Recovery of Pfc in Mice Exposed to High Pressure Stress by Olfactory Stimulation with Fragrance

Abstract

Aromatherapy has been observed with very few experimental observations to provide information on fragrance and various diseases. Although Rovesti & Colombo (1973) recently reported that mint, lavender, lemon or jasmine were found to have improved the symptoms of anxious or depressive states following the exposure to various fragrances, we have previously demonstrated that various forms of stresses applied to mice influenced the humoral immune response (Fujiwara & Orita, 1987; Shibata, Shichijo, Tsuda, Matsuoka & Yokoyama, 1988), and the altered immune response was returned to the normal level by the exposure to aromatic fragrance in the stressed mice (Shibata, Fujiwara, Harada, Matsuoka & Yokoyama, 1989). Furthermore, the alteration of the humoral immune response was not recovered by the pretreatment of the stressed mice with procain before the exposure to the fragrance (Shibata, Fujiwara, Shichijo & Yokoyama, 1989a). Therefore, the effect of the fragrance on the stressed mice was proved to be recovered via the olfactory system. In this paper, we demonstrated the effects of various fragrances on the suppressed humoral immune response in mice after the exposure to high pressure stress. The mice were tested by plaque forming cell (PFC) count to evaluate the antistress effect of the fragrance. BALB/c male mice, 8-10 wks old, were used throughout the experiments. PFC was measured according to the method of Cunningham and Szenberg (1968). Sheep red blood cells (SRBC), at a concentration of 2 x los, were injected into the tail vein immediately after exposure of the animal to high pressure stress. The spleen was removed 5 days after the immunization, and assayed for anti-SRBC IgM PFC. Three mice were put into a chamber (diameter 125mm, length 180mm, volume 2210 cm3), and were exposed to 2.2 kg/cm3 pressure of compressed air for 60 min once a day for 2 days. Aromatic fragrances were obtained from Shiseido Corporation, Tokyo, Japan, as pure odors: labdanum, jasmine, cardamon, tuberose, and oakmoss. These odors were applied to the mice for 4 days after the stress was given. As shown in Table 1, a significant reduction of anti-SRBC PFC count in the spleen cells of the mice injected with SRBC immediately after the exposure to high pressure stress was observed on day 5. However, the reduced PFC count by stress was restored