Many studies have been done that demonstrate the antibacterial properties of a number of different helichrysum species. Helichrysum aureonitens, for example, has been demonstrated to be effective at killing both Staphylococcus aureus, Micrococcus luteus, Penicillium and Escherichia coli bacteria, among others. (Journal of Ethnopharmacology. Antibacterial activity of Helichrysum aureonitens (Asteraceae). J.J. M. Meyer & A. J. Afolayan. Botany Department, University of Pretoria, Pretoria 0002, South Africa. Volume 47, Issue 2, 7 July 1995, Pages 109-111 (doi:10.1016/0378-8741(95)01261-B) [PMID: 7500636].) The antibacterial effect has been shown in both the essential oil and diethyl ether extracts of Helichrysum italicum, likely due to the flavonoids and terpenes found therein.

As an adjunct to helichrysum’s inherent antibacterial properties, Helichrysum italicum essential oil has been found to increase the effects of antibacterial drugs such as penicillin when fighting antibiotic-resistant bacteria. It is thought this effect may be due to geraniol, a compound found in many helichrysum species. In a society where the overuse of antibiotics is causing widespread resistance, it is beneficial to examine other avenues to increase their effectiveness. Authors of these many studies speculate that the antibacterial effect of helichrysum is likely due to its pro-inflammatory enzyme inhibition and free radical scavenging abilities.