Indo-malayan stingless bees’ propolis extract-loaded chitosomes: Characterization and storage stability evaluation

Abstract

Therapeutic effects of stingless bees’ propolis are continually been explored in nutraceutical studies until recent years. Despite owing a wide range of health-promoting effects, the bioactive compounds composed in the propolis face risk of degradation. This research was intended on synthesizing chitosan-coated liposomes (chitosomes) as a nanocarrier to encapsulate Indo-Malayan stingless bees’ propolis extract to protect the bioactive compounds against degradation and enhance its bioavailability upon oral administration. The propolis extract-loaded chitosomes (PEC) were prepared by using the film hydration method and followed by probe sonication for downsizing. The chitosomes were characterized by zetasizer in terms of average size, polydispersity index and zeta potential. The morphology of chitosomes was examined using SEM and determination of functional groups had been performed using FTIR. The performance of chitosomes was evaluated based on encapsulation efficiency, loading capacity and storage stability within one month. Results indicated an increment of encapsulation efficiency of the propolis extract in PEC up to 90.1% and loading capacity of 21.7% compared to uncoated liposomes. The vesicle change rate for PEC at 4oC after one month was 8.4% while its leakage ratio was 9.5%. These rates presented by PEC were significantly lower than uncoated liposomes and made the suspension more stable after one month of storage. Chitosan-coated liposomes have shown promising performance in the protection of encapsulated propolis extract and perhaps will be useful for a wider spectrum of bioactive compounds which have diverse therapeutic effects for human health.