Dietary supplements containing bitter orange unripe fruit
extract/p-synephrine are consumed worldwide for lose weight. This study
were conducted to determine the concentration of p-synephrine in unripe
fruits and leaves from Citrus aurantium Lin, C. sinensis Osbeck, C.
deliciosa Ten, C. limon Burm and C. limonia Osbeck, collected in
Southern Brazil, and to evaluate the acute toxicity of C. aurantium
extract and p-raw Synephrine powder.
A high performance liquid chromatographic method with diode array
detector (HPLC-DAD) was optimized and validated for determination of
p-synephrine. The results indicate that all of analyzed samples present
p-synephrine in amounts that range from 0.012% to 0.099% in the unripe
fruits and 0.029 to 0.438% in the leaves. Acute oral administration of
C. aurantium extracts (2.5% p-synephrine, 300-5,000 mg/kg) in mice
produced reduction of locomotor activity, p-synephrine (150-2,000 mg/kg)
produced piloerection, gasping, salivation, exophtalmia and reduction
in locomotor activity, which was confirmed in spontaneous locomotor
activity test. All the effects were reversible and persisted for 3-4h.
The toxic effects observed seem to be related with adrenergic
stimulation and should alert for possible side effects of p-synephrine
and C. aurantium.
