Bitter Orange Does Not Affect Blood Pressure, Heart Rate

Bitter Orange Does Not Affect Blood Pressure, Heart Rate

STORRS, Conn. Bitter orange (Citrusaurantium) does not alter blood pressure or heartrate, suggests a recent study published in Pharmacotherapy(25, 12:1719-24, 2005) (www.pharmacotherapy.org). Theresults of the new trial corroborate similar findings from earlier studiesconducted on the compound.

Researchers from the University of Connecticut conducted arandomized, double blind, placebo-controlled, crossover study on healthyvolunteers (n=18) aged 18 years or older. Test subjects were administeredplacebo or extract of dried bitter orange fruit (450 mg standardized to 27 mg ofm- or p-synephrine) in Phase 1 of the experiment. After a washout period of atleast seven days, the opposite treatment was given during Phase 2.

The researchers measured the rate-corrected QT (QTc) intervaland blood pressure in test subjects before dosing and at one, three, five andeight hours after dosing, and compared the data between groups. Subjects givenbitter orange extract had similar postdose QTc intervals and systolic anddiastolic blood pressure versus individuals administered placebo. Theresearchers concluded bitter orange dried fruit extract standardized to 27 mg m-or p-synephrine did not significantly alter QTc interval or blood pressure aftera single dose was administered, and noted future studies are necessary to ensurethe safety of bitter orange with multiple doses.

Bitter orange has been around for hundreds of years intraditional Chinese medicine, and continues to be a leading ingredient forweight loss and sports nutrition, commented Bob Green, president of Nutratech(www.nutratechinc.com), which distributes a patented bitter orange ingredient.