The Experts below are selected from a list of 690 Experts worldwide ranked by ideXlab platform
Sidney J Stohs - One of the best experts on this subject based on the ideXlab platform.
-
safety efficacy and mechanistic studies regarding citrus aurantium bitter orange extract and p Synephrine
Phytotherapy Research, 2017Co-Authors: Sidney J StohsAbstract:Citrus aurantium L. (bitter orange) extracts that contain p-Synephrine as the primary protoalkaloid are widely used for weight loss/weight management, sports performance, appetite control, energy, and mental focus and cognition. Questions have been raised about the safety of p-Synephrine because it has some structural similarity to ephedrine. This review focuses on current human, animal, in vitro, and mechanistic studies that address the safety, efficacy, and mechanisms of action of bitter orange extracts and p-Synephrine. Numerous studies have been conducted with respect to p-Synephrine and bitter orange extract because ephedra and ephedrine were banned from use in dietary supplements in 2004. Approximately 30 human studies indicate that p-Synephrine and bitter orange extracts do not result in cardiovascular effects and do not act as stimulants at commonly used doses. Mechanistic studies suggest that p-Synephrine exerts its effects through multiple actions, which are discussed. Because p-Synephrine exhibits greater adrenergic receptor binding in rodents than humans, data from animals cannot be directly extrapolated to humans. This review, as well as several other assessments published in recent years, has concluded that bitter orange extract and p-Synephrine are safe for use in dietary supplements and foods at the commonly used doses. Copyright © 2017 The Authors Phytotherapy Research Published by John Wiley & Sons Ltd.
-
RESEARCH ARTICLE Open Access The
2016Co-Authors: Nicholas A Ratamess, Sidney J Stohs, Jill A Bush, Jie Kang, William J Kraemer, Vincenzo G Nocera, Megan D Leise, Keith B Diamond, Avery D. FaigenbaumAbstract:effects of supplementation with P-Synephrine alone and in combination with caffeine on resistance exercise performanc
-
the effects of supplementation with p Synephrine alone and in combination with caffeine on metabolic lipolytic and cardiovascular responses during resistance exercise
Journal of The American College of Nutrition, 2016Co-Authors: Nicholas A Ratamess, Sidney J Stohs, Jill A Bush, Jie Kang, William J Kraemer, Vincenzo G Nocera, Megan D Leise, Keith B Diamond, Sara C Campbell, Howard MillerAbstract:Objective: The purpose of this study was to examine the metabolic, lipolytic, and cardiovascular responses to supplementation with p-Synephrine alone and in combination with caffeine during resistance exercise (RE).Methods: Twelve healthy men performed a control RE protocol (6 × 10 repetitions of squats) and were randomly assigned (using a double-blind crossover design with random protocol sequencing) to a supplement sequence: p-Synephrine (S; 100 mg), p-Synephrine + caffeine (SCF; 100 mg of p-Synephrine plus 100 mg of caffeine), or a placebo (P). Subjects reported to the lab at a standard time, consumed a supplement, sat quietly for 45 minutes, performed the RE protocol, and sat quietly for 30 minutes. Blood samples were collected at rest (T1), after sitting quietly for 45 minutes (T2), immediately following RE (T3), and 15 minutes (T4) and 30 minutes (T5) postexercise. Oxygen consumption (VO2) and heart rate (HR) data were collected throughout. Results: Serum glycerol was significantly elevated at T2 on...
-
a 60day double blind placebo controlled safety study involving citrus aurantium bitter orange extract
Food and Chemical Toxicology, 2013Co-Authors: Gilbert R Kaats, Harry G Preuss, Howard Miller, Sidney J StohsAbstract:Bitter orange (Citrus aurantium) extract and its primary protoalkaloid p-Synephrine are widely consumed in dietary supplements for weight management and sports performance. p-Synephrine is also present in foods derived from a variety of Citrus species. Bitter orange extract is commonly used in combination with multiple herbal ingredients. Most clinical studies conducted on bitter orange extract alone have involved single doses. The purpose of this study was to assess the safety of bitter orange extract (approximately 49mg p-Synephrine) alone or in combination with naringin and hesperidin twice daily given to 25 healthy subjects per group for 60days in a double-blinded, placebo-controlled protocol. No significant changes occurred in systolic or diastolic blood pressures, blood chemistries or blood cell counts in control or p-Synephrine treated groups. Small, clinically insignificant differences in heart rates were observed between the p-Synephrine plus naringin and hesperidin group and the p-Synephrine alone as well as the placebo group. No adverse effects were reported in the three groups. Bitter orange extract and p-Synephrine appear to be without adverse effects at a dose of up to 98mg daily for 60days based on the parameters measured.
-
a review of the human clinical studies involving citrus aurantium bitter orange extract and its primary protoalkaloid p Synephrine
International Journal of Medical Sciences, 2012Co-Authors: Sidney J Stohs, Harry G Preuss, Mohd SharaAbstract:This review summarizes the published as well as unpublished human studies involving Citrus aurantium (bitter orange) extract and its primary protoalkaloid p-Synephrine, providing information and an assessment of the safety and efficacy of these widely used products. The results of over 20 studies involving a total of approximately 360 subjects that consumed p-Synephrine alone or in combination with other ingredients are reviewed and critiqued. Over 50 % of the subjects involved in these studies were overweight/obese, and approximately two-thirds of these overweight/obese subjects consumed caffeine (132-528 mg/day) in conjunction with p-Synephrine (10-53 mg/day). Bitter orange/p-Synephrine containing products were consumed for up to 12 weeks. Approximately 44 % of the subjects consumed a bitter orange/p-Synephrine only product, while the remainder consumed a complex product that contained multiple ingredients in addition to p-Synephrine. In general, bitter orange extract alone (p-Synephrine) or in combination with other herbal ingredients did not produce significant adverse events as an increase in heart rate or blood pressure, or alter electrocardiographic data, serum chemistry, blood cell counts or urinalysis. p-Synephrine alone as well as in combination products were shown to increase resting metabolic rate and energy expenditure, and modest increases in weight loss were observed with bitter orange extract/p-Synephrine-containing products when given for six to 12 weeks. Longer term studies are needed to further assess the efficacy of these products and affirm their safety under these conditions.
Federica Pellati - One of the best experts on this subject based on the ideXlab platform.
-
chromatographic and electrophoretic methods for the analysis of phenetylamine alkaloids in citrus aurantium
Journal of Chromatography A, 2007Co-Authors: Federica Pellati, Stefania BenvenutiAbstract:Citrus aurantium (bitter orange) is a plant belonging to the family Rutaceae, whose fruit extracts have been used recently for the treatment of obesity. The most important biologically active constituents of the C. aurantium fruits are phenethylamine alkaloids (i.e. octopamine, Synephrine, tyramine, N-methyltyramine and hordenine). Synephrine is a primary synthesis compound with pharmacological activities such as vasoconstriction, elevation of blood pressure and relaxation of bronchial muscle. Synephrine is present in the peel and the edible part of Citrus fruit. Of the adrenergic amines of natural origin, Synephrine has been found to be the main constituent of C. aurantium fruits and extracts; the other alkaloids are either absent or present in only low concentrations. It is known that Synephrine and the other amines found in C. aurantium have adverse effects on the cardiovascular system, owing to adrenergic stimulation. In light of the great commercial proliferation of C. aurantium herbal medicines in recent years, this review provides an overview of various extraction, separation and detection techniques employed for the qualitative and quantitative determination of the alkaloids in C. aurantium and related species. The application of chromatographic and electrophoretic methods for the separation and determination of these active components in C. aurantium plant material and derivatives are described. Since Synephrine is a chiral compound, enantioselective chromatographic and electrophoretic techniques for the analysis of Synephrine enantiomers in natural products are presented. Furthermore, examples of identification of these active compounds in complex matrices by hyphenated methods, such as gas chromatography-mass spectrometry and high-performance liquid chromatography-mass spectrometry, are described. The advantages and limitations of these separation and identification methods are assessed and discussed.
-
development and validation of hplc methods for the analysis of phenethylamine and indoloquinazoline alkaloids in evodia species
IEEE Journal of Solid-state Circuits, 2006Co-Authors: Federica Pellati, Stefania Benvenuti, F. Yoshizaki, Margherita MelegariAbstract:The aim of this study was to evaluate the chromatographic performance of a PEG stationary phase, in comparison with those of C18 columns, for the HPLC analysis of phenethylamine ((+/-)-Synephrine) and indoloquinazoline (rutaecarpine and evodiamine) alkaloids in methanolic extracts of fruits of Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (i.e., E. officinalis Dode) (Rutaceae family). The method was validated and showed good linearity, precision, accuracy, sensitivity, and specificity. The highest content of both phenethylamine and indoloquinazoline alkaloids was found in methanolic fruit extracts of E. rutaecarpa, and it was closely related to the degree of maturity. E. officinalis fruits displayed low amounts of both types of alkaloids. Furthermore, an enantioselective HPLC method for the enantioseparation of (+/-)-Synephrine from Evodia fruits was applied, by using a protein-based chiral stationary phase with cellobiohydrolase (CBH) as the chiral selector (Chiral-CBH). Isolation of Synephrine from Evodia aqueous fruit extracts was carried out by strong cation-exchange SPE. The results of the application of the method to the analysis of Evodia samples showed that (-)-Synephrine was the main component while (+)-Synephrine was present in low concentration.
-
high performance liquid chromatography methods for the analysis of adrenergic amines and flavanones in citrus aurantium l var amara
Phytochemical Analysis, 2004Co-Authors: Federica Pellati, Stefania Benvenuti, Margherita MelegariAbstract:Reverse-phase HPLC coupled with photodiode array detection was used for the simultaneous separation and determination of naturally occurring adrenergic amines (octopamine, Synephrine and tyramine) in fruits and dry extracts of Citrus aurantium L. var. amara and in herbal medicines derived therefrom. Synephrine was the main component in fruits (0.10–0.35%) and in dry extracts (3.00–3.08%) and was present in the range 0.25–0.99% in herbal medicines. Flavanones were analysed in the same samples using a reverse-phase HPLC technique which allowed the identification and quantification of neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, naringenin and hesperetin. C. aurantium fruits and derivatives contained mainly glycosylated flavanones: in particular, naringin and neohesperidin were found to be the major flavonoids and their concentrations ranged from 1.80 to 26.30 and from 3.90 to 14.71 mg/g, respectively. The levels of aglycones were very low in all samples tested. Copyright © 2004 John Wiley & Sons, Ltd.
-
high performance liquid chromatography methods for the analysis of adrenergic amines and flavanones in citrus aurantium l var amara
Phytochemical Analysis, 2004Co-Authors: Federica Pellati, Stefania Benvenuti, Margherita MelegariAbstract:Reverse-phase HPLC coupled with photodiode array detection was used for the simultaneous separation and determination of naturally occurring adrenergic amines (octopamine, Synephrine and tyramine) in fruits and dry extracts of Citrus aurantium L. var. amara and in herbal medicines derived therefrom. Synephrine was the main component in fruits (0.10-0.35%) and in dry extracts (3.00-3.08%) and was present in the range 0.25-0.99% in herbal medicines. Flavanones were analysed in the same samples using a reverse-phase HPLC technique which allowed the identification and quantification of neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, naringenin and hesperetin. C. aurantium fruits and derivatives contained mainly glycosylated flavanones: in particular, naringin and neohesperidin were found to be the major flavonoids and their concentrations ranged from 1.80 to 26.30 and from 3.90 to 14.71 mg/g, respectively. The levels of aglycones were very low in all samples tested.
-
determination of adrenergic agonists from extracts and herbal products of citrus aurantium l var amara by lc
Journal of Pharmaceutical and Biomedical Analysis, 2002Co-Authors: Federica Pellati, Margherita Melegari, Stefania Benvenuti, Fabio FirenzuoliAbstract:Abstract The purpose of this study was to set up a HPLC method to separate adrenergic amines (dl-octopamine, dl-Synephrine and tyramine) and to determine their content in fruits, extracts and herbal products of Citrus aurantium L. var. amara. A rapid method for the quantitative analysis of these amines is described, based on their separation by RP-HPLC technique with UV detection. The analysis were conducted on a Lichrospher RP-18 column at room temperature, using a mobile phase consisting of 0.02 M citric acid–0.02 M NaH2PO4 (7:3 v/v) and adjusted to a final pH of 3. The detection was at 220 nm. Since some of these amines are chiral compounds and their enantiomers showed different pharmacological activity, the direct separation of Synephrine enantiomers was carried out with HPLC on a β-cyclodextrin stationary phase. The mobile phase consisted of methanol–NaH2PO4 25 mM pH 3.5 (20:80 v/v) and tetrabutylammonium hydrogen sulfate 10 mM in ratio of 30:70 v/v in isocratic condition and the detection was at 220 nm. The two proposed methods were applied to the analysis of fruits, extracts and herbal products of C. aurantium L. var. amara. Taking into account that some authors have reported that l-Synephrine may be converted into its d-form by high temperature, this optical isomerization was monitored by the same HPLC method used for the separation of enantiomers.
Margherita Melegari - One of the best experts on this subject based on the ideXlab platform.
-
development and validation of hplc methods for the analysis of phenethylamine and indoloquinazoline alkaloids in evodia species
IEEE Journal of Solid-state Circuits, 2006Co-Authors: Federica Pellati, Stefania Benvenuti, F. Yoshizaki, Margherita MelegariAbstract:The aim of this study was to evaluate the chromatographic performance of a PEG stationary phase, in comparison with those of C18 columns, for the HPLC analysis of phenethylamine ((+/-)-Synephrine) and indoloquinazoline (rutaecarpine and evodiamine) alkaloids in methanolic extracts of fruits of Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (i.e., E. officinalis Dode) (Rutaceae family). The method was validated and showed good linearity, precision, accuracy, sensitivity, and specificity. The highest content of both phenethylamine and indoloquinazoline alkaloids was found in methanolic fruit extracts of E. rutaecarpa, and it was closely related to the degree of maturity. E. officinalis fruits displayed low amounts of both types of alkaloids. Furthermore, an enantioselective HPLC method for the enantioseparation of (+/-)-Synephrine from Evodia fruits was applied, by using a protein-based chiral stationary phase with cellobiohydrolase (CBH) as the chiral selector (Chiral-CBH). Isolation of Synephrine from Evodia aqueous fruit extracts was carried out by strong cation-exchange SPE. The results of the application of the method to the analysis of Evodia samples showed that (-)-Synephrine was the main component while (+)-Synephrine was present in low concentration.
-
high performance liquid chromatography methods for the analysis of adrenergic amines and flavanones in citrus aurantium l var amara
Phytochemical Analysis, 2004Co-Authors: Federica Pellati, Stefania Benvenuti, Margherita MelegariAbstract:Reverse-phase HPLC coupled with photodiode array detection was used for the simultaneous separation and determination of naturally occurring adrenergic amines (octopamine, Synephrine and tyramine) in fruits and dry extracts of Citrus aurantium L. var. amara and in herbal medicines derived therefrom. Synephrine was the main component in fruits (0.10–0.35%) and in dry extracts (3.00–3.08%) and was present in the range 0.25–0.99% in herbal medicines. Flavanones were analysed in the same samples using a reverse-phase HPLC technique which allowed the identification and quantification of neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, naringenin and hesperetin. C. aurantium fruits and derivatives contained mainly glycosylated flavanones: in particular, naringin and neohesperidin were found to be the major flavonoids and their concentrations ranged from 1.80 to 26.30 and from 3.90 to 14.71 mg/g, respectively. The levels of aglycones were very low in all samples tested. Copyright © 2004 John Wiley & Sons, Ltd.
-
high performance liquid chromatography methods for the analysis of adrenergic amines and flavanones in citrus aurantium l var amara
Phytochemical Analysis, 2004Co-Authors: Federica Pellati, Stefania Benvenuti, Margherita MelegariAbstract:Reverse-phase HPLC coupled with photodiode array detection was used for the simultaneous separation and determination of naturally occurring adrenergic amines (octopamine, Synephrine and tyramine) in fruits and dry extracts of Citrus aurantium L. var. amara and in herbal medicines derived therefrom. Synephrine was the main component in fruits (0.10-0.35%) and in dry extracts (3.00-3.08%) and was present in the range 0.25-0.99% in herbal medicines. Flavanones were analysed in the same samples using a reverse-phase HPLC technique which allowed the identification and quantification of neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, naringenin and hesperetin. C. aurantium fruits and derivatives contained mainly glycosylated flavanones: in particular, naringin and neohesperidin were found to be the major flavonoids and their concentrations ranged from 1.80 to 26.30 and from 3.90 to 14.71 mg/g, respectively. The levels of aglycones were very low in all samples tested.
-
determination of adrenergic agonists from extracts and herbal products of citrus aurantium l var amara by lc
Journal of Pharmaceutical and Biomedical Analysis, 2002Co-Authors: Federica Pellati, Margherita Melegari, Stefania Benvenuti, Fabio FirenzuoliAbstract:Abstract The purpose of this study was to set up a HPLC method to separate adrenergic amines (dl-octopamine, dl-Synephrine and tyramine) and to determine their content in fruits, extracts and herbal products of Citrus aurantium L. var. amara. A rapid method for the quantitative analysis of these amines is described, based on their separation by RP-HPLC technique with UV detection. The analysis were conducted on a Lichrospher RP-18 column at room temperature, using a mobile phase consisting of 0.02 M citric acid–0.02 M NaH2PO4 (7:3 v/v) and adjusted to a final pH of 3. The detection was at 220 nm. Since some of these amines are chiral compounds and their enantiomers showed different pharmacological activity, the direct separation of Synephrine enantiomers was carried out with HPLC on a β-cyclodextrin stationary phase. The mobile phase consisted of methanol–NaH2PO4 25 mM pH 3.5 (20:80 v/v) and tetrabutylammonium hydrogen sulfate 10 mM in ratio of 30:70 v/v in isocratic condition and the detection was at 220 nm. The two proposed methods were applied to the analysis of fruits, extracts and herbal products of C. aurantium L. var. amara. Taking into account that some authors have reported that l-Synephrine may be converted into its d-form by high temperature, this optical isomerization was monitored by the same HPLC method used for the separation of enantiomers.
Stefania Benvenuti - One of the best experts on this subject based on the ideXlab platform.
-
chromatographic and electrophoretic methods for the analysis of phenetylamine alkaloids in citrus aurantium
Journal of Chromatography A, 2007Co-Authors: Federica Pellati, Stefania BenvenutiAbstract:Citrus aurantium (bitter orange) is a plant belonging to the family Rutaceae, whose fruit extracts have been used recently for the treatment of obesity. The most important biologically active constituents of the C. aurantium fruits are phenethylamine alkaloids (i.e. octopamine, Synephrine, tyramine, N-methyltyramine and hordenine). Synephrine is a primary synthesis compound with pharmacological activities such as vasoconstriction, elevation of blood pressure and relaxation of bronchial muscle. Synephrine is present in the peel and the edible part of Citrus fruit. Of the adrenergic amines of natural origin, Synephrine has been found to be the main constituent of C. aurantium fruits and extracts; the other alkaloids are either absent or present in only low concentrations. It is known that Synephrine and the other amines found in C. aurantium have adverse effects on the cardiovascular system, owing to adrenergic stimulation. In light of the great commercial proliferation of C. aurantium herbal medicines in recent years, this review provides an overview of various extraction, separation and detection techniques employed for the qualitative and quantitative determination of the alkaloids in C. aurantium and related species. The application of chromatographic and electrophoretic methods for the separation and determination of these active components in C. aurantium plant material and derivatives are described. Since Synephrine is a chiral compound, enantioselective chromatographic and electrophoretic techniques for the analysis of Synephrine enantiomers in natural products are presented. Furthermore, examples of identification of these active compounds in complex matrices by hyphenated methods, such as gas chromatography-mass spectrometry and high-performance liquid chromatography-mass spectrometry, are described. The advantages and limitations of these separation and identification methods are assessed and discussed.
-
development and validation of hplc methods for the analysis of phenethylamine and indoloquinazoline alkaloids in evodia species
IEEE Journal of Solid-state Circuits, 2006Co-Authors: Federica Pellati, Stefania Benvenuti, F. Yoshizaki, Margherita MelegariAbstract:The aim of this study was to evaluate the chromatographic performance of a PEG stationary phase, in comparison with those of C18 columns, for the HPLC analysis of phenethylamine ((+/-)-Synephrine) and indoloquinazoline (rutaecarpine and evodiamine) alkaloids in methanolic extracts of fruits of Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (i.e., E. officinalis Dode) (Rutaceae family). The method was validated and showed good linearity, precision, accuracy, sensitivity, and specificity. The highest content of both phenethylamine and indoloquinazoline alkaloids was found in methanolic fruit extracts of E. rutaecarpa, and it was closely related to the degree of maturity. E. officinalis fruits displayed low amounts of both types of alkaloids. Furthermore, an enantioselective HPLC method for the enantioseparation of (+/-)-Synephrine from Evodia fruits was applied, by using a protein-based chiral stationary phase with cellobiohydrolase (CBH) as the chiral selector (Chiral-CBH). Isolation of Synephrine from Evodia aqueous fruit extracts was carried out by strong cation-exchange SPE. The results of the application of the method to the analysis of Evodia samples showed that (-)-Synephrine was the main component while (+)-Synephrine was present in low concentration.
-
high performance liquid chromatography methods for the analysis of adrenergic amines and flavanones in citrus aurantium l var amara
Phytochemical Analysis, 2004Co-Authors: Federica Pellati, Stefania Benvenuti, Margherita MelegariAbstract:Reverse-phase HPLC coupled with photodiode array detection was used for the simultaneous separation and determination of naturally occurring adrenergic amines (octopamine, Synephrine and tyramine) in fruits and dry extracts of Citrus aurantium L. var. amara and in herbal medicines derived therefrom. Synephrine was the main component in fruits (0.10–0.35%) and in dry extracts (3.00–3.08%) and was present in the range 0.25–0.99% in herbal medicines. Flavanones were analysed in the same samples using a reverse-phase HPLC technique which allowed the identification and quantification of neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, naringenin and hesperetin. C. aurantium fruits and derivatives contained mainly glycosylated flavanones: in particular, naringin and neohesperidin were found to be the major flavonoids and their concentrations ranged from 1.80 to 26.30 and from 3.90 to 14.71 mg/g, respectively. The levels of aglycones were very low in all samples tested. Copyright © 2004 John Wiley & Sons, Ltd.
-
high performance liquid chromatography methods for the analysis of adrenergic amines and flavanones in citrus aurantium l var amara
Phytochemical Analysis, 2004Co-Authors: Federica Pellati, Stefania Benvenuti, Margherita MelegariAbstract:Reverse-phase HPLC coupled with photodiode array detection was used for the simultaneous separation and determination of naturally occurring adrenergic amines (octopamine, Synephrine and tyramine) in fruits and dry extracts of Citrus aurantium L. var. amara and in herbal medicines derived therefrom. Synephrine was the main component in fruits (0.10-0.35%) and in dry extracts (3.00-3.08%) and was present in the range 0.25-0.99% in herbal medicines. Flavanones were analysed in the same samples using a reverse-phase HPLC technique which allowed the identification and quantification of neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, naringenin and hesperetin. C. aurantium fruits and derivatives contained mainly glycosylated flavanones: in particular, naringin and neohesperidin were found to be the major flavonoids and their concentrations ranged from 1.80 to 26.30 and from 3.90 to 14.71 mg/g, respectively. The levels of aglycones were very low in all samples tested.
-
determination of adrenergic agonists from extracts and herbal products of citrus aurantium l var amara by lc
Journal of Pharmaceutical and Biomedical Analysis, 2002Co-Authors: Federica Pellati, Margherita Melegari, Stefania Benvenuti, Fabio FirenzuoliAbstract:Abstract The purpose of this study was to set up a HPLC method to separate adrenergic amines (dl-octopamine, dl-Synephrine and tyramine) and to determine their content in fruits, extracts and herbal products of Citrus aurantium L. var. amara. A rapid method for the quantitative analysis of these amines is described, based on their separation by RP-HPLC technique with UV detection. The analysis were conducted on a Lichrospher RP-18 column at room temperature, using a mobile phase consisting of 0.02 M citric acid–0.02 M NaH2PO4 (7:3 v/v) and adjusted to a final pH of 3. The detection was at 220 nm. Since some of these amines are chiral compounds and their enantiomers showed different pharmacological activity, the direct separation of Synephrine enantiomers was carried out with HPLC on a β-cyclodextrin stationary phase. The mobile phase consisted of methanol–NaH2PO4 25 mM pH 3.5 (20:80 v/v) and tetrabutylammonium hydrogen sulfate 10 mM in ratio of 30:70 v/v in isocratic condition and the detection was at 220 nm. The two proposed methods were applied to the analysis of fruits, extracts and herbal products of C. aurantium L. var. amara. Taking into account that some authors have reported that l-Synephrine may be converted into its d-form by high temperature, this optical isomerization was monitored by the same HPLC method used for the separation of enantiomers.
Renata Pereira Limberger - One of the best experts on this subject based on the ideXlab platform.
-
Toxicological Effects of a Mixture Used in Weight Loss Products: p-Synephrine Associated With Ephedrine, Salicin,
2016Co-Authors: Gabriela C. Schmitt, Marcelo Dutra Arbo, Eliane Dallegrave, Andreia Louise Lorensi, Erica Santos Maciel, Carolina L Krahn, Kristiane C. Mariotti, Mirna B. Leal, Renata Pereira LimbergerAbstract:p-Synephrine is an adrenergic amine found in Citrus aurantium L. fruits and has been used for weight loss in dietary supplements. There are commercial products containing this substance associated to caffeine, salicin, and ephedrine. The aim of this study was to evaluate the acute toxicity of this mixture in mice of both sexes. The significative results observed after acute oral adminis-tration to male and female mice of 300, 350, and 400 mg/kg total of p-Synephrine, ephedrine, salicin, plus caffeine in a 10:4:6:80 w/w ratio included a reduction in locomotor activity and ptosis in all treated groups for both sexes. Seizures were also observed in male (400 mg/kg) and female groups (350 and 400 mg/kg). Gasping and tearing were observed in males. Salivation (400 mg/kg), agitation (350 and 400 mg/kg), and piloerection (all treated groups) were significantly observed only in females. Deaths occurred in males at 350 and 400 mg/kg treated groups and the necropsy showed cardiopulmonary hemorrhage. A reduction in locomotor activity was confirmed through the spontaneous locomotor activity test, in which the number of crossings considerably decreased (P <.01) in all treated groups. The rotarod test showed a decrease in motor coordination at 400 mg/kg. Body temperature decreased significantly (P <.01) in all treated groups compared to controls. The results suggested clear signs of toxicity of p-Synephrine, ephedrine, salicin, and caffeine association; this toxicity augments the attentiveness on commercial products containing this mixture, given the expressive number of adverse events related to its utilization
-
Gender differences in biochemical markers and oxidative stress of rats after 28 days oral exposure to a mixture used for weight loss containing p-Synephrine, ephedrine, salicin, and caffeine
Brazilian Journal of Pharmaceutical Sciences, 2016Co-Authors: Gabriela Cristina Schmitt, Marcelo Dutra Arbo, Eliane Dallegrave, Solange Cristina Garcia, Mirna Bainy Leal, Andreia Louise Lorensi, Kristiane De Cassia Mariotti, Ana Laura Bemvenuti Jacques, Sabrina Nascimento, Renata Pereira LimbergerAbstract:The association of p-Synephrine, ephedrine, salicin, and caffeine in dietary supplements and weight loss products is very common worldwide, even though ephedrine has been prohibited in many countries. The aim of this study was to evaluate a 28-day oral exposure toxicity profile of p-Synephrine, ephedrine, salicin, and caffeine mixture (10:4:6:80 w/w respectively) in male and female Wistar rats. Body weight and signs of toxicity, morbidity, and mortality were observed daily. After 28 days, animals were euthanized and blood collected for hematological, biochemical, and oxidative stress evaluation. No clinical signs of toxicity, significant weight loss or deaths occurred, nor were there any significant alterations in hematological parameters. Biochemical and oxidative stress biomarkers showed lipid peroxidation, and hepatic and renal damage (p < 0.05; ANOVA/Bonferroni) in male rats (100 and 150 mg/kg) and a reduction (p < 0.05; ANOVA/Bonferroni) in glutathione (GSH) levels in all male groups. Female groups displayed no indications of oxidative stress or biochemical alterations. The different toxicity profile displayed by male and female rats suggests a hormonal influence on mixture effects. Results demonstrated that the tested mixture can alter oxidative status and promote renal and hepatic damages.
-
toxicological effects of a mixture used in weight loss products p Synephrine associated with ephedrine salicin and caffeine
International Journal of Toxicology, 2012Co-Authors: Gabriela Cristina Schmitt, Marcelo Dutra Arbo, Eliane Dallegrave, Mirna Bainy Leal, Andreia Louise Lorensi, Erica Santos Maciel, Carolina L Krahn, Kristiane De Cassia Mariotti, Renata Pereira LimbergerAbstract:p-Synephrine is an adrenergic amine found in Citrus aurantium L. fruits and has been used for weight loss in dietary supplements. There are commercial products containing this substance associated ...
-
subchronic toxicity of citrus aurantium l rutaceae extract and p Synephrine in mice
Regulatory Toxicology and Pharmacology, 2009Co-Authors: Marcelo Dutra Arbo, Gabriela Cristina Schmitt, Mariana Fagundes Limberger, Mariele F Charao, ângela M Moro, Gianine Ribeiro, Eliane Dallegrave, Solange Cristina Garcia, Mirna Bainy Leal, Renata Pereira LimbergerAbstract:Extracts of Citrus aurantium L. (Rutaceae) unripe fruits have gained popularity for the treatment of obesity. Due to the wide use of C. aurantium/p-Synephrine-containing products, this research was undertaken to evaluate its subchronic toxicity in mice and their actions in oxidative stress biomarkers. Groups of 9-10 mice received for 28 consecutive days a commercial C. aurantium dried extract (containing 7.5% p-Synephrine) 400, 2000 or 4000 mg/kg and p-Synephrine 30 or 300 mg/kg by oral gavage. There was a reduction in body weight gain of animals treated with both doses of p-Synephrine. Organs relative weight, biochemical and hematological parameters were not altered in all treated mice. There was an increase in reduced glutathione (GSH) concentration in groups treated with C. aurantium 4000 mg/kg and p-Synephrine 30 and 300 mg/kg. In glutathione peroxidase (GPx), there were an inhibition of the activity in C. aurantium 400 and 2000 mg/kg and p-Synephrine 30 and 300 mg/kg treated animals, respectively, and was no alteration in malondialdehyde (MDA) levels. Thus, the results indicate a low subchronic toxicity of the tested materials in mice and a possible alteration in the oxidative metabolism. However, further tests are required to better elucidate the effects of these compounds in the antioxidant system.
-
screening for in vivo anti estrogenic activity of ephedrine and p Synephrine and their natural sources ephedra sinica stapf ephedraceae and citrus aurantium l rutaceae in rats
Archives of Toxicology, 2009Co-Authors: Marcelo Dutra Arbo, Eliane Dallegrave, Solange Cristina Garcia, Mirna Bainy Leal, Marcia Toniolo Franco, Elisa Rupp Larentis, Viviane Cristina Sebben, Renata Pereira LimbergerAbstract:Formulations containing Ephedra sinica Stapf. (Ephedraceae) and Citrus aurantium L. (Rutaceae) are consumed worldwide for body weight control. Considering the related adverse effects and the risk potential, the aim of this study is to evaluate the effects of the thermogenic compounds ephedrine, p-sinephrine, E. sinica and C. aurantium in the female reproductive system through the uterotrophic assay in immature female rats. The animals (n = 6-7) received E. sinica 85.5 and 855.0 mg/kg/day, C. aurantium 25.0 and 50.0 mg/kg/day, ephedrine 5.0 mg/kg/day and p-Synephrine 50.0 mg/kg/day for three consecutive days by oral gavage. For detection of antiestrogenicity, tamoxifen 20.0 mg/kg/day, E. sinica 855.0 mg/kg/day, C. aurantium 50.0 mg/kg/day, ephedrine 5.0 mg/kg/day and p-Synephrine 50.0 mg/kg/day were administered to estrogen-treated females. Macroscopical alterations were evaluated in liver, kidneys, adrenals and uterus. All analyzed substances showed an antiestrogenic potential, but only ephedrine at 0.5 mg/kg/day presented a significative antiestrogenic effect (P < 0.01). Adrenals relative mass were reduced (P < 0.01) in all tested compounds when compared to the control, which seems to be related to the alfa-1-adrenoceptor agonist activity, which promote a vasoconstriction and reduction of the liquid in the organ. The endocrine system is highly complex and there are a number of ways in which a chemical may interfere with it, other in vivo and in vitro assays are being necessary to support this mechanism of action.
