The Effect of Topical Administration of an Ointment Prepared From Trifolium repens Hydroethanolic Extract on the Acceleration of Excisional Cutaneous Wound Healing

Introduction: Natural agents with antioxidant and anti-inflammatory properties are safer than synthetic agents and may improve wound healing.

Objective: The purpose of this study is to evaluate the in vivo wound healing potential of an ointment prepared from Trifolium repens hydroethanolic extract (T repens) concerning excisional wounds in a rat model.

Materials and methods: Seventy-two adult Wistar rats were divided into 4 groups: a control group and 3 groups of animals treated with 1.5% T repens, 3% T repens, and 6% T repens. A full-thickness wound with an area of 314 mm2 was created in each rat. To investigate the effect of T repens on wound healing, the wound area, histological analyses (eg, angiogenesis, fibroblast, fibrocyte, mast-cell distribution), intracytoplasmic carbohydrate storage, and B-cell lymphoma 2-like protein 4 (BAX), B-cell lymphoma 2 (Bcl-2), and p53 gene expression in the wound tissue were evaluated for 21 days. Antioxidant activity was further measured by 2,20-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-Di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) assays.

Results: The animals in the treated groups showed higher wound contraction ratios (P ⟨ .05), angiogenesis, fibroblast, fibrocyte, and mast-cell distribution and intracytoplasmic carbohydrate storage compared with the control group (P ⟨ .05). Moreover, the topical administration of T repens increased the messenger ribonucleic acid (mRNA) level of Bcl-2 and reduced the BAX and p53 mRNA levels (P ⟨ .05). These findings further revealed the strong antioxidant activity of T repens.

Conclusions: The topical administration of T repens accelerated wound healing by increasing angiogenesis; fibroblast, fibrocyte, and mast-cell distribution; intracytoplasmic carbohydrate storage; and modulation in genes involved in apoptosis in a rat model.