Evaluation of the inflammatory process, collagen production, and MMP-2 and MMP-9 expressions produced by Luffa aegyptiaca Mill using the subcutaneous rat implanted model

Abstract

The subcutaneous rat implanted model is a preclinical approach used in studies to characterize the histocompatibility of materials that could be used as biomaterials. Biomaterials are obtained synthetically or from the environment, and they can be used to treat or replace any tissues or organs that the body has lost. To execute their roles, the biomaterials must present any level of histocompatibility and a lower level of inflammatory reaction. This work aimed to evaluate some aspects of histocompatibility, such as the inflammatory process, collagen production, and MMP-2 and 9 expression as responses to the Luffa aegyptiaca Mill using the subcutaneous rat implanted model. Luffa fragments were implanted into the dorsal subcutaneous region of twelve male Wistar rats, and the number of eosinophils, mast cells, the production of collagen to form the fibrous capsule, and the expression of MMP-2 and MMP-9 were evaluated on the 15th, 45th, and 90th days. Results showed statistical differences (p < 0.05) in the number of eosinophils and mast cells present inside and outside the fibrous capsule among the days evaluated. The permanent presence of macrophages and giant foreign body cells circumjacent to all implants was also observed. A progressive increase in the production of collagen was also detected, along with a significant reduction on day 90 (p < 0.05). The expression of MMP-9 was detected as being specifically expressed in the giant foreign body cells on all days evaluated, while the expression of MMP-2 was detected in fat cells present around the implants, mainly on day 90. Taken together, these results indicate a general reduction level for the inflammatory process during the days evaluated, which allows us to conclude that Luffa, being a natural product that is simple to obtain, could be a potential candidate to become a biomaterial to be tested in further approaches.