Chromatographic hair analysis for natural kavalactones and their metabolites. A preliminary study

Abstract

-Purpose: Kava is a traditional Pacific beverage made from the root of Piper methysticum. It is mainly used for its sedative properties due to lipophilic lactones called kavalactones. Kava action mechanisms include cell membrane stabilisation, inhibition of intracellular Ca 2+ increase and enzyme inactivation. Chronic or heavy consumption of kava is responsible for the skin taking on a scaly aspect. Biologically, an isolated increase in serum gamma-glutamyltransferase is noted. "Kava bars" or "nakamals" are numerous in the Pacific. In northern Australia, the use of kava is regulated in order to fight against the abuse of this drink. In metropolitan France, we note the presence of some kava bars in several cities. In New Caledonia, in ten years (December 2002-May 2013, we identified twenty-six cases where kavalactones were found in the blood of perpetrators or victims of fatal accidents (resulting in nineteen deaths and twenty-one people seriously injured), suicides and attacks. In addition, in nine cases of sudden unexplained deaths, significant concentrations of kavalactones were found in the blood of the victims. These figures, however, are understated as toxicological screening was not done systematically. As all toxicological laboratories are not identically equipped, we developed three simple and sensitive methods for the determination of kavalactones in human hair using HPLC-DAD, LC-MS/MS and GC/TOF-MS. Methods: Hair samples were collected from nine people of different origins (Caucasian, Melanesian, Indonesian and African). Kava consumption varied among these people (from a single oral dose of a medication sold on the internet, to a daily intake of several units of the kava beverage). Results: Using HPLC-DAD, the concentrations of kavalactones in human hair samples ranged between 0.2 and 25 ng/mg for kavain, 0.5 and 34 ng/mg for 7,8-dihydrokavain, 0.7 and 8 ng/mg for yangonin, 1 and 14 ng/mg for 5,6-dehydrokavain (=desmethyoxyyango-nin) and 0.9 and 6 ng/mg for the metabolite 12-hydroxy-5,6-dehydrokavain. Methysticin, 7,8-dihydromethysticin and the metabolite 11-hydroxy-5,6-dehydrokavain were detected but not quantified. Additionally, 12-hydroxykavain and 12-hydroxy-7,8-dihydrokavain were detected by LC-MS/MS in one case. General screening for other drugs as well as confirmation of the HPLC-DAD results was performed by GC/TOF-MS. Conclusions: The results of this pilot study indicate that kavalactones (kavain, 7,8-dihydrokavain, methysticin, 7,8-dihydromethysticin, 5,6-dehydrokavain (=desmethyoxyyangonin) and yangonin) accumulate in the keratin matrix of hair and can provide an easily applicable system for assessing chronic consumption of kava. This preliminary study must continue on a larger number of subjects using GC/TOF-MS and LC-MS/MS in order to conduct a comparative analysis among the three methods. Internet, à l'absorption quotidienne de plusieurs unités de boisson kava). Résultats : Déterminées par HPLC-DAD, les concentrations de kavalactones dans des échantillons de cheveux variaient de...

A stable isotope dilution tandem mass spectrometry method of major kavalactones and its applications

“…In summary, our method demonstrated a wider linear range for quantification (0.02–5 mg/g) and higher sensitivity (LOD: 27–155 pg/g) when employed to quantify kavalactones in kava products in comparison to previous methods (linear range: 0.25–1 mg/g; LOD: 0.5–1.1 μ g/mL) [ 31 , 34 , 35 , 50 , 51 ]. Similarly, previous pharmacokinetics study of kavain in rat needed 100 μ L plasma sample [ 14 ] while our method can quantify five kavalactones with 5 μ L serum or urine sample.…”

Kavain detection in post‐race equine urine sample: A case report

“…CONCLUSIONDuring routine screening analysis, 4 0 -hydroxy-kavain was detected in a post-race equine urine sample. Deeper inspection of the data allowed the detection of additional potential Phase I metabolites in urine which supported a kavain consumption as described in literature in human4 and associated putative sulfate Phase II metabolites. Moreover, qualitative analysis of the plasma sample supported the finding with the detection of kavain.…”

Kava ichthyosis: a nitric oxide synthase inhibition?

“…The GGT blood levels of the volunteers, originally twice the upper normal value (N < 43 UI/L), returned to normal after the abstinence period, as did the appearance of the skin. Kava consumption or non-consumption was verified by highperformance liquid chromatography of the volunteers' urine and hair according to the methods previously described [7,8].…”