Optimasi Mikroenkapsulasi Ekstrak Etanol Daun Karet Kebo (Ficus elastica Roxb. ex Hornem.) Menggunakan Kitosan dan Uji Aktivitasnya sebagai Antioksidan

Abstract

Background: Karet kebo leaves have high potential as antioxidant and anti-inflammatory agent due to their rich flavonoid compounds, namely quercitrin, myricitrin, and kaempferol, which show stronger antioxidant activity than the positive control, namely vitamin E analog (trolox) (Kiem et al 2012). However, the low bioavailability of flavonoids in the gastrointestinal tract results in low bioavailability in the body if given orally. One way to overcome this is to encapsulate ethanol extract of karet kebo leaves (EEKKL) with chitosan polymer to improve its physicochemical stability and bioavailability. Objectives: This study intents to encapsulate the ethanol extract of karet kebo leaves utilizing chitosan polymer, characterize, and evaluate the antioxidant activity. Methods: Rubber kebo leaf extract was acquired by maceration extraction method with 96% ethanol solvent. The extract that has been characterized (phytochemical screening and antioxidant test) was then encapsulated by ionic gelation method followed by drying the sample utilizing oven (temperature 40°C). Encapsulation was carried out with variations in chitosan concentration, namely 0.05; 0.05; 0.1; 1; 2% (F0, F1, F2, F3, and F4). Furthermore, microcapsule characterization involved particle size analysis, particle morphology with SEM and TEM, main functional group content with FTIR to determine the success of the encapsulation process, encapsulation yield, and encapsulation efficiency. Then, stability test was conducted by recalculating the encapsulation efficiency after one month storage and antioxidant activity test utilizing DPPH method. Results: Rubber kebo leaf extract was found to contain flavonoids, tannins, glycosides, saponins, and steroids. The microcapsules acquired were powdery, light to dark green in color, and does not have the characteristic odor of rubber kebo leaf extract. The particle size ranged from 0.0793-2.2328 µm. The results of microcapsule analysis with SEM showed the shape of round and agglomerated, while TEM testing showed a spherical microcapsule structure with a core in the center. FTIR results showed that all microcapsule formulas contained functional groups resulting from the interaction between chitosan and NaTPP which indicated the success of microcapsule formation. The best encapsulation efficiency in F2 (0.1% chitosan) was 56.64 ± 0.79%. Furthermore, all samples were stable after one month storage. The antioxidant activity test results concluded that F2 has the best IC50 value of 76.67 μg/ml which is involved in the strong category. Conclusion: Ethanol extract of karet kebo leaves can be microencapsulated utilizing chitosan with good characterization results and strong antioxidant activity. Thus, EEDKK microcapsules have the potential to be used in oral dosage formulations.