Correction: Future antimalarials from Artemisia? A rationale for natural product mining against drug-refractory Plasmodium stages.

Correction for 'Future antimalarials from Artemisia? A rationale for natural product mining against drug-refractory Plasmodium stages' by Alexandre Maciuk et al., Nat. Prod. Rep., 2023, 40, 1130-1144, https://doi.org/10.1039/D3NP00001J.

Future antimalarials from Artemisia? A rationale for natural product mining against drug-refractory Plasmodium stages.

Covering: up to 2023Infusions of the plants Artemisia annua and A. afra are gaining broad popularity to prevent or treat malaria. There is an urgent need to address this controversial public health question by providing solid scientific evidence in relation to these uses. Infusions of either species were shown to inhibit the asexual blood stages, the liver stages including the hypnozoites, but also the sexual stages, the gametocytes, of Plasmodium parasites. Elimination of hypnozoites and sterilization of mature gametocytes remain pivotal elements of the radical cure of P. vivax, and the blockage of P. vivax and P. falciparum transmission, respectively. Drugs active against these stages are restricted to the 8-aminoquinolines primaquine and tafenoquine, a paucity worsened by their double dependence on the host genetic to elicit clinical activity without severe toxicity. Besides artemisinin, these Artemisia spp. contain many natural products effective against Plasmodium asexual blood stages, but their activity against hypnozoites and gametocytes was never investigated. In the context of important therapeutic issues, we provide a review addressing (i) the role of artemisinin in the bioactivity of these Artemisia infusions against specific parasite stages, i.e., alone or in association with other phytochemicals; (ii) the mechanisms of action and biological targets in Plasmodium of ca. 60 infusion-specific Artemisia phytochemicals, with an emphasis on drug-refractory parasite stages (i.e., hypnozoites and gametocytes). Our objective is to guide the strategic prospecting of antiplasmodial natural products from these Artemisia spp., paving the way toward novel antimalarial "hit" compounds either naturally occurring or Artemisia-inspired.

Biodereplication of Antiplasmodial Extracts: Application of the Amazonian Medicinal Plant Piper coruscans Kunth.

Improved methodological tools to hasten antimalarial drug discovery remain of interest, especially when considering natural products as a source of drug candidates. We propose a biodereplication method combining the classical dereplication approach with the early detection of potential antiplasmodial compounds in crude extracts. Heme binding is used as a surrogate of the antiplasmodial activity and is monitored by mass spectrometry in a biomimetic assay. Molecular networking and automated annotation of targeted mass through data mining were followed by mass-guided compound isolation by taking advantage of the versatility and finely tunable selectivity offered by centrifugal partition chromatography. This biodereplication workflow was applied to an ethanolic extract of the Amazonian medicinal plant Piper coruscans Kunth (Piperaceae) showing an IC50 of 1.36 µg/mL on the 3D7 Plasmodium falciparum strain. It resulted in the isolation of twelve compounds designated as potential antiplasmodial compounds by the biodereplication workflow. Two chalcones, aurentiacin (1) and cardamonin (3), with IC50 values of 2.25 and 5.5 µM, respectively, can be considered to bear the antiplasmodial activity of the extract, with the latter not relying on a heme-binding mechanism. This biodereplication method constitutes a rapid, efficient, and robust technique to identify potential antimalarial compounds in complex extracts such as plant extracts.

Anti-protozoal and anti-fungal evaluation of 3,5-disubstituted 1,2-dioxolanes.

Endoperoxides are a class of compounds, which is well-known for their antimalarial properties, but few reports exist about 3,5-disubstituted 1,2-dioxolanes. After having designed a new synthetic route for the preparation of these substances, they were evaluated against 4 different agents of infectious diseases, protozoa (Plasmodium and Leishmania) and Fungi (Candida and Aspergillus). Whereas moderate antifungal activity was found for our products, potent antimalarial and antileishmanial activities were observed for a few compounds. The nature of the substituents linked to the endoperoxide ring seems to play an important role in the bioactivities.

Correlation study on methoxylation pattern of flavonoids and their heme-targeted antiplasmodial activity.

A library of 33 polymethoxylated flavones (PMF) was evaluated for heme-binding affinity by biomimetic MS assay and in vitro antiplasmodial activity on two strains of P. falciparum. Stability of heme adducts was discussed using the dissociation voltage at 50% (DV50). No correlation was observed between the methoxylation pattern and the antiparasitic activity, either for the 3D7 chloroquine-sensitive or for the W2 chloroquine-resistant P. falciparum strains. However, in each PMF family an increased DV50 was observed for the derivatives methoxylated in position 5. Measurement of intra-erythrocytic hemozoin formation of selected derivatives was performed and hemozoin concentration was inversely correlated with heme-binding affinity. Kaempferol showed no influence on hemozoin formation, reinforcing the hypothesis that this compound may exert in vitro antiplasmodial activity mostly through other pathways. Pentamethoxyquercetin has simultaneously demonstrated a significant biological activity and a strong interaction with heme, suggesting that inhibition of hemozoin formation is totally or partially responsible for its antiparasitic effect.

Revisiting Previously Investigated Plants: A Molecular Networking-Based Study of Geissospermum laeve.

Three new monoterpene indole alkaloids (1-3) have been isolated from the bark of Geissospermum laeve, together with the known alkaloids (-)-leuconolam (4), geissolosimine (5), and geissospermine (6). The structures of 1-3 were elucidated by analysis of their HRMS and NMR spectroscopic data. The absolute configuration of geissolaevine (1) was deduced from the comparison of experimental and theoretically calculated ECD spectra. The isolation workflow was guided by a molecular networking-based dereplication strategy using an in-house database of monoterpene indole alkaloids. In addition, five known compounds previously undescribed in the Geissospermum genus were dereplicated from the G. laeve alkaloid extract network and were assigned with various levels of identification confidence. The antiparasitic activities against Plasmodium falciparum and Leishmania donovani as well as the cytotoxic activity against the MRC-5 cell line were determined for compounds 1-5.

Hsp90 stabilizes Cdc25A and counteracts heat shock-mediated Cdc25A degradation and cell-cycle attenuation in pancreatic carcinoma cells.

Pancreas cancer cells escape most treatment options. Heat shock protein (Hsp)90 is frequently over-expressed in pancreas carcinomas and protects a number of cell-cycle regulators such as the proto-oncogene Cdc25A. We show that inhibition of Hsp90 with geldanamycin (GD) destabilizes Cdc25A independent of Chk1/2, whereas the standard drug for pancreas carcinoma treatment, gemcitabine (GEM), causes Cdc25A degradation through the activation of Chk2. Both agents applied together additively inhibit the expression of Cdc25A and the proliferation of pancreas carcinoma cells thereby demonstrating that both Cdc25A-destabilizing/degrading pathways are separated. The role of Hsp90 as stabilizer of Cdc25A in pancreas carcinoma cells is further supported by two novel synthetic inhibitors 4-tosylcyclonovobiocic acid and 7-tosylcyclonovobiocic acid and specific Hsp90AB1 (Hsp90ß) shRNA. Our data show that targeting Hsp90 reduced the resistance of pancreas carcinoma cells to treatment with GEM.

Scientific opinion on the tolerable upper intake level for preformed vitamin A and ß-carotene.

Following two requests from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for preformed vitamin A and ß-carotene. Systematic reviews of the literature were conducted for priority adverse health effects of excess vitamin A intake, namely teratogenicity, hepatotoxicity and endpoints related to bone health. Available data did not allow to address whether ß-carotene could potentiate preformed vitamin A toxicity. Teratogenicity was selected as the critical effect on which to base the UL for preformed vitamin A. The Panel proposes to retain the UL for preformed vitamin A of 3000 µg RE/day for adults. This UL applies to men and women, including women of child-bearing age, pregnant and lactating women and post-menopausal women. This value was scaled down to other population groups using allometric scaling (body weight0.75), leading to ULs between 600 µg RE/day (infants 4-11 months) and 2600 µg RE/day (adolescents 15-17 years). Based on available intake data, European populations are unlikely to exceed the UL for preformed vitamin A if consumption of liver, offal and products thereof is limited to once per month or less. Women who are planning to become pregnant or who are pregnant are advised not to consume liver products. Lung cancer risk was selected as the critical effect of excess supplemental ß-carotene. The available data were not sufficient and suitable to characterise a dose-response relationship and identify a reference point; therefore, no UL could be established. There is no indication that ß-carotene intake from the background diet is associated with adverse health effects. Smokers should avoid consuming food supplements containing ß-carotene. The use of supplemental ß-carotene by the general population should be limited to the purpose of meeting vitamin A requirements.

'Citicoline' and support of the memory function: Evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006.

Following an application from Egde Pharma Sp. z o.o, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Poland, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to citicoline and memory. The Panel considers that the food, citicoline (cytidine 5-diphosphocholine, CDP-Choline) inner salt, is sufficiently characterised. Improvement, maintenance or reduced loss of memory is a beneficial physiological effect for middle-aged or elderly adults encountering age-associated subjective memory impairment. The applicant identified three pertinent human intervention studies in healthy individuals that investigated the effect of citicoline on memory. In weighing the evidence, the Panel took into account that only one randomised controlled trial in healthy participants showed a beneficial effect of citicoline on episodic memory when consumed at doses of 500 mg/day for 12 weeks, whereas this effect has not been observed in another study using citicoline at doses of 1 g/day for 3 months or supported by data obtained in patients with dementia using doses of 1 g/day for 12 weeks and 12 months. No convincing evidence of a plausible mechanism by which citicoline or any of its components (in addition to their endogenous synthesis) could exert an effect on memory in humans has been provided. The Panel concludes that a cause-and-effect relationship has not been established between the consumption of citicoline (CDP-Choline) inner salt and improvement, maintenance or reduced loss of memory in middle-aged or elderly adults encountering age-associated subjective memory impairment.

Joselito® and lowering of LDL-cholesterol concentration, blood pressure, and reduction of coronary heart disease risk: Evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006.

Following an application from Cárnicas Joselito S.A. pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of Spain, the Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to 'Joselito ham increases antioxidant substances in the body, reduces blood pressure and plasma triglycerides, decreases oxidative stress and prevents effect in diseases related to the cardiovascular and intestinal systems'. The scope of the application was proposed to fall under a health claim referring to disease risk reduction. The food constituent that is the subject of the health claim is Joselito, an Iberian ham characterised by a high content of oleic acid. The Panel considers that the food is sufficiently characterised. The Panel considers that lowering of LDL-cholesterol concentration and blood pressure is a beneficial effect by decreasing the risk of coronary heart disease. Upon a request from EFSA, the applicant identified one human intervention study as being pertinent to the claim. However, due to methodological limitations, the Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claim. The Panel notes that no human intervention studies from which conclusions could be drawn for the scientific substantiation of the claim were provided by the applicant. The Panel concludes that a cause and effect relationship has not been established between the intake of Joselito® ham and the reduction of LDL-cholesterol concentration or blood pressure.

Scientific Opinion on additional scientific data related to the safety of preparations of Rheum palmatum L., Rheum officinale Baill. and their hybrids, Rhamnus purshiana DC., Rhamnus frangula L. and Cassia senna L., submitted pursuant to Article 8(4) of Regulation (EC) No 1925/2006.

The Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the safety of plant preparations from the root or rhizome of Rheum palmatum L., Rheum officinale Baill. and their hybrids, from the bark of Rhamnus frangula L. and Rhamnus purshiana DC. and from the leaf or fruit of Cassia senna L., which have been placed under Union scrutiny in Part C of Annex III in accordance with Article 8(4) of Regulation (EC) No 1925/2006. The NDA Panel reviewed the additional scientific data submitted during the period of scrutiny and the public consultation by interested parties. The pertinent scientific data were in vitro and in vivo genotoxicity studies on the plant preparations under consideration. All the results of the genotoxicity studies on plant preparations were negative. However, the plant preparations that were tested in the submitted studies were not sufficiently characterised with respect to the content of total and individual hydroxyanthracene derivatives (HADs) and components other than HADs. The studies confirmed the presence of ■■■■■, known to be genotoxic in vivo, and ■■■■■, shown to be genotoxic in vitro. In line with the EFSA Scientific Committee statement on genotoxicity assessment of chemical mixtures, considering the presence of an in vivo genotoxic compound, the plant preparations used in these studies have to be considered of concern for genotoxicity. Thus, the safety of preparations containing HADs from the root or rhizome of Rheum palmatum L., Rheum officinale Baill. and their hybrids, from the leaf or fruit of Cassia senna L. and from the bark of Rhamnus frangula L. and Rhamnus purshiana DC. cannot be established based on the submitted studies.

Safety of isomaltulose syrup (dried) as a novel food pursuant to Regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on isomaltulose syrup (dried) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF consists of a mixture of mono- and disaccharides in powder form, mainly composed of isomaltulose (≥ 75%) and trehalulose (< 13%). The applicant intends to use the NF as a replacement for sucrose already on the market. The information provided on the manufacturing process, composition and specifications of the NF is sufficient and does not raise safety concerns. No absorption, distribution, metabolism and excretion (ADME) or toxicological data were provided for the NF. Instead, the safety of the NF was assessed based on literature data available on isomaltulose and mixtures of isomaltulose and trehalulose. In addition, considering the nature, compositional characterisation and production process of the NF, the Panel considered that such data were sufficient to conclude that the NF is as safe as sucrose.

Extension of use of isomalto-oligosaccharide as a novel food pursuant to Regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the extension of use of isomalto-oligosaccharide (IMO) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF consists of glucose oligomers with degrees of polymerisation of 3-9, along with various amounts of mono- and disaccharides. The NF comes in both syrup and powder form. The applicant intends to extend the current uses of the NF as an ingredient in several foods, and use the NF in food supplements aimed at the general population older than 10 years of age. The information provided on the manufacturing process, composition and specifications of the NF is sufficient and does not raise safety concerns. Along with literature data, the applicant carried out a tolerability study in adult volunteers with the NF at doses up to 120 g/day. The Panel concludes that this study provides reassurance that the NF is tolerable at doses of 120 g/day. Conservative intake estimates resulting from the use of the NF as an ingredient according to the currently authorised uses and new proposed uses result in a highest intake estimate in adolescents of 112 g/day at the 95th percentile, and reach 142 g/day in adolescents when the use as a food supplement is included. The Panel notes this amount is higher than the dose of 120 g/day for which tolerability has been demonstrated. However, considering the source, compositional characterisation, production process and nature of the NF, as well as the available nutritional and toxicological data on the NF, the Panel considers that the NF does not present safety concerns under the proposed conditions of use.

Safety of magnesium l-threonate as a novel food pursuant to regulation (EU) 2015/2283 and bioavailability of magnesium from this source in the context of Directive 2002/46/EC.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of magnesium l-threonate as a novel food (NF) pursuant to Regulation (EU) 2015/2283 and to address the bioavailability of magnesium from this source in the context of Directive 2002/46/EC. The NF, produced by chemical synthesis, is intended to be used as new source for magnesium in food supplements at a maximum intake level of 3000 mg per day by adults, except for pregnant and lactating women. This dose corresponds to ~ 2730 mg l-threonate and 250 mg magnesium, which also corresponds to the UL for supplemental magnesium from readily dissociable magnesium salts. Based on results obtained from a dissociation study, two rat studies and one human trial, the Panel considers that magnesium is bioavailable from the NF. The NF may contain up to 1% oxalic acid. The Panel considers that an additional exposure to oxalic acid, that is up to 30 mg daily from the NF, is not to be of safety concern. The Panel concludes that the NF is not nutritionally disadvantageous. In 2008, the EFSA ANS Panel concluded that a human intake of l-threonate of 2700 mg per day is safe. This intake is similar to the maximum intake of l-threonate from the NF under the maximum proposed uses, and the NDA Panel concurs with the ANS Panel that this intake is safe. The Panel considers that there are no concerns regarding the genotoxicity of the NF. The Panel concludes that the NF, Mg l-threonate, is safe under the proposed conditions of use. The Panel concludes that the NF is a source from which magnesium is bioavailable.

Safety of vitamin D2 mushroom powder as a Novel food pursuant to Regulation (EU) 2015/2283 (NF 2020/2226).

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on vitamin D2 mushroom powder as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is produced from Agaricus bisporus mushroom powder that has been exposed to ultraviolet (UV) irradiation to induce the conversion of provitamin D2 (ergosterol) to vitamin D2 (ergocalciferol). The NF contains concentrations of vitamin D in the form of vitamin D2 in the range of 245-460 µg/g. The information provided on the production process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF as an ingredient in a variety of foods and beverages in amounts that result in either 1.2 or 2.4 µg vitamin D2 per 100 g or 100 mL of the food as consumed. The applicant also intends to add the NF in food supplements at a maximum of 15 µg vitamin D2/day for individuals above 1 year of age, as well as in foods for special medical purposes (FSMPs). The estimates for combined intake of vitamin D from the NF, the background diet and fortified foods, were below the ULs for vitamin D as established previously by the NDA Panel for children, adolescents and adults, i.e. 50 and 100 µg/day. The estimated combined vitamin D intake in infants (6-12 months) is also below the UL for vitamin D of 35 µg/day. The Panel considers that taking into account the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous for the proposed target population. The Panel concludes that the NF is safe under the proposed conditions of use.

Scientific opinion on the tolerable upper intake level for iron.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the tolerable upper intake level (UL) for iron. Systematic reviews were conducted to identify evidence regarding high iron intakes and risk of chronic diseases, adverse gastrointestinal effects and adverse effects of iron supplementation in infancy, young childhood and pregnancy. It is established that systemic iron overload leads to organ toxicity, but no UL could be established. The only indicator for which a dose-response could be established was black stools, which reflect the presence of large amounts of unabsorbed iron in the gut. This is a conservative endpoint among the chain of events that may lead to systemic iron overload but is not adverse per se. Based on interventions in which black stools did not occur at supplemental iron intakes of 20-25 mg/day (added to a background intake of 15 mg/day), a safe level of intake for iron of 40 mg/day for adults (including pregnant and lactating women) was established. Using allometric scaling (body weight0.75), this value was scaled down to children and adolescents and safe levels of intakes between 10 mg/day (1-3 years) and 35 mg/day (15-17 years) were derived. For infants 7-11 months of age who have a higher iron requirement than young children, allometric scaling was applied to the supplemental iron intakes (i.e. 25 mg/day) and resulted in a safe level of supplemental iron intake of 5 mg/day. This value was extended to 4-6 month-old infants and refers to iron intakes from fortified foods and food supplements, not from infant and follow-on formulae. The application of the safe level of intake is more limited than a UL because the intake level at which the risk of adverse effects starts to increase is not defined.

Safety of ashitaba sap as a Novel food pursuant to Regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on ashitaba sap as a novel food (NF) pursuant to Regulation (EU) 2015/2283. Ashitaba sap is collected from harvested stems of Angelica keiskei plants. The principal constituents of the sap with regard to the safety assessment are chalcones (1%-2.25%) and furanocoumarins (< 0.01%). The applicant proposed to use the NF in food supplements at a maximum dose of 780 mg per day. The target population is adults excluding pregnant and lactating women. Taking into consideration the composition of the NF and the proposed uses, the composition of the NF is not nutritionally disadvantageous. There are no concerns regarding genotoxicity of the NF. Based on a 90-day oral toxicity study performed with the product as intended to be placed on the market (30% ashitaba sap powder and 70% cyclodextrins), the Panel establishes a safe dose of 0.5 mg/kg body weight (bw) per day for the product as it is intended to be placed on the market. For the target population, i.e. adults, this safe dose corresponds to 35 mg per day of the product as it is intended to be placed on the market and 137 mg per day of the NF, which is lower than the use level proposed by the applicant. The Panel concludes that the NF is safe for the target population at intake levels up to 137 mg per day.

Safety of HelixComplex snail mucus (HSM) as a novel food pursuant to Regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on HelixComplex Snail Mucus (HSM) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF consists of snail mucus collected from Helix aspersa maxima and is proposed to be used by adults as a food supplement. The data provided by the applicant about the composition and stability of the NF together with the report of the subchronic toxicity study were overall considered unsatisfactory. The Panel noted inconsistencies in the reporting of the certificates of analysis and of the data on the subchronic toxicity provided by the applicant. Owing to these deficiencies, the Panel cannot establish a safe intake level of the NF. The Panel concludes that the safety of the NF has not been established.

Solid-state electrochemical assay of heme-binding molecules for screening of drugs with antimalarial potential.

The interaction between heme and ligands is the basis for a variety of tests aimed at the discovery of antiplasmodial molecules. Two electrochemical methods for the screening of molecules with potential antimalarial activity through heme-binding mechanism are described. The first method is applicable to lipophilic environment, by using solution phase electrochemistry in DMSO solutions of Fe(III)-heme plus the tested compounds at carbon electrodes. This method provides well-defined voltammetric signals, characteristic of the heme-ligand (L) interaction. The second method involves aqueous media at biological pH and the use of voltammetry of immobilized particles, by means of microparticulate films of the tested compounds immersed into Fe(III)-heme solutions with no need of prior incubation. These methodologies are applied to the testing of heme-binding activity in macromolecular level systems like hemoglobin, or much more complex mixtures like total blood, erythrocytes, or hemolyzed samples.

Spontaneous formation of nitrarine and polycyclic skeletons related to Nitraria indolic alkaloids under non-enzymic conditions.

Mixtures of tryptamine and reactive C5 units, presumably derived from lysine in nature, were studied to ascertain the spontaneous formation of the complex polycyclic alkaloid nitrarine. Several indolic compounds tracing the unified metabolism within the Nitraria genus were also characterized.