Effect of Polysaccharides from Bletilla striata on the Healing of Dermal Wounds in Mice

Abstract

Bletilla striata has been largely used in traditional folk medicine in China as a wound healing agent and to treat gastritis and several other health problems. Some studies have shown that plant polysaccharides may have the ability to promote wound healing. The aim of this work was to evaluate the wound healing activity of the polysaccharide extracted from Bletilla striata. Firstly, a Bletilla striata polysaccharide was extracted by water extraction and alcohol precipitation and characterized by Fourier transform infrared spectroscopy. The Bletilla striata polysaccharide was then tested for cell migration and proliferation using the mouse fibroblast cell line. Then, the Bletilla striata hydrogel was fabricated for acute wound health care of the mouse full-thickness excision. The results showed that the BSP enhanced the proliferation and migration of L929 cells. The superior wound healing capacity of the BSP hydrogel was demonstrated that it significantly accelerated the wound healing process in vivo in full-thickness skin defect wounded models. Compared to the saline group, the BSP hydrogel could accelerate wound healing and promote re-epithelialization and collagen deposition by means of TGF-β/Smad signal pathway activation. Taken together, BSP hydrogel would be a useful pharmaceutic candidate for acute cutaneous wound health care.

Figure 1

SEM micrographs of the lyophilized BSP hydrogel in cross-sectional view at magnification of × 100 (a) and × 500 (b).

Figure 2

(a) Photographic appearance of the BSP and BSP hydrogel. (b) FT-IR spectra of the BSP showing the various absorption peaks. (c) TG-DTA weight loss curve of the BSP under inert atmosphere at a heating rate of 10°C/min.

Figure 3

Effects of various concentrations of the BSP on cell proliferation of L929 cells after 24 h (a) and 48 h (b) treatment (mean ± SD, n = 3).

Figure 4

Wound healing assay using L929 cells treated with the BSP at concentrations of 5 μg/mL and 10 μg/mL (mean ± SD, n = 3).

Figure 5

In vivo wound healing effect of the BSP hydrogel on the full-thickness excision wound model. (a) Wound photographs at 0, 3, 6, 9, and 12 days post injury in saline, the BSP hydrogel group. The scale bar indicates 5 mm. (b) Wound closure rate on wound area at 0, 3, 6, 9, and 12 days.

Figure 6

The effect of the BSP hydrogel on epithelium proliferation and collagen deposition in full-thickness excision wound by H&E and Masson's trichrome staining.

Figure 7

The levels of TNF-α (a), IL-1β (b), iNOS (c), and SOD (d) of the serum in the saline control and the BSP hydrogel group at 12 days after injury using test kits. Quantitative assessment of TGF-β, Smad2, and Smad4 mRNA expression in various groups at day 6 (e) and day 12 (f) postinjury wounding. Note: ^∗p < 0.05 vs. saline-treated group.