Dermal tissue histology shows that topical application of FB promotes wound healing in rats, in vivo. Images show the histopathology of sections (Movat’s stain) of skin punch biopsy on days 1, 2, 3 (A), 4 (B), and 10 (C, D), after daily wound treatment with the PCEGS derived Fraction-B (proteins + lipids). Note in the FB-treated animals enhanced collagen deposition (yellow), new connective tissue containing more extracellular matrix with yellow collagen, more leukocytes (round cells) and fibroblasts (elongated cells with space in between containing yellow collagen) and more mature capillaries (n = 3, in each condition, and total 30 rats).

Ft promotes the production of extracellular matrix components by human fibroblasts, ex vivo. (A) Collagen and fibronectin (green fluorescence) from vehicle- and Ft-treated fibroblast cultures. (B) Quantitative data show the effect of Ft on increasing level of fibroblast collagen and fibronectin from these experiments (n=3, 5–6 images were analyzed in each experiment, p < 0.05; *, significantly different compared to the control).

Ft promotes fibroblast migration into the scratch wound, ex vivo. Assessment of migration of fibroblasts into a midline gap evoked by incubation with Ft. (A) photographs of the midline gaps in the presence of Ft or its vehicle control at gap initiation (0 h) and 24 h following incubation. Photographs show the transparent cells on a dark background. (B) Quantitative analyses show the cell migration into the scratch wound (n = 3, p < 0.05; *, significantly different, as indicated by horizontal bars).

F6 and S5 promote fibroblast migration into the scratch wound, ex vivo. Assessment of migration of fibroblasts into a midline gap evoked by incubation with furan fatty acid F6 and the steroid S5 at indicated doses. (A) photographs of the midline gaps in the presence of the two compounds (S5 or F6 and their vehicle control) at gap initiation (0 h) and 24 h following incubation. Photographs show the transparent cells on a dark background with manual integration. (B) the number of cells infiltrated into the gap after 0, 24, and 48 h from binarized images using an automated segmentation and quantification program designed to measure black-to-white (B/W) pixel ratio (based on similar images shown on panel A). Blue lines represent the B/W pixel ratios for the 1600 columns of the images taken immediately following monolayer disruption (0 h). The red and grey lines describe the B/W pixel ratios for the 1600 columns of the images taken 24 h and 48 h following monolayer disruption, respectively. (C) Quantitative analyses of the data at 24 h in terms of cell to space ratio, show the fibroblast migration into the scratch wound (n = 3-4, p < 0.05; *, significantly different compared to the control).

Ft promotes neutrophil recruitment to the tailfin injury sites of transgenic zebrafishes. (A) images showing the migration of green fluorescent protein labeled neutrophils in transgenic zebrafish larvae after tail fin transection with Ft (50 µg/ml) or vehicle treatment for 6 h. No specific neutrophil recruitment is detectable at the uncut tailfin fish tips. (B) Quantitative differences in neutrophil accumulation at the tip of the tailfin (n=10, p < 0.05; *, significantly different compared to the uncut control).

Two Ft components, F6 and S5, promote neutrophil recruitment to the tailfin injury sites of transgenic zebrafishes. (A) Fluorescence microscopy images show that F6 and S5 at 30 µg/ml cause enhanced migration of green fluorescent neutrophils to the dissected caudal fins in zebrafish larvae by 6 h and 24 h. (B) Quantitative analyses of neutrophil accumulation at wound sites (n=10, p < 0.05; *, significantly different, as indicated by horizontal bars).

Ft promotes regeneration of injured tailfin in transgenic zebrafishes. Quantitative analyses of the regeneration of tailfin in freshly dissected zebrafish tailfins after days 2 and 6. Indicated p-values (< 0.05) show that the slopes are more than 0 (n = 10).

A scheme showing cascades of steps leading to application of FB, Ft, F6, and S5 from epidermal secretions of the catfish in wound healing. PCEGS preparations were fractionated into FB that contained proteins and lipids. Total lipid preparations derived from PCEGS were further fractionated into Ft. This study used a biologically active lipid fraction, Ft, containing its subtractions F6 (or furan fatty acid) and S5 (or cholesta-3,5-diene). Commercially available pure F6 and S5 were used to confirm their biological properties, as enlisted at the last row of the summary diagram.