A Targeted and an Untargeted Metabolomics Approach to Study the Phytochemicals of Tomato Cultivars Grown Under Different Salinity Conditions

In this study, we evaluated the effect of increasing the salinity of irrigation water on the metabolic content and profiles of two tomato cultivars ('Jaune Flamme' (JF) and 'Red Pear' (RP)) using targeted and untargeted metabolomics approaches. Irrigation of tomato plants was performed with four different salt concentrations provided by chloride (treatment 1) and sulfate (treatment 2) salts. Targeted analysis of the methanolic extract resulted in the identification of nine major polyphenols. Among them, chlorogenic acid, rutin, and naringenin were the prominent compounds in both cultivars. In addition, the quantification of 18 free amino acids from both tomato cultivars showed that different salinity treatments significantly enhanced the levels of glutamine, glutamic acid, and γ-aminobutyric acid (GABA). Using the untargeted metabolomic approach, we identified 129 putative metabolites encompassing a diverse array of phytochemicals including polyphenols, organic acids, lipids, sugars, and amino acids. Principal component analysis (PCA) of mass spectral data acquired under positive and negative ionization modes showed a clear separation between the two cultivars. However, only positive ionization showed separation among different salinity treatments. Unsupervised and supervised learning algorithms were applied to mine the generated data and to pinpoint metabolites different from the two cultivars. These findings suggest that different salinity conditions significantly influenced the accumulation of phytochemicals in tomato cultivars. This study will help tomato breeding programs to develop value-added tomato cultivars under varying environmental conditions.

Understanding the salt overly sensitive pathway in Prunus: Identification and characterization of NHX, CIPK, and CBL genes

Salinity is a major abiotic stress factor that can significantly impact crop growth, and productivity. In response to salt stress, the plant Salt Overly Sensitive (SOS) signaling pathway regulates the homeostasis of intracellular sodium ion concentration. The SOS1, SOS2, and SOS3 genes play critical roles in the SOS pathway, which belongs to the members of Na+/H+ exchanger (NHX), CBL-interacting protein kinase (CIPK), and calcineurin B-like (CBL) gene families, respectively. In this study, we performed genome-wide identifications and phylogenetic analyses of NHX, CIPK, and CBL genes in six Rosaceae species: Prunus persica, Prunus dulcis, Prunus mume, Prunus armeniaca, Pyrus ussuriensis × Pyrus communis, and Rosa chinensis. NHX, CIPK, and CBL genes of Arabidopsis thaliana were used as controls for phylogenetic analyses. Our analysis revealed the lineage-specific and adaptive evolutions of Rosaceae genes. Our observations indicated the existence of two primary classes of CIPK genes: those that are intron-rich and those that are intron-less. Intron-rich CIPKs in Rosaceae and Arabidopsis can be traced back to algae CIPKs and CIPKs found in early plants, suggesting that intron-less CIPKs evolved from their intron-rich counterparts. This study identified one gene for each member of the SOS signaling pathway in P. persica: PpSOS1, PpSOS2, and PpSOS3. Gene expression analyses indicated that all three genes of P. persica were expressed in roots and leaves. Yeast two-hybrid-based protein-protein interaction analyses revealed a direct interaction between PpSOS3 and PpSOS2; and between PpSOS2 and PpSOS1C-terminus region. Our findings indicate that the SOS signaling pathway is highly conserved in P. persica.

Dissemination of antibiotic resistance genes through soil-plant-earthworm continuum in the food production environment

Treated municipal wastewater (TMW) can provide a reliable source of irrigation water for crops, which is especially important in arid areas where water resources are limited or prone to drought. Nonetheless, TMW may contain residual antibiotics, potentially exposing the crops to these substances. The goal of this study was to investigate the dissemination of antibiotics resistance genes (ARGs) in the soil-plant-earthworm continuum after irrigation of spinach and radish plants with TMW containing trimethoprim, sulfamethoxazole, and sulfapyridine in a greenhouse experiment, followed by feeding of earthworms with harvested plant materials. Our results showed that antibiotic resistance genes (ARGs) were enriched in the soil-plant-earthworm microbiomes irrigated with TMW and TMW spiked with higher concentrations of antibiotics. The number of ARGs and antibiotic-resistant bacteria (ARB) enrichment varied with plant type, with spinach harboring a significantly higher amount of ARGs and ARB compared to radish. Our data showed that bulk and rhizosphere soils of spinach and radish plants irrigated with MilliQ water, TMW, TMW10, or TMW100 had significant differences in bacterial community (p < 0.001), ARG (p < 0.001), and virulence factor gene (VFG) (p < 0.001) diversities. The abundance of ARGs significantly decreased from bulk soil to rhizosphere to phyllosphere and endosphere. Using metagenome assembled genomes (MAGs), we recovered many bacterial MAGs and a near complete genome (>90 %) of bacterial MAG of genus Leclercia adecarboxylata B from the fecal microbiome of earthworm that was fed harvested radish tubers and spinach leaves grown on TMW10 irrigated waters, and this bacterium has been shown to be an emerging pathogen causing infection in immunocompromised patients that may lead to health complications and death. Therefore, crops irrigated with TMW containing residual antibiotics and ARGs may lead to increased incidences of enrichment of ARB in the soil-plant-earthworm continuum.

Combined effects of Limonene and Ivermectin on P-glycoprotein-9 gene expression of lambs Infected with Haemonchus contortus

Although ivermectin (IVM) has a wide spectrum and long half-life, its frequent use as an anthelmintic for the last 42 years led to its worldwide tolerance by Haemonchus contortus. We evaluated the combination of limonene (LIM), a P-glycoprotein (Pgp) modulator, with IVM in lambs infected with a multidrug-resistant H. contortus. Twenty-four male Dorper lambs were artificially infected with two doses (seven days apart) of 8000 infective larvae of a multidrug-resistant isolate of H. contortus. The infection was patent 25 days later. Fifteen days before treatment with IVM (DAY -15), animals were divided into 4 groups: Infected-untreated control (CTL), IVM, LIM, and LIM+IVM. From DAY -15 to DAY + 14, groups LIM and LIM+IVM received 200 mg/kg of body weight/day of LIM via oral. On DAY 0, a single dose of IVM at 200 µg/kg of body weight was administered orally to groups IVM and LIM+IVM. On DAY + 7 and DAY + 14, fecal egg counts (FEC) were performed and on DAY + 14 animals were euthanized for total worm count (TWC), worm length, fecundity of females, and Pgp-9 gene expression. On DAY + 7, group LIM+IVM had 96.29% efficacy based on Fecal Egg Count Reduction TEST (FECRT) and a highly significant reduction in FEC (P = 0.0005) when compared to CTL. On DAY + 14, the efficacy of LIM+IVM was 82.87% on FECRT, although no differences were found among groups for FEC, TWC, worm length, or Pgp-9 gene expression. Female worms from the CTL group had higher egg counts in their uterus when compared to LIM. No differences were found for hematological or biochemical parameters, body weight, or weight gain among groups. Thus, LIM given daily at 200 mg/kg was safe for animals and, when combined with IVM, decreased egg shedding and could reduce pasture contamination, although it was unable to kill multidrug-resistant H. contortus.

Plant phase extraction: A method for enhanced discovery of the RNA-binding proteome and its dynamics in plants

RNA-binding proteins (RBPs) play critical roles in posttranscriptional gene regulation. Current methods of systematically profiling RBPs in plants have been predominantly limited to proteins interacting with polyadenylated (poly(A)) RNAs. We developed a method called plant phase extraction (PPE), which yielded a highly comprehensive RNA-binding proteome (RBPome), uncovering 2,517 RBPs from Arabidopsis (Arabidopsis thaliana) leaf and root samples with a highly diverse array of RNA-binding domains. We identified traditional RBPs that participate in various aspects of RNA metabolism and a plethora of nonclassical proteins moonlighting as RBPs. We uncovered constitutive and tissue-specific RBPs essential for normal development and, more importantly, revealed RBPs crucial for salinity stress responses from a RBP-RNA dynamics perspective. Remarkably, 40% of the RBPs are non-poly(A) RBPs that were not previously annotated as RBPs, signifying the advantage of PPE in unbiasedly retrieving RBPs. We propose that intrinsically disordered regions contribute to their nonclassical binding and provide evidence that enzymatic domains from metabolic enzymes have additional roles in RNA binding. Taken together, our findings demonstrate that PPE is an impactful approach for identifying RBPs from complex plant tissues and pave the way for investigating RBP functions under different physiological and stress conditions at the posttranscriptional level.

Dissemination of antibiotics through the wastewater-soil-plant-earthworm continuum

Under the ongoing climate change scenario, treated municipal wastewater (TMW) is a potential candidate for irrigated agriculture but may result in the exposure of agricultural environments to antibiotics. We studied the transfers of trimethoprim, sulfamethoxazole, and sulfapyridine in the TMW-soil-plant-earthworm continuum under greenhouse/laboratory conditions. Irrigation of potted spinach and radish with as-collected TMW resulted in no transfers of antibiotics into soil or plants owing to their low concentrations in the tertiary-treated TMW. However, TMW spiked with higher antibiotic concentrations led to transfers through this continuum. High initial inputs, slow soil degradation, and chemical speciation of the antibiotics, coupled with an extensive plant-root distribution, were important factors enhancing the plant uptake of antibiotics. In microcosm studies, transfers from vegetable materials into earthworms were low but showed potential for bioaccumulation. Such food chain transfers of antibiotics may be a driver for antibiotic resistance in agricultural systems, which is an area worthy of future study. These issues can perhaps be mitigated through high levels of TMW purification to effectively remove antibiotic compounds.

Morphological, physiological, biochemical, and transcriptome studies reveal the importance of transporters and stress signaling pathways during salinity stress in Prunus

The almond crop has high economic importance on a global scale, but its sensitivity to salinity stress can cause severe yield losses. Salt-tolerant rootstocks are vital for crop economic feasibility under saline conditions. Two commercial rootstocks submitted to salinity, and evaluated through different parameters, had contrasting results with the survival rates of 90.6% for 'Rootpac 40' (tolerant) and 38.9% for 'Nemaguard' (sensitive) under salinity (Electrical conductivity of water = 3 dS m^-1). Under salinity, 'Rootpac 40' accumulated less Na and Cl and more K in leaves than 'Nemaguard'. Increased proline accumulation in 'Nemaguard' indicated that it was highly stressed by salinity compared to 'Rootpac 40'. RNA-Seq analysis revealed that a higher degree of differential gene expression was controlled by genotype rather than by treatment. Differentially expressed genes (DEGs) provided insight into the regulation of salinity tolerance in Prunus. DEGs associated with stress signaling pathways and transporters may play essential roles in the salinity tolerance of Prunus. Some additional vital players involved in salinity stress in Prunus include CBL10, AKT1, KUP8, Prupe.3G053200 (chloride channel), and Prupe.7G202700 (mechanosensitive ion channel). Genetic components of salinity stress identified in this study may be explored to develop new rootstocks suitable for salinity-affected regions.

Deciphering Molecular Mechanisms Involved in Salinity Tolerance in Guar (Cyamopsis tetragonoloba (L.) Taub.) Using Transcriptome Analyses

Guar is a commercially important legume crop known for guar gum. Guar is tolerant to various abiotic stresses, but the mechanisms involved in its salinity tolerance are not well established. This study aimed to understand molecular mechanisms of salinity tolerance in guar. RNA sequencing (RNA-Seq) was employed to study the leaf and root transcriptomes of salt-tolerant (Matador) and salt-sensitive (PI 340261) guar genotypes under control and salinity. Our analyses identified a total of 296,114 unigenes assembled from 527 million clean reads. Transcriptome analysis revealed that the gene expression differences were more pronounced between salinity treatments than between genotypes. Differentially expressed genes associated with stress-signaling pathways, transporters, chromatin remodeling, microRNA biogenesis, and translational machinery play critical roles in guar salinity tolerance. Genes associated with several transporter families that were differentially expressed during salinity included ABC, MFS, GPH, and P-ATPase. Furthermore, genes encoding transcription factors/regulators belonging to several families, including SNF2, C₂H₂, bHLH, C3H, and MYB were differentially expressed in response to salinity. This study revealed the importance of various biological pathways during salinity stress and identified several candidate genes that may be used to develop salt-tolerant guar genotypes that might be suitable for cultivation in marginal soils with moderate to high salinity or using degraded water.

Linking genetic determinants with salinity tolerance and ion relationships in eggplant, tomato and pepper

The Solanaceae family includes commercially important vegetable crops characterized by their relative sensitivity to salinity. Evaluation of 8 eggplant (Solanum melongena), 7 tomato (Solanum lycopersicum), and 8 pepper (Capsicum spp.) heirloom cultivars from different geographic regions revealed significant variation in salt tolerance. Relative fruit yield under salt treatment varied from 52 to 114% for eggplant, 56 to 84% for tomato, and 52 to 99% for pepper. Cultivars from all three crops, except Habanero peppers, restricted Na transport from roots to shoots under salinity. The high salt tolerance level showed a strong association with low leaf Na concentration. Additionally, the leaf K-salinity/K-control ratio was critical in determining the salinity tolerance of a genotype. Differences in relative yield under salinity were regulated by several component traits, which was consistent with the gene expression of relevant genes. Gene expression analyses using 12 genes associated with salt tolerance showed that, for eggplant and pepper, Na⁺ exclusion was a vital component trait, while sequestration of Na⁺ into vacuoles was critical for tomato plants. The high variability for salt tolerance found in heirloom cultivars helped characterize genotypes based on component traits of salt tolerance and will enable breeders to increase the salt tolerance of Solanaceae cultivars.

Influence of seasonal changes and salinity on spinach phyllosphere bacterial functional assemblage

The phyllosphere is the aerial part of plants that is exposed to different environmental conditions and is also known to harbor a wide variety of bacteria including both plant and human pathogens. However, studies on phyllosphere bacterial communities have focused on bacterial composition at different stages of plant growth without correlating their functional capabilities to bacterial communities. In this study, we examined the seasonal effects and temporal variabilities driving bacterial community composition and function in spinach phyllosphere due to increasing salinity and season and estimated the functional capacity of bacterial community16S V4 rRNA gene profiles by indirectly inferring the abundance of functional genes based on metagenomics inference tool Piphillin. The experimental design involved three sets of spinach (Spinacia oleracea L., cv. Racoon) grown with saline water during different seasons. Total bacteria DNA from leaf surfaces were sequenced using MiSeq® Illumina platform. About 66.35% of bacteria detected in the phyllosphere were dominated by four phyla- Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. Permutational analysis of variance (PERMANOVA) showed that phyllosphere microbiomes were significantly (P < 0.003) affected by season, but not salinity (P = 0.501). The most abundant inferred functional pathways in leaf samples were the amino acids biosynthesis, ABC transporters, ribosome, aminoacyl-tRNA biosynthesis, two-component system, carbon metabolism, purine metabolism, and pyrimidine metabolism. The photosynthesis antenna proteins pathway was significantly enriched in June leaf samples, when compared to March and May. Several genes related to toxin co-regulated pilus biosynthesis proteins were also significantly enriched in June leaf samples, when compared to March and May leaf samples. Therefore, planting and harvesting times must be considered during leafy green production due to the influence of seasons in growth and proliferation of phyllosphere microbial communities.

Germination and Growth of Spinach under Potassium Deficiency and Irrigation with High-Salinity Water

Information is scarce on the interaction of mineral deficiency and salinity. We evaluated two salt-tolerant spinach cultivars under potassium (K) doses (0.07, 0.15, 0.3, and 3.0 mmol_c L^-1) and saline irrigation (5, 30, 60, 120, and 160 mmol_c L^-1 NaCl) during germination and growth. There was no interaction between salinity and K. Salinity decreased germination percent (GP), not always significantly, and drastically reduced seedling biomass. 'Raccoon' significantly increased GP at 60 mmol_c L^-1 while 'Gazelle' maintained GP up to 60 or 120 mmol_c L^-1. After 50 days under saline irrigation, shoot biomass increased significantly at 30 and 60 mmol_c L^-1 at the lowest K dose but, in general, neither salinity nor K dose affected shoot biomass, suggesting that salinity supported plant growth at the most K-deficient dose. Salinity did not affect shoot N, P, or K but significantly reduced Ca, Mg, and S, although plants had no symptoms of salt toxicity or mineral deficiency. Although spinach seedlings are more sensitive to salt stress, plants adjusted to salinity with time. Potassium requirement for spinach growth was less than the current crop recommendation, allowing its cultivation with waters of moderate to high salinity without considerable reduction in yield, appearance, or mineral composition.

Functional relationships between aboveground and belowground spinach (Spinacia oleracea L., cv. Racoon) microbiomes impacted by salinity and drought

Salinity is a major problem facing agriculture in arid and semiarid regions of the world. This problem may vary among seasons affecting both above- and belowground plant microbiomes. However, very few studies have been conducted to examine the influence of salinity and drought on microbiomes and on their functional relationships. The objective for the study was to examine the effects of salinity and drought on above- and belowground spinach microbiomes and evaluate seasonal changes in their bacterial community composition and diversity. Furthermore, potential consequences for community functioning were assessed based on 16S V4 rRNA gene profiles by indirectly inferring the abundance of functional genes based on results obtained with Piphillin. The experiment was repeated three times from early fall to late spring in sand tanks planted with spinach (Spinacia oleracea L., cv. Racoon) grown with saline water of different concentrations and provided at different amounts. Proteobacteria, Cyanobacteria, and Bacteroidetes accounted for 77.1% of taxa detected in the rhizosphere; Proteobacteria, Bacteroidetes, and Actinobacteria accounted for 55.1% of taxa detected in soil, while Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria accounted for 55.35% of taxa detected in the phyllosphere. Salinity significantly affected root microbiome beta-diversity according to weighted abundances (p = 0.032) but had no significant effect on the relative abundances of microbial taxa (p = 0.568). Pathways and functional genes analysis of soil, rhizosphere, and phyllosphere showed that the most abundant functional genes were mapped to membrane transport, DNA repair and recombination, signal transduction, purine metabolism, translation-related protein processing, oxidative phosphorylation, bacterial motility protein secretion, and membrane receptor proteins. Monoterpenoid biosynthesis was the most significantly enriched pathway in rhizosphere samples when compared to the soil samples. Overall, the predictive abundances indicate that, functionally, the rhizosphere bacteria had the highest gene abundances and that salinity and drought affected the above- and belowground microbiomes differently.

Spinach Plants Favor the Absorption of K+ over Na+ Regardless of Salinity, and May Benefit from Na+ When K+ is Deficient in the Soil

Two spinach (Spinacea oleracea L.) cultivars were evaluated for their response to deficient (0.25 mmolc L-1 or 0.25 K) and sufficient (5.0 mmolc L-1 or 5.0 K) potassium (K) levels combined with salinities of 5, 30, 60, 90, and 120 mmolc L-1 NaCl. Plants substituted K for Na proportionally with salinity within each K dose. Plants favored K+ over Na+, regardless of salinity, accumulating significantly less Na at 5.0 K than at 0.25 K. Salinity had no effect on N, P, and K shoot accumulation, suggesting that spinach plants can maintain NPK homeostasis even at low soil K. Ca and Mg decreased with salinity, but plants showed no deficiency. There was no Na+ to K+ or Cl- to NO3- competition, and shoot biomass decrease was attributed to excessive NaCl accumulation. Overall, 'Raccoon' and 'Gazelle' biomasses were similar regardless of K dose but 'Raccoon' outproduced 'Gazelle' at 5.0 K at the two highest salinity levels, indicating that 'Raccoon' may outperform 'Gazelle' at higher NaCl concentrations. At low K, Na may be required by 'Raccoon', but not 'Gazelle'. This study suggested that spinach can be cultivated with recycled waters of moderate salinity, and less potassium than recommended, leading to savings on crop input and decreasing crop environmental footprint.

Expression of the high-affinity K+ transporter 1 (PpHKT1) gene from almond rootstock 'Nemaguard' improved salt tolerance of transgenic Arabidopsis

Soil salinity affects plant growth and development, which directly impact yield. Plants deploy many mechanisms to cope with, or mitigate, salt stress. One of such mechanism is to control movement of ions from root to shoot by regulating the loading of Na⁺ in the transpiration stream. The high-affinity K⁺ transporter 1 (HKT1) is known to play a role in the removal of Na⁺ from the xylem and bring it back to the root. As almond is a salt-sensitive crop, the rootstock plays an important role in successful almond cultivation in salt-affected regions. We currently lack knowledge on the molecular mechanisms involved in salt tolerance of almond rootstocks. In this study, we complemented the Arabidopsis athkt1 knockout mutant with HKT1 ortholog (PpHKT1) from the almond rootstock ‘Nemaguard’. Arabidopsis transgenic lines that were generated in athkt1 background with the constitutive promoter (PpHKT1OE2.2) and the native promoter (PpHKT1NP6) were subjected to different salt treatments. Both transgenic lines survived salt concentrations up to 120 mM NaCl, however, the mutant athkt1 died after 18 days under 120 mM NaCl. At 90 mM NaCl, the dry weight of athkt1 decreased significantly compared to the transgenic lines. Both transgenic lines showed significantly longer lateral roots compared to the athkt1 mutant at 80 mM NaCl treatment. The transgenic lines, PpHKT1OE2.2 and PpHKTNP6 had lower electrolyte leakage and higher relative water content compared to athkt1, suggesting that transgenic plants coped well with increased salt concentration by maintaining the integrity of the membranes. The expression analyses showed that PpHKT1 was induced in PpHKT1OE2.2 and PpHKTNP6 lines under salt treatment, which confirmed that both over-expression and native expression of PpHKT1 in the Arabidopsis mutant can complement salt tolerance function.

Evaluation of encapsulated anethole and carvone in lambs artificially- and naturally-infected with Haemonchus contortus

Molecules from natural sources, such as essential oils, have shown activity against parasites in vitro, but have not yet been explored extensively in vivo. Anethole and carvone (10% each), encapsulated with 80% of a solid matrix, referred to as EO (encapsulated oils), were tested in vivo in 2 experiments. In Experiment 1: Lambs were artificially infected with multidrug resistant Haemonchus contortus, or left uninfected, and treated (or not) with 50 mg/kg bw (body weight) of EO in a controlled environment. Thirty-two male lambs were kept in individual cages for a period of 45 days, after which animals were evaluated for parasitological, hematological, toxicological, and nutritional parameters. After 45 days of treatment, EO at 50 mg/kg bw provided a significant (P ≤ 0.05) reduction in fecal egg count (FEC). Although FEC was reduced, animals from both treatments had similar counts of total adult worms. The low FEC was caused probably by a significant reduction (P ≤ 0.05) in both male worm size and female fecundity. Dry matter intake of uninfected controls was significantly (P ≤ 0.05) reduced, although no toxicity was observed in treated animals. Thus, in Experiment 2, conducted for five months we used an EO dose of 20 mg/kg bw. Thirty-four weaned lambs, free of parasites, were divided in two groups and kept in collective pens. One group received EO at 20 mg/kg bw mixed with concentrate for 5 months and the other was kept as a control group (CTL). Parasitological and hematological parameters as well as body weight were evaluated. In the first 2.5 months, CTL and EO groups were confined, and both presented similar clinical parameters. Then, animals were allotted to graze on contaminated pastures to acquire natural infection for the next 2.5 months. The infection was patent after 25 days and both groups had similar decreases in weight gain, increases in FEC, and decreases in blood parameters. Coprocultures from CTL and EO groups established that parasite population was 90% Haemonchus sp. We concluded that the technology of encapsulation is safe and practical to deliver to lambs at the farm level and anethole and carvone at 50 mg/kg bw caused a significant decrease in FEC and, consequently, in pasture contamination by free living stages of H. contortus. However, EO at 20 mg/kg bw was not effective to prevent or treat sheep naturally-infected with gastrointestinal nematodes.

Inclusion complex and nanoclusters of cyclodextrin to increase the solubility and efficacy of albendazole

Albendazole (ABZ), a benzimidazole widely used to control gastrointestinal parasites, is poorly soluble in water, resulting in variable and incomplete bioavailability. This has favored the appearance ABZ-resistant nematodes and, consequently, an increase in its clinical ineffectiveness. Among the pharmaceutical techniques developed to increase drug efficacy, cyclodextrins (CDs) and other polymers have been extensively used with water-insoluble pharmaceutical drugs to increase their solubility and availability. Our objective was to prepare ABZ formulations, including β-cyclodextrin (βCD) or hydroxypropyl-β-cyclodextrin (HPβCD), associated or not to the water-soluble polymer polyvinylpyrrolidone (PVP). These formulations had their solubility and anthelmintic effect both evaluated in vitro. Also, their anthelmintic efficacy was evaluated in lambs naturally infected with gastrointestinal nematodes (GIN) through the fecal egg count (FEC) reduction test. In vitro, the complex ABZ/HPβCD had higher solubility than ABZ/βCD. The addition of PVP to the complexes increased solubility and dissolution rates more effectively for ABZ/HPβCD than for ABZ/βCD. In vivo, 48 lambs naturally infected with GIN were divided into six experimental groups: control, ABZ, ABZ/βCD, ABZ/βCD-PVP, ABZ/HPβCD, and ABZ/HPβCD-PVP. Each treated animal received 10 mg/kg of body weight (based on the ABZ dose) for three consecutive days. After 10 days of the last administered dose, treatment efficacy was calculated. The efficacy values were as follows: ABZ (70.33%), ABZ/βCD (85.33%), ABZ/βCD-PVP (82.86%), ABZ/HPβCD (78.37%), and ABZ/HPβCD-PVP (43.79%). In vitro, ABZ/HPβCD and ABZ/HPβCD-PVP had high solubility and dissolution rates. In vivo, although the efficacies of ABZ/βCD, ABZ/βCD-PVP, and ABZ/HPβCD increased slightly when compared to pure ABZ, this increase was not significant (P > 0.05).

Selection and Clonal Propagation of High Artemisinin Genotypes of Artemisia annua

Artemisinin, produced in the glandular trichomes of Artemisia annua L. is a vital antimalarial drug effective against Plasmodium falciparum resistant to quinine-derived medicines. Although work has progressed on the semi-synthetic production of artemisinin, field production of A. annua remains the principal commercial source of the compound. Crop production of artemisia must be increased to meet the growing worldwide demand for artemisinin combination therapies (ACTs) to treat malaria. Grower artemisinin yields rely on plants generated from seeds from open-pollinated parents. Although selection has considerably increased plant artemisinin concentration in the past 15 years, seed-generated plants have highly variable artemisinin content that lowers artemisinin yield per hectare. Breeding efforts to produce improved F₁ hybrids have been hampered by the inability to produce inbred lines due to self-incompatibility. An approach combining conventional hybridization and selection with clonal propagation of superior genotypes is proposed as a means to enhance crop yield and artemisinin production. Typical seed-propagated artemisia plants produce less than 1% (dry weight) artemisinin with yields below 25 kg/ha. Genotypes were identified producing high artemisinin levels of over 2% and possessing improved agronomic characteristics such as high leaf area and shoot biomass production. Field studies of clonally-propagated high-artemisinin plants verified enhanced plant uniformity and an estimated gross primary productivity of up to 70 kg/ha artemisinin, with a crop density of one plant m^-2. Tissue culture and cutting protocols for the mass clonal propagation of A. annua were developed for shoot regeneration, rooting, acclimatization, and field cultivation. Proof of concept studies showed that both tissue culture-regenerated plants and rooted cutting performed better than plants derived from seed in terms of uniformity, yield, and consistently high artemisinin content. Use of this technology to produce plants with homogeneously-high artemisinin can help farmers markedly increase the artemisinin yield per cultivated area. This would lead to increased profit to farmers and decreased prices of ACT.

Seasonal and Differential Sesquiterpene Accumulation in Artemisia annua Suggest Selection Based on Both Artemisinin and Dihydroartemisinic Acid may Increase Artemisinin in planta

Commercial Artemisia annua crops are the sole source of artemisinin (ART) worldwide. Data on seasonal accumulation and peak of sesquiterpenes, especially ART in commercial A. annua, is lacking while current breeding programs focus only on ART and plant biomass, but ignores dihydroartemisinic acid (DHAA) and artemisinic acid (AA). Despite past breeding successes, plants richer in ART are needed to decrease prices of artemisinin-combination therapy (ACT). Our results show that sesquiterpene concentrations vary greatly along the growing season and that sesquiterpene profiles differ widely among chemotypes. Field studies with elite Brazilian, Chinese, and Swiss germplasms established that ART peaked in vegetative plants from late August to early September, suggesting that ART is related to the photoperiod, not flowering. DHAA peaks with ART in Chinese and Swiss plants, but decreases, as ART increases, in Brazilian plants, while AA remained stable through the season in these genotypes. Chinese plants peaked at 0.9% ART, 1.6% DHAA; Brazilian plants at 0.9% ART, with less than 0.4% DHAA; Swiss plants at 0.8% ART and 1% DHAA. At single-date harvests, seeded Swiss plants produced 0.55-1.2% ART, with plants being higher in DHAA than ART; Brazilian plants produced 0.33-1.5% ART, with most having higher ART than DHAA. Elite germplasms produced from 0.02-0.43% AA, except Sandeman-UK (0.4-1.1% AA). Our data suggest that different chemotypes, high in ART and DHAA, have complementary pathways, while competing with AA. Crossing plants high in ART and DHAA may generate hybrids with higher ART than currently available in commercial germplasms. Selecting for high ART and DHAA (and low AA) can be a valuable approach for future selection and breeding to produce plants more efficient in transforming DHAA into ART in planta and during post-harvest. This novel approach could change the breeding focus of A. annua and other pharmaceutical species that produce more than one desired metabolite in the same pathway. Obtaining natural variants with high ART content will empower countries and farmers who select, improve, and cultivate A. annua as a commercial pharmaceutical crop. This selection approach could enable ART to be produced locally where it is most needed to fight malaria and other parasitic neglected diseases.

Seasonal induced changes in spinach rhizosphere microbial community structure with varying salinity and drought

Salinity is a common problem under irrigated agriculture, especially in low rainfall and high evaporative demand areas of southwestern United States and other semi-arid regions around the world. However, studies on salinity effects on soil microbial communities are relatively few while the effects of irrigation-induced salinity on soil chemical and physical properties and plant growth are well documented. In this study, we examined the effects of salinity, temperature, and temporal variability on soil and rhizosphere microbial communities in sand tanks irrigated with prepared solutions designed to simulate saline wastewater. Three sets of experiments with spinach (Spinacia oleracea L., cv. Racoon) were conducted under saline water during different time periods (early winter, late spring, and early summer). Bacterial 16S V4 rDNA region was amplified utilizing fusion primers designed against the surrounding conserved regions using MiSeq® Illumina sequencing platform. Across the two sample types, bacteria were relatively dominant among three phyla-the Proteobacteria, Cyanobacteria, and Bacteroidetes-accounted for 77.1% of taxa detected in the rhizosphere, while Proteobacteria, Bacteroidetes, and Actinobacteria accounted for 55.1% of taxa detected in soil. The results were analyzed using UniFrac coupled with principal coordinate analysis (PCoA) to compare diversity, abundance, community structure, and specific bacterial groups in soil and rhizosphere samples. Permutational analysis of variance (PERMANOVA) analysis showed that soil temperature (P=0.001), rhizosphere temperature (P=0.001), rhizosphere salinity (P=0.032), and evapotranspiration (P=0.002) significantly affected beta diversity of soil and rhizosphere microbial communities. Furthermore, salinity had marginal effects (P=0.078) on soil beta diversity. However, temporal variability differentially affected rhizosphere microbial communities irrigated with saline wastewater. Therefore, microbial communities in soils impacted by saline irrigation water respond differently to irrigation water quality and season of application due to temporal effects associated with temperature.

Flower morphology and floral sequence in Artemisia annua (Asteraceae)1

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PREMISE OF THE STUDY

Artemisia annua produces phytochemicals possessing antimalarial, antitumor, anti-inflammatory, and anthelmintic activities. The main active ingredient, artemisinin, is extremely effective against malaria. Breeding to develop cultivars producing high levels of artemisinin can help meet worldwide demand for artemisinin and its derivatives. However, fundamental reproductive processes, such as the sequence of flowering and fertility, are not well understood and impair breeding and seed propagation programs.•

METHODS

Capitulum structure and floral sequence were studied using light and scanning electron microscopy to describe inflorescence architecture, floret opening, and seed set.•

KEY RESULTS

Florets are minute and born in capitula containing pistillate ray florets and hermaphroditic disk florets. Ray florets have elongated stigmatic arms that extend prior to disk floret opening. Disk florets exhibit protandry. During the staminate phase, pollen is released within a staminate tube and actively presented with projections at the tip of stigmas as the pistil elongates. During the pistillate phase, stigmatic arms bifurcate and reflex. Stigmas are of the dry type and stain positively for polysaccharides, lipids, and an intact cuticle. Floret numbers vary with genotype, and capitula are predominantly composed of disk florets. Both ray and disk florets produce filled seed.•

CONCLUSIONS

Gynomonoecy, early opening of ray florets, and dichogamy of disk florets promote outcrossing in A. annua For breeding and seed development, flowering in genotypes can be synchronized under short days according to the floral developmental stages defined. Floret number and percentage seed fill vary with genotype and may be a beneficial selection criterion.

Effects of Artemisia annua and Foeniculum vulgare on chickens highly infected with Eimeria tenella (phylum Apicomplexa)

Background

Intensive poultry production systems depend on chemoprophylaxis with anticoccidial drugs to combat infection. A floor-pen study was conducted to evaluate the anticoccidial effect of Artemisia annua and Foeniculum vulgare on Eimeria tenella infection. Five experimental groups were established: negative control (untreated, unchallenged); positive control (untreated, challenged); a group medicated with 125 ppm lasalocid and challenged; a group medicated with A. annua leaf powder at 1.5% in feed and challenged; and a group treated with the mixed oils of A. annua and Foeniculum vulgare in equal parts, 7.5% in water and challenged. The effects of A. annua and oil extract of A. annua + F. vulgare on E. tenella infection were assessed by clinical signs, mortality, fecal oocyst output, faeces, lesion score, weight gain, and feed conversion.

Results

Clinical signs were noticed only in three chickens from the lasalocid group, six from the A. annua group, and nine from the A. annua + F. vulgare group, but were present in 19 infected chickens from the positive control group. Bloody diarrhea was registered in only two chickens from A. annua group, but in 17 chickens from the positive control group. Mortality also occurred in the positive control group (7/20). Chickens treated with A. annua had a significant reduction in faecal oocysts (95.6%; P = 0.027) and in lesion score (56.3%; P = 0.005) when compared to the positive control. At the end of experiment, chickens treated with A. annua leaf powder had the highest body weight gain (68.2 g/day), after the negative control group, and the best feed conversion (1.85) among all experimental groups.

Conclusions

Our results suggest that A. annua leaf powder (Aa-p), at 1.5% of the daily diet post-infection, can be a valuable alternative for synthetic coccidiostats, such as lasalocid.

Anthelmintic effect of plant extracts containing condensed and hydrolyzable tannins on Caenorhabditis elegans, and their antioxidant capacity

Although tannin-rich forages are known to increase protein uptake and to reduce gastrointestinal nematode infections in grazing ruminants, most published research involves forages with condensed tannins (CT), while published literature lacks information on the anthelmintic capacity, nutritional benefits, and antioxidant capacity of alternative forages containing hydrolyzable tannins (HT). We evaluated the anthelmintic activity and the antioxidant capacity of plant extracts containing either mostly CT, mostly HT, or both CT and HT. Extracts were prepared with 70% acetone, lyophilized, redissolved to doses ranging from 1.0mg/mL to 25mg/mL, and tested against adult Caenorhabditis elegans as a test model. The extract concentrations that killed 50% (LC(50)) or 90% (LC(90)) of the nematodes in 24h were determined and compared to the veterinary anthelmintic levamisole (8 mg/mL). Extracts were quantified for CT by the acid butanol assay, for HT (based on gallic acid and ellagic acid) by high-performance liquid chromatography (HPLC) and total phenolics, and for their antioxidant activity by the oxygen radical absorbance capacity (ORAC) assay. Extracts with mostly CT were Lespedeza cuneata, Salix X sepulcralis, and Robinia pseudoacacia. Extracts rich in HT were Acer rubrum, Rosa multiflora, and Quercus alba, while Rhus typhina had both HT and CT. The extracts with the lowest LC(50) and LC(90) concentrations, respectively, in the C. elegans assay were Q. alba (0.75 and 1.06 mg/mL), R. typhina collected in 2007 (0.65 and 2.74 mg/mL), A. rubrum (1.03 and 5.54 mg/mL), and R. multiflora (2.14 and 8.70 mg/mL). At the doses of 20 and 25mg/mL, HT-rich, or both CT- and HT-rich, extracts were significantly more lethal to adult C. elegans than extracts containing only CT. All extracts were high in antioxidant capacity, with ORAC values ranging from 1800 μmoles to 4651 μmoles of trolox equivalents/g, but ORAC did not correlate with anthelmintic activity. The total phenolics test had a positive and highly significant (r=0.826, p ≤ 0.01) correlation with total hydrolyzable tannins. Plants used in this research are naturalized to the Appalachian edaphoclimatic conditions, but occur in temperate climate areas worldwide. They represent a rich, renewable, and unexplored source of tannins and antioxidants for grazing ruminants, whereas conventional CT-rich forages, such as L. cuneata, may be hard to establish and adapt to areas with temperate climate. Due to their high in vitro anthelmintic activity, antioxidant capacity, and their adaptability to non-arable lands, Q. alba, R. typhina, A. rubrum, and R. multiflora have a high potential to improve the health of grazing animals and must have their anthelmintic effects confirmed in vivo in both sheep and goats.

Rumen fermentation and production effects of Origanum vulgare L. leaves in lactating dairy cows

A lactating cow trial was conducted to study the effects of dietary addition of oregano leaf material (Origanum vulgare L.; OV; 0, control vs. 500 g/d) on ruminal fermentation, methane production, total tract digestibility, manure gas emissions, N metabolism, organoleptic characteristics of milk, and dairy cow performance. Eight primiparous and multiparous Holstein cows (6 of which were ruminally cannulated) were used in a crossover design trial with two 21-d periods. Cows were fed once daily. The OV material was top-dressed and mixed with a portion of the total mixed ration. Cows averaged 80 ± 12.5 d in milk at the beginning of the trial. Rumen pH, concentration of total and individual volatile fatty acids, microbial protein outflow, and microbial profiles were not affected by treatment. Ruminal ammonia-N concentration was increased by OV compared with the control (5.3 vs. 4.3mM). Rumen methane production, which was measured only within 8h after feeding, was decreased by OV. Intake of dry matter (average of 26.6 ± 0.83 kg/d) and apparent total tract digestibly of nutrients did not differ between treatments. Average milk yield, milk protein, lactose, and milk urea nitrogen concentrations were unaffected by treatment. Milk fat content was increased and 3.5% fat-corrected milk yield tended to be increased by OV, compared with the control (3.29 vs. 3.12% and 42.4 vs. 41.0 kg/d, respectively). Fat-corrected (3.5%) milk feed efficiency and milk net energy for lactation (NE(L)) efficiency (milk NE(L) ÷ NE(L) intake) were increased by OV compared with the control (1.64 vs. 1.54 kg/kg and 68.0 vs. 64.4%, respectively). Milk sensory parameters were not affected by treatment. Urinary and fecal N losses, and manure ammonia and methane emissions were unaffected by treatment. Under the current experimental conditions, supplementation of dairy cow diets with 500 g/d of OV increased milk fat concentration, feed and milk NE(L) efficiencies, and tended to increase 3.5% fat-corrected milk yield. The sizable decrease in rumen methane production with the OV supplementation occurred within 8h after feeding and has to be interpreted with caution due to the large within- and between-animal variability in methane emission estimates. The OV was introduced into the rumen as a pulse dose at the time of feeding, thus most likely having larger effect on methane production during the period when methane data were collected. It is unlikely that methane production will be affected to the same extent throughout the entire feeding cycle.

Caenorhabditis elegans as a model to screen plant extracts and compounds as natural anthelmintics for veterinary use

The most challenging obstacles to testing products for their anthelmintic activity are: (1) establishing a suitable nematode in vitro assay that can evaluate potential product use against a parasitic nematode of interest and (2) preparation of extracts that can be redissolved in solvents that are miscible in the test medium and are at concentrations well tolerated by the nematode system used for screening. The use of parasitic nematodes as a screening system is hindered by the difficulty of keeping them alive for long periods outside their host and by the need to keep infected animals as sources of eggs or adults when needed. This method uses the free-living soil nematode Caenorhabditis elegans as a system to screen products for their potential anthelmintic effect against small ruminant gastrointestinal nematodes, including Haemonchus contortus. This modified method uses only liquid axenic medium, instead of agar plates inoculated with Escherichia coli, and two selective sieves to obtain adult nematodes. During screening, the use of either balanced salt solution (M-9) or distilled water resulted in averages of 99.7 (± 0.73)% and 96.36 (± 2.37)% motile adults, respectively. Adult worms tolerated DMSO, ethanol, methanol, and Tween 80 at 1% and 2%, while Labrasol (a bioenhancer with low toxicity to mammals) and Tween 20 were toxic to C. elegans at 1% and were avoided as solvents. The high availability, ease of culture, and rapid proliferation of C. elegans make it a useful screening system to test plant extracts and other phytochemical compounds to investigate their potential anthelmintic activity against parasitic nematodes.

In vitro trematocidal effects of crude alcoholic extracts of Artemisia annua, A. absinthium, Asimina triloba, and Fumaria officinalis: trematocidal plant alcoholic extracts

Trematode infections negatively affect human and livestock health, and threaten global food safety. The only approved human anthelmintics for trematodiasis are triclabendazole and praziquantel with no alternative drugs in sight. We tested six crude plant extracts against adult Schistosoma mansoni, Fasciola hepatica, and Echinostoma caproni in vitro. Mortality was best achieved by ethanolic extracts of Artemisia annua (sweet Annie), Asimina triloba (paw-paw), and Artemisia absinthium (wormwood) which, at 2 mg/mL, killed S. mansoni and E. caproni in 20 h or less (except for wormwood), F. hepatica between 16 and 23 h (sweet Annie), or 40 h (paw-paw). Some extracts were active at 0.2 mg/mL and 20 μg/mL, although more time was required to kill trematodes. However, aqueous A. annua and methanol extracts of Fumaria officinalis had no activity. Chromatographic analysis of the three best extracts established that A. annua and A. triloba extracts contained bioactive artemisinin and acetogenins (asimicin and bullatacin), respectively. The anthelmintic activity of our extracts at such low doses indicates that their anthelmintic activity deserves further testing as natural alternative controls for parasites of both animals and humans. Our results also support recent evidence that synergistic effects of multiple bioactive compounds present in crude plant extracts is worth exploring.

Effects of artemisinin and Artemisia extracts on Haemonchus contortus in gerbils (Meriones unguiculatus)

Haemonchus contortus is a blood-sucking abomasal parasite of small ruminants that is responsible for major losses to producers worldwide. Resistance of this nematode to commercial anthelmintics has produced a demand for alternative control methods. Plants in the genus Artemisia have traditionally been used as anthelmintics and whole plants and plant extracts have demonstrated activity against gastrointestinal nematodes in several studies. In addition, Artemisia annua is the sole commercial source of artemisinin, the raw material used to produce drugs effective against the hemoprotozoan malaria parasites (Plasmodium species). Artemisinin derivatives have also shown efficacy against some trematodes, including Fasciola hepatica and Schistosoma species. In this study, artemisinin was tested for efficacy against H. contortus in a gerbil model of infection. Also tested in the gerbil model were an aqueous extract, an ethanolic extract and the essential oil of A. annua, and an ethanolic extract of Artemisia absinthium. In all experiments, gerbils were infected with 600 third-stage H. contortus larvae. In experiment 1, gerbils were treated orally with 400 milligrams per kilogram body weight (mg/kg BW) artemisinin once or 200mg/kg BW artemisinin daily for 5 days (Days 4-8 post-infection). In experiment 2, gerbils were treated daily for 5 days with 600 mg/kg BW of A. annua ethanolic or aqueous extract. In Experiment 3, gerbils were treated with 1000 mg/kg BW of A. annua or A. absinthium ethanolic extract or with 300 mg/kg BW of A. annua essential oil daily for five consecutive days (Days 4-8 post-infection). No significant effects of treatment were seen with artemisinin or any of the Artemisia species extracts at the dosages studied. The non-ionic surfactant Labrosol(®) was an effective nontoxic solvent for delivery of hydrophilic plant extracts and the lipophilic essential oil used in the study.

Drying affects artemisinin, dihydroartemisinic acid, artemisinic acid, and the antioxidant capacity of Artemisia annua L. leaves

There is limited information on how postharvest drying of Artemisia annua affects artemisinin (ART) biosynthesis and A. annua antioxidant capacity. Antioxidants may boost the bioactivity of ART and the crop commercial value. We evaluated the effect of freeze, oven, shade, and sun drying, time of drying, and light intensity on the leaf concentration of ART, dihydroartemisinic acid (DHAA), artemisinic acid (AA), and on the leaf antioxidant capacity. Freeze-dried samples had the lowest ART concentrations as compared to the other drying methods. However, the ferric reducing antioxidant power assay showed that freeze- and oven-dried samples had similarly high antioxidant activities, which declined significantly after plants were shade- and sun-dried. Shade drying for 1, 2, and 3 weeks, under ambient or low light, did not change the ART content but significantly decreased the leaf antioxidant activity, mainly if sun-dried. A significant decrease (82% average) in DHAA was observed for all drying procedures as compared to freeze drying, with a simultaneous, significant increase in ART (33% average). The average bioconversion of DHAA to ART was 43% for oven- and shade-dried plants and 94% for sun-dried plants, reiterating the hypothesis that DHAA, not AA, is the main biosynthetic precursor of ART and suggesting that sun drying improves the bioconversion from DHAA to ART. Data also indicate that oven drying for 24 h at 45 degrees C can provide good levels of both ART and antioxidants in leaves. These findings are valuable for the commercial production of ART and of bioactive antioxidants that might synergize with the antimalarial and anticancer effects of ART when combined in traditional preparations to improve human and animal health.

Analysis of underivatized artemisinin and related sesquiterpene lactones by high-performance liquid chromatography with ultraviolet detection

INTRODUCTION

Although high-performance liquid chromatography with ultraviolet detection (HPLC-PAD) is widely available, it has not been used for artemisinin (1) analysis because of the lack of UV absorption reported for this lactone. Increased Artemisia annua cultivation for production of 1 requires an affordable and reliable method to analyse 1 and its precursors dihydroartemisinic acid (2) and artemisinic acid (3) simultaneously from underivatized plant extracts.

OBJECTIVE

To validate HPLC-PAD for the quantification of underivatized artemisinin from A. annua and artemisinin-based drugs.

METHODOLOGY

Dried A. annua leaves were extracted with petroleum ether, dried, reconstituted in acetonitrile, and analysed by HPLC-PAD at 192 nm using an isocratic mobile phase (60:40, acetonitrile:0.1% acetic acid). HPLC-PAD was evaluated through accuracy, precision, recovery and comparison with HPLC with evaporative light scattering detection (HPLC-ELSD).

RESULTS

HPLC-PAD proved accurate, precise and reproducible for the direct quantification of 1 and related compounds, and was more sensitive than ELSD for most of the compounds tested. The limit of quantification of 1-3 from plants was 0.048, 0.024 and 0.008 g/100 g dry weight, respectively. Recoveries were over 98%, with good intra- and inter-day repeatability. HPLC-PAD correlated significantly (r(2 )= 0.99, p < 0.001) with HPLC-ELSD for artemisinin analysis. HPLC-PAD was also reliable for the analysis of dihydroartemisinin, artesunate and artelinic acid.

CONCLUSION

HPLC with ultraviolet detection was validated for the quantification of underivatized 1, 2, and 3 from crude plant samples, and is readily applicable for the quality control of herbals and artemisinin-related pharmaceutical compounds.

Chemical and biological stability of artemisinin in bovine rumen fluid and its kinetics in goats (Capra hircus)

There is a pressing need to develop alternative, natural anthelmintics to control widespread drug-resistant gastrointestinal nematodes in ruminants, such as Haemonchus contortus. Artemisinin and its semi-synthetic derivatives are widely used against drug-resistant Plasmodium falciparum, but their role in veterinary medicine is only emerging. Artemisinin may be useful in controlling gastrointestinal parasites including Haemonchus. However, no ruminant studies involving artemisinin have been reported. The stability of artemisinin in capsules, crystals, or stock solutions in ethanol and dimethyl sulfoxide was evaluated in bovine rumen culture medium incubated for 24 hours at 39 degrees C. A second study established artemisinin kinetics in goats after oral administration of artemisinin capsules at 23 mg/kg of body weight. Artemisinin recovered from rumen culture ranged from 67 to 92% at pH 6.8 and was 95% at pH 3.0. The kinetics data showed that artemisinin was metabolized to dihydroartemisinin by goats, while unabsorbed artemisinin was eliminated in feces. Dihydroartemisinin peaked in the blood (0.7 mug/mL) at 12 hours, and decreased to 0.18 mug/mL at 24 hours. At 24 hours, artemisinin concentration in feces was 2.4 mug/g, indicating its poor bioavailability in goats when provided orally and as capsules. These results suggest that the bioavailability of artemisinin to goats can improve by dissolving capsules in ethanol or dimethyl sulfoxide, by using more stable and bioavailable artemisinin-derived drugs, and by using routes of delivery other than oral.

Affordable and sensitive determination of artemisinin in Artemisia annua L. by gas chromatography with electron-capture detection

Artemisinin demand has increased sharply since the World Health Organization recommended its use as part of the artemisinin combination therapies in 2001. The area for the crop cultivation has expanded in Africa and Asia and simpler and affordable methods for artemisinin analysis are needed for crop quality control. This work presented a novel chromatographic method of artemisinin analysis using gas chromatography with electron-capture detection. The sample extraction and preparation involved a single-solvent one-step extraction, with samples being analyzed in the extraction solvent directly after extraction. This method was accurate and reproducible with over 97% recoveries. The limit of detection was less than 3 microg/mL and the limit of quantification was less than 9 microg/mL, allowing samples as low as 100mg dry weight to be analyzed for artemisinin. The method can be applied to quality control of commercial plant extracts and to artemisinin-derived pharmaceuticals.

Nutrient deficiency in the production of artemisinin, dihydroartemisinic acid, and artemisinic acid in Artemisia annua L

Artemisia annua became a valuable agricultural crop after the World Health Organization recommended artemisinin as a component of ACT (artemisinin-combination based therapies) for malaria in 2001. A cloned, greenhouse-grown, A. annua (Artemis) subjected to an acidic soil and macronutrient deficit was evaluated for artemisinin production. Lack of lime (L) and macronutrients (N, P, and K) reduced leaf biomass accumulation. When L was provided (pH 5.1), the highest average leaf biomass was achieved with the "complete" (+N, +P, +K, and +L) treatment (70.3 g/plant), and the least biomass was achieved with the untreated (-N, -P, -K, and -L) treatment (6.18 g/plant). The nutrient least required for biomass accumulation per plant (g) was K (49.0 g), followed by P (36.5 g) and N (14.3 g). The artemisinin concentration (g/100 g) was significantly higher (75.5%) in -K plants when compared to plants under the complete treatment (1.62 vs 0.93%). Although the artemisinin total yield (g/plant) was 21% higher in -K plants, it was not significantly different from plants under the complete treatment (0.80 vs 0.66 g/plant). There were no marked treatment effects for concentration (g/100 g) or yield (g/plant) of both dihydroartemisinic acid and artemisinic acid, although higher levels were achieved in plants under the complete or -K treatments. There was a positive and significant correlation between artemisinin and both artemisinic acid and dihydroartemisin acid, in g/100 g and g/plant. This is the first report where potassium deficiency significantly increases the concentration (g/100 g) of artemisinin. Thus, under a mild potassium deficiency, A. annua farmers could achieve similar gains in artemisinin/ha, while saving on potassium fertilization, increasing the profitability of artemisinin production.

Direct analysis of artemisinin from Artemisia annua L. using high-performance liquid chromatography with evaporative light scattering detector, and gas chromatography with flame ionization detector

Since the isolation of artemisinin 32 years ago, it has been analyzed by different chromatographic techniques. This work compared the analysis of artemisinin from crude plant samples by GC with flame ionization detection (GC-FID) and HPLC with evaporative light scattering detector (HPLC-ELSD). Data is also presented indicating that GC is suitable for the quantification of two of artemisinin precursors (arteannuin B and artemisinic acid) if a mass spectrometer is available. GC-FID and HPLC-ELSD were chosen because of their low cost compared to other detection methods, their ease of operation compared to HPLC with electrochemical detection, and because neither require artemisinin derivatization. Both GC-FID and HPLC-ELSD provided sensitive (ng level) and reproducible results for the analysis of artemisinin from field plants, with a correlation coefficient of r(2)=0.86 between the two methods. Both methods could be easily adapted to the analysis of pharmaceutical-grade artemisinin.

Simplified extraction of ginsenosides from American ginseng (Panax quinquefolius L.) for high-performance liquid chromatography-ultraviolet analysis

Four methods were tested for extraction and recovery of six major ginsenosides (Rb1, Rb2, Rc, Rd, Re, and Rg1) found in roots of American ginseng (Panax quinquefolius): method A, sonication in 100% methanol (MeOH) at room temperature (rt); method B, sonication in 70% aqueous MeOH at rt; method C, water extraction (90 degrees C) with gentle agitation; and method D, refluxing (60 degrees C) in 100% MeOH. After 0.5-1 h, the samples were filtered and analyzed by high-performance liquid chromatography (HPLC)-UV. A second extraction by methods C and D was done, but 85-90% of ginsenosides were obtained during the first extraction. Lyophilization of extracts did not influence ginsenoside recovery. Method D resulted in the highest significant recoveries of all ginsenosides, except Rg1. Method C was the next most effective method, while method A resulted in the lowest ginsenoside recoveries. Method B led to similar recoveries as method C. All methods used one filtration step, omitted time-consuming cleanup, but maintained clear peak resolution by HPLC, and can be used for quantitative screening of ginsenosides from roots and commercial ginseng preparations.