Insights into an endemic medicinal plant species of Madagascar and Comoros: The case of Famelona (Chrysophyllum boivinianum (Pierre) Baehni, Sapotaceae family)

Chrysophyllum boivinianum (Pierre) Baehni is an endemic plant of Madagascar and Comoros. In Madagascar, it is known by the local name “famelona”. The wood of C. boivinianum is exploited for carpentry as material for building houses and ships. Its leaves are used in traditional medicine to treat fever, muscle pain and scorpion bites as well as to heal wounds. In Madagascar, it is widely used by the local population to treat many diseases. Thus, a deeper assessment of its valorisation strategy is becoming ever more crucial. The objective of this study was to determine the phenolic and organic compounds in the leaves and stems of C. boivinianum in relation to their biological activities and local uses. Solvents composed of methanol, water and chloridric acid were used for leaf and stem extractions. The two extracts were then compared with leaf infusions and stem decoctions by spectrophotometric and chromatographic analysis in order to determine phytochemical composition, and antioxidant and antimicrobial activities. The results showed that the leaf extracts contained the highest amount of total polyphenolic compounds (TPC) (805.16 ± 1.08 mgGAE/100 gDW), followed by leaf infusions at 477.87 ± 38.49 mgGAE/100 gDW. The stem extracts and stem decoctions had lower TPC than did the leaf extracts, with 249.12 ± 7.11 mgGAE/100 gDW and 191.66 ± 14.88 mgGAE/100 gDW, respectively. The leaf infusions showed much higher antioxidant activity (49.67 ± 0.45 mmol Fe2 +/kgDW) than did leaf extracts (27.60 ± 0.32 mmol Fe2 +/kgDW). This activity was influenced by high amounts of chlorogenic acid and caffeic acid, at 217.08 ± 2.89 mgGAE/100 gDW and 13.02 ± 0.15 mgGAE/100 gDW, respectively. The leaf infusions were also rich in gallic acid (15.19 ± 1.63 mgGAE/100 gDW). The stem extracts and stem decoctions also had lower antioxidant activity, at 19.86 ± 7.35 mmol Fe2 +/kgDW and 12.53 ± 0.15 mmol Fe2 +/kgDW, respectively. The leaves of C. boivinianum showed a higher content of bioactive compounds than the stems, and the infusions represented the best method for extracting biomolecules with high amounts of healthy properties and antioxidant activity. Regarding antimicrobial activities, leaf extracts had higher antimicrobial activity against Salmonella typhii, Escherichia coli and Candida albicans than did stem extracts. This activity was influenced by the high rates of polyphenols in the leaves.