Improved Storage Properties and Cellular Uptake of Casticin-Loaded Nanoemulsions Stabilized by Whey Protein-Lactose Conjugate.

Bei Zhang,Wenjing Huang,Dengfeng Peng,Weiping Jin,Qingrong Huang,Fangcheng Jiang,Miao Lei,Gang Liu

doi:10.3390/foods10071640

Abstract

Casticin has wide-ranging functional activities, but its water solubility is poor in food products. Here, a nanoemulsion stabilized by Maillard whey protein isolate conjugates (MWPI) was fabricated to encapsulate casticin. The nanoemulsion, with an average diameter of 200 nm, possessed the capability to load 700 μg/g casticin. MWPI-stabilized nanoemulsion showed better stability than that of the WPI nanoemulsion during 4 weeks of storage. Both the inhibition effects of the casticin-loaded nanoemulsion on cancer cells and the process of cellular uptake were studied. Results revealed that the casticin-loaded nanoemulsion had better inhibitory activity in HepG2 and MCF-7 cells than free casticin. Cellular uptake of the nanoemulsion displayed a time-dependent manner. After the nanoemulsion passed into HepG2 and MCF-7 cells, it would locate in the lysosome but not in the nucleus. The main pathway for the nanoemulsion to enter HepG2 cells was pinocytosis, whereas, it entered MCF-7 predominantly through the clathrin-mediated pit. This work implies that MWPI-stabilized nanoemulsions could be utilized as an effective delivery system to load casticin and have the potential to be applied in the food and pharmaceutical industries.

Highlights

Casticin, 5,3 -dihydroxy-3,6,7,4-tetramthoxyflavone, is a kind of polymethoxy-flavonoid (PMF) extracted from the traditional Chinese medicine Vitex (Fructus Vititcis) [1]
When the hydrophobic bioactive compounds are encapsulated in the nanoemulsion, they can be accurately delivered to a specific location in vivo, thereby enhancing their physical stability, reducing side effects, and improving bioavailability at the same time [9,10]
The nanoemulsion prepared by Maillard whey protein isolate conjugates (MWPI) has better stability than that prepared by whey protein isolate (WPI)

Summary

Introduction

5,3 -dihydroxy-3,6,7,4-tetramthoxyflavone, is a kind of polymethoxy-flavonoid (PMF) extracted from the traditional Chinese medicine Vitex (Fructus Vititcis) [1]. Numerous studies have demonstrated that casticin has potential functional activities, including antiinflammatory [2], anti-hyperprolactinemia [3], and anti-cancer [4]. [5] One molecule of casticin contains four methoxy groups that are connected to the flavone ring. This structure possesses a strong planar structure that resists the entry of water [6]. The fabrication of an emulsion is a potential way to encapsulate the poorly watersoluble PMFs and improve their bioavailability. When the hydrophobic bioactive compounds are encapsulated in the nanoemulsion, they can be accurately delivered to a specific location in vivo, thereby enhancing their physical stability, reducing side effects, and improving bioavailability at the same time [9,10]. Soy protein isolate-stabilized nanoemulsions encapsulated the supersaturated tangeretin, and, with the addition of glycerin, the high loading of tangeretin was maintained and stabilized [14]

Methods

Results

Conclusion