Antimicrobial activity and chemical composition of fixed oil extracted from the body fat of the snake Spilotes pullatus.

CONTEXT: Ethnozoological studies have shown that Spilotes pullatus Linn. (Colubridae: Ophidia), is associated with medicinal and magic-religious uses in Brazil. OBJECTIVES: This study was designed to determine the chemical composition of the oil extracted from the body fat of S. pullatus and to test its antimicrobial properties, alone and in association with aminoglycosides, against fungi and bacterial strains in concentrations ranging between 1024 and 0.5 µg/mL. MATERIAL AND METHODS: The snakes were collected in the Chapada do Araripe, county of Crato, Ceará State, Brazil. The oil was extracted in a Soxhlet apparatus using hexane. The methyl esters of the fatty acids present in the samples were identified using GC-MS. The antimicrobial and drug modulatory activities of oil were tested by microdilution against fungal and bacterial strains. RESULTS: The chemical composition of the fixed oils of S. pullatus identified 10 constituents representing 94.97% of the total sample. The percentages of saturated and unsaturated fatty acids were 33.59 and 61.38%, respectively, with the most abundant components being elaidic (37.26%). The oil did not demonstrate any antimicrobial or antifungal activity when tested alone, presenting MIC values ≥ 1024 µg/mL. However, when associated with antibiotics, it demonstrated synergistic effects with gentamicin against all the bacterial lineages assayed, and antagonistic effects with amikacin and neomycin against strains of Escherichia coli. CONCLUSIONS: Oil extracted from the body fat of S. pullatus did not demonstrate any inhibitory effects on bacterial or fungal activities, but was effective in modulating the effects of certain antibiotics.

[Idiopathic skin calcinosis with transepithelial elimination]. / Calcinose cutánea idiopática com eliminação transepitelial.

A case of universal cutaneous calcinosis developed without apparent cause is reported. It had an evolution towards epidermic perforation and was treated with aluminium hydroxide. A discussion was made on the rarity of the idiopathic calcinosis as well as on the interesting phenomenon of transepidermal elimination.

The mu opiate receptor is responsible for descending pain inhibition originating in the periaqueductal gray region of the rat brain.

Opiate agonists exhibiting selectivity for mu, kappa, sigma, and delta opiate receptors were microinjected into the periaqueductal gray region (PAG) of the brain of rats to determine the receptor subtype(s) associated with the initiation of descending pain inhibition. The spinally organized, heat nociceptive tail-flick reflex was used to detect analgesia. Only morphine (mu) and [D-Ala2,D-Leu5]enkephalin (DADLE) (delta greater than mu) produced analgesia. However, both drugs appeared to be acting through the mu (morphine) receptor, since: (1) the action of DADLE was not inhibited by delta receptor antagonists, (2) a more highly selective delta agonist [D-Pen2,D-Pen5]enkephalin was ineffective and (3) agonists selective at other non-mu receptor sites (ethylketocyclazocine and U50,488H for kappa; n-allylnormetazocine for sigma) were also ineffective. It appeared that DADLE might be acting as a partial agonist at the morphine receptor in the PAG. The peptide was an agonist with low efficacy, and when a maximally effective dose of the peptide was administered simultaneously with morphine antagonism was observed. Ethylketocyclazocine and n-allylnormetazocine were also found to antagonize morphine, an observation that is consistent with the suggestion that they may act as mu receptor antagonists in addition to their agonistic action at kappa and sigma receptors, respectively. Thus, mu receptors appear to be responsible for the spinopetal analgesia from the PAG of the rat.