Preventive and curative effects of Gyokuheifu-san, a formula of traditional Chinese medicine, on allergic rhinitis induced with Japanese cedar pollens in guinea pig.

Gyokuheifu-san (GHS; Jade Windscreen Powder in English, Yupingfeng-san in Chinese) is an herbal formula in traditional Chinese medicine that consolidates the superficial resistance to protect from invasion by external pathogenic influences. We evaluated the preventive and curative effects of GHS on allergic rhinitis induced by Japanese cedar pollens in guinea pigs, since the pollen can be considered one of external pathogens indicated by GHS. Guinea pigs were sensitized by intranasal instillation of cedar pollen extract with alum twice a day for 7 d, and the animals were then forced to inhale the pollens for challenge once a week for 5 weeks. We administered GHS once a day for 2 weeks in the period of sensitization to evaluate its preventive effect, or for 2 weeks from the 2nd to the 4th week of pollen inhalation, once pollinosis had begun, to evaluate its curative effect on allergic rhinitis. GHS significantly suppressed the frequency of sneezing induced by pollens and tended to reduce nose-scratching behavior after ceasing its administration in both designs of medicinal treatment. Tranilast, which is an anti-allergic drug we used as a positive control, could not suppress these rhinitic symptoms. GHS appears to have non-symptomatic and non-allopathic effects on allergic rhinitis. Our results suggest that traditional medicines have their own characteristics different from modern medicines, and the original pharmacological experiments are important to evaluate traditional medicines scientifically.