First report on the phytochemical composition and pharmacological activities of Breonia perrieri Homolle, An endemic RUBIACEAE of Madagascar

Breonia perrieri Homolle (RUBIACEAE) is a tree species belonging to an endemic Malagasy genus. It is currently threatened by the overexploitation of its timber, which is widely used in carpentry and construction. Apart from existing botanical information, no scientific studies have been conducted on its chemical composition or biological properties to date. This study aimed, to promote the valorization of this species through phytochemical and pharmacological investigations, as well as to disseminate the first scientific findings concerning this plant to contribute to its conservation. Phytochemical analyses of crude extracts from leaves, bark, and wood revealed a high diversity of secondary metabolites of pharmacological interest, which are characteristic of the RUBIACEAE family, and exhibit variable distribution among the different plant organs. This variability suggests metabolic specialization within the various plant tissues. Biologically, antibacterial activity, as assessed by the agar diffusion and broth microdilution methods, demonstrated selectivity effect against Streptococcus pneumoniae, with a minimum inhibitory concentration (MIC) of 250 µg/ml. The extracts also exhibited remarkable free radical scavenging activity in the DPPH assay, with IC₅₀ values ranging from 6.56 to 99.47 µg/ml, comparable to those of the reference compounds used. These results implay that B. perrieri is a promising source of bioactive molecules that could be used to develop of new phytomedicines for treating bacterial infections and disorders related to oxidative stress-related. This first comprehensive study enriches our knowledge of the species and underscores the importance of implementing conservation and propagation strategies to ensure its long-term sustainability.