Hexarelin · research summary

Hexarelin modulates lung mechanics, inflammation, and fibrosis in acute lung injury.

Drug target insights · 2021. Summary drawn from the study's full text. Each statement is followed by the exact sentence it comes from. This is a research summary, not medical advice.

Study type

Experimental animal study using a murine model of unilateral acid aspiration lung injury to test hexarelin.
“In this article we explore the therapeutic potential of hexarelin, a synthetic hexapeptide growth hormone secretagogue (GHS), in an experimental model of ARDS.”

Subjects

Male C57/BL6J mice.
“Male C57/BL6J mice (23-25 g; Harlan Laboratories, Udine, Italy) were used in this experimental study.”

Sample size

Group sizes ranged from n=3 to n=18 depending on the specific experimental arm and time point.
“Healthy: no surgical interventions or treatment (n = 15); Vehicle: HCl instillation + Vehicle treatment (n = 18); Hexarelin: HCl instillation + Hexarelin treatment (n = 18).”

Duration

Acute assessments at 6 and 24 hours post-injury, with a late assessment at 14 days post-injury.
“In an extended study, mice were observed for a subsequent 14 days in order to assess lung fibrosis.”

Reported findings

Hexarelin treatment improved respiratory system static compliance 24 hours after HCl instillation.
“Hexarelin induced a significant (p<0.05) improvement in respiratory compliance 24 hours after lung injury.”
Hexarelin treatment reduced the number of total immune cells and neutrophils in bronchoalveolar lavage fluid.
“Hexarelin induced a significant improvement in lung compliance and a reduction of the number of total immune cells in BAL 24 hours after HCl instillation, accompanied with a lower recruitment of neutrophils compared with the vehicle group.”
Hexarelin-treated mice exhibited less pulmonary collagen deposition at 14 days compared to vehicle-treated controls.
“At day 14, hexarelin-treated mice presented with less pulmonary collagen deposition compared with vehicle-treated controls.”

Limitations stated by the authors

The study did not confirm findings in a different ARDS model, mechanisms of action are speculative, inflammatory cytokines were not measured, and indices of lung edema, septal thickening, and hemorrhage were not assessed.
“First, we did not confirm the findings in a different model of ARDS. Second, the possible mechanisms of action of hexarelin are only speculative. Third, the levels of inflammatory cytokines were not measured, which could support the results on inflammation obtained for local and peripheral inflammatory cell count. Fourth, as index of lung, edema, septal thickening, and hemorrhage were not assessed in this study.”

Source: PubMed 34871336 · DOI 10.33393/dti.2021.2347 · all study summaries

Reported findings

Hexarelin treatment improved respiratory system static compliance 24 hours after HCl instillation.

“Hexarelin induced a significant (p<0.05) improvement in respiratory compliance 24 hours after lung injury.”

Hexarelin treatment reduced the number of total immune cells and neutrophils in bronchoalveolar lavage fluid.

“Hexarelin induced a significant improvement in lung compliance and a reduction of the number of total immune cells in BAL 24 hours after HCl instillation, accompanied with a lower recruitment of neutrophils compared with the vehicle group.”

Hexarelin-treated mice exhibited less pulmonary collagen deposition at 14 days compared to vehicle-treated controls.

“At day 14, hexarelin-treated mice presented with less pulmonary collagen deposition compared with vehicle-treated controls.”

Limitations stated by the authors

The study did not confirm findings in a different ARDS model, mechanisms of action are speculative, inflammatory cytokines were not measured, and indices of lung edema, septal thickening, and hemorrhage were not assessed.

“First, we did not confirm the findings in a different model of ARDS. Second, the possible mechanisms of action of hexarelin are only speculative. Third, the levels of inflammatory cytokines were not measured, which could support the results on inflammation obtained for local and peripheral inflammatory cell count. Fourth, as index of lung, edema, septal thickening, and hemorrhage were not assessed in this study.”