Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update

Abstract

Obesity is a major health problem facing the developed and developing world. Efforts by individuals, health professionals, educators, and policy makers to combat the escalating trend of growing obesity prevalence have been multifaceted and mixed in outcome. Various dietary supplements have been marketed to reduce obesity. These products have been suggested to accomplish this by decreasing energy intake and energy absorption, and/or increasing metabolic rate. Ephedra, one such supplement, was banned from sale in the US market because of concerns about adverse events. Another substance, Citrus aurantium, which contains several compounds including synephrine alkaloids, has been suggested as a safe alternative. This review examines the evidence for safety and efficacy of C. aurantium and synephrine alkaloids as examined in animal studies, clinical weight loss trials, acute physiologic studies and case reports. Although at least three reviews of C. aurantium have been published, our review expands upon these by: (i) distinguishing and evaluating the efficacy of C. aurantium and related compounds; (ii) including results from previously unreviewed research; (iii) incorporating recent case reports that serve to highlight, in an anecdotal way, potential adverse events related to the use of C. aurantium and related compounds; and (iv) offering recommendations to guide the design of future trials to evaluate the safety and efficacy of C. aurantium. While some evidence is promising, we conclude that larger and more rigorous clinical trials are necessary to draw adequate conclusions regarding the safety and efficacy of C. aurantium and synephrine alkaloids for promoting weight loss.

Synephrine, a Component of Evodiae Fructus, Constricts Isolated Rat Aorta via Adrenergic and Serotonergic Receptors

“…Synephrine has been reported to act on α-adrenoceptors (4) and to reduce portal pressure and elevate mean arterial pressure in sham-operated and portal hypertensive rats (5). Moreover, synephrine has been reported to have anti-obesity activity (6), exerted through its action on β 3 -adrenoceptors, which function to activate lipolysis. In addition, synephrine has been reported to have antidepressant-like effects (7).…”

Effect of essential oil from Citrus aurantium in maternal reproductive outcome and fetal anomaly frequency in rats

“…Fruits of Citrus aurantium L. (Rutaceae family), commonly known as bitter orange, sour orange or Seville orange, are used as food, but this popular plant is more commonly used as a medicinal or dietary supplement (Fugh-Berman and Myers 2004). Similar to ephedra, it contains alkaloids that are adrenergic agonists and is often incorporated into supplements designed to aid in weight loss (Haaz et al 2006). It was confirmed that its essential oil has an antibiotic effect against Helicobacter pylori (Bergonzelli et al 2003).…”

“…The substances that reduce body weight are similar to ephedra, a component of the fruit, that contains alkaloids that are adrenergic agonists and is often incorporated to supplements designed to aid in weight loss (Preuss et al 2002). In some reports, Citrus aurantium products were combined with other agents, making it unclear which caused the benefit (Haaz et al 2006). …”

Raspberry Ketone Promotes the Differentiation of C3H10T1/2 Stem Cells into Osteoblasts

“…1), which lower adipose tissue weight. 23,24 RK has also been reported to exert anti-obesity action and alter lipid metabolism. 25,26 We, therefore, analyzed whether RK has a positive effect on osteogenesis, because there has been no report on its effect on bone formation.…”