Quantitative validation of nicotine production in tea (Camellia sinensis L.)

Cotinine levels influence the risk of rupture of brain aneurysms

Cotinine, the primary metabolite of nicotine, is currently regarded as the best biomarker of tobacco smoke exposure. We aim to assess whether cotinine levels are associated with (1) intracranial aneurysm and (2) intracranial aneurysm rupture.

METHODS

We performed a single-center case-control study. Cases were consecutive patients admitted with diagnosis of brain aneurysm (ruptured or unruptured). We randomly selected controls without intracranial aneurysm from the same source population that produced the cases. Smoking data were collected by questionnaire, and serum levels of cotinine were used as an objective measure of nicotine exposure. Logistic regression models were used to assess the relationship between cotinine levels and aneurysm rupture.

RESULTS

We included 86 patients with intracranial aneurysm and 96 controls. Smoking status (p < .001), cotinine levels (p = .009), and female sex (p = .006) were associated with diagnosis of intracranial aneurysm. In the multivariate analysis, controlling for sex, smoker status and age, levels of cotinine were independently associated with aneurysm rupture (OR 1.53, 95% CI 1.10-2.13, p = .012).

CONCLUSIONS

Our results suggest that high cotinine levels in smokers with brain aneurysm are significantly associated with high rupture risk, independently of smoker status, age, and sex.

Pretreatment and posttreatment in the biolistic transformation of tea plant (Camellia sinensis) somatic embryos

The tea plant (Camellia sinensis) contains various metabolic substances, including catechins and caffeine, for which genetic transformation techniques are essential for investigating the associated metabolic pathways. In this study, we sought to optimize the conditions and culture process for particle bombardment-mediated transformation of tea plant somatic embryos. We describe somatic embryo pretreatment for effective transient transformation in biolistic bombardment and the posttreatment conditions of somatic embryos for accelerating differentiation after bombardment. For the purpose of transformation, we used the somatic embryos of C. sinensis var. assamica 'Tingamira normal,' which were cultured in Murashige and Skoog (MS) medium containing 2 mg l^-1 indole-3-butyric acid (IBA) and 4 mg l^-1 6-benzyladenine (BA) at 25°C ±2°C under a 16-h photoperiod. With respect to the optimization of particle bombardment conditions for tea somatic embryos, we examined the effects of different Au colloid particle diameters and bombardment pressures, and accordingly established bombardment with 1.0-µm-diameter DNA-coated Au colloid at 1,100 psi as optimal conditions for introducing DNA for the transient expression of GUS. Additionally, we found that transplantation of tea somatic embryos from IBA/BA medium to a hormone-free medium prior to bombardment and incubation in the dark post-bombardment increased the frequency of secondary embryo production. Furthermore, osmotic treatment by culturing the somatic embryos in medium supplemented with 0.4 M mannitol improved transient transformation efficiency. After transformation, the culture of somatic embryos on filter papers or Kimwipes soaked in MS medium facilitated rapid and effective development of the somatic embryos.

HILIC HPLC-ESI-MS/MS identification and quantification of the alkaloids from the genus Equisetum

INTRODUCTION

The plant family Equisetaceae (Equisetopsida, Monilophyta; common name: horsetails) is part of an ancient group of spore producing plants. Today, Equisetum is the only surviving genus comprising 15 species in two subgenera (Equisetum and Hippochaete). Several unique alkaloids are described to occur in this genus, so far there is very little data on the occurrence and the amount of those alkaloids for the different species.

OBJECTIVE

To establish an extraction method and an analytical method to detect and quantify the relevant Equisetum-type alkaloids and to create a quantitative data set on the alkaloid content of all Equisetum species worldwide.

METHODOLOGY

Hydrophilic interaction liquid chromatography high-performance liquid chromatography tandem mass spectrometry (HILIC HPLC-MS/MS) in electrospray ionisation (ESI) positive mode was used to analyse and quantify the alkaloid content of 68 Equisetum samples.

RESULTS

The presence of nicotine in at least one sample of each Equisetum species could be demonstrated. The total nicotine amount rarely exceeded 250 μg/kg and 50 μg/kg for the subgenus Equisetum and Hippochaete, respectively. Besides nicotine, Equisetum-type alkaloids (mainly palustrine and palustridiene) were only detected in three species, namely E. palustre, E. bogotense and E. giganteum. For E. giganteum, palustridiene was detected at levels around the limit od detection (LoD) (25 μg/kg), whereas in E. palustre and E. bogotense, both alkaloids (palustrine and palustridiene) were detected at much higher levels (20-800 mg/kg).

CONCLUSIONS

All Equisetum species occurring worldwide were successfully subjected to a detailed qualitative and quantitative alkaloid analysis using a newly developed HILIC-HPLC-ESIpos-MS/MS approach. The data set can be used to distinguish different Equisetum-chemotypes.

Molecular mechanisms for nicotine intoxication

Nicotine, one of the more than 4700 ingredients in tobacco smoke, is a neurotoxin and once used as pesticides in agriculture. Although its use in agriculture is prohibited in many countries, nicotine intoxication is still a problem among the workers in tobacco farms, and young children as well as adults due to the accidental or suicidal ingestions of nicotine products. Understanding the mechanism of nicotine intoxication is important not only for the prevention and treatment but also for the appropriate regulatory approaches. Here, we review pharmacokinetics of nicotine and the molecular mechanisms for acute and chronic intoxication from nicotine that might be relevant to the central and the peripheral nervous system. We include green tobacco sickness, acute intoxication from popular nicotine products, circadian rhythm changes, chronic intoxication from nicotine through prenatal nicotine exposure, newborn behaviors, and sudden infant death syndrome.