Anti-Elastase Activity of Extract, Extract-loaded Nanoparticles, and Serum Gels of Indonesian Bilberry Leaves: A Comparison

Background: Elastin is about 1000 times more flexible than collagens. The main function is to provide elasticity and resilience to expandable tissues such as skin, aorta, and lungs.

Aims: To do a comparative study of the anti-elastase activity of the extract, extract-loaded gelatin nanoparticles and serum gels of Indonesian Bilberry leaves.

Methods: Extraction of the leaves used the maceration method with 70% ethanol at a pH of 2 and dried using a rotavapor and an oven. The dry extracts were phytochemical screened and tested for specific and non-specific parameters. The synthesis of gelatin nanoparticles used the desolvation method with polymer gelatin and cross-linker glutaraldehyde, and then they were characterized. The extracts and the gelatin nanoparticles were formulated into serum gels and evaluated for physical, chemical, and anti-elastase activity at 40°C for six weeks. The extracts, nanoparticles, and formulations were assayed for anti-elastase activity at 410 nm.

Results: The extracts met standards, while the nanoparticles showed particle sizes of 174.7 nm, polydispersity index of 0.34, zeta potential of 2.82 mV, entrapment efficiency of 38.6%, aldimine on FTIR and shape of stacked nanoparticles. The anti-elastase activity of the extract was 49.37 ppm, while the nanoparticles were 72.92 ppm, respectively. In addition, the serum gels of F1 were 117.92 ppm, and F2 were 142.92 ppm. F1 and F2 were stable during storage. It is still possible to enhance the activity of the serum gels, such as by increasing the addition of actives.

Conclusion: The extract, gelatin nanoparticles, and serum gels of F1 and F2 have anti-elastase activity in the potent category for the extract and nanoparticles, while moderate category for F1 and F2. The serum gels are physicochemically stable during storage. Increasing the activity of the serum gels is possible by adding the extract concentration.