Abstract
Tea infusions prepared from fig (Ficus carica L.) leaves have been shown to possess antiallergenic properties. The leaves of many fig cultivars contain furocoumarins, such as psoralen and bergapten, which, when ingested at high doses, can cause cytochrome P450 inhibition and phototoxicity. In the present study, we examined the furocoumarin contents and allergenic effects of fig leaf tea using storage tests. Sterilized or unsterilized tea samples were stored at 4℃, 30℃, and 55℃ for 12 weeks. The results showed that after unsterilized storage at 30℃, the furocoumarin contents increased by approximately two-fold in the first four weeks of storage and the allergy (degranulation)-inhibiting effects were suppressed. In the samples subjected to unsterilized storage at 4℃ and 55℃ and all samples subjected to sterilized storage, the furocoumarin contents did not change and the degranulation-inhibitory effects were maintained. The microorganisms that grow in unsterilized tea have been suggested to metabolize furocoumarin precursors (glycosides),leading to furocoumarin production. Hence, during fig leaf tea storage, measures to inhibit microbial growth, such as sterilization and low-temperature treatments, are recommended.
https://ror.org/03pjf9v33 
