Tangerine seasons generally begins from October and can go on until Late April. This amazing fruit contains Vitamin C, beta carotene and has high nutrient content.
The phenolic composition of some citrus peels and seeds was described for the first time. No clear relationship could be shown between the antioxidant activity and the phenolic composition of the extracts.
Anti-Inflammatory - Despite the fact that the enhancing effect of heat treatment on the antioxidant activity of citrus fruit peels has been well documented, the impact of heat treatment on citrus peel beneficial activities regarding anti-inflammation is unclear.
To address this issue, we determined the anti-inflammatory activities of heat-treated citrus peel extracts by measuring their inhibitory effect upon NO production by lipopolysaccharide-activated RAW 264.7 macrophages.
Results showed that the anti-inflammatory activity of citrus peel was significantly elevated after 100 °C heat treatment in a time-dependent fashion during a period from 0 to 120 min.
Proper and reasonable heat treatment helped to release nobiletin and tangeretin, which were responsible for the increased anti-inflammatory activity of heat-treated citrus peels.
Anti-Fungal - The essential oil (EO) isolated by hydro-distillation from the peel of fully matured ripen fruits of Citrus reticulata Blanco were analyzed by GC and GC–MS. Thirty seven different components were identified constituting approximately ≥99% of the oil.
Fungal sporulation was also completely inhibited at 2 ml/100 ml of the oil except for Cl and Ho, which was only 0.5% (±0.5) and 0.25% (±0.25) respectively as compared to control.
Alzheimer's Disease Support - Our recent studies have demonstrated that nobiletin, a polymethoxylated flavone from citrus peels, enhances cAMP/protein kinase A/extracellular signal-regulated kinase/cAMP response element-binding protein signaling in cultured hippocampal neurons and ameliorates Aβ-induced memory impairment in AD model rats.
For the first time, they report that this natural compound improves memory deficits in amyloid precursor protein (APP) transgenic mice that overexpress human APP695 harboring the double Swedish and London mutations [APP-SL 7-5 transgenic (Tg) mice].
Consistent with the results of ELISA, by immunohistochemistry with anti-Aβ antibody, it was evidently shown that the administration of nobiletin decreased the Aβ burden and plaques in the hippocampus of APP-SL 7-5 Tg mice. These findings suggest that this natural compound has potential to become a novel drug for fundamental treatment of AD.
Following the chronic oral administration (10 mg/kg/day for 28 days), significant levels of tangeretin were detected in the hypothalamus, striatum and hippocampus.
Sub-chronic treatment of the rats with high doses of tangeretin (20 mg/kg/day for 4 days; p.o.) before 6-OHDA lesioning markedly reduced the loss of both TH+ cells and striatal dopamine content.
These studies, for the first time, give evidence that tangeretin crosses the blood–brain barrier. The significant protection of striato-nigral integrity and functionality by tangeretin suggests its potential use as a neuroprotective agent.
Anti-Cancer - Tangeretin and nobiletin are citrus flavonoids that are among the most effective at inhibiting cancer cell growth in vitro and in vivo. The antiproliferative activity of tangeretin and nobiletin was investigated in human breast cancer cell lines MDA-MB-435 and MCF-7 and human colon cancer line HT-29.
Both flavonoids inhibited proliferation in a dose- and time-dependent manner, and blocked cell cycle progression at G1 in all three cell lines.
Thus, tangeretin and nobiletin could be effective cytostatic anticancer agents. Inhibition of proliferation of human cancers without inducing cell death may be advantageous in treating tumors as it would restrict proliferation in a manner less likely to induce cytotoxicity and death in normal, non-tumor tissues.
Apoptosis - Here we show that a naturally occurring flavone of citrus origin, tangeretin (5,6,7,8,4'-pentamethoxyflavone), induces apoptosis in human promyelocytic leukaemia HL-60 cells, whereas the flavone showed no cytotoxicity against human peripheral blood mononuclear cells (PBMCs).
The growth of HL-60 cells in vitro assessed by [3H]thymidine incorporation or tetrazolium crystal formation was strongly suppressed in the presence of tangeretin; the IC50 values range between 0.062 and 0.173 microM.
These results suggest that tangeretin inhibits growth of HL-60 cells in vitro, partially through induction of apoptosis, without causing serious side-effects on immune cells.