Impact of Mummy Substance on Proliferation and Migration of Human Wharton’s Jelly-Derived Stem Cells and Fibroblasts in an In Vitro Culture System

Introduction Skin, as the covering of the body, serves as a barrier against foreign pathogens, controls body temperature, provides sensation and prevents body water loss (1,2). The skin is composed of an outermost layer called the epidermis which overlies the underlying dermis (3). The dermis is an irregular, dense connective tissue predominantly consisting of extracellular matrix (ECM) with different origins and functions (4). Fibroblasts are the main dermal cells responsible for the synthesis and maintenance of ECM components (3). A wound is an impairment of the normal structure of the skin that disrupts its function (5). Cutaneous wounds can occur as a result of surgical laceration, burns, pressure and diabetic ulcers (6). The prevalence of wounds is a financial burden. It is estimated that about $20 billion is spent annually on treatment of wounds and related complications (6,7). Wounds can be classified as acute or chronic. Acute wounds occur as a result of surgical incisions, abrasions or lacerations and generally heal within three weeks (8). Chronic wounds involve all skin layers and normally occur as a result of diabetic foot ulcers or neurodegenerative disorders and tend to heal minimally within three months (7). Wound healing is a complicated and dynamic process and proceeds through 4 distinct and overlapping phases: hemostasis, inflammation, proliferation and migration Abstract Objectives: Because of the high prevalence of chronic wounds, wound repair has become one of the health challenges. Numerous therapeutic strategies have been proposed for repairing wounds and recently, the use of herbal medicines has been considered because of lower costs and complications. The use of mummy is recommended in traditional medicine for treating bone fractures, bleeding control, poisoning treatment, headache relief and wound repair. Therefore, the purpose of the present study was to provide a scientific assessment of the effect of mummy on wound healing. Materials and Methods: Human fetal foreskin fibroblast cells (HFFF-2) were purchased from Pasteur Institute (Tehran, Iran). The fibroblast cell lines and stem cells derived from Wharton’s jelly (WJSCs) were isolated by means of explant culture. MTT assay was used to determine the effective concentration of mummy. Scratch assay method was used to examine the effect of mummy on cell migration rate and flow cytometry was used to assess the rate of cell proliferation using Ki-67 antibody. WJSCs and HFFF-2, each under mono-culture and two-cell co-culture condition with 50-50 and 30/70 ratio respectively, were in an experimental group including culture medium and mummy and in a control group including culture medium only. Results: Scratch assay results for HFFF-2 cell migration showed a significant increase (P ≤ 0.0001), but the mummy had no significant impact on WJSCs and a significant increase was observed in 50/50 and 30/70 co-culture conditions with P ≤ 0.001 and P ≤ 0.0001, respectively. The proliferation rate of WJSCs increased significantly while no significant increase was found in fibroblast groups in mono-culture and co-culture conditions. Conclusions: Results showed that by stimulating fibroblast cell migration both in mono-culture and co-culture conditions with stem cells and by increasing WJSCs proliferation, the mummy can be used as a treatment to accelerate wound repair procedure.