Investigating volatiles as the secondary metabolome of Piper methysticum from root powder and water extracts using comprehensive two-dimensional gas chromatography.

ETHNOPHARMACOLOGICAL RELEVANCE: Kava (Piper methysticum G. Forst) is a plant grown in the Pacific that is used in traditional medicines. The roots are macerated and powdered for consumption as a beverage in social settings as well as in ceremonies. Other types of preparations can also be used as traditional medicines. There has been an increase in demand for kava as there is continued traditional use and as it is becoming utilized more both socially and medicinally outside of Oceania. Currently, most research of this plant has focused on bioactive kavalactones and flavokawains, and there are few studies focusing on the other compounds that kava contains, such as volatile and semivolatile components. AIM OF THE STUDY: This study investigated the kava volatile organic compound (VOC) profile from nine different commercially available samples of dried, powdered kava root sourced across the Pacific region. MATERIALS AND METHODS: The headspace above the kava samples was analyzed, both from the root powder as originally purchased and by performing a scaled-down extraction into water mimicking traditional preparation of the beverage. The headspace of each sample was extracted using solid-phase microextraction arrow (SPME Arrow), followed by analysis using comprehensive two-dimensional gas chromatography - quadrupole mass spectrometry/flame ionization detection (GC×GC-qMS/FID). The superior peak capacity of GC×GC was invaluable in effectively separating the complex mixture of compounds found in all samples, which enabled improved monitoring of minor differences between batches. RESULTS: Dry root powder samples contained high levels of ß-caryophyllene while water extracted samples showed high levels of camphene. Many alcohols, aldehydes, ketones, terpenes, terpenoids, and aromatics were also characterized from both types of samples. All water extracted samples from the different brands followed similar trends in terms of compounds being detected or not. Additional major compounds found in water extracts included benzaldehyde, hexanal, methoxyphenyloxime, camphor, limonene, 1-hexanol, endoborneol, and copaene. While some samples could be differentiated based on brand, samples did not group by purported geographic origin. CONCLUSIONS: This study provides foundational data about a different subset of compounds within kava than previous research has studied, and also informs the community of the compounds that transfer into the consumed beverage during the traditional means of preparing kava.

A non-targeted data processing workflow for volatile organic compound data acquired using comprehensive two-dimensional gas chromatography with dual channel detection.

There has been an influx of technology for comprehensive two-dimensional gas chromatography analyses in recent years, calling for development of guided workflows and rigorous reporting of processes. This research focuses on the processing method for data collected on a dual channel detection system using flame ionization detection (FID) and quadrupole mass spectrometry (qMS) for the analysis of volatile organic compounds (VOCs). The samples analyzed were kava (Piper methysticum), which has a rich VOC profile that benefits substantially from a multidimensional approach due to enhanced peak capacity. The procedure which was customized here was the data processing workflow from a manual single-sample analysis to an integrated batch workflow that can be applied across studies.•Parameter choice for baseline correction and peak detection were defined when handling batch data.•Elution regions were defined using qMS data to automate compound identification.•Stencils were transformed onto FID data and sequenced for quantitative information.This dataset can be used as a training tool, as all details, methods and results for the workflow have been provided for users to compare with. The focus on data workflow reproducibility in the field of multidimensional chromatography will assist in adoption by users in new application areas.

A chemical test of critical point isomorphism: reactive dissolution of ionic solids in isobutyric acid + water near the consolute point.

Binary liquid mixtures having a consolute point can be used as solvents for chemical reactions. When excess cerium(IV) oxide is brought into equilibrium with a mixture of isobutyric acid + water, and the concentration of cerium in the liquid phase is plotted in van't Hoff form, a straight line results for temperatures sufficiently in excess of the critical solution temperature. Within 1 K of the critical temperature, however, the concentration becomes substantially suppressed, and the van't Hoff slope diverges toward negative infinity. According to the phase rule, one mole fraction can be fixed. Given this restriction, the temperature behavior of the data is in exact agreement with the predictions of both the principle of critical point isomorphism and the Gibbs-Helmholtz equation. In addition, we have determined the concentration of lead in the liquid phase when crystalline lead(II) sulfate reacts with potassium iodide in isobutyric acid + water. When plotted in van't Hoff form, the data lie on a straight line for all temperatures including the critical region. The phase rule indicates that two mole fractions can be fixed. With this restriction, the data are in exact agreement with the principle of critical point isomorphism.

Contemporary Pacific and Western perspectives on `awa (Piper methysticum) toxicology.

In 2010, a National Science Foundation project in Hawai`i assembled a collaboration of Pacific indigenous scientists, Hawaiian cultural practitioners and scientists trained in Western pharmacology. The objective of the collaborative project was to study Kava, a culturally significant Pacific beverage, and to address and ultimately transcend, long-standing barriers to communication and collaboration between these groups. Kava is a product of the `awa plant (Piper methysticum) that has been used ceremonially and medicinally throughout the history of Pacific Island cultures, and is now in widespread recreational and nutraceutical use in the US. This project, culminating in 2015, has enriched the participants, led to published work that integrates cultural and Western pharmacologic perspectives and established a paradigm for collaboration. This review paper integrates cultural and Western perspectives on efficacy, toxicity and the future cultural and commercial significance of `awa in the Pacific. Here we present a detailed review of traditional and non-traditional kava usage, medicinal efficacy and potential toxicological concerns. Recent mechanistic data on physiological action and potential pathological reactions are evaluated and interpreted.

Tradition and toxicity: evidential cultures in the kava safety debate.

This paper examines the debate about the safety of kava (Piper methysticum Forst. f, Piperaceae), a plant native to Oceania, where it has a long history of traditional use. Kava became popular as an anti-anxiety treatment in Western countries in the late 1990s, but it was subsequently banned in many places due to adverse reports of liver toxicity. This paper focuses on the responses to the bans by scientists involved in kava research, contrasting their evidential culture with that employed by clinicians and regulatory officials. Cultural constructions and social negotiations of risk are shown to be context-specific, and are shaped by professional, disciplinary, and organizational factors, among others. Though the science of hepatotoxicity is uncertain enough to allow for multiple interpretations of the same data, the biomedical/clinical narrative about kava remains dominant. This case study explores the influence of these cultural, social, and political factors on the production of scientific knowledge and the assessment of benefit/risk posed by comestibles.

Cycle training increased GLUT4 and activation of mammalian target of rapamycin in fast twitch muscle fibers.

PURPOSE: To determine whether cycle training of sedentary subjects would increase the expression of the principle muscle glucose transporters, six volunteers completed 6 wk of progressively increasing intensity stationary cycle cycling. METHODS: In vastus lateralis muscle biopsies, changes in expression of GLUT1, GLUT4, GLUT5, and GLUT12 were compared using quantitative immunoblots with specific protein standards. Regulatory pathway components were evaluated by immunoblots of muscle homogenates and immunohistochemistry of microscopic sections. RESULTS: GLUT1 was unchanged, GLUT4 increased 66%, GLUT12 increased 104%, and GLUT5 decreased 72%. A mitochondrial marker (cytochrome c) and regulators of mitochondrial biogenesis (peroxisome proliferator-activated receptor gamma coactivator 1 alpha and phospho-5'-adenosine monophosphate-activated protein kinase) were unchanged, but the muscle hypertrophy pathway component, phospho-mammalian target of rapamycin (mTOR), increased 83% after the exercise program. In baseline biopsies, GLUT4 by immunohistochemical techniques was 37% greater in Type I (slow twitch, red) muscle fibers, but the exercise training increased GLUT4 expression in Type II (fast twitch, white) fibers by 50%, achieving parity with the Type I fibers. Baseline phospho-mTOR expression was 50% higher in Type II fibers and increased more in Type II fibers (62%) with training but also increased in Type I fibers (34%). CONCLUSION: Progressive intensity stationary cycle training of previously sedentary subjects increased muscle insulin-responsive glucose transporters (GLUT4 and GLUT12) and decreased the fructose transporter (GLUT5). The increase in GLUT4 occurred primarily in Type II muscle fibers, and this coincided with activation of the mTOR muscle hypertrophy pathway. There was little impact on Type I fiber GLUT4 expression and no evidence of change in mitochondrial biogenesis.

Traditional kava beverage consumption and liver function tests in a predominantly Tongan population in Hawaii.

PURPOSE: To determine the effects of traditionally prepared kava beverages on the liver function tests of regular kava beverage consumers in a population of Tongan and non-Tongan residents of Hawaii (Oahu). METHODS: The liver function tests of 31 healthy adult kava drinkers were compared against a control group of 31 healthy adult non-kava drinkers. Subjects were recruited from the general population, a kava bar, and Tongan kava drinking circles. The liver function profile included AST, ALT, ALP, GGT, and bilirubin (total and direct). Other tests included total protein, albumin, and screens for viral hepatitis and hemochromatosis when indicated. RESULTS: Chronic kava beverage consumption was associated with elevation of GGT in 65% of the kava drinkers versus 26% in the controls (P = .005). ALP was elevated in 23% of kava drinkers versus 3% in the controls (P = .053). CONCLUSION: Heavy kava beverage consumption was associated with significantly elevated GGT levels.