IADR Abstract Archives
Effects of Hinokitiol on Salivary Secretory IgA Secretion
Objectives: Hinokitiol (β-thujaplicin; HNK) is well-known as antimicrobial and antifungal agents, and widely used in various formulations including tooth paste, mouth rinses, aromatic, cosmetic and food. We have limited information about immunobiological activity of HNK. It is previously reported that the inhalation of HNK elicited increased levels of salivary secretory IgA (SIgA) antibody (Ab) in human. In this study, we investigated the effects on salivary SIgA Ab secretion when given nasally HNK in mice.
Methods: BALB/c mice were given 50 µg of HNK four times at weekly intervals (Day 0, 7, 14 and 21) via the nasal route. Saliva samples were collected before administration (-0 hour) as well as 0.5, 1.5, 3 and 6 hour after nasal administration of HNK. The levels of salivary SIgA Ab were determined by ELISA. Further, the numbers of SIgA Ab producing cells (APCs) in submandibular glands (SMGs) were examined by ELISPOT and proliferation responses of IgA+ B cells were measured by MTT assays on at the same schedule on Day 21.
Results: On Day 0, 7, 14 and 21, the maximum level of SIgA Ab secretion in saliva was seen at 1.5 hour after nasal administration of HNK. Interestingly, there were not significant differences between different time as far the numbers of APCs in SMGs on Day 21. However, significantly increased levels of IgA+ B cell proliferative responses were noted 0.5 and 1.5 hour after nasal administration of HNK on Day 21.
Conclusions: In this present study, we show that nasal administration of HNK induces salivary IgA secretion, and the level of salivary SIgA Ab secretion reaches the peak at 1.5 hour after nasal administration of HNK. These findings suggest that nasal administration of HNK might cause induction of salivary SIgA Ab secretion through elevated proliferative activity of IgA+ B cell in SMGs.
Methods: BALB/c mice were given 50 µg of HNK four times at weekly intervals (Day 0, 7, 14 and 21) via the nasal route. Saliva samples were collected before administration (-0 hour) as well as 0.5, 1.5, 3 and 6 hour after nasal administration of HNK. The levels of salivary SIgA Ab were determined by ELISA. Further, the numbers of SIgA Ab producing cells (APCs) in submandibular glands (SMGs) were examined by ELISPOT and proliferation responses of IgA+ B cells were measured by MTT assays on at the same schedule on Day 21.
Results: On Day 0, 7, 14 and 21, the maximum level of SIgA Ab secretion in saliva was seen at 1.5 hour after nasal administration of HNK. Interestingly, there were not significant differences between different time as far the numbers of APCs in SMGs on Day 21. However, significantly increased levels of IgA+ B cell proliferative responses were noted 0.5 and 1.5 hour after nasal administration of HNK on Day 21.
Conclusions: In this present study, we show that nasal administration of HNK induces salivary IgA secretion, and the level of salivary SIgA Ab secretion reaches the peak at 1.5 hour after nasal administration of HNK. These findings suggest that nasal administration of HNK might cause induction of salivary SIgA Ab secretion through elevated proliferative activity of IgA+ B cell in SMGs.