Collagen extract obtained from Nile tilapia (Oreochromis niloticus L.) skin accelerates wound healing in rat model via up regulating VEGF, bFGF, and α-SMA genes expression.

BACKGROUND: Collagen is the most abundant structural protein in the mammalian connective tissue and represents approximately 30% of animal protein. The current study evaluated the potential capacity of collagen extract derived from Nile tilapia skin in improving the cutaneous wound healing in rats and investigated the underlying possible mechanisms. A rat model was used, and the experimental design included a control group (CG) and the tilapia collagen treated group (TCG). Full-thickness wounds were conducted on the back of all the rats under general anesthesia, then the tilapia collagen extract was applied topically on the wound area of TCG. Wound areas of the two experimental groups were measured on days 0, 3, 6, 9, 12, and 15 post-wounding. The stages of the wound granulation tissues were detected by histopathologic examination and the expression of vascular endothelial growth factor (VEGF), and transforming growth factor (TGF-ß1) were investigated using immunohistochemistry. Moreover, relative gene expression analysis of transforming growth factor-beta (TGF-ß1), basic fibroblast growth factor (bFGF), and alpha-smooth muscle actin (α-SMA) were quantified by real-time qPCR. RESULTS: The histopathological assessment showed noticeable signs of skin healing in TCG compared to CG. Immunohistochemistry results revealed remarkable enhancement in the expression levels of VEGF and TGF-ß1 in TCG. Furthermore, TCG exhibited marked upregulation in the VEGF, bFGF, and α-SMA genes expression. These findings suggested that the topical application of Nile tilapia collagen extract can promote the cutaneous wound healing process in rats, which could be attributed to its stimulating effect on recruiting and activating macrophages to produce chemotactic growth factors, fibroblast proliferation, and angiogenesis. CONCLUSIONS: The collagen extract could, therefore, be a potential biomaterial for cutaneous wound healing therapeutics.

Healing potential of Spirulina platensis for skin wounds by modulating bFGF, VEGF, TGF-ß1 and α-SMA genes expression targeting angiogenesis and scar tissue formation in the rat model.

Blue-green microalga Spirulina platensis (SP) gained more attention for its antioxidant and/or anti-inflammatory properties magnifying its beneficial effects as a feed additive and for cosmetic and biomedical applications. This study was performed to examine the impact of SP on the cutaneous wound and burn healing and to develop an understanding of the correlation between the sequelae of wound healing and the molecular expression patterns of wound healing-related genes as angiogenic basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) and fibrosis-related genes as transforming growth factor-ß (TGF-ß) and α-smooth muscle actin (α-SMA) in rat wound models. To achieve these goals, two experiments were performed on 32 Wister male rats that were divided into 4 groups of 8 rats each. Each experiment was represented by 2 groups; the control group (CG) and the Spirulina group (SG). A full-thickness wound (1.5 × 1.5 cm) and burn wound (2 × 2 cm) were made on the back of each generally anaesthetized rat and the areas of wound and burn were measured on days of 0, 3, 6, 9, 12, and 15 and 0, 3, 6, 9, 12, 15, 18, and 21 post-wound and post-burn respectively. In both experiments, SP was topically applied on the backs of wounded and burned rats in Spirulina treated groups. The phases of wound granulation tissues were detected histopathologically. Immunohistochemistry was used to determine the expressions of (TGF-B1) and (VEGF). Furthermore, the relative quantification of gene expression was implemented using the (bFGF), (VEGF), (TGF-Ɓ1), and (α-SMA) as target genes. Histopathological examination revealed inflammatory cell infiltration, angiogenesis, epithelialization, and extracellular matrix deposition and wound contraction in SG as compared to CG in both experiments. Immunohistochemistry results showed a significant improvement in the VEGF and TGF-ß1 expression levels of SG in both experiments. Interestingly, SG in both experiments revealed upregulation of angiogenic genes (bFGF and VEGF) and downregulation of fibrotic genes (TGF-ß1 and α-SMA). In conclusion, our findings suggest that the topically applied Spirulina promoted wound healing. Thus, SP can be used as a biomedical application to treat various skin wounds and may reveal a potential molecular basis for future promising antifibrotic agents against scar formation.