Analysis of the inflammatory process induced by <i>Premolis semirufa's</i> bristles extract.

<p>Mice were injected with samples of 10 µg of protein of bristles extract or with PBS, seven times, at intervals of two weeks and 24 h after the last injection, the whole paws were harvested from euthanized animals, sectioned and stained with hematoxylin and eosin (H&E). Panels correspond to paws sections from mouse injected with PBS [A, A1, A2] and <i>Premolis semirufa's</i> bristles extract [B, B1]. Epithelial (ep), connective (co), fat tissue [Panel A: rectangle A1] and sweat glands [Panel A: rectangle A2]. Note that the fat tissue and sweat glands were replaced by connective tissue in the bristles extract injected paws [panels B and B1]. In controls, all structures remained preserved and there was no inflammatory process in the paws sections from mouse injected with PBS [Panels: A, A1 (zoom in the rectangle A1 from panel A) and A2 (zoom in the rectangle A2 from panel A)]. In bristles extract injected paws a marked inflammatory cell infiltration, consisting of neutrophils was observed (Panel B1: thin arrows), while the amount of fat tissue and sweat glands was reduced [Panels: B and B1 (zoom in the rectangle B1 from panel B)]. Panels A and B: original magnification ×100; Panels A1, A2 and B1: original magnification ×1000.