Effect of aqueous extract from Scutellaria baicalensis Georgi roots on CD4+ and CD8+ T cell responses during experimental infection with Trichinella spiralis in mice.

The aim of this study was to investigate the effect of aqueous extract from Scutellaria baicalensis Georgi roots (SB) on blood parameters and immune response during an experimental trichinellosis. A total of 60 mice infected with 200 Trichinella spiralis larvae were assigned into two groups. One of them served as a control and the second received SB extract orally from day 5 before infection to day 28 after infection (dpi). Blood was sampled at 7, 14, 21 dpi. Lymphocytes obtained from the spleen and mesenteric lymph nodes (MLN) at 7, 14, 21, and 28 dpi were counted, CD4+ and CD8+ subpopulations were analyzed by flow cytometry, and lymphocyte proliferation was estimated with colorimetric (MTT) assay. The intensity of intestinal and muscle invasion was also studied. SB caused a remarkable elevation of banded neutrophils in the blood at 7 dpi. SB increased ConA-stimulated splenocyte proliferation and CD4+ and CD8+ splenocyte subsets at 14 and 21 dpi, whereas MLN lymphocyte subset stimulation involved only CD4+ at 14 dpi. After administration of SB a downward trend in the number of T. spiralis larvae in the muscle was observed. These results suggest that Scutellaria baicalensis root extract stimulates murine cellular immune response during intestinal phase of T. spiralis infection.