Antioxidative Phytochemicals and Anti-Cholinesterase Activity of Native Kembayau (Canarium Odontophyllum) Fruit of Sabah, Malaysian Borneo

Abstract

Canarium odontophyllum, known locally as "Kembayau" or "Dabai", is a highly seasonal fruit which is popular among local people in Borneo Island. This study was conducted to determine the antioxidant activity, phytochemicals (total phenolic, total flavonoid, total anthocyanin and total carotenoid contents) and acetylcholinesterase inhibitor potential of extracts of the flesh and seed of this fruit. C. odontophyllum was collected in Beaufort, Sabah, Malaysian Borneo and subsequently freeze-dried and extracted using 80% methanol and distilled water. Antioxidant activities were analyzed using DPPH free radical scavenging, ABTS decolourization and FRAP (Ferric reducing / antioxidant power) assays. Anti-Alzheimer's potential was determined using acetylcholinesterase enzyme inhibition assay. The results showed that the total phenolic and flavonoid contents were higher in the flesh of C. odontophyllum with the values of 11.96 ± 0.05 mg gallic acid equivalent (GAE)/g and 10.11 ± 1.54 mg rutin equivalent (RU)/g, respectively. Total anthocyanin and carotenoid content were also higher in the flesh of the fruit with the values of 12.75 ± 0.28 mg/100g and 2.84 ± 0.11 mg/100g. The flesh of the fruit also showed higher antioxidant activity as assessed using DPPH, ABTS and FRAP assays. However, anti-cholinesterase activity was higher in the seed of C. odontophyllum which showed that possible other phytochemical content (besides phenolic and flavonoid) which might responsible to the observed effects. The same trend of phytochemicals, antioxidant and anti-cholinesterase activity were also observed in the distilled water extract. These findings suggested that C. odontophyllum is not only nutritious but also displayed potential pharmacological properties.