The effects of common house fly (Musca domestica) larvaederived substances on wound healing in mouse model

Abstract

Background: Maggot debridement therapy is a therapeutic wound myiasis that depends mainly on L. sericatalarva. Owing to its availability and cheap breeding, M. domestica was suggested as an alternative to Lucilia.Objective: The present study was designed to assess the role of M. domestica larvae-derived substances onwound healing in immunocompetent and immunosuppressed mice.Material and Methods: Chitosan and gut extracts, obtained from M. domestica larvae, were applied dailyon skin wounds of Swiss albino mice. Mice were divided into two groups, control non-treated mice (I), andexperimental treated mice (II). Each group included immunocompetent (a), and immunosuppressed (b) mice.The experimental subgroups were treated with either chitosan (1) or gut extracts (2). Wounds were assessedby macroscopic evaluation, wound contracture, histopathological, immunohistochemical and bacteriologicalparameters.Results: In control non treated mice hair growth was evident with normal underlying skin by the end ofthe experiment (4 weeks) except in immunosuppressed (Ib) subgroup. Significant reduction in wound sizewas detected on the 7th day post wounding (PW) in the immunocompetent-chitosan-treated subgroup (IIa1)compared to Ia, IIb1, and IIa2 subgroups. Histopathological examination showed early epidermal creepingon the 3rd day PW in IIa1, IIa2, and IIb2 subgroups. Significant increase in collagen deposition was bestdetected in both gut extract-treated subgroups (IIa2 and IIb2) compared to the control subgroups (Ia, andIb). Strong immunohistochemical reaction was evident in all immunocompetent treated mice (IIa1 and IIa2)by the 7th day PW and in IIb2 by the 14th day PW. Delay in keratin maturation was detected in both controlsubgroups and IIb1. Significant reduction in staphylococcal colonies was detected by the 7th day PW in allimmunosuppressed treated subgroups compared to their control subgroup (Ib).Conclusion: The difference in the rapid wound closure as detected by chitosan treatment, and the effectiveskin architecting by gut extract treatment recommends further trial by their combined therapy.