Sink strength, nutrient allocation, cannabinoid yield and associated transcript profiles vary in two drug-type Cannabis chemovars.

Cannabis sativa L. is one of the oldest domesticated crops. Hemp-type cultivars, which predominantly produce non-intoxicating cannabidiol (CBD), have been selected for their fast growth, seed, and fibre production, while drug-type chemovars were bred for high accumulation of tetrahydrocannabinol (THC). We investigated how the generation of CBD-dominant chemovars by introgression of hemp- into drug-type Cannabis impacted plant performance. The THC-dominant chemovar showed superior sink strength, higher flower biomass and demand-driven control of nutrient uptake. By contrast, the CBD-dominant chemovar hyperaccumulated phosphate in sink organs leading to reduced carbon and nitrogen assimilation in leaves, which limited flower biomass and cannabinoid yield. RNA-seq analyses determined organ- and chemovar-specific differences in expression of genes associated with nitrate and phosphate homeostasis as well as growth-regulating transcription factors that were correlated with measured traits. Among these were genes positively selected for during Cannabis domestication encoding an inhibitor of the phosphate starvation response SPX DOMAIN GENE3, nitrate reductase and two nitrate transporters. Altered nutrient sensing, acquisition or distribution are likely a consequence of adaption to growth on marginal, low-nutrient input lands in hemp. Our data provide evidence that such ancestral traits may become detrimental for female flower development and consequently overall CBD yield in protected cropping environments.

Metabolomic analysis of methyl jasmonate treatment on phytocannabinoid production in Cannabis sativa.

Cannabis sativa is a multi-use and chemically complex plant which is utilized for food, fiber, and medicine. Plants produce a class of psychoactive and medicinally important specialized metabolites referred to as phytocannabinoids (PCs). The phytohormone methyl jasmonate (MeJA) is a naturally occurring methyl ester of jasmonic acid and a product of oxylipin biosynthesis which initiates and regulates the biosynthesis of a broad range of specialized metabolites across a number of diverse plant lineages. While the effects of exogenous MeJA application on PC production has been reported, treatments have been constrained to a narrow molar range and to the targeted analysis of a small number of compounds. Using high-resolution mass spectrometry with data-dependent acquisition, we examined the global metabolomic effects of MeJA in C. sativa to explore oxylipin-mediated regulation of PC biosynthesis and accumulation. A dose-response relationship was observed, with an almost two-fold increase in PC content found in inflorescences of female clones treated with 15 mM MeJA compared to the control group. Comparison of the inflorescence metabolome across MeJA treatments coupled with targeted transcript analysis was used to elucidate key regulatory components contributing to PC production and metabolism more broadly. Revealing these biological signatures improves our understanding of the role of the oxylipin pathway in C. sativa and provides putative molecular targets for the metabolic engineering and optimization of chemical phenotype for medicinal and industrial end-uses.

Biosynthetic origins of unusual cannabimimetic phytocannabinoids in Cannabis sativa L: A review.

Plants of Cannabis sativa L. (Cannabaceae) produce an array of more than 160 isoprenylated resorcinyl polyketides, commonly referred to as phytocannabinoids. These compounds represent molecules of therapeutic importance due to their modulation of the human endocannabinoid system (ECS). While understanding of the biosynthesis of the major phytocannabinoids Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) has grown rapidly in recent years, the biosynthetic origin and genetic regulation of many potentially therapeutically relevant minor phytocannabinoids remain unknown, which limits the development of chemotypically elite varieties of C. sativa. This review provides an up-to-date inventory of unusual phytocannabinoids which exhibit cannabimimetic-like activities and proposes putative metabolic origins. Metabolic branch points exploitable for combinatorial biosynthesis and engineering of phytocannabinoids with augmented therapeutic activities are also described, as is the role of phytocannabinoid remodelling to accelerate the therapeutic portfolio expansion in C. sativa.

Immunomodulatory Polysaccharide from Chlorophytum borivilianum Roots.

Chlorophytum borivilianum Santapau & Fernandes (Liliaceae) is an ayurvedic Rasayana herb with immunostimulating properties. The polysaccharide fraction (CBP) derived from hot water extraction of C. borivilianum (CB), comprising of ∼31% inulin-type fructans and ∼25% acetylated mannans (of hot water-soluble extract), was evaluated for its effect on natural killer (NK) cell activity (in vitro). Human peripheral blood mononuclear cells (PBMCs), isolated from whole blood on a Ficoll-Hypaque density gradient, were tested in the presence or absence of varying concentrations of each C. borivilianum fraction for modulation of NK cell cytotoxic activity toward K562 cells. Preliminary cytotoxicity evaluation against P388 cells was performed to establish non-cytotoxic concentrations of the different fractions. Testing showed the observed significant stimulation of NK cell activity to be due to the CBP of C. borivilianum. Furthermore, in vivo evaluation carried out on Wistar strain albino rats for humoral response to sheep red blood cells (SRBCs) and immunoglobulin-level determination using enzyme-linked immunosorbent assay (ELISA), exhibited an effectiveness of C. borivilianum aqueous extract in improving immune function. Present results provide useful information for understanding the role of CBP in modulating immune function.

Twelve-Week Mediterranean Diet Intervention Increases Citrus Bioflavonoid Levels and Reduces Inflammation in People with Type 2 Diabetes Mellitus.

The benefits of a Mediterranean Diet (MedDiet) in the management of diabetes have been reported, but the contribution of polyphenol-rich citrus fruit has not been studied widely. Here, we report the sub-study findings of a previously conducted MedDiet intervention clinical trial in patients with type 2 diabetes mellitus (T2DM), where we aimed to measure the diet intervention effects on plasma citrus bioflavonoids levels and biomarkers of inflammation and oxidative stress. We analysed plasma samples from 19 (of original 27) participants with T2DM who were randomly assigned to consume the MedDiet intervention or their usual diet for 12 weeks and then crossed over to the alternate diet. Compared with baseline, MedDiet significantly increased levels of the citrus bioflavonoids naringin, hesperitin and hesperidin (by 60%, 58% and 39%, respectively, p < 0.05) and reduced plasma levels of the pro-inflammatory cytokine IL-6 (by 49%, p = 0.016). Oxidative stress marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) decreased by 32.4% (p = 0.128). Usual diet did not induce these beneficial changes. The reduced inflammatory profile of T2DM participants may, in part, be attributed to the anti-inflammatory actions of citrus bioflavonoids. Together with indications of improved oxidative stress, these findings add to the scientific evidence base for beneficial consumption of citrus fruit in the MedDiet pattern.

Diarylheptanoid from Pleuranthodium racemigerum with in vitro prostaglandin E(2) inhibitory and cytotoxic activity.

Bioactivity-guided fractionation of an ethanolic extract of the rhizome of Pleuranthodium racemigerum, a tropical Zingiberaceae species from Northeastern Australia, resulted in the isolation and structural elucidation of 1-(4''-methoxyphenyl)-7-(4'-hydroxyphenyl)-(E)-hept-2-ene (1), a new diarylheptanoid related to curcumin. Compound 1 was a fairly potent inhibitor of prostaglandin E(2) production in 3T3 murine fibroblasts (IC(50) approximately 34 microM) and also displayed moderate cytotoxicity against this cell line (IC(50) = 52.8 microM). The compound also demonstrated cytotoxic activity against the P388D1 murine lymphoblast cell line (IC(50) = 117.0 microM) and four human cell lines: Caco-2 colonic adenocarcinoma (IC(50) = 44.8 microM), PC3 prostate adenocarcinoma (IC(50) = 23.6 microM), HepG2 hepatocyte carcinoma (IC(50) = 40.6 microM), and MCF7 mammary adenocarcinoma (IC(50) = 56.9 microM). The cytotoxicity of compound 1 closely resembled that of curcumin, in terms of both IC(50) values and dose-response curves.

Antioxidant activity and polyphenol composition of sugarcane molasses extract.

The antioxidant activity of sugarcane molasses ethanol extract (ME) and its fraction (ME-RBF) was evaluated using ABTS, ORAC 6.0 and CAA assays and ME-RBF demonstrated 26-fold, 12-fold and 2-fold higher values, respectively than ME. Likewise, total polyphenol and flavonoid concentration in ME-RBF are more than 10-fold higher than ME, that suggested antioxidant activity is correlated with polyphenol composition. Quantitative analysis of 13 polyphenols (chlorogenic acid, caffeic acid, sinapic acid, syringic acid, vanillin, homoorientin, orientin, vitexin, swertisin, diosmin, apigenin, tricin and diosmetin) was carried out by LCMS. MS/MS analysis allowed the tentative identification of seven apigenin-C-glycosides, three methoxyluteolin-C-glycosides and three tricin-O-glycosides some of which have not been reported in sugarcane before to the best of our knowledge. The results demonstrated that sugarcane molasses can be used as potential source of polyphenols that can be beneficial to health.

Utilisation of Design of Experiments Approach to Optimise Supercritical Fluid Extraction of Medicinal Cannabis.

Carbon dioxide supercritical fluid extraction (CO2 SFE) is a clean and cost-effective method of extracting cannabinoids from cannabis. Using design of experiment methodologies an optimised protocol for extraction of medicinal cannabis bud material (population of mixed plants, combined THC:CBD approximately 1:1.5) was developed at a scale of one kg per extraction. Key variables investigated were CO2 flow rate, extraction time and extraction pressure. A total of 15 batches were analysed for process development using a two-level, full factorial design of experiments for three variable factors over eleven batches. The initial eleven batches demonstrated that CO2 flow rate has the most influence on the overall yield and recovery of the key cannabinoids, particularly CBD. The additional four batches were conducted as replicated runs at high flow rates to determine reproducibility. The highest extraction weight of 71 g (7.1%) was obtained under high flow rate (150 g/min), with long extraction time (600 min) at high pressure (320 bar). This method also gave the best recoveries of THC and CBD. This is the first study to report the repeated extraction of large amounts of cannabis (total 15 kg) to optimise the CO2 SFE extraction process for a pharmaceutical product.

Development of a validated method for the qualitative and quantitative analysis of cannabinoids in plant biomass and medicinal cannabis resin extracts obtained by super-critical fluid extraction.

The social push for the therapeutic use of cannabis extracts has increased significantly over recent years. Cannabis is being used for treatment for conditions such as epilepsy, cancer and pain management. There are a range of medicinal cannabis products available, but the use of cannabis resin obtained by super critical fluid extraction, often diluted in oil, is becoming increasingly more prominent. Much of the research on cannabis has focused on plant biomass or the final therapeutic product with a concerning lack of information on the intermediate resin. This study aims to bridge the gap between current methods of analysis for biomass and the final therapeutic product by describing a fully developed and validated ultra-high-performance-liquid-chromatography method with diode array detection (UHPLC-DAD) for the qualification and quantification of the cannabinoids CBDA, CBD, CBN, THC, CBC and THCA, in medicinal cannabis biomass and resin obtained by super-critical fluid extraction (SFE). The method was validated for specificity, linearity, limit of detection (LOD), limit of quantitation (LOQ), precision, accuracy, robustness, spike recovery and stability in accordance with the Validation of Analytical Procedures: Text and Methodology Q2 to meet the requirements of the International Council for Harmonisation (ICH), Therapeutic Goods Authority (TGA) and the Food and Drug Administration (FDA) test method validation regulations.

Toxic Indole Diterpenes from Endophyte-Infected Perennial Ryegrass Lolium perenne L.: Isolation and Stability.

The most potent of the indole diterpenes, lolitrem B, is found in perennial ryegrass (Lolium perenne L.) infected with the endophyte Epichloë festucae var. lolii (also termed LpTG-1). Ingestion causes a neurological syndrome in grazing livestock called ryegrass staggers disease. To enable the rapid development of new forage varieties, the toxicity of lolitrem B and its biosynthetic intermediates needs to be established. However, most of these indole diterpenes are not commercially available; thus, isolation of these compounds is paramount. A concentrated endophyte-infected perennial ryegrass seed extract was subjected to silica flash chromatography followed by preparative HPLC and purification by crystallization resulting in lolitrem B and the intermediate compounds lolitrem E, paspaline and terpendole B. The four-step isolation and purification method resulted in a 25% yield of lolitrem B. After isolation, lolitrem B readily degraded to its biosynthetic intermediate, lolitriol. We also found that lolitrem B can readily degrade depending on the solvent and storage conditions. The facile method which takes into consideration the associated instability of lolitrem B, led to the purification of indole diterpenes in quantities sufficient for use as analytical standards for identification in pastures, and/or for toxicity testing in pasture development programs.

Novel polyketide metabolites from Streptomyces rimosus mutant strain R1059.

Three novel polyketide metabolites were isolated from laboratory-scale fermentation of the Streptomyces rimosus mutant strain R1059. Structural elucidation of the compounds was based on NMR experiments. The compounds were characterized as naphthalene derivatives: (rel)-4beta,8-dihydroxy-3alpha-hydroxymethyl-4alpha-methyl-1,2,3,4-tetrahydronaphthalene1-one (1), 4xi8-dihydroxy-3-hydroxymethyl-4xi-methyl-1,4-dihydronaphthalene-1-one (2) and (rel)-4beta,8-dihydroxy-3alpha-O-[alpha-glucopyranosyl]hydroxymethyl-4alpha-methyl-1,2,3,4-tetrahydronaphthalene-1-one (3). The compounds isolated appear to be derived via a shorter polyketide backbone than oxytetracycline (4), the normal end-product made by the parent of this strain. Compound 3 was the glucoside of 1 and must be formed as a post-PKS reaction by the activation of a glycosyl transferase, which has not been reported in this species before.

The Leaf Essential Oil of Eugenia reinwardtiana Growing in Australia.

The leaf essential oils of the two chemotypes of Eugenia reinwardtiana (Blume) DC growing in Australia have been investigated. Chemotype 1, isolated in 0.2% yield, w/w, dry weight, contained major amounts of α-pinene (10-26%), limonene (1-15%), ß-caryophyllene (0.7-11%), α-humulene (0.9-16%) and bicyclogermacrene (1-23%). The second chemotype, found only on coastal dunes SW of Lockerbie Qld, and isolated in 0.4-0.6% (w/w, dry weight), contained α-pinene (tr-8.5%) ß-caryophyllene (12-27%) and α-humulene (1-17%) as the major terpenes. This chemotype also contained the novel aliphatic diketone, 2-butyl-2,4,4-trimethyl-5-methoxycyclohex-5-en-1,3-dione (18-33%), whose structure determination is reported herein.

Characterization and in vitro immunomodulatory screening of fructo-oligosaccharides of Asparagus racemosus Willd.

Asparagus racemosus Linn. (Fam. Liliaceae) is an ethno-pharmacologically acclaimed Ayurvedic medicinal plant. In the present study, aqueous extract of A. racemosus (ARC) was fractionated and screened for the polysaccharide fraction (ARP). The characterization was done by enzymatic, Size Exclusion, gas chromatography with flame ionization detector (GC-FID), high pressure anion exchange chromatography (HPAEC) and thin layer chromatographic analyses. Phyto-chemical evaluation confirmed the presence of 26.7% of 2→1 linked fructo-oligosaccharides (FOS). They have a degree of polymerization (DP) of nearly 7-8. Cytotoxicity evaluation on P388 cell lines was consistent with low cytotoxicity of the extracts. In vitro Natural Killer (NK) cell activity was evaluated using human peripheral blood mononuclear cells (PBMC) isolated from whole blood on a ficoll-hypaque density gradient. K562 a myeloid leukemia cell line, were used as target cells. ARC, tested over the range 0.2-50 µg/ml, showed a dose-related stimulation of NK cell activity with a peak increase of 16.9±4.4% at 5.6 µg/ml. However, ARP demonstrated a higher stimulatory activity of 51.8±1.2% at 25 µg/ml. The results indicate that the FOS from A. racemosus potentiates the NK cell activity and this could be an important mechanism underpinning the 'Rasayana' properties of this plant.