Morphological study of cytotoxicity produced by PSK-induced polymorphonuclear leukocytes (PMNs) and Nocardia rubra cell wall skeleton

Nocardia rubra cell wall skeleton accelerates cutaneous wound healing by enhancing macrophage activation and angiogenesis

Objective

This study was performed to investigate the effect of Nocardia rubra cell wall skeleton (N-CWS) on wound healing of full-thickness skin defects.

Methods

Two 2- × 2-cm full-thickness wounds, one on each side of the midline, were made on the back of 12 rats. One wound was covered with Vaseline gauze soaked in normal saline, whereas the other was covered with Vaseline gauze and N-CWS. Wound dressings were changed every other day from day 0 (wound creation) to day 11. Four of the 12 rats were killed on day 7, and biopsy samples were obtained for biochemical and histopathological analyses. The expression levels of CD31, CD68, and F4/80 in the tissues were examined immunohistologically. The expression of transforming growth factor (TGF)-β1 in the wound was determined by western blot.

Results

N-CWS increased the wound healing rate, reduced the complete wound healing time, and increased the expression levels of CD31, CD68, and F4/80 on day 7. The TGF-β1 expression level in the wound was significantly higher in the N-CWS group than in the control group on day 7.

Conclusions

N-CWS can activate macrophages, increase TGF-β1 expression, and enhance angiogenesis and thus accelerate cutaneous wound healing.

Immunomodulatory activities and subacute toxicity of a novel β-glucan from Paenibacillus polymyxa JB115 in rats

Subacute toxicity and immunopharmacological activities of β-glucan from P. polymyxa JB115 was evaluated in a 28-day feeding study in rats. The white blood cell count, red blood cell count, hematocrit, hemoglobin, thrombocytes (THR) and thrombocytocrit were significantly higher in male fed with β-glucan than control rats and the insignificant lower eosinophil count, mean corpuscular volume, mean cell hemoglobin and uninfected THR (uTHR) levels were observed in male whereas no marked changes in female rats. No other significant differences in serum chemistry and liver, kidney, and spleen weights were observed. The pathological changes and other abnormal indicators were not detected in urine. Female rats fed with diet supplemented with 0.01% β-glucan also showed marked increase in the percentage of blood cytotoxic T-lymphocytes compared to that of the control group while not significant differences in the percentage of blood B-lymphocytes. No adverse effects on general condition and behavior, growth, feed and water consumption and feed conversion efficiency were found. The results suggest that consumption of the novel β-1, 3/1, 6-glucan from P. polymyxa JB115 was not associated with any obvious toxic effects in rats, indicating its safety as a potential immunostimulant or as an adjuvant of some animal vaccines.