Evaluation of antioxidant activity and phytochemicals of selected methanol rattan shoot extracts from Morong, Bataan

Background: Rattan is a member of the Arecaceae family grown in the tropical or subtropical climates. These plants are used as raw materials for furniture-making. In some cases, its shoots are also used as food and may possess bioactive potentials. In this study, rattan root methanolic extracts were screened for phytochemicals and evaluated for antioxidant activities. Methodology: Six (6) methanolic extracts of selected rattan shoots were subjected to in vitro antioxidant assays, which include DPPH, FRAP, metal chelation, superoxide, and nitric oxide. Qualitative and quantitative phytochemical analyses were also employed. Results: Shoots of Calamus sp . 02 (Bangaw-Bangaw; 85.59±0.430%), C. usitatus (Talola; 82.45±2.215%), and C. spinifolius (Kurakling; 75.54±1.599%) showed the most effective DPP radical inhibition at 66.67μg/mL. Concentration-dependent reducing power (>30% scavenging at 6.64μg/mL) with no-to-low metal chelating activity was also observed in these plant food. C. sp 02 and C. usitatus demonstrated an effective scavenging activity against superoxide anions at 227.3μg/mL. Nitric oxide scavenging activity was observed in all shoots with C. merrilli (Palasan) exhibiting highest at 78.13μg/mL. Qualitative phytochemical analyses showed that rattan shoots all contained reducing sugars, phenolics, terpenoids, and quinone compounds. Quantitative phytochemical analyses revealed that C. sp . 02 (66.024±4.183mg GAE/g) and C. merrilli (1.767±0.056mg QE/g) contained the highest amounts of phenolic and flavonoids, respectively. These phytochemicals present may explain their behavior as antioxidants. Conclusion: The study revealed that different rattan shoots showed different capacities to scavenge particular oxidants. Of these, C. sp . 02, C. spinifolius , and C. merrilli may be considered promising sources of natural antioxidants.