Hydrogen sulfide (H2S) has been identified as a novel gasotransmitter and a substantial antioxidant that can activate various cellular targets to regulate physiological and pathological processes in mammals. However, under physiological conditions, it remains unclear whether it is involved in regulating cardiomyocyte (CM) proliferation during postnatal development in mice. This study mainly aimed to evaluate the role of H2S in postnatal CM proliferation and its regulating molecular mechanisms. We found that sodium hydrosulfide (NaHS, the most widely used H2S donor, 50-200 μM) increased neonatal mouse primary CM proliferation in a dose-dependent manner in vitro. Consistently, exogenous administration of H2S also promoted CM proliferation and increased the total number of CMs at postnatal 7 and 14 days in vivo. Moreover, we observed that the protein expression of SIRT1 was significantly upregulated after NaHS treatment. Inhibition of SIRT1 with EX-527 or si-SIRT1 decreased CM proliferation, while enhancement of the activation of SIRT1 with SRT1720 promoted CM proliferation. Meanwhile, pharmacological and genetic blocking of SIRT1 repressed the effect of NaHS on CM proliferation. Taken together, these results reveal that H2S plays a promotional role in proliferation of CMs in vivo and in vitro and SIRT1 is required for H2S-mediated CM proliferation, which indicates that H2S may be a potential modulator for heart development in postnatal time window.

While it is widely recognized that hydrogen sulfide (H2S) promotes plant stress tolerance, the precise processes through which H2S modulates this process remains unclear. The processes by which H2S promotes phosphorus deficiency (PD) and salinity stress (SS) tolerance, simulated individually or together, were examined in this study. The adverse impacts on plant biomass, total chlorophyll and chlorophyll fluorescence were more pronounced with joint occurrence of PD and SS than with individual application. Malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL) levels in plant leaves were higher in plants exposed to joint stresses than in plants grown under an individual stress. When plants were exposed to a single stress as opposed to both stressors, sodium hydrosulfide (NaHS) treatment more efficiently decreased EL, MDA, and H2O2 concentrations. Superoxide dismutase, peroxidase, glutathione reductase and ascorbate peroxidase activities were increased by SS alone or in conjunction with PD, whereas catalase activity decreased significantly. The favorable impact of NaHS on all the evaluated attributes was reversed by supplementation with 0.2 mM hypotaurine (HT), a H2S scavenger. Overall, the unfavorable effects caused to NaHS-supplied plants by a single stress were less severe compared with those caused by the combined administration of both stressors.

In recent years, the cardiotoxicity and hepatotoxicity induced by chemotherapeutic drugs such as cisplatin (CP) have become significant issues. The current research looks into the effects of sodium hydrosulfide (NaHS) on CP-induced hepatotoxicity and cardiotoxicity in rats. A total of 32 male Sprague Dawley rats were separated into four different groups: (1) control group, received only normal saline; (2) NaHS group, was intraperitoneally injected with NaHS (200 µg/kg/d, dissolved in saline) for 15 days; (3) CP group, was intraperitoneally injected only one dose of CP (5 mg/kg) and (4) CP plus NaHS group, received CP along with NaHS. Blood and tissues samples were harvested for biochemical, histopathological, and immunohistochemical investigations. To determine the data\'s statistical significance, a one-way analysis of variance was used. CP injection significantly increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), Creatine phospho kinase (CK-MB), cholesterol, low-density lipoprotein (LDL), triglyceride (TG), and lipid peroxidation levels, while high-density lipoprotein (HDL), albumin, glutathione peroxidase, superoxide dismutase, and catalase (CAT) levels were significantly reduced with pathological alterations in liver and heart tissues. Co-treatment NaHS with CP ameliorates the biochemical and histological parameters. Also, Treatment solely with CP resulted in increased tissue expression of interleukin-1β (IL-1β) in liver and heart but co-treatment NaHS with CP reduced the expression of this inflammatory factor. We conclude that NaHS operates in the liver and heart as an anti-inflammatory and powerful free radicals\' scavenger to inhibit the toxic effects of CP, both at the biochemical and histopathological levels.
NaHS protects the liver and heart against Cisplatin-induced toxicity.

Duchenne muscular dystrophy (DMD) is an incurable disease caused by mutations in the X-linked DMD gene that encodes a structural muscle protein, dystrophin. This, in turn, leads to progressive degeneration of the skeletal muscles and the heart. Hydrogen sulfide (H2S), the pleiotropic agent with antioxidant, anti-inflammatory, and pro-angiogenic activities, could be considered a promising therapeutic factor for DMD. In this work, we studied the effect of daily intraperitoneal administration of the H2S donor, sodium hydrosulfide (NaHS, 100 μmol/kg/day for 5 weeks) on skeletal muscle (gastrocnemius, diaphragm and tibialis anterior) pathology in dystrophin-deficient mdx mice, characterized by decreased expression of H2S-generating enzymes. NaHS reduced the level of muscle damage markers in plasma (creatine kinase, lactate dehydrogenase and osteopontin). It lowered oxidative stress by affecting the GSH/GSSG ratio, up-regulating the level of cytoprotective heme oxygenase-1 (HO-1) and down-regulating the NF-κB pathway. In the gastrocnemius muscle, it also increased angiogenic vascular endothelial growth factor (Vegf) and its receptor (Kdr) expression, accompanied by the elevated number of α-SMA/CD31/lectin-positive blood vessels. The expression of fibrotic regulators, like Tgfβ, Col1a1 and Fn1 was decreased by NaHS in the tibialis anterior, while the level of autophagy markers (AMPKα signalling and Atg genes), was mostly affected in the gastrocnemius. Histological and molecular analysis showed no effect of H2S donor on regeneration and the muscle fiber type composition. Overall, the H2S donor modified the gene expression and protein level of molecules associated with the pathophysiology of DMD, contributing to the regulation of oxidative stress, inflammation, autophagy, and angiogenesis.

Ferroptosis is a form of iron-dependent programmed cell death discovered in recent years that has been shown to be involved in diverse neurological disorders. Hydrogen sulfide (H2S) is an important signaling molecule with neuroprotective effects, including antioxidation. However, whether the protective mechanism of H2S is related to ferroptosis remains unknown. Therefore, in this study, we focused on the protective mechanisms of sodium hydrosulfide (NaHS, a donor of H2S) against ferroptosis caused by intracerebral hemorrhage (ICH) using a hemin-induced BV2 cell injury model in vitro. Our results indicated that NaHS enhanced cell viability and reduced hemin-induced lactate dehydrogenase (LDH) release. NaHS suppressed ferroptosis after hemin treatment, which was confirmed by attenuated reactive oxygen species (ROS) and lipid peroxidation, maintained iron homeostasis, recovery of the expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7-member 11 (SLC7A11), and increased glutathione (GSH) production. Moreover, we demonstrated that inhibiting ferroptosis improved cell survival and prevented hemin-induced oxidative stress. In addition, NaHS was also able to block ferroptosis inducer RSL3-induced ferroptotic cell death. We also found that NaHS increased cystathionine-β-synthase (CBS) expression and H2S levels after hemin treatment. Furthermore, NaHS-induced ferroptosis reduction was inhibited by the CBS inhibitor aminooxyacetic acid (AOAA) as well as by CBS small interference RNA (siCBS). In summary, these findings demonstrated that NaHS protects against hemin-induced ferroptosis by reducing lipid peroxidation, inhibiting iron overload, increasing GSH production, and improving GPX4 and SLC7A11 via the CBS/H2S system. The CBS/H2S system may be a promising target for preventing ferroptosis after ICH.

Photodynamic therapy (PDT) is a non-surgical treatment that has been approved for its human medical use in many cancers. PDT involves the interaction of a photosensitizer (PS) with light. The amino acid 5- aminolevulinic acid (ALA) can be used as a pro-PS, leading to the synthesis of Protoporphyrin IX. Hydrogen sulfide (H2S) is an endogenously produced gas that belongs to the gasotransmitter family, which can diffuse through biological membranes and have relevant physiological effects such as cardiovascular functions, vasodilatation, inflammation, cell cycle and neuro-modulation. It was also proposed to have cytoprotective effects. We aimed to study the modulatory effects of H2S on ALAPDT in the mammary adenocarcinoma cell line LM2. Exposure of the cells to NaHS (donor of H2S) in concentrations up to 10 mM impaired the response to ALA-PDT in a dose-dependent manner. The addition of 3 doses of NaHS showed the highest effect. This decreased response to the photodynamic treatment was correlated to an increase in the GSH levels, catalase activity, a dose dependent reduction of PpIX and increased intracellular ALA, decreased levels of oxidized proteins and a decrease of PDT-induced ROS. NaHS also reduced the levels of singlet oxygen in an in vitro assay. H2S also protected other cells of different origins against PDT mediated by ALA and other PSs. These results suggest that H2S has a role in the modulation of the redox state of the cells, and thus impairs the response to ALA-PDT through multifactor pathways. These findings could contribute to developing new strategies to improve the effectiveness of PDT particularly mediated by ALA or other ROS-related treatments.

To obtain higher yield of natural astaxanthin, the present study aims to develop a viable and economic induction strategy for astaxanthin production comprising succinic acid (SA) combined with sodium hydrosulfide (NaHS). The biomass (1.33 g L-1), astaxanthin concentration (44.96 mg L-1), astaxanthin content (163.55 pg cell-1), and lipid content (55.34%) were achieved under 1.0 mM SA and 100 μM NaHS treatment. These results were concomitant with enhanced hydrogen sulfide (H2S) but diminished reactive oxide species (ROS). Further study discovered that endogenous H2S could improve astaxanthin and lipid coproduction under SA induction by mediating related gene transcript levels and ROS signalling. Additionally, the concentrations of biomass and astaxanthin increased to 2.14 g L-1 and 66.25 mg L-1, respectively, under the induction of SA and NaHS in a scaled-up bioreactor. Briefly, the work proposed a novel feasible strategy for high yields of biomass and astaxanthin by H. pluvialis.

Hydrogen sulfide (H2S) prevents endothelial cells injury. However, the complicated mechanism of sodium hydrosulfide (NaHS, a donor that produces H2S) which inhibits the endothelial cells injury which correlated the activation of neutrophil in the type 1 diabetes mellitus (T1DM) rats has not been previously investigated.
In the experiment, the T1DM animal model was established, the IL-1β, IL-8 were determined by western blotting and ELISA, the expressions of the Bax and Bcl-2 of endothelial cells and the CXCR2, CSE, phosphor-IκBα and NF-kB of neutrophils were measured by western blotting. Additionally, the concentration of serum dsDNA was tested by PicoGreen commercial Kits, changes in the H2S concentration of neutrophils were determined by Multiskan spectrum microphate spectrophotometer, the cellular ROS levels of neutrophils were detected by DCFH-DA staining and flow cytometry. The IL-1β, IL-8 concentration and expression increased, the endothelial cells injury which stimulated by high glucose and the concentration of dsDNA in serum increased, the expression of CXCR2, phosphor-IκBα and NF-kB increased while the expression of CSE and concentration of H2S decreased in neutrophils in the T1DM group compared to the control group. NaHS significantly inhibited the injury of endothelial cell, the production of ROS in neutrophils, reversed the expressions of CXCR2, CSE, phosphor-IκBα and NF-κB and decreased concentration of dsDNA in serum which were caused by T1DM.
Our results demonstrated that the donor of H2S inhibits endothelial cells injury and neutrophils activation via the IL-8/CXCR2/ROS/NF-κB axis in T1DM rat.

In view of the significant role of H2S in brain functioning, it is proposed that H2S may also possess protective effects against adverse effects of neurotoxicants. Therefore, the objective of the present review is to discuss the neuroprotective effects of H2S against toxicity of a wide spectrum of endogenous and exogenous agents involved in the pathogenesis of neurological diseases as etiological factors or key players in disease pathogenesis. Generally, the existing data demonstrate that H2S possesses neuroprotective effects upon exposure to endogenous (amyloid β, glucose, and advanced-glycation end-products, homocysteine, lipopolysaccharide, and ammonia) and exogenous (alcohol, formaldehyde, acrylonitrile, metals, 6-hydroxydopamine, as well as 1-methyl-4-phenyl- 1,2,3,6- tetrahydropyridine (MPTP) and its metabolite 1-methyl-4-phenyl pyridine ion (MPP)) neurotoxicants. On the one hand, neuroprotective effects are mediated by S-sulfhydration of key regulators of antioxidant (Sirt1, Nrf2) and inflammatory response (NF-κB), resulting in the modulation of the downstream signaling, such as SIRT1/TORC1/CREB/BDNF-TrkB, Nrf2/ARE/HO-1, or other pathways. On the other hand, H2S appears to possess a direct detoxicative effect by binding endogenous (ROS, AGEs, Aβ) and exogenous (MeHg) neurotoxicants, thus reducing their toxicity. Moreover, the alteration of H2S metabolism through the inhibition of H2S-synthetizing enzymes in the brain (CBS, 3-MST) may be considered a significant mechanism of neurotoxicity. Taken together, the existing data indicate that the modulation of cerebral H2S metabolism may be used as a neuroprotective strategy to counteract neurotoxicity of a wide spectrum of endogenous and exogenous neurotoxicants associated with neurodegeneration (Alzheimer\'s and Parkinson\'s disease), fetal alcohol syndrome, hepatic encephalopathy, environmental neurotoxicant exposure, etc. In this particular case, modulation of H2S-synthetizing enzymes or the use of H2S-releasing drugs should be considered as the potential tools, although the particular efficiency and safety of such interventions are to be addressed in further studies.

Stress is a common phenomenon that is attracting increasing attention. Hydrogen sulfide (H2S) is a gasotransmitter that plays an important role in many physiological and pathological events. Our study aimed to estimate the effect and the underlying mechanisms of the H2S donor, sodium hydrosulfide (NaHS), against immobilization stress (IS)-induced lung injury. Forty adult male rats were classified into control group, NaHS group, and IS groups with and without NaHS treatment. Serum was obtained to determine corticosterone (CORT), total antioxidant capacity (TAC), tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) levels. Lung H2S, nitric oxide (NO), inducible nitric oxide synthase (iNOS), and malondialdehyde (MDA) levels were measured. Lung expressions of H2S synthesizing enzymes and Western blot analysis of nuclear factor erythroid 2-related factor 2 (Nrf2) and hypoxia-inducible factor 1 alpha (HIF 1α) were estimated. Histopathological changes and immunohistochemical assessment of nuclear factor kappa B (NF-κB) and caspase-3 were also done. Pretreatment with NaHS led to marked histological protection from lung damage seen in IS rats. Furthermore, pretreatment with NaHS before IS protected lung H2S levels and expressions of H2S-synthesizing enzymes. Similarly, the levels of CORT, TNF-α, IL-10, MDA, TAC, NO, iNOS, HIF-1 α, and nuclear Nrf2 and expressions of NF-kB and caspase 3 were all maintained at near control levels in contrast to that in the IS rats. In conclusion, NaHS is protective against stress-induced lung injury due to its antioxidant, anti-inflammatory, anti-fibrotic, and antiapoptotic effects. Thus, NaHS can be used to minimize stress complications on lung.