Patients with metabolic disorders frequently suffer from side effects induced by long-term oral medications. The present study using a rat model system indicated that leflunomide (LF) and amlodipine (AMD), the active ingredients contained in the medications for rheumatoid arthritis and hypertension, respectively, appeared to induce various bowel problems including constipation and inflammation. In the small and large intestine, LF increased the expression of tumour necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 compared to the null control and AMD increased the expression of both TNF-α and IL-1β, although its effect on IL-6 was only increased in the large intestine. It is noteworthy that the probiotic blend tested was found to alleviate intestinal complications caused by LF and AMD. Analysis of the gut microbiota revealed that AMD induced compositional changes in the gut microbiota. Namely, members of the phylum Bacteroidetes, which constituted only about 0.3% of the microbiota in the null control, made up more than 10% of the total composition in the AMD-administered rats. Interestingly, the probiotic blend was also found to normaliSe the gut microbiota.

The increasing prevalence of allergic asthma has become the world’s major health issue. Current treatments for allergic asthma focus on treating symptoms, while permanent cures still remain undiscovered. In this study, we investigated the effect of Korean traditional herbal remedy, Pyunkang-tang (PGT)—composed of six plants—on asthma alleviation in a mouse model. The PGT mixture was orally gavaged to mice (PM group, 20 mg/mouse/day) from 7 days before sensitization with ovalbumin (OVA) (day −7). On day 0 and day 14, mice from OVA-control (n = 9) and PM group (n = 8) were sensitized with OVA and alum through intraperitoneal injection. On days 18~20, OVA was challenged to mice through nasal injection and sacrificed next day. Cell profile in lung tissue was analyzed by flow cytometry and RT-qPCR analysis, and the number of eosinophils and expression of siglec-F were significantly reduced in the PM group. Lung tissue was examined with hematoxylin and eosin (H&E) and Alcian blue/periodic acid–Schiff (AB-PAS) staining. Noticeably reduced eosinophil infiltration around bronchioles was displayed in the PM group compared to the OVA-control group. Furthermore, PGT-treated mice showed a significant reduction in IL-13 and a mild reduction in IL-5 in lungs. A decreasing tendency of IL-5/13 (+) CD4+ T cells and IL-13(+) innate lymphoid cells (ILCs) and a significant reduction in IL5(+) ILCs were also observed. When treating PGT on murine lung epithelial cells stimulated by papain, there was a significant reduction in IL-33 mRNA expression levels. Taken together, oral delivery of PGT successfully alleviated asthmatic responses provoked by OVA in a mouse model and could lead to novel therapies for allergic asthma.