A systematic review and quality assessment of case reports of adverse events for borage (Borago officinalis), coltsfoot (Tussilago farfara) and comfrey (Symphytum officinale)

Pyrrolizidine Alkaloids in Foods, Herbal Drugs, and Food Supplements: Chemistry, Metabolism, Toxicological Significance, Analytical Methods, Occurrence, and Challenges for Future

Consumers are increasingly seeking natural alternatives to chemical compounds, including the use of dried aromatic plants as seasonings instead of salt. However, the presence of pyrrolizidine alkaloids (PAs) in food supplements and dried plants has become a concern because of their link to liver diseases and their classification as carcinogenic by the International Agency for Research on Cancer (IARC). Despite European Union (EU) Regulation (EU) 2023/915, non-compliance issues persist, as indicated by alerts on the Rapid Alert System for Food and Feed (RASFF) portal. Analyzing PAs poses a challenge because of their diverse chemical structures and low concentrations in these products, necessitating highly sensitive analytical methods. Despite these challenges, ongoing advancements in analytical techniques coupled with effective sampling and extraction strategies offer the potential to enhance safety measures. These developments aim to minimize consumer exposure to PAs and safeguard their health while addressing the growing demand for natural alternatives in the marketplace.

LC-MS/MS Evaluation of Pyrrolizidine Alkaloids Profile in Relation to Safety of Comfrey Roots and Leaves from Polish Sources

Comfrey (Symphytum officinale L.) has a long tradition of use in the treatment of musculoskeletal disorders. However, due to hepatotoxic pyrrolizidine alkaloids (PAs), the EMA restricts the use of comfrey root (CR) to external use only and for short periods of time. Recent studies indicate a low permeability of PAs across the skin, calling into question the safety of topical application of products containing comfrey preparations. The aim of our work was to develop and validate an HPLC method enabling the separation of isomeric PAs from comfrey and, on this basis, to assess the potential toxicity of CR and comfrey leaf (CL) obtained from various Polish sources. The qualitative and quantitative analysis of PAs via HPLC-MS/MS was performed in MRM mode. The results obtained confirmed a lower content of PAs in CL than in CR and showed a wide variation in the composition of PAs in CR, with a much more stable profile of PAs in CL. Factor analysis confirmed that CRs and CLs differ in PA content, which is influenced by the growth conditions and geographical origin. The determined concentrations of PAs prove that in some CRs available on the Polish herbal market, the content of PAs may exceed the daily dose considered safe.

New advances in Nrf2-mediated analgesic drugs

BACKGROUND

Oxidative stress is an inevitable process that occurs during life activities, and it can participate in the development of inflammation. Although great progress has been made according to research examining analgesic drugs and therapies, there remains a need to develop new analgesic drugs to fill certain gaps in both the experimental and clinical space.

PURPOSE

This review reports the research and preclinical progress of this class of analgesics by summarizing known nuclear factor E-2-related factor-2 (Nrf2) pathway-modulating substances.

STUDY DESIGN

We searched and reported experiments that intervene in the Nrf2 pathway and its various upstream and downstream molecules for analgesic therapy.

METHODS

The medical literature database (PubMed) was searched for experimental studies examining the reduction of pain in animals through the Nrf2 pathway, the research methods were analyzed, and the pathways were classified and reported according to the pathway of these experimental interventions.

RESULTS

Humans have identified a variety of substances that can fight pain by regulating the expression of Nrf2 and its upstream and downstream pathways.

CONCLUSION

The Nrf2 pathway exerts anti-inflammatory activity by regulating oxidative stress, thereby playing a role in the fight against pain.

Wild leafy vegetables: A potential source for a traditional Mediterranean food from Lebanon

Introduction

In Lebanon, wild leafy vegetables (WLVs) continue to be an essential component of people's diet. Nevertheless, little ethnobotanical research has addressed this important potential source for food and nutrition.

Methods

In this study, an ethnobotanical survey was carried out between 2018 and 2022 across 21 villages/towns involving 151 local informants by semi-structured interviews.

Results and discussion

A list of 158 plant species which was still gathered and consumed by traditional Lebanese communities was compiled. The species belonged to 21 families and the most diverse families were Asteraceae (77 species), Brassicaceae (22), and Apiaceae (11). Native species accounted for 147 of the cited species, five of which were endemics to Lebanon and Syria. According to the Relative Frequency of Citation (RFC) index, Anchusa azurea, Centaurea hyalolepis, Chondrilla juncea, Eruca vesicaria, Pseudopodospermum molle, Pseudopodospermum papposum, and Taraxacum sect. Taraxacum were reported for the first time among the top popular species. Basal rosettes were the main parts consumed both raw and/or cooked. Informants perceived a decline in availability primarily due to habitat loss and land degradation. According to the International Union for Conservation of Nature (IUCN), six of cited species were classified as globally threatened (EN or VU), five of which were narrow endemics. These species scored substantial RFC values. Findings indicate that WEVs of Lebanon offer a promising potential to support food diversity and dietary quality of traditional communities and that threatened endemic species present a high conservation priority. Future research on nutritional contents of these species and highly rated WLVs is recommended.

Simultaneous Determination of 32 Pyrrolizidine Alkaloids in Two Traditional Chinese Medicine Preparations by UPLC-MS/MS

Pyrrolizidine alkaloids (PAs) constitute a class of phytotoxin which demonstrates strong hepatotoxicity. In China, many plants containing PAs are used as traditional medicines or medicinal preparations, which could harm human health and safety. Xiaoyao Tablet (XYT) is an antidepressant drug registered in the European Union (EU), Compound Danshen Dropping Pills (CDDP) is a commonly used drug for coronary heart disease, and phase III clinical study is ongoing in the United States. The purpose of this study is to provide data to support the use of Chinese medicine preparations internationally and to establish analytical methods for 32 PAs in XYT and CDDP. The extraction parameters that were optimized include solid-phase extraction (SPE) cartridge, extraction method, and extraction solvent. Then ultra-performance liquid chromatography coupled with triple-quadrupole linear ion-traptandem mass spectrometry (UPLC-MS/MS) was developed to effectively and efficiently quantify the 32 PAs of the XYT and CDDP. The analytical methods for XYT and CDDP were verified respectively. For XYT, the analytical method for 32 PAs was linear, and the correlation coefficient r was greater than 0.994; the recovery (REC%) at 10-2000 μg/kg was 73.3%-118.5%, and the relative standard deviation (RSD%) was 2.1%-15.4%. The CDDP REC% was 71.8%-112.0%, and the RSD% was 2.0%-17.1%. This study provides technical and data support for the registration of Chinese patented medicines in the EU, controls quality and ensures safety, and is committed to the internationalization and standardization of Chinese patented medicines.

Neuroprotective Profile of Edible Flowers of Borage (Borago officinalis L.) in Two Different Models: Caenorhabditis elegans and Neuro-2a Cells

The flowers of Borago officinalis L. (Boraginaceae), commonly known as borage, are widely used as a culinary ingredient. The aim of this study was to assess the potential benefits of fresh borage flower extract related to antioxidant, neuroprotective and anti-aging properties. The extract was obtained by Soxhlet extraction with ethanol as a solvent, and fatty acids were detected by GC-FID. The antioxidant activity was evaluated in vitro through the DPPH, FRAP and ORAC assays. Regarding the fatty acid (FA) composition, the extract showed high amounts of polyunsaturated FA. The Neuro-2a cell line was used to determine the cytoprotective capacity of the extract subjected to oxidative stress (H2O2). Moreover, the model organism Caenorhabditis elegans was used to assess antioxidant activity, delayed ageing as well as cytoprotection and reduced β-amyloid toxicity. Cells treated with the extract and H2O2 showed a better response to oxidative stress than the control group, particularly in terms of mitochondrial activity (MTT assay), redox state (ROS formation) and the activity of antioxidant enzymes (catalase and superoxide dismutase). B. officinalis flower extract showed promising antioxidant activity in the selected models, without causing toxicity. Hence, the results obtained support the antioxidant properties of borage flowers in different bioassays using living organisms.

A Comparative Analysis of the Anatomy, Phenolic Profile, and Antioxidant Capacity of Tussilago farfara L. Vegetative Organs

Tussilago farfara L., a perennial species, is a medicinal herb used in traditional medicine, mainly for the treatment of respiratory tract-related pathology. In traditional Chinese medicine, flower buds are preferred; in Europe, the leaves are used; and in some parts of India, the whole plant is utilized. This preferential usage of the plant organs might be based on differences in the chemical composition due to environmental conditions, along with preferred traditional and cultural approaches. In this article, the impact of pedoclimatic growth conditions on the morpho-anatomical development and phytochemical profile of the plant were studied on T. farfara in the vegetative state, collected from two different locations in the Romanian spontaneous flora, revealing significant variations. Furthermore, the antioxidant profile of the specific extracts from the aerial and subterranean plant parts is also in accordance with these discrepancies. The plant anatomy was assessed histologically by optical microscopy, while the analytical chemistry evaluation was based on LC/MS and spectral methods for the evaluation of the antioxidant and enzyme inhibitory activity. To our knowledge, this is the first comparative analysis contextually reporting on the histology, phenolic profile, antioxidant capacity, and geographical location of the vegetative form of T. farfara.

Anti-inflammatory Properties of the Genus Symphytum L.: A Review

: The Symphytum genus has been mainly used in traditional medicine, containing its anti-inflammatory activity. Symphytum spp.’s active components, such as allantoin, polyphenols, flavonoids, and alkaloids, can act on several intentions in the signaling pathway, constrain pro-inflammatory enzymes, reducing the construction of inflammatory chemokine’s and cytokines, and decreasing oxidative stress, which afterward suppresses inflammation procedures. Preclinical and clinical trials have reported the prevailing anti-inflammatory effect of several Symphytum species. This review presents an overview of the anti-inflammatory activities of different products and bioactive constituents in this genus. The papers with the English language were gathered from 2000 to 2021. This review may provide a scientific base for establishing innovative and alternative techniques for isolating a single individual from this genus to attenuate inflammatory disorders. The Symphytum genus is waiting for researchers to develop safe and effective anti-inflammatory agents for additional investigation of other different mechanisms of action.

Evaluation of Borage (Borago officinalis L.) Genotypes for Nutraceutical Value Based on Leaves Fatty Acids Composition

Borage (Borago officinalis L.) is a traditional vegetable grown and consumed in some Spanish regions. The objective of this study was to determine the variability and evolution of fatty acid composition in a borage germplasm collection formed by wild types, breeding lines, commercial varieties, and landraces. Fatty acids were analysed in petioles, the commonly edible part of the leaves, and the leaf blades, the by-product of the borage industry, in two growth stages: at the optimal harvest period (120 days after sowing) and at the end of the harvest period (150 days after sowing). The results showed that for each of the eight fatty acids identified, there were significant differences among the twelve borage genotypes depending on the developmental plant stage at sampling date and the part of the leaf analysed, the interaction effect also being statistically significant. The main polyunsaturated fatty acids identified were: linoleic acid (18:2 n6, LA), α-linolenic acid (18:3 n3, ALA), γ-linolenic acid (18:3 n6, GLA), and stearidonic acid (SDA, 18:4, n-3), account for approximately 70% of polyunsaturated fatty acids. Blue-flowered genotypes differ from white-flowered genotypes by their high content of ALA and SDA, which can be exploited in borage breeding programs. Petioles from young plants present higher n6 fatty acids, while older plants produce a great amount of n3 fatty acids. Besides, the higher content of ALA in the leaf blades gives them a good dietary potential. All these fatty acids, with multiple health benefits, support the nutraceutical interest of borage leaves (both petioles and leaf blades) for human consumption, animal feeding, medicine, and pharmacy.

Streptomyces pactum and Bacillus consortium influenced the bioavailability of toxic metals, soil health, and growth attributes of Symphytum officinale in smelter/mining polluted soil

Soil microbes influence the uptake of toxic metals (TMs) by changing soil characteristics, bioavailability and translocation of TMs, and soil health indicators in polluted environment. The potential effect of Streptomyces pactum (Act12) and Bacillus consortium (B. subtilis and B. licheniformis; 1:1) on soil enzymes and bacterial abundance, bioavailability and translocation of Zn and Cd by Symphytum officinale, and physiological indicators in soil acquired from Fengxian (FX) mining site. Act12 and Bacillus consortium were applied at 0 (CK), 0.50 (T1), 1.50 (T2), and 2.50 (T3) g kg^-1 in a split plot design and three times harvested (H). Results showed that soil pH significantly dropped, whereas, electrical conductivity increased at higher Act12 and Bacillus doses. The extractable Zn lowered and Cd increased at each harvest compared to their controls. Soil β-glucosidase, alkaline phosphatase, urease and sucrase improved, whereas, dehydrogenase reduced in harvest 2 and 3 (H2 and H3) as compared to harvest 1 (H1) after Act12 and Bacillus treatments. The main soil phyla individually contributed ∼5-55.6%. Soil bacterial communities' distribution was also altered by Act12 and Bacillus amendments. Proteobacteria, Acidobacteria, and Bacteroidetes increased, whereas, the Actinobacteria, Chloroflexi, and Gemmatimonadetes decreased during the one-year trial. The Zn and Cd concentration significantly decreased in shoots at each harvest, whereas, the roots concentration was far higher than the shoots, implicating the rhizoremediation by S. officinale. Accumulation factor (AF) and bioconcentration ratio (BCR) of Zn and Cd in shoots were lower and remained higher in case of roots than the standard level (≥1). BCR values of roots indicated that S. officinale can be used for rhizoremediation of TMs in smelter/mines-polluted soils. Thus, field trials in smelter/mines contaminated soils and the potential role of saponin and tannin exudation in metal translocation by plant will broaden our understanding about the mechanism of rhizoremediation of TMs by S. officinale.

Comfrey (Symphytum spp.) as a feed supplement in pig nutrition contributes to regional resource cycles

In smallholder agriculture, the fast-growing and perennial accumulator plant comfrey (Symphytum spp.) was used to supply pigs with protein and minerals. Comfrey leaves show similar values in dry matter as soybean or blue lupine in crude protein content, but much higher levels of calcium and phosphorus. However, in terms of increased efficiency in animal husbandry, comfrey has been displaced by mainly soybean and cereals. Due to its profile of macro- and micronutrients the use of comfrey could have the potential to re-establish local resource cycles and help remediate over-fertilized soils. The aim of the study was to evaluate whether a modern pig breed accepts a continuous feed supplement of dried comfrey leaves. After an initial adaptation period post-weaning, German Landrace piglets were subjected to either a standard control diet or a diet supplemented with 15% dried comfrey leaves for 4 weeks. Body weight was reduced in comfrey-supplemented piglets compared to controls, which might be attributed to reduced palatability in the experimental setting. Nevertheless, comfrey-supplemented piglets exhibited adequate bone mineralization and intestinal integrity. The microbiome profile in feces and digesta revealed higher diversity in comfrey-supplemented piglets compared to controls, with pronounced effects on the abundances of Treponema and Prevotella. This may be due to described bio-positive components of the comfrey plant, as data suggest that the use of comfrey leaves may promote intestinal health. Digestive tract phosphorus levels were reduced in piglets receiving comfrey supplementation, which may ultimately affect phosphorus levels in manure. Results indicate that comfrey leaves could serve as a feed component in integrated agricultural systems to establish regional nutrient cycles. The trial provides a basis for further work on comfrey as a regionally grown protein source and effective replacement for rock mineral supplements.

CRISPR/Cas9-Mediated Genome Editing in Comfrey (Symphytum officinale) Hairy Roots Results in the Complete Eradication of Pyrrolizidine Alkaloids

Comfrey (Symphytum officinale) is a medicinal plant with anti-inflammatory, analgesic, and proliferative properties. However, its pharmaceutical application is hampered by the co-occurrence of toxic pyrrolizidine alkaloids (PAs) in its tissues. Using a CRISPR/Cas9-based approach, we introduced detrimental mutations into the hss gene encoding homospermidine synthase (HSS), the first pathway-specific enzyme of PA biosynthesis. The resulting hairy root (HR) lines were analyzed for the type of gene-editing effect that they exhibited and for their homospermidine and PA content. Inactivation of only one of the two hss alleles resulted in HRs with significantly reduced levels of homospermidine and PAs, whereas no alkaloids were detectable in HRs with two inactivated hss alleles. PAs were detectable once again after the HSS-deficient HRs were fed homospermidine confirming that the inability of these roots to produce PAs was only attributable to the inactivated HSS and not to any unidentified off-target effect of the CRISPR/Cas9 approach. Further analyses showed that PA-free HRs possessed, at least in traces, detectable amounts of homospermidine, and that the PA patterns of manipulated HRs were different from those of control lines. These observations are discussed with regard to the potential use of such a CRISPR/Cas9-mediated approach for the economical exploitation of in vitro systems in a medicinal plant and for further studies of PA biosynthesis in non-model plants.

Comfrey (Symphytum spp.) as an alternative field crop contributing to closed agricultural cycles in chicken feeding

Local cultivars of comfrey (Symphytum spp.) have been used to cover protein and mineral requirements of farm animals in low-input systems. Due to its known health-promoting (e.g. allantoin), but also anti-nutritive ingredients (e.g. pyrrolizidine alkaloids), multidisciplinary approaches are essential in order to quantify the nutritional value and the potential of its use in poultry and farm animals in terms of meeting animal needs, using local resources as well as remediating over-fertilized soils. Focusing on animal effects, here one-day old sexed Cobb500 broiler chickens were subjected to either a standard control diet or a standard diet supplemented with 4% dried comfrey leaves for 32 days. Performance traits indicate good acceptance of supplementation with comfrey leaves. Parameters for liver function, mineral homeostasis, bone mineral density as well as intestinal microanatomy revealed no signs of impairment. Quantified pyrrolizidine alkaloids were below the detection limit in liver and breast muscle (<5 μg/kg tissue). Comfrey supplemented male broiler chickens showed higher ash content in breast muscle and revealed altered gene expression profiles for metabolic pathways in blood cells. In healthy broiler chickens, the transcriptome analyses revealed no aberrations in the immune-related pathways due to comfrey supplementation. The results imply that the use of comfrey leaves in a high-performance broiler line seems feasible and offers the potential for closed nutrient cycles in site-adapted local agricultural systems. Further analyses need to focus on possible growth-promoting and health-improving components of comfrey and the safe use of chicken products for human consumption.