Humans usually get dietary
carotenoids from foods such as green and yellow vegetables and algae.
Carotenoids have been reported to effectively reduce the risk of developing lifestyle-related diseases. β-
Cryptoxanthin, which is an antioxidative
carotenoid and a type of
provitamin A, is metabolically converted to
vitamin A. β-
Cryptoxanthin has recently gained attention for its risk-reducing effects on lifestyle-related diseases, especially on
non-alcoholic fatty liver disease (
NAFLD), from epidemiological, interventional, and mechanistic studies.
Retinoids (
vitamin A) have also been reported to be useful as a therapeutic agent for
NAFLD.
Provitamin A is known to serve as a supply source of
retinoids through metabolic conversion by the regulated activity of β-
carotene 15,15'-monooxygenase 1 (BCMO1) to the retina only when
retinoids are deficient. From mechanistic studies using
NAFLD-model mice, β-
cryptoxanthin has been shown to contribute to the improvement of
NAFLD through a multifaceted approach, including improved
insulin resistance, suppression of oxidative stress and
inflammation, a reduction of macrophages and a shift of their subsets, and control of lipid metabolism by
peroxisome proliferator-activated receptor (
PPAR) family activation, which are also expected to have clinical applications. β-
Cryptoxanthin has the potential to prevent lifestyle-related diseases from different angles, not only as an
antioxidant but also as a
retinoid precursor.