β‐Carotene and β‐cryptoxanthin but not lutein evoke redox and immune changes in RAW264 murine macrophages

Abstract

The mechanism of immunological benefits induced by carotenoids has not been fully elucidated. Here, we investigated some of the immunity-related properties of beta-carotene and two other carotenoids, beta-cryptoxanthin, and lutein, on the murine macrophages cell line RAW264. beta-Carotene added to the culture medium accumulated in the cells in a time- and dose-dependent manner. The accumulation was positively correlated with cellular lipid peroxidation, demonstrating the pro-oxidative activity of beta-carotene, and also with the synthesis of glutathione, an intracellular antioxidant. Conversely, accumulation of beta-carotene was negatively correlated with the transcription of immune-active molecules, such as IL-1beta, IL-6, and IL-12 p40, in cells stimulated by LPS and INF-gamma. The transcription of the pro-inflammatory cytokines IL-1beta and IL-6 was more sensitive to the accumulation of beta-carotene than was IL-12 p40. The accumulation of beta-cryptoxanthin in cells resulted in effects similar to those of beta-carotene. However, lutein accumulated minimally and did not significantly affect the cells. These results demonstrate that beta-carotene, and beta-cryptoxanthin as well, can accumulate in RAW264 cells and induce changes in intracellular redox status, which in turn regulate the immune function of macrophages.

Cerebrospinal fluid levels of inflammation, oxidative stress and NAD+are linked to differences in plasma carotenoid concentrations

“…Similarly an increase in total carotenoids was also associated with reduced CSF IL-6 levels. This is consistent with in vitro work by others showing that β-cryptoxanthin significantly attenuates both the release and transcription of various cytokines [63,64]. Astaxanthin, another member of the carotenoid xanthophyll family, has also been shown to decrease IL-6 mRNA in activated microglia [65].…”

Nonalcoholic Fatty Liver Disease and Insulin Resistance: New Insights and Potential New Treatments

“…Recent epidemiological studies have shown that high levels of serum β-cryptoxanthin are associated with improved insulin resistance and alcoholic liver dysfunction in non-diabetic individuals [79,80]. In addition, in both in vivo and in vitro studies, β-cryptoxanthin was shown to have anti-inflammatory effects that operate, primarily, by modulating the innate immune response induced by macrophages [82]. Of note, the expressions of genes encoding chemokines, including MCP-1, CXCL10, and macrophage inflammatory protein-1α, and pro-inflammatory cytokines, such as TNF-α, IL-1β, and IL-6, are significantly decreased in liver and adipose tissue exposed to β-cryptoxanthin [83].…”

Protective Effects of Rooibos (Aspalathus Linearis) and/or Red Palm Oil (Elaeis Guineensis) Supplementation on Tert-Butyl Hydroperoxide-Induced Oxidative Hepatotoxicity in Wistar Rats

“…Tocopherols, tocotrienols, and carotenes in RPO are able to quench peroxyl radicals generated by t-BHP biotransformation by donating hydrogen from their phenolic hydroxyl group to the peroxyl radical thereby forming a stable radical species [113] and thus spare GSH and protect the cells from oxidative stress. RPO could also increase the biosynthesis of GSH because previous in vitro and in vivo studies have indicated that -tocopherol [114,115] and -carotene [116,117] increased intracellular GSH levels by upregulating the mRNA expression of -GCS.…”