*5.3.2 Dipeptidyl peptidase-4 (DPP-4) inhibitors*

Dipeptidyl peptidase-4 is a significant enzyme that deactivates the cretin hormones glucagon-like peptide-1 and glucagon-like peptide. FDA-approved oral drugs known as 43 DPP-4 inhibitors for type II diabetes mellitus block dipeptidyl peptidase, improve the flow of infused hormones, and provide glycemic control as well as increased islet cell function. By reducing blood glucose levels, DPP-4 inhibitors including sitagliptin, vildagliptin, and anagliptin are used to treat diabetes. Exendin-4, a glucagon-like peptide-1 (GLP-1) receptor agonist derived from the saliva of the Gila monster, a large poisonous lizard found in the South Western region of the United States, was applied topically on experimental animals to speed up the healing of diabetic foot ulcer wounds whether or not adipose-derived stem cells were also present [34, 35].

*Targeting Matrix Metallopeptidase 9 (MMP-9) and Role of Quorum Sensing (QS) in Diabetic… DOI: http://dx.doi.org/10.5772/intechopen.106514*

## **5.4 Use of stem cells in diabetic foot ulcer**

Diabetic foot ulcer can produce blood vessel and extracellular matrix cell precursors when stem cells, such as adipose-derived stem cells and endothelian progenitor cells, are introduced from bone marrow or other sources [36, 37]. To encourage the growth of new cells in the wound area, these progenitor cells can be injected into the wound [38].
