FORMULATION AND CHARACTERIZATION OF GOTU KOLA (CENTELLA ASIATICA (L.) URB.) HERB EXTRACT LIPOSOMES FOLLOWED BY IN VITRO ACETYLCHOLINESTERASE INHIBITOR AND ANTIOXIDANT ACTIVITY TESTS

• Main Author: Clarissa Puan Adira, Hayfa
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/82534
• Institution: Institut Teknologi Bandung

Alzheimer's is a disease that can cause a decline in brain function, including decreased behavior and cognitive function. One of the causes of Alzheimer's is too low amount of acetylcholine in the brain. This is caused by the breakdown of acetylcholine by the enzyme Acetylcholinesterase into its inactive form. Gotu kola (Centella asiatica (L.) Urb.) is one of the plants that contain compounds with acetylcholinesterase inhibitor activity so it can be used to treat Alzheimer's symptoms. However, gotu kola extract has low solubility and bioavailability. Liposome preparation was chosen to increase bioavailability, solubility and can be well accepted by the body. This study aims to determine the optimum formulation and characterization of liposomes containing gotu kola herb extract as well as testing the acetylcholinesterase inhibitor and antioxidant activities in vitro. Stability test was also conducted to evaluate the stability of gotu kola herb extract liposomes (LEP) at 4°C, 25°C, and 40°C. LEP was prepared by thin layer hydration method and characterized by determining particle size, polydispersity index, zeta potential, morphology, and encapsulation efficiency. Acetylcholinesterase inhibitor activity testing was carried out using the Ellman method while antioxidant activity testing with the DPPH method. Activity testing was conducted on gotu kola extract and LEP, as well as positive control in the form of donepezil in acetylcholinesterase inhibitor testing and ascorbic acid in antioxidant testing. The optimal liposome formula obtained based on optimization was liposome with phosphatidylcholine-cholesterol ratio of 2:1 and gotu kola herb extract 1 mg/mL. LEP has a particle size suitable for oral administration, which is 113.00 ± 13.49 nm, polydispersity index of 0.22 ± 0.08 which indicates homogeneous LEP, zeta potential of -34.09 ± 3.41 mV, dosage pH of 7.40 ± 0.03, spherical shape, and high encapsulation efficiency of 93.61 ± 3.69%. LEP preparation showed physical stability when stored at 4°C for 14 days. LEP can increase the acetylcholinesterase inhibitor activity by 6.5 times from the gotu kola herb extract with an IC50 value of 88.50 ± 4.81 ?g/mL. In addition, LEP can also increase antioxidant activity by 2 times when compared to gotu kola herb extract with an equivalence value of 65.17 ± 4.51 mg ascorbic acid in 1 gram sample.