Naringin Does Not Alter Caffeine Pharmacokinetics, Energy Expenditure, or Cardiovascular Haemodynamics in Humans Following Caffeine Consumption

Abstract

1. Naringin, a grapefruit constituent interacts with many medications including caffeine, a popular weight loss supplement. The purpose of the current study was to identify changes in caffeine pharmacokinetics, resting energy expenditure (REE), oxygen consumption (VO(2)) and respiratory exchange ratio (RER) after an acute dosage of caffeine and naringin. 2. Using a double-blinded, counterbalanced design, REE, VO(2), and RER were measured before and systematically for 8 h after a single dosage of caffeine (CAF, 200 mg) with and without naringin (100 mg (CN100) or 200 mg (CN200)) in 10 apparently healthy individuals. A standardized meal was provided following 240-minute measurements (400 kcals; 35 g carbohydrate; 27 g protein; 7 g fat). 3. Caffeine, CN100, CN200 did not alter VO(2) or VO(2) area under the curve (137 301 +/- 8318, 139 729 +/- 9300, 134 297 +/- 8318, mL/480 min). Resting energy expenditure (k/cals) was 10.0 +/- 1.4% higher with CAF versus CN200 (6.0 +/- 1.4%) and CN100 (6 +/- 1.5%) at 240 min (P = 0.07) which was then negated following a standardized meal. Percent change in RER from pre to 240 min and pre to 480 min was not different between the CAF, CN100, or CN200 (-0.2 +/- 1.7%, 1.7 +/- 1.7%, -2.8 +/- 1.9%). 4. Although caffeine alone suggests a trend of increased REE, the results of the present study indicate that concurrent consumption of caffeine with naringin in acute dosages does not affect RER, VO(2), and prevents the increase of REE in adult humans. The results suggest that the interaction of grapefruit juice and caffeine may be due to constituents of grapefruit juice other than naringin or in addition to naringin.

Effect of grapefruit juice and food on the pharmacokinetics of pirfenidone in healthy Chinese volunteers: a diet–drug interaction study

“…Although a 13% increase in AUC was observed, the difference was of no statistical significance (n ¼ 10). In addition, the pharmacokinetic profiles and parameters for caffeine were not significantly different after co-administration with naringin (Ballard et al, 2006), an important constituent of grapefruit juice (n ¼ 10). Two studies have been published on the pharmacokinetic impact of grapefruit juice on theophylline, another classical CYP1A2 substrate.…”

Caffeine (1, 3, 7‐trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters

“…Although caffeine is being researched in a variety of areas regarding human health the focus of this review will be on its potential as an aid in weight loss, thus reducing the overall risk for developing the metabolic syndrome (Ballard and others 2006; Fujioka and others 2006). The metabolic syndrome is a significant and growing health concern affecting approximately 25% of the United States population (Ford and others 2002; Zimmet and Alberti 2008).…”

“…Energy balance is the main determinant of weight regulation. In this context, research on caffeine has demonstrated its role in increasing metabolic rate, energy expenditure (EE), lipid oxidation, and lipolytic and thermogenic activities; all favorable components in regards to weight management and possible weight loss in humans (Acheson and others 2004; Ballard and others 2006; Dallas and others 2008). Although the role of thermogenic activity in weight control is in the process of being analyzed, multiple studies have shown that caffeine can influence energy balance in humans.…”

Preclinical Evidence for the Pharmacological Actions of Naringin: A Review

“…Naringin also inhibits various CYP isoenzymes, thus increasing the bioavailability of calcium channel blockers such as verapamil [40] via CYP3A4 and paclitaxel via CYP3A1/2 inhibition [41]. Nevertheless, naringin has also been shown to have no effect on the pharmacokinetics of drugs such as doxorubicin [42] and caffeine [43].…”