1,8-cineole protects against liver failure in an in-vivo murine model of endotoxemic shock

The effects of 1,8-cineole on D-galactosamine/lipopolysaccharide (GalN/LPS)-induced shock model of liver injury was investigated in mice. The co-administration of GalN (700 mg kg(-1), i.p.) and LPS (5 microg kg(-1), i.p.) greatly elevated serum concentrations of tumour necrosis factor-alpha (TNF-alpha), alanine aminotransferase and aspartate aminotransferase, and induced massive hepatic necrosis and lethality in 100% of control mice. Pretreatment with 1,8-cineole (400 mg kg(-1), p.o.) and dexamethasone (1 mg kg(-1), s.c.), 60 min before GalN/LPS, offered complete protection (100%) against the lethal shock and acute elevation in serum TNF-alpha and serum transaminases. Hepatic necrosis induced by GalN/LPS was also greatly reduced by both 1,8-cineole and dexamethasone treatment. The results indicate that 1,8-cineole protects mice against GalN/LPS-induced liver injury through the inhibition of TNF-alpha production, and suggest that 1,8-cineole may be a promising agent to combat septic-shock-associated pathologies.

Indomethacin treatment slows disease progression and enhances a Th1 response in susceptible BALB/c mice infected with Leishmania major

Prostaglandins of the E series inhibit the development of Th1 responses. When infected with Leishmania major, BALB/c mice fail to develop a Th1 response, but instead mount a Th2 response and die of the disease. Therefore, we treated L. major-infected BALB/c mice with indomethacin, which inhibits prostaglandin production. Indomethacin lessened disease severity (parasite burden and pathology), and promoted a Th1 response, but the mice still succumbed to infection. The explanation for these observations may be two-fold: (1) the beneficial effects of indomethacin were predominantly observed later in infection (beyond two weeks), a time at which indomethacin was unable to sufficiently block the development of a Th2 response; (2) indomethacin was unable to induce a Th1 response in BALB/c mice that was of the same magnitude as the Th1 response observed in C57BL/6 mice infected with L. major.

Biological behavior of Leishmania amazonensis isolated from humans with cutaneous, mucosal, or visceral leishmaniasis in BALB/C mice

Leishmania amazonensis causes a wide spectrum of disease in humans. In this study, we evaluated BALB/c mice infected with five strains of L. amazonensis isolated from patients with either cutaneous, mucosal, or visceral leishmaniasis. Mice infected with cutaneous and mucosal isolates developed ulcerating footpad lesions with parasite-loaded macrophages and extensive tissue destruction. Skin metastases, early dissemination of parasites to the spleen, and high anti-Leishmania antibody levels were also noted. Mice infected with L. amazonensis strains isolated from patients with visceral disease had a controlled infection, with small footpad lesions with mononuclear cell infiltration, few infected macrophages, and granuloma formation. They had no skin metastases, delayed dissemination of the parasite to the spleen, lower levels of IgG and higher levels of IgG2a against L. amazonensis. These findings demonstrate an unexpected resistance of BALB/c mice to the infection with L. amazonensis isolated from patients with visceral leishmaniasis. This resistance seems to be due to differences in these parasites that may be related to the altered course of the disease in humans and in isogenic BALB/c mice.