LC-MS/MS measurement of alkaloids in alkaline extracts of Areca nut preparations and their physiological effects

Betel quid (BQ) containing Piper betle leaf (L), green unripe Areca catechu nut (AN) and slaked lime (Ca(OH)2) is an addictive carcinogenic stimulant, with no pharmacotherapy, chewed by millions of people in Asia. We measured the effect of the constituents of slaked lime, NaOH and Ca(OH)2, on the levels of endogenous alkaloids in aqueous extracts of AN alone and L+AN (LAN) using UHPLC-MS/MS. Alkaloid levels in AN and LAN extracts were arecoline> >guvacoline>arecaidine>guvacine. In vitro hydrolyzation of extracts of AN and LAN by NaOH or Ca(OH)2, as occurs in vivo when BQ is chewed, dose-dependently decreased levels of muscarinic esters, arecoline (maximum 65%↓) and guvacoline (maximum 69%↓), and increased carboxylic acid GABA uptake inhibitors, arecaidine (maximum 275%↑) and guvacine (maximum 18%↑). In five volunteers, chewing BQ but not LAN, increased heart rate (maximum 19b/min), forehead temperature (maximum 1 °C), facial flushing and sweating, all symptoms of BQ stimulation. Hydrolysis of compounds in LAN is necessary to induce stimulant effects. Levels of arecoline, considered to mediate stimulant and addictive properties of BQ, negatively correlate with the physiological stimulant effects while levels of GABA uptake inhibitors positively correlate. Unripe, green AN warrants investigation as replacement therapy in the treatment of BQ substance use disorder.