Acaricidal activity of essential oil of Syzygium aromaticum, hydrolate and eugenol formulated or free on larvae and engorged females of Rhipicephalus microplus.

The cattle tick, Rhipicephalus microplus (Canestrini, 1888) (Ixodida: Ixodidae), is the most important ectoparasite in cattle-breeding areas and is responsible for severe economic losses. Synthetic acaricides have been used to control this parasite. However, the need for safer products has stimulated the search for new acaricides, such as those to be obtained from medicinal plants. The essential oil of Syzygium aromaticum (clove) has many biological properties and shows great potential for use in veterinary applications. In the context of the need for new agents, this study investigated the in vitro properties of the hydrolate, essential oil and the main constituent of S. aromaticum, eugenol, in formulated and free applications against larvae and females of R. microplus. Eugenol and the essential oil caused 100% mortality in larvae at starting applications of 2.5 mg/mL and 5.0 mg/mL, respectively. The hydrolate showed no activity. Both eugenol and essential oil had good efficacy in adult immersion tests at 50 mg/mL and achieved 100% efficacy at a concentration of 100 mg/mL. The results of these tests reaffirm the important potential of clove essential oil and eugenol.

The use of vancomycin with its therapeutic and adverse effects: a review.

OBJECTIVE: Vancomycin (VCM) is a tricyclic glycopeptide antibiotic produced by Streptococcus orientalis. Widely used in hospitals, it is indicated to fight severe infections caused by Gram-positive bacteria, especially with the advent of MRSA (methicillin-resistant Staphylococcus aureus), penicillin-resistant pneumococci among others. Furthermore, it is indicated for the treatment of patients allergic to penicillins and cephalosporins. Dose recommendations, dilution rates and types of infusion are controversial and also result in toxic effects. Aim of this paper was to perform a literature review showing the therapeutic and adverse effects of vancomycin. MATERIALS AND METHODS: This is a literature review of recent articles published on MEDLINE and SciELO databases in English, Portuguese and Spanish. RESULTS: The main adverse effects of vancomycin are: hypotension, phlebitis, nephrotoxicity, ototoxicity, hypersensitivity reactions, red man syndrome, neutropenia, chills, fever, interstitial nephritis. CONCLUSIONS: The use of vancomycin is still very common; however, inadequate doses and prolonged therapy pose a risk of increasing minimum inhibitory concentrations (MICs), resulting in subtherapeutic levels, treatment failures and toxicity. Therefore, further studies should be conducted to optimize the administration of vancomycin, monitoring treatments from the beginning in order to ensure a safe and effective use of the drug.

Cholestasis induced by chronic treatment with alpha-naphthyl-isothiocyanate (ANIT) affects rat renal mitochondrial bioenergetics.

Chronic cholestasis is characteristic of many human liver diseases. Renal injury has been often associated with this type of disease. The aim of this study was to evaluate the effect of cholestasis on kidney mitochondrial bioenergetics following in vivo chronic administration of alpha-naphthyl-isothiocyanate (ANIT), a known cholestatic agent. Serum markers of renal injury, kidney morphology and endogenous adenine nucleotides were measured in ANIT-treated rats (80 mg/kg per week s.c. for 16 weeks). Changes in membrane potential and mitochondrial respiration as well as alterations in mitochondrial calcium homeostasis were monitored. Cholestatic animals shown no alterations in renal morphology when compared with control. Additionally, following chronic ANIT administration, no significant alterations in mitochondrial respiratory function have been shown. The phosphorylation capacity of cholestatic kidney mitochondria was enhanced. Associated with these parameters, mitochondria from treated animals exhibited a decreased susceptibility to disruption of mitochondrial calcium homeostasis, due to permeability transition induction. These data suggest that, despite being submitted to chronic treatment with ANIT, kidney mitochondria from cholestasis-induced rats present some defense mechanisms to circumvent this aggression. They show improved phosphorylative capacity and, moreover, a decreased susceptibility to mitochondrial permeability transition induction, probably due to adaptative mechanisms of calcium transport.

Age-related alterations in liver mitochondrial bioenergetics of diabetic Goto-Kakizaki rats.

Type 2 diabetes mellitus is one of the most common chronic metabolic diseases in man. Due to long-term complications of the disease, severely decreasing the quality of life of diabetic patients, early interventions to obviate the risk of complications are of major importance. Therefore, diabetic animal models are of major importance in research for interventional treatment of type 2 diabetes. In this work we investigated the possible alterations in mitochondrial energetic metabolism of Goto-Kakizaki (GK) rats during the progression of the disease, since glucose metabolism is closely related to intracellular ATP content. For that reason, respiratory indexes (state 4, state 3, RCR and ADP/O) were evaluated either in the presence of NAD- or FAD-linked substrates (glutamate + malate and succinate, respectively) in mitochondrial preparations of GK and control rats with 8, 12, 26 and 52 weeks of age. Until the age of 1 year (52 weeks) we found no impairment of mitochondrial respiratory indexes both in the presence of glutamate + malate and succinate. In conclusion, this study indicates that GK rat is a good model for studying the initial events of diabetes, since it presents no impairment of liver mitochondrial functions during the first year of life, contrasting clearly with pharmacological induced diabetes.