Tannin extracts from immature fruits of Terminalia chebula Fructus Retz. promote cutaneous wound healing in rats

Abstract

BackgroundTannins extracted from immature fruits of Terminalia chebula Fructus Retz. are considered as effective components promoting the process of wound healing. The objective of this study is to explore the optimal extraction and purification technology (OEPT) of tannins, while studying the use of this drug in the treatment of a cutaneous wound of rat as well as its antibacterial effects.MethodsThe content of tannin extracts was measured by the casein method, and antibacterial ability was studied by the micro-dilution method in vitro. In wound healing experiment, animals in group Ⅰ, Ⅱ and Ⅲ were treated with vaseline ointment, tannin extracts (tannin content: 81%) and erythromycin ointment, respectively (5 mg of ointment were applied on each wound). To evaluate the process of wound healing, selected pharmacological and biochemical parameters were applied.ResultsAfter optimal extraction and purification, content of tannin extracts was increased to 81%. Tannin extracts showed the inhibition of Staphylococcus aureus and Klebsiella Pneumonia in vitro. After excision of wounds, on days 7 and 10, the percent of wound contraction of group Ⅱ was higher than that of group Ⅰ. After being hurt with wounds, on days 3, 7, and 10, the wound healing quality of group Ⅱ was found to be better than that of group Ⅰ in terms of granulation formation and collagen organization. After wound creation, on day 3, the vascular endothelial growth factor expression of group Ⅱ was higher than that of group Ⅰ.ConclusionThe results suggest that tannin extracts from dried immature fruits of Terminalia chebula Fructus Retz. can promote cutaneous wound healing in rats, probably resulting from a powerful anti-bacterial and angiogenic activity of the extracts.

The medicinal properties and phytochemistry of plants of the genus Terminalia (Combretaceae)

“…Of these, perhaps the best documented and the most extensively studied are the Asian Terminalia species used in Ayurvedic medicine. T. arjuna (Chaudhari and Mengi 2006), T. chebula (Li et al 2011;Suguna et al 2002) and T. coriacea (Ali Khan et al 2012) have all demonstrated an ability to hasten the wound healing process. As wound healing is a complex process involving several bioactivities, no single experimental model is adequate to evaluate wound healing and various individual bioactivities need to be considered.…”

“…Transcription factors are active in their reduced form and their translocation to the nucleus is also redox dependent (Okamato et al 1999). Studies have demonstrated that T. chebula treatment increases transcription and translation rates as well as DNA replication (Li et al 2011;Suguna et al 2002). These studies also linked these increases to the very high antioxidant activity of T. chebula.…”

“…Furthermore, the same study also demonstrated an increase in the levels of the extracellular matrix components hexosamine and uronic acid following T. chebula treatment in the early stages of wound healing (when the extracellular matrix forms), followed by a return to normal levels in the later stages. In addition, T. chebula tannin extracts have been shown to have angiogenic potential, increasing the amount of newly formed capillaries during the inflammatory phase of wound healing, as well as increasing the degree of wound contraction in granulation tissue (Li et al 2011).…”

The development of Terminalia chebula Retz. (Combretaceae) in clinical research

“…Topical administration of an alcoholic extract of T. chebula leaves on the healing of rat dermal wounds showed that T. chebula treated wounds healed faster as indicated by improved rates of contraction and decreased period of epithelialization [85] .…”

Effect of Ethanolic Extract of Cyanotis Cristata Leaves Applied Topically on Wound Healing in Wistar Rats

“…Tannins have antioxidant effect and may act in similar fashion to promote collagen deposition [37]. They also increase angiogenesis by increasing vascular endothelial growth factor formation, thus maintaining adequate supply of oxygen necessary for collagen stability [38].…”