Kavain

Carfentanil in Impaired Driving Cases and the Importance of Drug Seizure Data.[Pubmed:29659874]

J Anal Toxicol. 2018 Sep 1;42(7):476-484.

Drug seizures containing carfentanil continue to increase in Palm Beach County, FL, USA despite international efforts to control the distribution of the drug. The analysis of drug seizures from the county in 2016 and 2017 demonstrated that carfentanil was the most commonly identified fentanyl analog and was most often detected in combination with heroin, fentanyl, furanyl fentanyl and/or other fentanyl analogs. Carfentanil is an ultra-potent opioid requiring a method with adequate sensitivity for detection in blood specimens from impairment cases. Previous research indicated that carfentanil could not be identified in biological specimens by routine drug testing protocols and that detection requires targeted analysis with greater sensitivity. Due to the prevalence of carfentanil in drug seizures, a sensitive targeted qualitative method by liquid chromatography tandem mass spectrometry in antemortem blood samples was evaluated, validated and implemented. The method included identification of carfentanil, acetyl fentanyl, beta-hydroxythiofentanyl, butyryl fentanyl, fentanyl, furanyl fentanyl, Kavain, mitragynine, MT-45 and U-47700. In 2017 carfentanil was the second most frequently detected drug, after ethanol, in driving under the influence blood cases. Of all blood cases in which drug testing was performed (n = 145), carfentanil was detected in 38% followed by alprazolam (29%), fentanyl (27%), delta-9-tetrahydrocannabinol (24%) and morphine (23%). In toxicology cases carfentanil was rarely identified alone (only four cases) and was most commonly identified with other opioids (73% of cases), benzodiazepines (43%) and stimulants (29%). The high incidence of carfentanil-positive cases detected by this method underscores the importance of continually monitoring regional drug seizure trends, and evaluating the adequacy of toxicology testing panels based on these trends.

Characterization of three small molecule inhibitors of enterovirus 71 identified from screening of a library of natural products.[Pubmed:28412182]

Antiviral Res. 2017 Jul;143:85-96.

Enterovirus 71 (EV-A71) is a major cause of hand, foot, and mouth disease (HFMD). Infection with EV-A71 is more often associated with neurological complications in children and is responsible for the majority of fatalities, but currently there is no approved antiviral therapy for treatment. Here, we identified auraptene, formononetin, and yangonin as effective inhibitors of EV-A71 infection in the low-micromolar range from screening of a natural product library. Among them, formononetin and yangonin selectively inhibited EV-A71 while auraptene could inhibit viruses within the enterovirus species A. Time of addition studies showed that all the three inhibitors inhibit both attachment and postattachment step of entry. We found mutations conferring the resistance to these inhibitors in the VP1 and VP4 capsid proteins and confirmed the target residues using a reverse genetic approach. Interestingly, auraptene- and formononetin-resistant viruses exhibit cross-resistance to other inhibitors while yangonin-resistant virus still remains susceptible to auraptene and formononetin. Moreover, auraptene and formononetin, but not yangonin protected EV-A71 against thermal inactivation, indicating a direct stabilizing effect of both compounds on virion capsid conformation. Finally, neither biochanin A (an analog of formononetin) nor DL-Kavain (an analog of yangonin) exhibited anti-EV-A71 activity, suggesting the structural elements required for anti-EV-A71 activity. Taken together, these compounds could become potential lead compounds for anti-EV-A71 drug development and also serve as tool compounds for studying virus entry.

A Behavioral Survey of the Effects of Kavalactones on Caenorhabditis elegans Neuromuscular Transmission.[Pubmed:28615969]

J Exp Neurosci. 2017 Jun 5;11:1179069517705384.

Kava is a plant root extract that is widely consumed by Pacific Islanders. Kava contains a class of lactone compounds called kavalactones. The sedative and anxiolytic effects of kava are likely attributed to the efficacies of kavalactones on the nervous system. Although some studies have implicated the potencies of certain kavalactone species on gamma-aminobutyric acid transmission, evidence supporting the action of kavalactones on the eukaryotic neuromuscular junction (NMJ) and acetylcholine (ACh) transmission is scant. Here, we used behavioral assays to demonstrate the effects of kavalactones at the Caenorhabditis elegans NMJ. Our results suggest that kavalactones disrupt the inhibitory-excitatory balance at the NMJ. Such perturbation of NMJ activity is likely due to excess or prolonged ACh transmission. In addition, we found that Kavain, a major constituent of kava, induced worm paralysis but not convulsions. Hence, the modulatory action of Kavain could be distinct from the other kavalactone species.

Quantitative Determination of Lactones in Piper methysticum (Kava-Kava) by Supercritical Fluid Chromatography.[Pubmed:28095587]

Planta Med. 2017 Aug;83(12-13):1053-1057.

A fast and validated supercritical fluid chromatography method for the quantitative determination of major lactones in Piper methysticum, a plant used against nervous anxiety, stress, and restlessness, was developed. The baseline separation of dihydroKavain, demethoxyyangonin, Kavain, yangonin, dihydromethysticin, and methysticin was possible in less than 4 min on an Aquity UPC(2) BEH 1.7 microm column, in combination with a mobile phase comprising CO2 and methanol with diethylamine. The column temperature had a great impact on the results because only at 70 degrees C could Kavain and yangonin be fully resolved. With correlation coefficients above 0.998, recovery rates between 95.9 and 104.1 % as well as limit of detection values below 1.5 ng on-column, the procedure fulfilled all validation requirements and was well suited for the quantitative analysis of commercial products containing P. methysticum root powder and/or extract. All of them contained the target analytes, however, the absolute content of lactones was quite variable. Accordingly, depending on the product, the total daily intake of lactones varied from 56 to 312 mg. Concerning speed, selectivity, and environmental friendly operation, this supercritical fluid chromatography approach surpasses all previously reported ones.

Kavain, the Major Constituent of the Anxiolytic Kava Extract, Potentiates GABAA Receptors: Functional Characteristics and Molecular Mechanism.[Pubmed:27332705]

PLoS One. 2016 Jun 22;11(6):e0157700.

Extracts of the pepper plant kava (Piper methysticum) are effective in alleviating anxiety in clinical trials. Despite the long-standing therapeutic interest in kava, the molecular target(s) of the pharmacologically active constituents, kavalactones have not been established. gamma-Aminobutyric acid type A receptors (GABAARs) are assumed to be the in vivo molecular target of kavalactones based on data from binding assays, but evidence in support of a direct interaction between kavalactones and GABAARs is scarce and equivocal. In this study, we characterised the functional properties of the major anxiolytic kavalactone, Kavain at human recombinant alpha1beta2, beta2gamma2L, alphaxbeta2gamma2L (x = 1, 2, 3 and 5), alpha1betaxgamma2L (x = 1, 2 and 3) and alpha4beta2delta GABAARs expressed in Xenopus oocytes using the two-electrode voltage clamp technique. We found that Kavain positively modulated all receptors regardless of the subunit composition, but the degree of enhancement was greater at alpha4beta2delta than at alpha1beta2gamma2L GABAARs. The modulatory effect of Kavain was unaffected by flumazenil, indicating that Kavain did not enhance GABAARs via the classical benzodiazepine binding site. The beta3N265M point mutation which has been previously shown to profoundly decrease anaesthetic sensitivity, also diminished Kavain-mediated potentiation. To our knowledge, this study is the first report of the functional characteristics of a single kavalactone at distinct GABAAR subtypes, and presents the first experimental evidence in support of a direct interaction between a kavalactone and GABAARs.

The involvement of Kav001 in inhibition of LPS/P. gingivalis-induced.[Pubmed:29637600]

J Cell Biochem. 2018 Jul;119(7):6072-6079.

TNF-a is an important cytokine mediator of inflammation which suggests that inhibition of TNF activity may provide potential for clinical application. Recent data indicated that treatment of both human and mouse cells with Kavain significantly modulates P. gingivalis- and LPS-induced TNF-alpha expression. In order to obtain a selective analog with optimized biological activity and structural physico-chemical properties of Kavain, Kavain analogs were designed and synthesized and found one Kavain analogue (named Kav001) that is similar to Kavain but soluble and does not induce a significant toxicity. Both studies in vitro and in vivo treatment by Kav001 showed stronger biological function as compared to Kavain. Furthermore, most mouse bone marrow macrophages up-regulated Bcl-6 while down-regulating LITAF expression after treatment with Kav001 for 36 h. Consequently, this led to an extension of macrophage pseudopods due to its immune response to P.g. infection/LPS stimulation.