EC Pharmacology and Toxicology

A wound is defined as any injury of the epithelial lining of the skin or mucosa. Despite advances in wound care, wounds remain a public health problem. The present study aims to assess the anti-inflammatory and wound healing activities of the hydroethanolic root bark extract of Piliostigma thonningii, a plant traditionally used as a hemostatic and wound healer. The plant extract was first subjected to phytochemical screening. Next, the anti-inflammatory activity of this extract was determined using the carrageenan-induced rat paw edema method. Wound healing activity was assessed in a rat excision wound model. Wounds were treated by topical application of 3%, 5% and 10% P. thonningii extract ointments and a reference healing ointment (Cicatryl) every other day for three weeks. Phytochemical screening revealed the presence of polyphenols, flavonoids, quinones, alkaloids, gallic tannins, sterols and polyterpenes in the hydroethanolic root bark extract of P. thonningii. Results also show that this extract inhibited the effect of carrageenan within the first hour after injection, and significantly reduced rat paw edema at 4, 5 and 6-hours post-injection. The maximum edema inhibition was reached at 6 hours in all pre-treated rat groups with edema inhibition percentages of 90.65%, 89.41% and 45.31% for P. thonningii extract at 100 and 200 mg/kg b.w. and diclofenac (10 mg/kg b.w.), respectively. In the wound healing study, the results show that after 12 days, 3% and 5% P. thonningii extract ointments significantly reduced wound surface. After 21 days, the percentage of wound contraction in rats treated with 3% extract ointment was 100% (complete healing) compared to 82.83% in Cicatryl. With 5% and 10% extract ointments, the contraction percentages were 82.71% and 74.03%, respectively. These results show that the hydroethanolic root bark extract of P. thonningii has anti-inflammatory and wound-healing properties, which may be related to the presence of phenolic compounds and tannins.

 Keywords: Wound; Healing; Anti-inflammatory Activity; Piliostigma thonningii

1. Qi L., et al. “Progress in hydrogels for skin wound repair”. Macromolecular Bioscience7 (2022): e2100475.
2. Nguyen DT., et al. “The pathophysiologic basis for wound healing and cutaneous regeneration”. In Orgill, D.P. and Blanco, C. (eds.). Biomaterials for Treating Skin Loss. Elsevier (2009): 25-57.
3. Stadelmann, W.K., et al. “Physiology and healing dynamics of chronic cutaneous wounds”. American Journal of Surgery2 (1998): 26-38.
4. Broughton G., et al. “The basic science of wound healing”. Plastic and Reconstructive Surgery7 (2006): 12S-34S.
5. Janis JE and Harrison B. “Wound Healing: Part I. Basic Science”. Plastic and Reconstructive Surgery3 (2016): 9S-17S.
6. Meaume, S., et al. “Workload and prevalence of open wounds in the community: French Vulnus initiative” Journal of Wound Care2 (2012): 62-66.
7. Olsson M., et al. “The humanistic and economic burden of chronic wounds: A systematic review”. Wound Repair and Regeneration1 (2019): 114-125.
8. , et al. “A review of the medicinal uses and biological activity of Piliostigma thonningii (Schum). Milne-Redh”. RPS Pharmacy and Pharmacology Reports 3.1 (2024): 1-15.
9. Maroyi A. “An ethnobotanical survey of medicinal plants used by the people in Nhema communal area, Zimbabwe”. Journal of Ethnopharmacology 136 (2011): 347-354.
10. Toafode NMC., et al. “Ethnomedicinal information on plants used for the treatment of bone fractures, wounds, and sprains in the northern region of the Republic of Benin”. Evidence-Based Complementary and Alternative Medicine (2022): 8619330.
11. Igoli JO., et al. “Traditional medicine practice amongst the Igede people of Nigeria. Part II”. African Journal of Traditional, Complementary and Alternative Medicines2 (2005): 134-152.
12. Burkill HM. “The useful plants of West Tropical Africa”. 2^nd Volume 3, Families J-L. Royal Botanic Gardens, Kew Richmond, London (1995): 1-857.
13. Zirihi, G.N., et al. “Evaluation de l’activité antifongique de Microglossa pyrifolia (Lamarck O. Kuntze Asteraceae) “PYMI” sur la croissance in vitro de Candida albicans”. Revue de Médecine et de Pharmacie3 (2003): 11-19.
14. Wagner H and Bladt S. “Plant drug analysis: A thin layer chromatography atlas”. 2^nd edition, Springer, Berlin (1996): 1-384.
15. “OECD Guideline 423 for testing of chemicals. Acute Oral Toxicity - Acute Toxic Class Method” (2001): 1-14.
16. Winter CA., et al. “Carrageenin induced oedema in hind paw of the rat as assays anti-inflammatory drugs”. Proceedings of the Society for Experimental Biology and Medicine 111 (1962): 544-547.
17. Sagliyan A., et al. “Effects of dietary supplementation with whey proteins on surgical wound healing in rats". Revue de Médecine Vétérinaire10 (2010): 455-462.
18. Alagbe JO. “Proximate, mineral and phytochemical analysis of Piliostigma thonningii stem bark and roots”. International Journal of Biological, Physical and Chemical Studies 1 (2019): 1-7.
19. Doh KS., et al. “Phytochemical screening and acute toxicity assessment of leaves from Piliostigma thonningii (Fabaceae), a plant used in traditional medicinal against diabetes in Côte d’Ivoire”. Journal of Pharmacognosy and Phytochemistry 3 (2023): 19-23.
20. Crunkhorn P and Meacock SC. “Mediators of the inflammation induced in the rat paw by carrageenan”. British Journal of Pharmacology3 (1971): 392-402.
21. Vinger R., et al. “Pathway to carrageenan-induced inflammation in the hind limb of the rat”. Federal Proceeding1 (1987): 118-126.
22. Di Rosa M. “Effect of non-steroidal anti-inflammatory drugs on leukocyte migration”. In: Velo, G.P. and Willoughby, P.A. (Eds.), Future Trends in Inflammation. Piccin Medical Books, Padova (1974): 143-152.
23. Maity TK., et al. “Studies on anti-inflammatory effect of Cassia tora leaf extract (Fam Leguminosae)”. Phytotherapy Research3 (1998): 221-223.
24. Hinz B., et al. “Bioavailability of diclofenac potassium at low doses”. British Journal of Clinical Pharmacology1 (2005): 80-84.
25. Guo W., et al. “Dietary polyphenols, inflammation, and cancer”. Nutrition and Cancer6 (2009): 807-810.
26. Gonzalez R., et al. “Effects of flavonoids and other polyphenols on inflammation”. Critical Reviews in Food Science and Nutrition 4 (2011): 331-362.
27. Reinkes JM and Sorg H. “Wound repair and regeneration”. European Surgical Research1 (2012): 35-43.
28. Mulisa E., et al. “Evaluation of wound healing and anti-inflammatory activity of the rhizomes of Rumex abyssinicus (Polygonaceae) in mice”. BMC Complementary Medicine and Therapies 15.1 (2015): 341-350.
29. Robert JN., et al. “Flavonoids: a review of probable mechanisms of action and potential applications”. The American Journal of Clinical Nutrition4 (2001): 418-425.
30. Tekleyes B., et al. “Wound healing activity of 80 percent methanol leaf extract of scabra (Lf) sond (cucurbitaceae) in mice”. Journal of Experimental Pharmacology 13 (2021): 537-544.
31. Du Toit K., et al. “The chemical structures, plant origins, ethnobotany and biological activities of homoisoflavanones”. Natural Product Research 5 (2010): 457-490.