Burn Wound Healing Activity of Hydroxyethylcellulose Gels with Different Water Extracts Obtained from Various Medicinal Plants in Pseudomonas aeruginosa-Infected Rabbits

Abstract

Burn injuries represent a significant problem in clinical practice due to the high risk of infection and the prolonged healing process. Recently, more attention has been given to natural remedies such as water extracts of various medicinal plants, which possess anti-inflammatory and wound healing properties. The aim of this study is to evaluate the efficacy and safety of Satureja montana L. and other water extracts in a burn wound model. The study involved male Californian rabbits (n = 52) divided into eight groups. Burn wounds were modeled on the animals and subsequently treated with gels based on Satureja montana L. and other water extracts. The reparative potential of the epidermis (assessed by Ki-67 expression), the state of local immunity (measured by the number of CD-45 cells), and the anti-inflammatory role of mast cells (measured by tryptase levels) were evaluated. Bacteriological and morphological studies were conducted. The most pronounced bactericidal, reparative, and immunostimulatory effects were observed after the treatment using a gel mixture of water extracts from Satureja montana L., Salvia sclarea, Coriandrum sativum L., and Lavandula angustifolia in equal proportions (1:1:1:1). The other gels also demonstrated high efficacy in treating burn wounds, especially when using a strain of Pseudomonas aeruginosa resistant to several antibiotics. Immunohistochemical studies showed a significant increase in the number of Ki-67-positive cells in the basal layer of the epidermis and a decrease in the number of CD-45-positive cells, indicating improved proliferative activity and reduced inflammation. This study confirms the hypothesis that the use of water extract mixtures significantly enhances the reparative potential, improves the immune response in the treatment of burns, and promotes wound healing. These findings pave the way for further research and the application of complex phytotherapeutic agents, specifically water extracts of medicinal plants containing phenols and antioxidants in burn wound therapy.

Keywords: Satureja montana L.; anti-inflammatory action; burn wound; cell proliferation; epidermis regeneration; essential oil water extracts.

Figure 1

Bacteriological examination of blood samples. Culture on various media (from left to right: YSA, MPA, blood agar, Sabouraud, and Endo).

Figure 2

Burn wounds of the skin of the control and experimental groups on different days of the experiment. Histological examination. Staining with hematoxylin and eosin, magnification ×200. Symbols (figure captions): ★—detritus, ∆—inflammation.

Figure 2

Burn wounds of the skin of the control and experimental groups on different days of the experiment. Histological examination. Staining with hematoxylin and eosin, magnification ×200. Symbols (figure captions): ★—detritus, ∆—inflammation.

Figure 2

Burn wounds of the skin of the control and experimental groups on different days of the experiment. Histological examination. Staining with hematoxylin and eosin, magnification ×200. Symbols (figure captions): ★—detritus, ∆—inflammation.

Figure 3

Burn wounds of the skin of the control and experimental groups at various study periods. Immunohistochemical study with antibodies to Ki-67 (red signal), nuclei—DAPI (blue signal); fluorescence microscopy; magnification ×400. Ki-67-positive cells were found in the epidermis (red signal).

Figure 3

Burn wounds of the skin of the control and experimental groups at various study periods. Immunohistochemical study with antibodies to Ki-67 (red signal), nuclei—DAPI (blue signal); fluorescence microscopy; magnification ×400. Ki-67-positive cells were found in the epidermis (red signal).

Figure 4

The number of Ki-67-positive cells in the epidermis of the control and experimental groups, (in %) at various study stages: (A) 3rd day, (B) 7th day, (C) 10th day, (D) 14th day, (E) 21st day. The experimental groups are numbered according to the design of the study. Statistically significant differences compared with the control group are indicated by * (p < 0.05); statistically significant differences between the III and VII groups are indicated by † (p < 0.01); statistically significant differences between the IV and VII groups are indicated by ø (p < 0.001).

Figure 5

Burn wounds of the skin of the control and experimental groups on different days of the study. Immunohistochemical examination with CD-45 antibodies with hematoxylin staining of the nuclei; magnification ×400. CD-45-positive lymphocytes are found in the dermis (brown cytoplasmic staining, ↑).

Figure 6

The number of CD-45-positive cells in the epidermis of the control and experimental groups (in %) at various study periods: (A) 3rd day, (B) 7th day, (C) 10th day, (D) 14th day, (E) 21st day. The experimental groups are numbered according to the design of the study. Statistically significant differences compared with the control group are indicated by * (p < 0.0001); statistically significant differences between III and VII are indicated by † (p < 0.001); statistically significant differences between IV and VII groups are indicated by ø (p < 0.0001).

Figure 7

Mitotic activity of the mast cells in the experiment. (A) Cb group, 14th day; (B) Mix group, 21st day; (C,D) SA group, 21st day; (E) SA group, 3rd day; (F–H) SAM group, 3rd day; (I–L) M group, 3rd day.

Figure 8

Design of the experiment.

Figure 9

Modeling of thermal skin burn of the III-degree via macro photography. (A) Linear localization of burns of the interscapular area; (B) prevention of contamination of the wound by isolating it with a sterile patch; (C) the appearance of granulation tissue in the burn area.