Liposomes Loaded with Unsaponifiable Matter from Amaranthus hypochondriacus as a Source of Squalene and Carrying Soybean Lunasin Inhibited Melanoma Cells

Amaranthus hypochondriacus is a source of molecules with reported health benefits such as antioxidant activity and cancer prevention. The objective of this research was to optimize the conditions for preparing a liposome formulation using amaranth unsaponifiable matter as a source of squalene in order to minimize the particle size and to maximize the encapsulation efficiency of liposomes for carrying and delivering soybean lunasin into melanoma cell lines. Amaranth oil was extracted using supercritical dioxide carbon extraction (55.2 MPa pressure, 80 °C temperature, solvent (CO₂)-to-feed (oil) ratio of 20). The extracted oil from amaranth was used to obtain the unsaponifiable enriched content of squalene, which was incorporated into liposomes. A Box–Behnken response surface methodology design was used to optimize the liposome formulation containing the unsaponifiable matter, once liposomes were optimized. Soybean lunasin was loaded into the liposomes and tested on A-375 and B16-F10 melanoma cells. The squalene concentration in the extracted oil was 36.64 ± 0.64 g/ 100 g of oil. The particle size in liposomes was between 115.8 and 163.1 nm; the squalene encapsulation efficiency ranged from 33.14% to 76.08%. The optimized liposome formulation contained 15.27 mg of phospholipids and 1.1 mg of unsaponifiable matter. Cell viability was affected by the liposome formulation with a half-maximum inhibitory concentration (IC₅₀) equivalent to 225 μM in B16-F10 and 215 μM in A-375. The liposomes formulated with lunasin achieved 82.14 ± 3.34% lunasin encapsulation efficiency and improved efficacy by decreasing lunasin IC₅₀ by 31.81% in B16-F10 and by 41.89% in A-375 compared with unencapsulated lunasin.

Corrigendum: Engineering Strategies in Microorganisms for the Enhanced Production of Squalene: Advances, Challenges and Opportunities

[This corrects the article DOI: 10.3389/fbioe.2019.00050.].

Engineering Strategies in Microorganisms for the Enhanced Production of Squalene: Advances, Challenges and Opportunities

The triterpene squalene is a natural compound that has demonstrated an extraordinary diversity of uses in pharmaceutical, nutraceutical, and personal care industries. Emboldened by this range of uses, novel applications that can gain profit from the benefits of squalene as an additive or supplement are expanding, resulting in its increasing demand. Ever since its discovery, the primary source has been the deep-sea shark liver, although recent declines in their populations and justified animal conservation and protection regulations have encouraged researchers to identify a novel route for squalene biosynthesis. This renewed scientific interest has profited from immense developments in synthetic biology, which now allows fine-tuning of a wider range of plants, fungi, and microorganisms for improved squalene production. There are numerous naturally squalene producing species and strains; although they generally do not make commercially viable yields as primary shark liver sources can deliver. The recent advances made toward improving squalene output from natural and engineered species have inspired this review. Accordingly, it will cover in-depth knowledge offered by the studies of the natural sources, and various engineering-based strategies that have been used to drive the improvements in the pathways toward large-scale production. The wide uses of squalene are also discussed, including the notable developments in anti-cancer applications and in augmenting influenza vaccines for greater efficacy.