Antimicrobial properties of select plant species within the Asteraceae Family

The Asteraceae family stands as the largest among flowering plants, encompassing over 1,600
genera grouped into 17 tribes and distributed across the globe. 25,000 different plant species
are represented in the global distribution, 750 of which are native to Madagascar. Among the
flowers and leaves of numerous plants within this family, reports have surfaced about their
potential antibacterial, antifungal, antiviral, and anti-inflammatory properties. This has led to
their integration into traditional medicinal practices. This particular research aimed to
evaluate the antibacterial effectiveness of 12 native plants from the Asteraceae family. These
included 11 species from the Helichrysum genus and one species from the Catatia genus.
Their efficacy was tested against 11 bacterial strains.
The methodology employed the liquid microdilution technique to establish the minimum
inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the crude
methanolic extracts obtained from each plant. The findings unveiled that all 12 plant species
exhibited MIC values ranging from 0.125 to 1 mg/ml, while their MBC values ranged from
0.25 to 4 mg/ml. This demonstrated their effectiveness against a range of bacterial strains,
encompassing two Gram-negative strains (E. cloacae and P. mirabilis) as well as four Gram-
positive strains (L. monocytogenes, B. cereus, B. megaterium, and S. pneumoniae).
These results underscore the potent antibacterial attributes of Asteraceae species. In order to
fully harness their therapeutic potential, future investigations could delve into identifying the
specific molecules responsible for these activities.