Phytosterols from Dunaliella tertiolecta Reduce Cell Proliferation in Sheep Fed Flaxseed during Post Partum

Abstract

The post partum period is characterized by immunosuppression and increased disease susceptibility. Both phytosterols from microalga Dunaniella tertiolecta and dietary supplementation with n-3 polyunsaturated fatty acids (PUFA) influence cell proliferation and cytokine release during inflammation. The objective of this paper was the evaluation of the effects of physterols, extracted and purified from D. tertiolecta, on the in vitro immune responses of ewes supplemented with flaxseed during post partum. Twenty Comisana parturient ewes were divided in two balanced groups, and supplemented with flaxseed (FS, 250 g/day) or fed with a conventional diet (CON). Blood samples (15 mL) were collected for five weeks, starting from lambing, in order to isolate peripheral blood mononuclear cells (PBMC). Stimulated PBMC were treated with a total sterols fraction from D. tertiolecta (TS), a mix of ergosterol and 7-dehydroporiferasterol (purified extract, PE), and a mix of acetylated ergosterol and 7-dehydroporiferasterol (acetylated purified extract, AcPE), extracted and purified from D. tertiolecta at two concentrations (0.4 and 0.8 mg/mL). Results of the experiment demonstrated that n-3 PUFA from flaxseed induced an anti-inflammatory cytokine profile, with an increase of both IL-10, IL-6 and a decrease of IL-1β. TS, PE, and AcPE purified from D. tertiolecta showed an anti-proliferative effect on sheep PBMC regardless their chemical composition and concentration.

Extracts from Microalga Chlorella sorokiniana Exert an Anti-Proliferative Effect and Modulate Cytokines in Sheep Peripheral Blood Mononuclear Cells

“…Recently, the anti-proliferative role of the two main phytosterols (7-dehydroporiferasterol and ergosterol) extracted and purified from D. tertiolecta was thoroughly studied on sheep PBMCs [11]. Similar inhibitory results of phytosterols from D. tertiolecta in sheep PBMCs during the postpartum period were found [10]. The immunological effects of phytosterols on cell proliferation are associated with their chemical structure; in particular, sterol components can relieve chronic gastric ulcers in a rat model [28], a mouse skin cancer model, and HT29 colon adenocarcinoma [29,30].…”

“…This mitigates excessive inflammation [39]. Moreover, PBMCs from sheep fed a diet rich in ω-3 and subsequently treated in vitro with phytosterols from D. tertiolecta had a main role exerted by ω-3 in driving cytokine production [10]. Conversely, sheep PBMCs treated with a mixture of ergosterol and 7-dehydroporiferasterol from D. tertiolecta had decreasing levels of IL-6 and TNF-α and an increased level of IL-10.…”

“…The ELISA for IL-6, IL-1β, and IL-10 in cell-free supernatants was determined according to Ciliberti et al [10]. Briefly, for IL-6 and IL-1β, all the incubations were at 37 °C, whereas for IL-10, they were at room temperature.…”

“…Previous experiments in a sheep model demonstrated that phytosterols extracted and purified from Dunaliella tertiolecta could exert an immunomodulatory effect by reducing cellular proliferation during the postpartum period [10] and could modify the peripheral blood mononuclear cells’ (PBMCs) cytokine profile [11]. The control of immune responses to non-infectious stressors—in particular, during the first days postpartum when sheep experience an inflammatory state, or, on the contrary, during immune depression—by feed enrichment with functional molecules could be a suitable strategy to combat antibiotic overuse and reduce antimicrobial resistance.…”

Lipids from Microalgae for Cosmetic Applications

“…In some studies, phytosterols and the total lipid fraction isolated from microalgae are identified as responsible for an anti-inflammatory activity due to an increase of anti-inflammatory cytokines and decrease of pro-inflammatory cytokines secretion. Therefore, their use in animal feed could control immune responses during inflammation and minimize the use of antibiotics [128,129]. These biological activities make them useful in the cosmetic sector.…”