Minthostachys verticillata essential oil activates macrophage phagocytosis and modulates the innate immune response in a murine model of Enterococcus faecium mastitis.

Minthostachys verticillata essential oil (EO) is a natural product that reports immunomodulatory effects on human T cells as well as anti-inflammatory activity. Bovine mastitis is a worldwide disease, mainly caused by bacteria, affecting milk quality and yield, leading to high economic losses. Environmental pathogens, as Enterococcus faecium, are implicated in the disease. Antibiotic therapy is adequate, although it can leave residues in milk, causing problems in human health. The search of immunomodulatory substances for bovine mastitis treatment is a promising alternative strategy. The aim of this study was to characterize the effect of M. verticillata EO on macrophage phagocytosis and evaluate its immunomodulatory and protective effects in mice challenged with E. faecium. The results showed that EO activated macrophage phagocytosis mechanisms inducing reactive oxygen species production. Moreover, EO modulated the innate immune response in mammary glands of female Balb/c mice challenged with E. faecium decreasing the infiltration of polymorphonuclear neutrophils and IL-1ß and TNF-α mRNA expression. In addition, EO increased the expression of IL-10 in the last hours of infection. Treatment with EO did not increase the number of activated CD4+ or CD8+ T cells or the production of specific antibodies. These results suggest that EO play an important role in helping to resolve the infection in the first hours without activating adaptive immunity. In addition, a marked decrease of the bacterial count in the glands of mice treated with EO was observed. A natural product such as M. verticillata EO could have a potential use to control bovine mastitis.

Safety assessment of essential oil from Minthostachys verticillata (Griseb.) Epling (peperina): 90-days oral subchronic toxicity study in rats.

Minthostachys verticillata (Lamiaceae), popularly known as peperina is largely used in popular medicine for its digestive, carminative, antispasmodic and antirheumatic properties. There are no reports of repeated exposure toxicity to guarantee their safety. The present study investigated the chemical composition, analyzed by GC-FID, and the 90-day toxicity and genotoxicity effect of M. verticillata essential oil (Mv-EO), using Wistar rats as test animals. The rats were divided into four groups (5 rats/sex/group) and Mv-EO was administered on diet at doses of 0, 1, 4 and 7 g/kg feed. The main components of Mv-EO were pulegone (64.65%) and menthone (23.92%). There was no mortality, adverse effects on general conditions or changes in body weight, food consumption and feed conversion efficiency throughout the study in male and female rats. Subchronic administration of Mv-EO did not alter the weights, morphological and histopathological analyses of liver, kidney and intestine. Genotoxicity was tested by micronucleus and comet assays. Mv-EO up to a concentration of 7 g/kg feed for 90 days did not exert a cyto-genotoxic effect on the bone marrow and cells blood of Wistar rats. These results suggest that Mv-EO appears to be safe and could be devoid of any toxic risk.

Aislamiento e identificación serológica de Erysipelothrix rhusiopathie de cerdos con lesiones sistémicas compatibles con las del mal rojo en la República Argentina / Isolation and serological identification of Erysipelothrix rhusiopathiae from systemic lesions resembling erysipelas in Argentina

Objetivos. Investigar la presencia Erysipelothrix rhusiopathiae en cerdos de las categorías crecimiento y engorde con lesiones sistémicas no cutáneas compatibles con las de mal rojo (MR) provenientes de dos granjas, situadas en la provincia de Buenos Aires, Argentina. Materiales y Métodos. Muestras de tonsilas, corazón (endocardio), bazo, riñón y líquido articular con lesiones compatibles con las del mal rojo se inocularon en caldo ESB y se repicaron en medio sólido MBA. A partir de colonias similares a las del género Erisipelothrix, se realizaron tinción de Gram y pruebas fisiológicas y bioquímicas. La identificación serológica se llevó a cabo por la prueba de inmunodifusión doble en gel de agarosa enfrentando antígenos extractados de las cepas en estudio contra sueros hiperinmunes de los 28 serotipos de referencia de E. rhusiopathiae.Resultados. Se aisló E. rhusiopathiae de dos cerdos a partir de tonsilas (sin lesiones aparentes), bazo (con esplenomegalia), endocardio valvular (con lesiones de endocarditis) y exudado articular (no purulento). En otro animal sólo se lo aisló de exudado articular. Las tres cepas de E. rhusiopathiae correspondieron al serotipo 10. El aislamiento de E. rhusiopathiae se dificultó debido al crecimiento de bacterias de los géneros Lactobacillus spp y Enterococcus spp que enmascararon o compitieron en el desarrollo de las colonias. Discusión. El E. rhusiopathiae serotipo 10 es raramente aislado de cerdos y no se lo ha asociado a cuadros clínicos de erisipela. El aislamiento E. rhusiopathiae serotipo 10 de lesiones sistémicas no cutáneas compatibles con las del MR del cerdo, constituye la primera referencia de la infección del cerdo por E. rhusiopathiae en el país así como de la patogenicidad de dicho serotipo.