Pelargonium sidoides is an herb that has been used in traditional medicine in South Africa for centuries. It is used in Europe to treat the common cold and bronchitis. In laboratory studies, this herb was shown to kill bacteria, viruses, and stimulate the immune system. Human studies show that it can reduce the symptoms of common cold and bronchitis.
Although P. sidoides is used to treat dysentery in traditional medicine, there is no scientific evidence to back this claim.
A few studies support use of P. sidoides in reducing symptoms.
Clinical trial data shows that P. sidoides is effective against acute and chronic bronchitis.
Pelargonium sidoides is an herb that has been used in traditional medicine in South Africa for centuries to treat infectious respiratory disease, dysentery, and diarrhea. The root extracts are currently being used in Germany for the treatment of respiratory infections (1). Patients take the supplemental form to treat common cold and acute bronchitis. In vitro studies indicate that P. sidoides has antibacterial (2), antiviral (3)(16)(17), immunomodulatory (4) and anti-adhesive (5) properties.
Data from clinical trials suggest its effectiveness against acute bronchitis in adults and children (6)(7)(8), and against rhinosinusitis (9). Conclusions of a meta-analysis also show a significant decrease in bronchitis symptoms with P. sidoides use (10). An herbal preparation from P. sidoides roots was found effective in treatment of moderate to severe chronic obstructive pulmonary disease (COPD) (15).
Polyphenols (eg, catechin) and 7-hydroxy-coumarins (eg, umckalin), the main constituents, have anti-microbial and immunomodulatory effects (1). Other constituents include polymeric proanthocyanidins and monomeric flavan-3-ols, phenolic acids, and gallic acid as well as small amounts of quercetin and sitosterol-glucoside(5).
P. sidoides extractwas shown to increase natural killer cell formation, tumor necrosis factor alpha, iNO and interferon-beta release, and also demonstrated anti-adhesive effects (5). In addition, the extract improved peripheral blood phagocytes by enhancing the oxidative burst and intracellular killing in vitro (11) and its anti-HIV effects occur through inhibiting the attachment of viral particles to target cells (17).