Preparation of carotenoid extracts and nanoemulsions fromLycium barbarumL. and their effects on growth of HT-29 colon cancer cells

Abstract

Lycium barbarum L., a traditional Chinese herb widely used in Asian countries, has been demonstrated to be protective against chronic diseases such as age-related macular degeneration. The objectives of this study were to determine the carotenoid content in L. barbarum by high-performance liquid chromatography-mass spectrometry, followed by preparation of a carotenoid nanoemulsion to evaluate the mechanism of inhibition on HT-29 colon cancer cells. The highest extraction yield of carotenoids was attained by employing a solvent system of hexane-ethanol-acetone (1:1:1, v/v/v). Nine carotenoids, including neoxanthin (4.47 μg g), all-trans-zeaxanthin and its cis-isomers (1666.3 μg g), all-trans-β-cryptoxanthin (51.69 μg g), all-trans-β-carotene and its cis-isomers (20.11 μg g), were separated within 45 min and quantified using a YMC C column and a gradient mobile phase of methanol-water (9:1, v/v) (A) and methylene chloride (B). A highly stable carotenoid nanoemulsion composed of Capryol 90, TranscutolHP, Tween 80 and deionized water was prepared with a mean particle size of 15.1 nm. Characterization of zeaxanthin standard, blank nanoemulsion, carotenoid extract and carotenoid nanoemulsion by differential scanning calorimetry curves and Fourier transform infrared spectra revealed a good dispersion of zeaxanthin-dominated carotenoid extract with no significant chemical change after incorporation into nanoemulsion. The in vitro release kinetic study showed a higher release profile at pH 5.2 than at physiological pH 7.4, suggesting a rapid release of carotenoids in the acidic environment (pH 4.5-6.5) characteristic of tumors. Both the carotenoid nanoemulsion and the extract were effective at inhibiting growth of HT-29 colon cancer cells, with an IC of 4.5 and 4.9 μg ml, respectively. Also, both treatments could up-regulate p53 and p21 expression and down-regulate CDK2, CDK1, cyclin A and cyclin B expression and arrest the cell cycle at G/M. The study may form a basis for further exploration of L. barbarum nanoemulsion in cancer treatment.

Goji Berries as a Potential Natural Antioxidant Medicine: An Insight into Their Molecular Mechanisms of Action

“…Some of its ingredients might have a better therapeutic effect on cancer than other foods. Hsu et al [68] have reported that the L. barbarum carotenoid nanoemulsion was more effective in inhibiting HT-29 cancer cells as compared to that of the carotenoid extract. Furthermore, both nanoemulsion and extract could upregulate p53 and p21 expression and downregulate CDK1, CDK2, cyclin A, and cyclin B expression and arrest the cell cycle at G2/M.…”

A SNP-Based High-Density Genetic Map of Leaf and Fruit Related Quantitative Trait Loci in Wolfberry (Lycium Linn.)

“…This valuable fruit is exported world-wide to consumers who have become increasingly accustomed to its taste and efficacy (Li and Jiang, 2014). Recently, Gouqizi consumption has risen steadily following the publication of medical research into the health benefits of ingesting wolfberry fruit (Amagase et al, 2009; Hsu et al, 2017; Yao et al, 2018b; Tian et al, 2019). The leaves of wolfberry can be used in cooking and dried to produce tea (Dong et al, 2009).…”

Comparison of Functional Components and Antioxidant Activity of Lycium barbarum L. Fruits from Different Regions in China

“…Until now, a total of 11 free carotenoids, such as zeaxanthin, β-cryptoxantin, β-carotene, etc., and 53 polyphenols, such as ethyl trans - p -coumarate, ethyl trans -ferulate, trans -sinapinic, syringenin, cis -ferulic acid, etc., were isolated from FLB [8,9]. Previous studies showed that carotenoids from FLB could enhance immune system functioning, prevent chronic diseases, and possess biological activities, such as antiaging, antidiabetic, anticancer, and so on [10,11,12,13]. Phenolic compounds from FLB show antioxidant, antiaging, anti-inflammatory, antihyperglycemic, etc.…”