Protective effects of hydrogen sulfide on anxiety in ovalbumin-induced chronic asthma

Introduction: Comorbidity of anxiety has been reported to aggravate the control of asthma symptoms. Considering the important role of oxidative stress in the pathophysiology of asthma and anxiety, the present study evaluated whether hydrogen sulfide (H2S) as an antioxidant agent, has anxiolytic effects in ovalbumin (OVA)-induced chronic asthma. Methods: BALB/c mice were randomly divided into 4 groups (n=8): control, asthma, NaHS (sodium hydrosulfide, a donor of H2S) and ascorbic acid (as a positive control). All animals except in the control group were sensitized and challenged with ovalbumin. Mice in the NaHS group, intraperitoneally received 14μmol/kg NaHS 30min before each challenge. In the ascorbic acid group, 130mg/kg ascorbic acid was given by gavage 30min before each challenge. On the day of the last challenge, animal body weight and anxiety-related behaviors were examined. Results: Asthma caused significant decreases in the percentages of open arm entries and spending time in open arms in the elevated plus maze as well as the spending time in the light side in the light-dark transition. Also, induction of asthma resulted in a significant decrease of the animal body weight. Administration of NaHS as well as ascorbic acid, attenuated anxiety-related behaviors and improved the body weight in asthmatic mice. Conclusion: The current study suggested that NaHS improves anxiety-related behaviors in OVA-induced asthma same as ascorbic acid, a strong antioxidant. Therefore, NaHS appears to be effective for managing the comorbidity of anxiety with asthma.