Burn wound healing activity of Lythrum salicaria L. and Hypericum scabrum L

Burns are complicated traumatic injuries caused by several physical or chemical factors. Plants with a wide range of secondary metabolites, with valuable properties like antioxidant and anti-inflammatory activities, can be a promising source of wound healing agents.

Effects of hydromethanolic extracts of Lythrum salicaria and Hypericum scabrum, individually and in combination, were assessed in second-degree burn wounds in rats in comparison to a white oleaginous base (negative control) and silver sulfadiazine (positive control). Histological assessments as well as total thiol molecules, lipid peroxidation, and total antioxidant power were evaluated in skin tissue samples. Total phenol, flavonoids, and tannins along with the antioxidant and antimicrobial activities of the extracts were also assessed.

Total phenol, total flavonoid, and total tannin amounts for L. salicaria and H. scabrum were 331 ± 3.7 and 308.1 ± 5.2 µg gallic acid/mg extract, 5.8 ± 0.4 and 4.3 ± 0.3 µg quercetin/mg extract, and 430 ± 2.33 and 13.4 ± 0.5 µg tannic acid/mg extract, respectively. H. scabrum significantly inhibited S. aureus and L. salicaria moderately suppressed Staphylococcus aureus and Candida albicans growth. Wound contraction percentage with L. salicaria and H. scabrum was 89.5 ± 3.7 and 77.6 ± 4.1, respectively. A well-organized epidermal layer and normal appearance in dermis layer were more observable in the L. salicaria group. Moreover, L. salicaria ointment individually displayed better influence on tissue oxidative stress parameters than H. scabrum and the negative control (P < 0.05).

Results of this study clearly confirm the effectiveness of L. salicaria topical ointment as a wound healing agent, possibly due to the considerable polyphenolic content and antioxidant properties.