Screening of Weight-Loss Herbal Products for Synthetic Anti-Obesity Adulterants: A Target-Oriented Analysis by Liquid Chromatography–Tandem Mass Spectrometry

Abstract

Background

The medical and social impact of being overweight, as well as the difficulty in making long-term changes in diet, physical activity, and pitfalls associated with allopathic management, lure obese individuals to over-the-counter weight-loss herbal products (WHPs). However, the safety of herbals is questionable, as reports from all over the world suggest adulteration with synthetic weight loss agents. Objective: The present study was carried out to develop a rapid and sensitive method to screen potential weight loss adulterants in WHPs. Methodology: We procured 33 licensed brands of WHPs that are available in Puducherry (India) and through web stores. Drug-free spiked herbal matrices were used for internal proficiency testing. Spiked herbal matrices and samples were extracted and centrifuged. The supernatant was collected and subjected to liquid chromatography–tandem mass spectrometry analyses. Isocratic elution was carried out by the mobile phase of methanol: 0.1% v/v formic acid (70%:30% v/v) through a C₁₈ column. Analytes were monitored in electrospray ionization positive and negative modes, and an multiple reaction monitoring (MRM) scan was used. Results: Run time was 12 min. Intra- and inter-day precision was < 15% and recoveries were in the range of 99% to 115%. Limit of quantification (LOQ) of the analytes were in the range of 0.1 to 0.3 ng/ml. Conclusion: We developed a sensitive and rapid validated method for the detection of potential adulterants in WHPs. None of the WHPs analyzed were found to contain adulterants. The proposed method will be useful for routine monitoring. WHPs analyzed in this study were not adulterated indicating that WHPs from licensed sources are reliable.

Keywords:

• Analytical method
• authentication
• dietary supplement
• herbal weight loss agents
• identity testing
• LC-MS/MS
• traditional Indian medicines

Acknowledgements

This study was funded by institutional intramural fund.

Disclosure of interest

The authors report no conflict of interest.

Additional information

Notes on contributors

P. Girish

P. Girish is pursuing a PhD in Pharmacology at JIPMER.

M. Jayanthi

M. Jayanthi, MD, DNB, Additional Professor of Pharmacology at Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry. Areas of interest: pharmacogenomics, pharmacovigilance, and medication safety.

B. Gitanjali

B. Gitanjali, MD, PhD, Director, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, India. Areas of interest: sleep medicine, medication safety, and rational use of drugs.

S. Manikandan

S. Manikandan, MD, Associate Professor of Pharmacology at JIPMER, Puducherry. Areas of interest: essential medicines, rational use of drugs, medication safety, and medical education.

S. Rajan

S. Rajan, M.Sc. Biotechnology, is a technical officer of Pharmacology at JIPMER. Areas of interest: molecular techniques and separation techniques.