Because grapefruit contains fibre, vitamin C, antioxidants and phytochemicals, the fruit and its juice are consumed widely to help meet daily nutritional requirements. However, in the past 15 years, studies have shown that grapefruit juice can induce a several-fold increase in the plasma levels of particular drugs that can result in increased therapeutic or even toxic effects. The effect seems ...

BACKGROUND The aim of the study was to verify that the concomitant presence of grapefruit flavonoid extract with inulin in a Western-type diet may provide synergistic effects to the hindgut metabolism, as well as blood lipid and mineral profiles. METHODS Forty male Wistar rats were distributed into 4 groups and fed for 28 days with diets rich in fat, cholesterol and protein. A two-way repeate...

Antioxidant compounds and the antioxidative activities of new Israeli citrus fruit sweetie [(Oroblanco, pummelo-grapefruit hybrid (Citrus grandis C. paradisi)] were compared with the better-known white grapefruit. Total and free phenols were determined with the Folin–Ciocalteu reagent, phenolic acids (free, esters and glycosides) by HPLC analysis and anthocyanins spectrophotometrically. The ant...

The effect of grapefruit juice and liqorice juice on salivary pharmacokinetics of paracetamol (acetaminophen, APAP) in 8 healthy subjects (4 males and 4 females) was investigated. Paracetamol tablet (500 mg) was administered to the volunteers with either 240 mL grapefruit juice, licorice juice or water followed by saliva samples collection at different time intervals in a sequential study desig...

OBJECTIVES/HYPOTHESIS The aim of this study was to investigate possible interactions between grapefruit juice and montelukast for up to 4 hours. STUDY DESIGN A prospective, crossover study with 23 healthy volunteers was performed in two sessions. METHODS In the first session, volunteers were treated with oral montelukast 10 mg once daily with 250 ml water. After a 10-day washout period, the...

We evaluated crop load, fruit yield and size in several grapefruit blocks on the central Florida Ridge and in the Indian River areas over three growing seasons to determine potential causes of elongated, sheepnosed grapefruit. Previous studies showed that relatively higher rates of N fertilization and high early season (February-July) temperatures within tree canopies resulted in high percentag...

the effects of rootstocks such as 'sour orange' (citrus aurantium l. var. ‘yerli’), 'carrizo' and 'troyer citranges' (citrus sinensis osb. x poncirus trifoliata raf), 'smooth flat seville sour orange' (citrus spp. hybrid of uncertain origin), 'brazilian sour orange' (citrus aurantiam l. var. ‘brasilian’), 'volkameriana' (citrus volkameriana tan. and pasq.) and 'calamondin' (possibly citrus reti...

The present study evaluated the pharmacokinetics of three different grapefruit flavanone forms in dog plasma and demonstrated their absorption after an oral intake of a grapefruit extract; pharmacokinetic parameters of these forms were also determined. Ten healthy beagles were administered 70 mg citrus flavonoids as a grapefruit extract contained in capsules, while two additional dogs were used...

There have been very limited reports on the effects of commercial fruit juices on human CYP3A activity. Therefore, the inhibitory effects of readily available commercial fruit juices on midazolam 1'-hydroxylase activity, a marker of CYP3A, were evaluated in pooled human liver microsomes. The fruit juices investigated were black raspberry, black mulberry, plum, and wild grape. White grapefruit, ...

OBJECTIVE Our objective was to assess the contribution of 6',7'-dihydroxybergamottin (DHB) to the inhibitory effect of grapefruit juice toward intestinal cytochrome P450 (CYP) 3A4. METHODS An aqueous extract was prepared from grapefruit juice by centrifugation, filtration, and repeated washing of the particulate with water. The concentrations of various furanocoumarins in this grapefruit juic...