Development and Validation of a GC-FID Method for the Quantitation of Δ 8-Tetrahydrocannabinol and Impurities Found in Synthetic Δ 8-Tetrahydrocannabinol and Vaping Products.

Concerns about health hazards associated with the consumption of trans-delta-8-tetrahydrocannabinol products were highlighted in public health advisories from the U. S. Food and Drug Administration and U. S. Centers for Disease Control and Prevention. Simple and rapid quantitative methods to determine trans-delta-8-tetrahydrocannabinol impurities are vital to analyze such products. In this study, a gas chromatography-flame ionization detection method was developed and validated for the determination of delta-8-tetrahydrocannabinol and some of its impurities (recently published) found in synthesized trans-delta-8-tetrahydrocannabinol raw material and included olivetol, cannabicitran, Δ 8-cis-iso-tetrahydrocannabinol, Δ 4-iso-tetrahydrocannabinol, iso-tetrahydrocannabifuran, cannabidiol, Δ 4,8-iso-tetrahydrocannabinol, Δ 8-iso-tetrahydrocannabinol, 4,8-epoxy-iso-tetrahydrocannabinol, trans-Δ 9-tetrahydrocannabinol, 8-hydroxy-iso-THC, 9α-hydroxyhexahydrocannabinol, and 9ß-hydroxyhexahydrocannabinol. Validation of the method was assessed according to the International Council for Harmonization guidelines and confirmed linearity with R2 ≥ 0.99 for all the target analytes. The limit of detection and limit of quantitation were 1.5 and 5 µg/mL, respectively, except for olivetol, which had a limit of detection of 3 µg/mL and a limit of quantitation of 10 µg/mL. Method precision was calculated as % relative standard deviation and the values were less than 8.4 and 9.9% for the intraday precision and inter-day precision, respectively. The accuracy ranged from 85 to 118%. The method was then applied to the analysis of 21 commercially marketed vaping products claiming to contain delta-8-tetrahydrocannabinol. The products analyzed by this method have various levels of these impurities, with all products far exceeding the 0.3% of trans-Δ 9-tetrahydrocannabinol limit for hemp under the Agriculture Improvement Act of 2018. The developed gas chromatography-flame ionization detection method can be an important tool for monitoring delta-8-tetrahydrocannabinol impurities in commercial products.

Quality specifications for articles of botanical origin from the United States Pharmacopeia.

BACKGROUND: In order to define appropriate quality of botanical dietary supplements, botanical drugs, and herbal medicines, the United States Pharmacopeia (USP) and the Herbal Medicines Compendium (HMC) contain science-based quality standards that include multiple interrelated tests to provide a full quality characterization for each article in terms of its identity, purity, and content. PURPOSE: To provide a comprehensive description of the pharmacopeial tests and requirements for articles of botanical origin in the aforementioned compendia. Selective chromatographic procedures, such as high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC), are used as Identification tests in pharmacopeial monographs to detect species substitution or other confounders. HPLC quantitative tests are typically used to determine the content of key constituents, i.e., the total or individual amount of plant secondary metabolites that are considered bioactive constituents or analytical marker compounds. Purity specifications are typically set to limit the content of contaminants such as toxic elements, pesticides, and fungal toxins. Additional requirements highlight the importance of naming, definition, use of reference materials, and packaging/storage conditions. METHODS: Technical requirements for each section of the monographs were illustrated with specific examples. Tests were performed on authentic samples using pharmacopeial reference standards. The chromatographic analytical procedures were validated to provide characteristic profiles for the identity and/or accurate determination of the content of quality markers. RESULTS: The multiple tests included in each monograph complement each other to provide an appropriate pharmacopeial quality characterization for the botanicals used as herbal medicines and dietary supplements. The monographs provide detailed specifications for identity, content of bioactive constituents or quality markers, and limits of contaminants, adulterants, and potentially toxic substances. Additional requirements such as labeling and packaging further contribute to preserve the quality of these products. CONCLUSION: Compliance with pharmacopeial specifications should be required to ensure the reliability of botanical articles used for health care purposes.

Alvaradoins E-N, antitumor and cytotoxic anthracenone C-glycosides from the leaves of Alvaradoa haitiensis.

Bioactivity-directed fractionation of an extract of the leaves of Alvaradoa haitiensis, using the KB (human oral epidermoid carcinoma) cell line, led to the isolation and identification of 10 new anthracenone C-glycosides, alvaradoins E-N (1-10), along with the known compound chrysophanol (11). The cytotoxicity of all compounds was evaluated, and preliminary structure-activity relationships are suggested. The most potent compounds in the in vitro assays (1 and 2) were evaluated in vivo versus the P388 (murine lymphocytic leukemia) model, and alvaradoin E (1) showed antileukemic activity (125% T/C) at a dose of 0.2 mg kg-1 per injection when administered intraperitoneally.

Anti-proliferative effect of horehound leaf and wild cherry bark extracts on human colorectal cancer cells.

Marubium vulgare (horehound) and Prunus serotina (wild cherry) have been traditionally used for the treatment of inflammatory-related symptoms such as cold, fever, and sore throat. In this report, we show that extracts of anti-inflammatory horehound leaves and wild cherry bark exhibit anti-proliferative activity in human colorectal cancer cells. Both horehound and wild cherry extracts cause suppression of cell growth as well as induction of apoptosis. We found that horehound extract up-regulates pro-apoptotic non-steroidal anti-inflammatory drug-activated gene (NAG-1) through transactivation of the NAG-1 promoter. In contrast, wild cherry extract decreased cyclin D1 expression and increased NAG-1 expression in HCT-116 and SW480 cell lines. Treatment with wild cherry extract resulted in the suppression of beta-catenin/T cell factor transcription, as assessed by TOP/FOP reporter constructs, suggesting that suppressed beta-catenin signaling by wild cherry extract leads to the reduction of cyclin D1 expression. Our data suggest the mechanisms by which these extracts suppress cell growth and induce apoptosis involve enhanced NAG-1 expression and/or down-regulation of beta-catenin signaling, followed by reduced cyclin D1 expression in human colorectal cancer cells. These findings may provide mechanisms for traditional anti-inflammatory products as cancer chemopreventive agents.

Milk thistle and prostate cancer: differential effects of pure flavonolignans from Silybum marianum on antiproliferative end points in human prostate carcinoma cells.

Extracts from the seeds of milk thistle, Silybum marianum, are known commonly as silibinin and silymarin and possess anticancer actions on human prostate carcinoma in vitro and in vivo. Seven distinct flavonolignan compounds and a flavonoid have been isolated from commercial silymarin extracts. Most notably, two pairs of diastereomers, silybin A and silybin B and isosilybin A and isosilybin B, are among these compounds. In contrast, silibinin is composed only of a 1:1 mixture of silybin A and silybin B. With these isomers now isolated in quantities sufficient for biological studies, each pure compound was assessed for antiproliferative activities against LNCaP, DU145, and PC3 human prostate carcinoma cell lines. Isosilybin B was the most consistently potent suppressor of cell growth relative to either the other pure constituents or the commercial extracts. Isosilybin A and isosilybin B were also the most effective suppressors of prostate-specific antigen secretion by androgen-dependent LNCaP cells. Silymarin and silibinin were shown for the first time to suppress the activity of the DNA topoisomerase IIalpha gene promoter in DU145 cells and, among the pure compounds, isosilybin B was again the most effective. These findings are significant in that isosilybin B composes no more than 5% of silymarin and is absent from silibinin. Whereas several other more abundant flavonolignans do ultimately influence the same end points at higher exposure concentrations, these findings are suggestive that extracts enriched for isosilybin B, or isosilybin B alone, might possess improved potency in prostate cancer prevention and treatment.

Analysis of herbal teas made from the leaves of comfrey (Symphytum officinale): reduction of N-oxides results in order of magnitude increases in the measurable concentration of pyrrolizidine alkaloids.

OBJECTIVES: To determine the relative quantities of two hepatotoxic pyrrolizidine alkaloids, symphytine and echimidine, in teas prepared from comfrey leaves (Symphytum officinale), and to determine the potential contribution of the N-oxide forms of these alkaloids to levels of the parent alkaloids. DESIGN: Comfrey leaves were purchased from three commercial sources and used to prepare tea in a manner consistent with the methods used by consumers. An extraction scheme was devised for extraction of the alkaloids, and a gas chromatographic method was developed to quantify the two major alkaloids, symphytine and echimidine. Recognising that the N-oxide derivatives of these alkaloids have also been identified in comfrey preparations, chemical reduction was applied to determine the total quantities of the alkaloids as free bases and as N-oxide derivatives. RESULTS: The concentration of symphytine and echimidine varied considerably between teas prepared from leaves purchased from the different vendors of plant material. Moreover, a much higher concentration of symphytine was found in the tea when steps were included to reduce N-oxides prior to analysis. The treatment of pure symphytine with hot water did not generate the N-oxide derivative de novo. CONCLUSIONS: Since the pyrrolizidine alkaloids are known to be hepatotoxic, consumption of herbal teas made from comfrey leaves may be ill-advised. The concentration of pyrrolizidine alkaloids in such teas may be underestimated substantially unless the concentration of N-oxides is taken into consideration.

Cytotoxic prenylated xanthones and the unusual compounds anthraquinobenzophenones from Cratoxylum sumatranum.

Six new xanthones, cratoxyarborenones A-F (1-6), were isolated from the leaves, twigs, and/or stem bark of Cratoxylum sumatranum along with the known compound, vismione B (9), as active constituents by bioassay-directed fractionation using the KB human cancer cell line cytotoxicity assay. In addition, two novel anthraquinobenzophenones, cratoxyarborequinones A (7) and B (8), and two known compounds, 2,4,6-trihydroxybenzophenone 4-O-geranyl ether and delta-tocotrienol, were obtained as inactive constituents.