O'Biolla

Abstract 

Some blood orange juice (BOJ) flavanones may have antioxidant, anti-inflammatory, anti-allergic, hypolipidaemic, vasoprotective and anticarcinogenic properties. The aim of the present study was to evaluate the pharmacokinetics of hesperetin and naringenin in human subjects after BOJ intake. In a cross-over study, seven healthy female volunteers consumed 150 and 300 ml BOJ corresponding to about 51–102 mg hesperetin and to 6–12 mg naringenin, respectively. Plasma samples were collected before, each hour for 8 h and 24 h after BOJ administration and analysed for their content of hesperetin and naringenin by liquid chromatography–MS/MS. The plasma concentrations of these compounds were dose dependent and the peak concentration (C_max) was reached in 5·1 (sd 0·6) h after BOJ intake. The C_max of hesperetin was 43·4 (sd 32·4) and 79·8 (sd 60·1) ng/ml after 150 and 300 ml intake, respectively. For naringenin the plasma peak was 16·4 (sd 11·9) and 34·0 (sd 20·6) ng/ml. Moreover, the conjugated forms of these flavanones represent more than 95 % of the plasma concentration. The results indicate that both hesperetin and naringenin are bioavailable after BOJ intake; naringenin seemingly more so than hesperetin.

b) The citrus flavonoid naringenin (abundant in Blood Orange Juice) may prevent cholesterol increases, and changes in insulin sensitivity and glucose metabolism linked to metabolic syndrome, says a new study with mice.

Animals fed a high fat diet and supplemented with the flavonoid did not gain weight, while other signs of the metabolic syndrome were also prevented, according to findings published in the journal Diabetes.

“The marked obesity that develops in [mice fed a high fat diet] was completely prevented by naringenin,” said lead researcher Murray Huff from the University of Western Ontario.

“What was unique about the study was that the effects were independent of caloric intake, meaning the mice ate exactly the same amount of food and the same amount of fat. There was no suppression of appetite or decreased food intake, which are often the basis of strategies to reduce weight gain and its metabolic consequences,” he added.

If the study’s findings can be repeated in other studies, including human trials, it could see naringenin added to the list of compounds with potential to prevent the metabolic syndrome.

Metabolic syndrome (MetS) is a condition characterised by central obesity, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type-2 diabetes and cardiovascular disease (CVD).

Study details

The Ontario-based researchers divided mice into four groups: one group was fed on normal chow (control group), while the other three groups were fed a high-fat, or Western, diet (42 per cent calories from fat) for four weeks. Two of the high-fat groups were also supplemented with either 1 or 3 per cent naringenin.

The animals fed only the high-fat diet became insulin and glucose intolerant, and obese. However, supplementation with the flavonoid reversed the increases in triglyceride and cholesterol levels, prevented the development of insulin resistance and completely normalized glucose metabolism, said the researchers.

Commenting on the mechanism, Huff and his co-workers note that naringenin was associated with an activation of PPAR-gamma coactivator 1 alpha, (PGC1-alpha)/PPARalpha-mediated transcription program in the liver, leading to a burning of excess fat, rather than storing it.

“Thus, naringenin, through its correction of many of the metabolic disturbances linked to insulin resistance, represents a promising therapeutic approach for metabolic syndrome,” wrote the researchers, led by Huff from the University of Western Ontario.

uff confirmed that research was ongoing in this are. “The next step is to find out if naringenin prevents heart disease in animal models and to explore the feasibility of clinical trials to determine its safety and efficacy in humans,” he said.

Source: Diabetes
Published online ahead of print, doi:10.2337/db09-0634
“Naringenin prevents dyslipidemia, apoB overproduction and hyperinsulinemia in LDL-receptor null mice with diet-induced insulin resistance”
Authors: E.E. Mulvihill, E.M. Allister, B.G. Sutherland, D.E. Telford, C.G. Sawyez, J.Y. Edwards, J.M. Markle, R.A. Hegele, M.W. Huff

LIST OF PUBLICATIONS

1. IFR, London: Oranges for a fit youth and ripe old age
2.  IFR, London: Phytochemicals and health: a diet rich in fruit and vegetables can reduce the risk of chronic illnesses such as cardiovascular disease, certain cancers and osteoporosis.
3. IFR, London: To improve iron absorption eat vitamin C-rich fruits (e.g., guava, oranges, grapefruit, kiwi fruit), or drink a large glass of fresh fruit juice
4. L'INTEGRATORE NUTRIZIONALE: Proprietà salutistiche delle arance rosse di Sicilia: un elisir dell’Etna
5. Diabetes Treatment With ROC(Red Orange Complex) 
6. Impatto su bambini specialmente con Asma 
7. Ruggeri, S., Aguzzi, A., Salvatore, P. & Carnovale, E. (2001). Content and form of folates in orange juices. In: XIV Congresso Nazionale S.I.S.A. Future traditional foods for health, safety and legislation, Rome, 12-13 October, 2000, in press.
8. Ruggeri, S., Aguzzi, A., Carnovale, E. (2001). Oranges folate and their retention in juices after mild technologies. Fourth International Food Data Conference. New Trends in the Management and uses of Food Databases. Bratislava, Slovakia, 24-26 August 2001.
9. Marchi, F. (2001). Thesis "Variability of folate content in orange cultivars and effect processing in orange juices", Agricultural University of Udine, July 2001
10. Journal of Food Composition: Article on Oranges