**9. Miscellaneous substances**

is extracted from the dried inner flesh of coconut [224] predominantly contains medium chain triglycerides, with 86.5% saturated fatty acids, 5.8% monounsaturated fatty acids, and 1.8% polyunsaturated fatty acids. Virgin coconut oil is also known to have antibacterial and antifungal properties [225, 226]. Excised wounds treated with virgin coconut oil healed much faster, as indicated by a decreased time of complete epithelization and increased in pepsin‐ soluble collagen, as well as an increase in fibroblast proliferation and neovascularization [227]. Also in burn wounds, there was improvement in wound contraction and decreased period of

Oil extracted from the seeds of grapes *Vitis vinifera* (Family Vitaceae) has been found to exhibit wound healing activity. In the excision wound model, grape oil‐treated animals had increased wound area contraction and hydroxyproline content. Also histological analysis of the grape

*Vaccinium macrocarpon* (family Ericaceae) is an evergreen creeping shrub native to North America [229]. Excision wounds on animals treated with cranberry oil showed faster rates of wound area contraction with higher hydroxyproline content. The cranberry oil‐treated wound

The essential oil derived from steam distillation of the leaves and terminal branches of *Melaleuca alternifolia* (family Myrtaceae) commonly known as tea tree [230], is composed of a mixture of monoterpenes, 1‐terpinen‐4‐ol, cineole and other hydrocarbons. Tea tree oil possesses antimicrobial, anti‐inflammatory and analgesic properties [231]. Tea tree oil has been reported to aid in healing of bacterial infected wounds, including diabetic wounds, character‐ ized by reduced healing time, rapid reduction in inflammation, pain and wound odor [232,

*Vitellaria paradoxa* (family Sapotaceae) commonly known as shea butter is an indigenous species of Sub‐Saharan African [234]. The nuts and seeds are a very rich source of fats and oils, from which shea butter is derived. Shea butter is known to accelerate healing after circumcision [235]. The healing effect of shea butter may be attributed to the presence of allantoin, since it is a substance known to stimulate the growth of healthy tissues in ulcerous wounds [236].

*Pistacia lentiscus* L. (Anacardiaceae) is a dioecious sclerophyllous evergreen species widely distributed along the Mediterranean basin. The essential oil of *P. lentiscus* obtained by hydro‐

oil‐treated wound tissue showed increased well organized collagen band [228].

epithelialization when treated with coconut oil [224].

**8.5.** *Vaccinium macrocarpon* **(cranberry) oil**

**8.6.** *Melaleuca alternifolia* **(Tea tree) oil**

**8.7.** *Vitellaria paradoxa* **(Shea tree) oil**

**8.8. Virgin fatty oil of** *Pistacia lentiscus*

233].

tissue had well organized bands of collagen [228].

**8.4.** *Vitis vinifera* **(grape) oil**

512 Wound Healing - New insights into Ancient Challenges

### **9.1. Wound healing properties of honey**

Honey is a collection of nectar processed by honey bees [240]. It is rich in nutrients and defined substances such as glucose, fructose, sucrose, minerals, vitamins, antioxidants, amino acids and many other products, which may be responsible for its numerous therapeutic roles and potency [241]. Its therapeutic properties include antimicrobial activity which may be attributed to its osmotic effect, a naturally low pH, and the production of hydrogen peroxide [242, 243]. Honey attacks antibiotic-resistant strains of bacteria and prevents bacterial growth even when wounds are heavily infected [244]. Again, honey has been reported to exhibit antioxidant activity [245, 246]. In wound care, honey has been used extensively as wound healing agent for almost all kinds of wounds. It has been assessed for the treatment of venous leg ulcers, burns, chronic leg ulcers, pressure ulcers, as well as diabetic wound [247], with scarless healing in cavity wounds, less edema, fewer polymorphonuclear and mononuclear cell infiltrations, less necrosis, better wound contraction, improved epithelialization, lower glycosaminoglycan and proteoglycan concentrations, increased granulation tissue formation and tissue growth, collagen synthesis and development of new blood vessels in the bed of wounds [241].

### **10. Conclusion**

Most of these medicinal plants and natural products traditionally used for the treatment and management of these various types of wounds had their wound healing properties, including wound contraction, tensile strength, antioxidant and antimicrobial activities, hydroxyproline content assay and histological investigations namely re-epithelization, collagen synthesis, granulation, proliferation and differentiation of fibroblasts and keratinocytes, assessed and evaluated through *in vitro* and *in vivo* model studies. Hence there is a need to subject these products to both primary and advanced clinical studies with specific types of wounds to ascertain or confirm the reported wound healing properties. These trials must be done after safety profiles of these products have been determined.
