Background: Benjakul remedy (BJK) is a traditional Thai herbal medicine prescribed as an adaptogen and for treatment of several diseases. Previous in vitro study showed that ethanolic extract of BJK exhibited potent anti-allergic activity by reducing the release of β-hexosaminidase in RBL-2H3 cells.

Objective: To investigate the clinical efficacy and safety of BJK extract in allergic rhinitis patients compared with loratadine treatment.

Materials and Methods: A phase 2, double blind clinical trial, randomized controlled trial was designed to investigate efficacy and safety of BJK in mild to moderate allergic rhinitis patients. In the present study, 60 patients diagnosed as allergic rhinitis by otolaryngologist were recruited. The patients were divided into two groups. During six weeks of treatment, the experimental group received 300 mg/day of the BJK extract and the control group was treated with 10 mg/day of loratadine. All patients were followed up at 21 and 42 days. The changes of total nasal symptom score (TNSS), acoustic rhinometry were evaluated as efficacy parameters. Regarding safety issue, clinical signs and symptoms, complete physical examination, and blood chemistries and components were evaluated.

Results: Sixty patients completed this clinical investigation. After treatments, TNSS parameters of both groups decreased from baseline, but the acoustic rhinometry parameters of both groups did not significantly decrease. Between the groups, comparison showed no differences. The blood analysis of both groups did not change after treatments.

Conclusion: Oral administration of 100 mg BJK extract three times daily for 42 days in allergic rhinitis patients can reduce allergic rhinitis symptoms and it showed safety on all parameters.