Table 3: Name, effect, and mechanisms of action of main components of red orange.

Food componentsEffectMechanisms of action

FlavonoidAnti-inflammatoryModulate apoB secretion and cellular cholesterol; help cholesterol levels by raising HDL and lowering LDL cholesterol
AntioxidantStimulate endothelial NO synthase; normalize lipid peroxidation markers
AntiaggregationInhibit TxA2-mediated responses and dense granule secretion
AnticarcinogenicPromote apoptosis in human pre-B NALM-6 cells and colon cancer cells; inhibit HIF-1α and VEGF expression in ovarian cancer and in lung cancer
AntiproliferativeInhibit the COX-2 and MMPs in lung, prostate, and hepatocellular carcinoma cells; inhibited the proliferation of MCF-7 human breast cancer cells and testosterone-induced proliferation of LNCaP cells; inhibit lung colonization by melanoma and sarcoma cell line; inhibit formation of new blood vessels in human breast cancer cells

AnthocyaninsAntioxidantProtect biomembranes from peroxidation by trapping peroxyl radicals in the cytosol; chelate metal ions like Cu2; ability in chelating metal ions like Cu2; form an ascorbic acid metal-anthocyanin complex (copigment)
AntimutagenicityForm a cyanidin-DNA copigmentation complex; inhibit the reverse mutation induced by heterocyclic amines in microsomal activation systems
Growth inhibitionInhibit the tyrosine kinase activity of the EGFR and the activation of the GAL4-Elk-1 fusion protein

CarotenoidsAntioxidantReact with singlet molecular oxygen and peroxyl radicals

Vitamin CBlow-flow increaseEnhance generation of NO; reduce nitrite; stabilize atherosclerotic plaques (due to effect on collagen synthesis)
AntioxidantReduce the affinity of LDL-bound apoB protein for transition metal ions; quench aqueous ROS and RNS, decreasing their bioavailability in the plasma; reduce potentially damaging ROS, forming resonance-stabilized and relatively stable ascorbate free radicals; attenuate LDL-oxidation and protection of human vascular smooth muscle cells against apoptosis

Hydroxycinnamic acidsAntioxidantEffect on phase II detoxification cascade; inhibit of superoxide dismutase and catalase; suppress of PG synthesis and cyclooxygenase-2
AnticarcinogenicPrevent the tumor onset and protect the biochemical and molecular abnormalities in mammary, buccal pouch, colon, and skin cancers

EGFR: epidermal growth-factor receptor; HDL: high-density lipoproteins; HIF-1α: hypoxia-inducible factor 1α; LDL: low-density lipoproteins; MMP: matrix metalloproteinase; NO: nitric oxide; PG: prostaglandins; RNS: reactive nitrogen species; ROS: reactive oxygen species.