Study of adjuvant effect of model surfactants from the groups of alkyl sulfates, alkylbenzene sulfonates, alcohol ethoxylates and soaps

The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice. The surfactant s were injected subcutaneously (sc) in concentrations of 1000, 100, 10 or 1 mg/l, respectively, together with 1 mug of ovalbumin (OVA). In addition, g roups of mice received OVA in saline (control group) or in Al(OH)(3) (posit ive adjuvant control group). After the primary immunization the mice were b oosted up to three times with OVA (0.1 mug sc) in saline. OVA-specific IgE antibodies were determined by the heterologous mouse rat passive cutaneous anaphylaxis test. The results were confirmed by a specific ELISA method. Af ter the first booster, the Al(OH)(3) group and the 10 mg/l SDS group showed a statistically significant increase in OVA specific IgE levels. After two boosters, a statistically significant suppression in OVA-specific IgE prod uction occurred with SDS (1000 mg/l), SDBS (1000 and 100 mg/l), coconut soa p (1000 mg/l) and the alcohol ethoxylate (10 mg/l). This study suggests tha t a limited number of surfactants possess an adjuvant effect whereas all su rfactants at certain levels can suppress specific IgE production. (C) 2000 Elsevier Science Ltd. All rights reserved.