In this short narrative review, we would like to discuss the immunomodulatory effects of South African geranium (Pelargonium sidoides) root extract EPs7630 in treating acute rhinosinusitis. The plant has been used for centuries to treat respiratory tract inflammation, such as sinusitis, pharyngitis and bronchitis. South African geranium is rich in polyphenols, flavonoids, tannins, diterpenes and proanthocyanidins, but the main constituent is a type of coumarin called ‘umckalin’ (6–hydroxy–5,5–dimethoxy–coumarin). The substance is standardised as an aqueous-ethanolic extract from the root of this plant under the code name EPs7630.

The article presents the results of in vitro and in vivo studies of administering this herbal drug in acute viral, post-viral and bacterial rhinosinusitis. The focus is on the immunomodulatory effects of EPs7630 during the therapy of this acute inflammation of the nasal mucosa.

According to the results of some studies, EPs7630 stimulates monocyte-dependent activity and inhibits neutrophil-dependent chemokine activity. However, given the small number of studies, the level of evidence is low, implying the need for new research.

Particular attention should be paid to the effect of EPs7630 on bradykinin, the mediator that triggers most inflammatory processes in acute rhinosinusitis.