Development and Evaluation of Phytosomes Containing Callistemon citrinus Leaf Extract: A Preclinical Approach for the Treatment of Obesity in a Rodent Model

Callistemon citrinus has several biological effects; it is anti-inflammatory, anti-obesogenic, antioxidant, hepatoprotection, and chemoprotective. Its bioactive compounds include terpenoids, phenolic acids, and flavonoids which have low oral bioavailability and absorption. This study aimed at developing phytosomes of C. citrinus to improve oral bioavailability and absorption. Phytosomes were formulated with soybean phosphatidylcholine and C. citrinus leaf extract using the thin layer sonication method. Phytosomes were evaluated by scanning electron microscopy (SEM), entrapment efficiency, solubility, and particle size determination. Antioxidant capacity and total phenolic, flavonoid, and terpenoid contents were also measured. The in vivo anti-obesogenic activity was evaluated. Phytosomes loaded with C. citrinus (P C.c) extract had small spherical shapes. The average particle size was 129.98 +/- 18.30 nm, encapsulation efficiency 80.49 +/- 0.07%, and solubility 90.00%; the stability study presented no significant changes in the average particle size at 20 degree celsius. P C.c presented high antioxidant capacity. For the first time, ellagic acid is reported in this plant. The in vivo obesity study showed a strong anti-obesogenic activity of phytosomes with C. citrinus to reduce 40% body weight as well as morphometric and biochemical parameters.

Automated summary

This study aimed to improve the oral bioavailability and absorption of Callistemon citrinus by developing phytosomes. The phytosomes showed small spherical shapes with high encapsulation efficiency and solubility. They exhibited strong antioxidant capacity and demonstrated anti-obesogenic activity in reducing body weight and improving biochemical parameters.