the diaphragmatic muscle were obviously changed; the content of MDA and the activity of caspase-3 were increased (both P<0.01), while the activity of SOD was decreased (P<0.01); the ratio of Bcl-2/Bax at mRNA level was decreased (P<0.01). Compared with the diabetes group, in the treatment group, the diaphragm contractility and ultrastructural damage were improved; the content of MDA and the activity of caspase-3 were decreased (P<0.05, P<0.01 respectively), while the activity of SOD was increased (P<0.01), the ratio of Bcl-2/Bax at mRNA level was also increased (P<0.01). The exogenous H2S can protect diaphragmatic muscle of Type 1 diabetic rats, which is related to reducing oxidative damage and suppressing cell apoptosis.

Sodium Hydrosulfide Exerts a Transitional Attenuating Effect on Spermatozoa Migration in Vitro.

Hydrogen sulfide (H2S) has been shown to have a prominent role in the regulation of reproductive system function and fertility. The aim of the study was to assess the effect of a H2S donor, sodium hydrosulfide (NaHS), on mouse sperm migration in vitro. Special plates with 4 corner wells filled with balanced salt solution (control) and various NaHS solutions in concentrations of 2.5 mmol/l, 5 mmol/l or 10 mmol/l were applied. Spermatozoa from each male mouse were injected (the experiment was repeated with ten BALB/c 5-month old males) into the central pocket, connected with the wells with ducts. After 1 h, 2 h and 4 h of incubation, the number of spermatozoa in each well was determined using Bürker's counting chambers. The number ofspermatozoa in all corner wells were summed and the number of the cells in each well was treated as the percentage share of all the migrated spermatozoa. At the time points of 1 hour and 4 hours, no differences regarding chemotactic features of spermatozoa to the utilized solutions were observed. After two hours of incubation the attenuating effect of NaHS medium and high level solutions on spermatozoa migration was observed, but not for the low concentration mixture: H(3, N = 40) = 9.65, P = 0.022; control group vs 5 mmol/l NaHS solution: 36.0% vs 18.5%, P = 0.023; control group vs 10 mmol/l NaHS solution group: 36.0% vs 17.0%, P 0.011. In conclusion, NaHS has a transitional attenuating effect on spermatozoa migration in vitro.

Thermal spring water drinking attenuates dextran-sulfate-sodium-induced colitis in mice.

The present study investigates the effect of oral consumption of hydrogen sulfide-containing Harkány thermal spring water, as well as sodium hydrogen sulfide (NaHS) solution on experimental colitis. Colitis was induced by 2% dextran sulfate sodium (DSS) in the drinking water of C57BL/6 mice for 7 days. Some animal groups drank Harkány thermal spring water or water supplemented with 21.68 mg/L NaHS. General signs of colitis, myeloperoxidase (MPO) enzyme activity of colon samples, histological features of colitis and function of the enteric nervous system were assessed. Oral administration of Harkány thermal spring water significantly attenuated general signs of colitis, MPO enzyme activity of colon samples and detrimental effect of colitis on the function of the enteric nervous system, but not histological signs of colitis. These findings could be reproduced using NaHS solution with additional significantly diminished histological damage. We conclude that oral treatment with Harkány thermal spring water relieves various aspects of DSS-evoked colitis in mice. This effect is most likely to be mediated by hydrogen sulfide content of the Harkány water. Our data might promote complementary utilization of sulfurous thermal spring water in the therapy of inflammatory bowel disease.

Cooperative effects of hydrogen sulfide and nitric oxide on delaying softening and decay of strawberry

Abstract: Hydrogen sulfide (H2S) and nitric oxide (NO) as two signal molecules play prominent roles in plant response to biotic stress. The combination effects of these two molecules on ripening and decay of postharvest strawberry were investigated. Strawberries were first dipped in distilled water, 0.8 mmol/L NaHS solution, 5 µmmol/L sodium nitroprusside (SNP) solution, and combinative solutions of 0.8 mmol/L NaHS and 5 µmmol/L SNP for 10 min, respectively, and then stored at 20°C. Results showed that the effects of the co-treatment of 0.8 mmol/L NaHS solution and 5 µmmol/L SNP solution were superior to that of other treatments. The former could suppress the percentage of fruit decay, inhibit respiration rate, maintain the original crust color, and slow down the decrease of firmness and the change of relative conductivity, which preserved the fruit quality. Further investigation showed that co-treatment of hydrogen sulfide and nitric oxide maintained higher activities of chitinase (CHI) and beta-1,3-glucanase (GNS), and lowered activities of pectin methylesterase (PME), polygalacturonase (PG) and endo-β-1,4-glucanase (EGase). The study indicated that the synergistic function of H2S and NO could effectively prolong the shelf life and reduce the decay rate of harvested strawberry. Keywords: hydrogen sulfide, nitric oxide, strawberry, enzyme activities, shelf life DOI: 10.3965/j.ijabe.20140706.014 Citation: Zhang C, Shi J Y, Zhu L P, Li C L, Wang Q G. Cooperative effects of hydrogen sulfide and nitric oxide on delaying softening and decay of strawberry. Int J Agric & Biol Eng, 2014; 7(6): 114－122

Hydrogen Sulfide Acts as a Fungicide to Alleviate Senescence and Decay in Fresh-cut Sweetpotato

Hydrogen sulfide (H2S) has been shown to be a gaseous molecule in the regulation of many processes in plants such as abiotic stress tolerance, root organogenesis, stomatal movement, and postharvest fruit senescence. We studied the role of H2S in the regulation of senescence and fungal decay in fresh-cut sweetpotato (Ipomoea batatas L., cv. Xushu 18) roots. H2S donor sodium hydrosulfide (NaHS) alleviated senescence in fresh-cut sweetpotato root tissue in a dose-dependent manner with the optimal concentration of 2.0 mmol·L−1 NaHS solution. At the optimal concentration of 2.0 mmol·L−1 NaHS, H2S fumigation maintained higher levels of reducing sugar in sweetpotato fresh-cut root. H2S treatment also significantly increased the activities of guaiacol peroxidase (POD) and decreased those of polyphenol oxidase (PPO) in sweetpotato during storage. Further investigation showed that H2S treatment maintained a lower level of lipoxygenase (LOX) activity compared with water control. Consistently, the accumulation of malondialdehyde (MDA) was reduced in H2S-treated groups. Three fungal pathogens, Rhizopus nigricans, Mucor rouxianus, and Geotrichum candidum, were isolated from sweetpotato tissue infected with black rot or soft rot. H2S fumigation at 1 to 2.5 mmol·L−1 NaHS resulted in effective inhibition of the three fungi when grown on medium. When the three fungi were inoculated on the surface of sweetpotato slices, H2S fumigation greatly reduced the percentage of fungal infection. In conclusion, these data suggest that H2S effectively alleviated the senescence and decay in sweetpotato slices and might be developed into a novel fungicide for reduction of black rot or soft rot in sweetpotato.

Effects of hydrogen sulphide on quality and antioxidant capacity of mulberry fruit

SummaryHere we investigated the effect of hydrogen sulphide (H2S) on postharvest quality of mulberry fruit and possible underlying mechanisms. Endogenous H2S content first increased after harvest and then decreased sharply with the process of ripening and senescence. A fumigation with H2S released from 0.8 mm NaHS solution could significantly enhance the endogenous H2S content by increasing the activities of D‐cysteine desulfhydrase and L‐cysteine desulfhydrase. NaHS could significantly slow down the ripening rate of mulberry fruit and reduce the respiratory intensity and anthocyanin content. Moreover, H2S fumigation was able to obviously delay or slow down the decreases in soluble protein, titratable acidity and ascorbate contents. Further results showed that activities of representative antioxidant enzymes in H2S‐treated sample were higher than those of control samples during storage, resulting in a decrease in superoxide anion production. Together, these results clearly indicate that H2S fumigation has a potential role in the preservation of mulberries.