salicylates and pelargonic-acid

The murine local lymph node assay is a method for predictive testing of contact allergenicity, but its ability to discriminate between allergens and irritants has been questioned. To explain some of the conflicting results with irritants, the proliferation induced by methyl salicylate and nonanoic acid, both considered to be non-sensitisers, was further investigated. Both substances showed a dose--response relationship and clearly positive results when tested at higher concentrations (> or = 50%) and would thus be classified as potential sensitisers according to the present criteria for a positive assay result. In the case of methyl salicylate, the use of either dimethyl formamide or methyl ethyl ketone as vehicle did not significantly influence the results. The negative results obtained for methyl salicylate in some earlier reports were probably due to testing at too low concentrations. The proliferation induced by irritants such as methyl salicylate and nonanoic acid and inter alia sodium dodecyl sulfate, Triton X-100, oxalic acid, chloroform/methanol (2:1) must be better recognized and elucidated before the assay can be generally accepted as a predictive test method.

Topics: Allergens; Animals; Butanones; Cell Division; Chloroform; Detergents; Dimethylformamide; Dose-Response Relationship, Drug; Fatty Acids; Female; Fixatives; Irritants; Lymph Nodes; Methanol; Mice; Mice, Inbred CBA; Mice, Inbred Strains; Octoxynol; Oxalic Acid; Pharmaceutical Vehicles; Predictive Value of Tests; Reducing Agents; Salicylates; Sodium Dodecyl Sulfate; Solvents; Surface-Active Agents

Three low molecular weight compounds were found in hexane:diethyl ether extracts of fed males of the African ticks, Amblyomma variegatum (tropical bont tick) and A. hebraeum (bont tick), namely, o-nitrophenol, methyl salicylate and 2,6-dichlorophenol. These same compounds were also fond in a rinse of fed A. variegatum males, but were absent or present in only trace amounts in a rinse of fed A. hebraeum males, o-Nitrophenol and methyl salicylate were present in much higher concentrations (i.e., amounts/tick) in A. variegatum than in A. hebraeum. 2,6-Dichlorophenol was also more abundant in A. variegatum than in A. hebraeum, but the differences were not as great as with the former two compounds. Extraction in hexane over a 3-week period revealed four additional compounds, benzaldehyde, benzyl alcohol, benzothiazole and nonanoic acid. The first three compounds were found in males of both species; nonanoic acid was found only in A. hebraeum males. Published reports consistently show strong attraction by o-nitrophenol and methyl salicylate for both sexes of the two bont tick species; 2,6-dichlorophenol and benzaldehyde have been reported to be attractive to both sexes of A. hebraeum. The possible roles of these compounds, as well as others occasionally reported from A. hebraeum and A. variegatum, as components of the aggregation/attachment pheromone or other pheromones is discussed.

Topics: Animals; Arachnid Vectors; Benzaldehydes; Benzothiazoles; Benzyl Alcohol; Benzyl Alcohols; Chlorophenols; Chromatography, Gas; Fatty Acids; Feeding Behavior; Female; Gas Chromatography-Mass Spectrometry; Heartwater Disease; Male; Nitrophenols; Salicylates; Sex Attractants; Sexual Behavior, Animal; Thiazoles; Tick Infestations; Ticks

Fifty percent of an Amblyomma variegatum female population were able to find upwind-positioned targets containing the synthetic aggregation-attachment pheromone of this species or the pheromone component o-nitrophenol alone. The ticks were not attracted to the other components of the pheromone: methyl-salicylate and pelargonic acid. The mean time required for the ticks to reach a target at 1 m from the starting point was 3 min and 20 s.

Topics: Animals; Fatty Acids; Female; Nitrophenols; Pheromones; Salicylates; Ticks