Minthostachys verticillata essential oil alone or microencapsulated activates Th1 cells and induces the production of opsonizing antibodies

MOLIVA M; CAMACHO N; MALETTO B; REINOSO E; ARSAUTE S; PAREDES A; PALMA S; CARIDDI LN; CAMPRA NA; RAVIOLO J; MORAN MC; ESTEIN S

MAR DEL PLATA

Congreso; Reunión de Sociedades de Biociencias; 2020

SAIC. SAFE. SAI.

In a previous study, the adjuvant capacity of the Minthostachys verticillata essential oil (EO) (2.5 mg/ml), alone or microencapsulated (EOMC), on the humoral and cellular immune response against Enterococcus faecium was demonstrated in Balb/c mice. The aim of this study was to evaluate the functionality of the antibodies produced and to quantify the cytokines IFN-γ and IL-4. Balb/c mice (n=4 per group) were inoculated by subcutaneous injection (day 0) and revaccinated (days 14 and 28) as follows: Group 1: 100 µl saline solution; Group 2: 100 µl bacterin of E. faecium+EO (2.5 mg/ml); Group 3: 100 µl bacterin+ microcapsule wall material (2.5 mg/ml); Group 4: 100 μl bacterin+ EOMC (5 mg/ml). Seven days after the last revaccination, blood was obtained and serum was separated and the animals were sacrificed by cervical dislocation. Spleens were removed to obtain splenic lymphocytes and cell proliferation assay was performed. To evaluate the functionality of the antibodies, the opsonophagocytosis death assay was carried out using different dilutions of the sera (1/100, 1/200, 1/500, 1/1000, 1/2000), a culture of E. faecium (1x107 CFU/ml), a source of bovine complement and a suspension of bovine PMNs (1x107cells/ml). The antibodies present in the Group 4 sera mediated the opsonization of the bacteria and allowed phagocytosis by PMNs up to the 1/500 dilution compared to Group 2, which was up to the 1/200 dilution (p