Abstract:
Background: Khat contains more than 40 alkaloids, terpenoids, flavonoids, sterols, glycosides, tannins, amino acids and others. Among these alkaloids are two controlled substances, cathinone and cathine. Both cathinone and cathine are central nervous system (CNS) stimulants. Cathinone is much more potent than cathine and is only present in fresh leaves. Health risks attributed to cathinone include acute myocardial infarction and acute cerebral infarctions. The content of cathinone in Khat is unspecified and depends on several factors, such as the Khat variety, the time after its harvest, soil composition and the geographical location. Fresh Khat leaves usually contain a higher proportion of the desirable cathinone, but it is highly variable and it degrades rapidly and converts into cathine and norephedrine. The aim of this study is to estimate cathinone concentrations in fresh Khat leaves in an effort to use in predicting the degrading rate of its content before Khat is wilted.
Methods: Two data sets are considered in this study. The first data set was provided by the Biochemistry Department, Khat Research Unit, College of Science, Sana’a University, Yemen. Cathinone and tannic acid assays were performed spectrophotometrically and the concentrations of cathinone and tannic acid were extracted (Al-Qirbi [3]). For the second data, high-performance liquid chromatography (HPLC) method was used to determine the quantitative composition of Khat alkaloid extracts. Khatamines are extracted from Khat samples bought between 1982 and 1986 at the Khat markets of Addis Ababa in Ethiopia, Nairobi and Mombasa in Kenya, Sanaa in Yemen and Anivorano in Madagascar (Geisshusler and Brenneisen [14]). Regression techniques are used to estimate and predict cathinone concentrations in fresh Khat leaves. Two models are fitted. In the first model, cathine and norephedrine are used as explanatory variables, whereas in the second model, tannic acid is used.
Results: A (95% CI) for the mean cathinone content of 39 varieties of Yemeni Khat was (161.4-202.8) mg/Kg. Analysis for these data has shown that cathinone content is highly correlated with tannic acid and cathine. The Pearson correlation coefficient between cathinone and tannic acid is 0.997, whereas for the other data set, the correlation between cathinone and cathine is –0.959, and cathinone with norephedrine –0.501. and  for the best regression models identified are both 99.4.
Conclusion: The level of cathinone was assessed by using three explanatory variables; cathine, norephedrine, and tannic acid in two illustrative examples. Results indicate that cathinone content is predicted very well for all Khat varieties that are included in the two data sets. |
