Phytochemical profiling and bioactivity assessment of underutilized Symphytum species in comparison with Symphytum officinale.

BACKGROUND: Symphytum (comfrey) genus, particularly Symphytum officinale, has been empirically used in folk medicine mainly for its potent anti-inflammatory properties. In an attempt to shed light on the valorization of less known taxa, the current study evaluated the metabolite profile and antioxidant and enzyme inhibitory effects of nine Symphytum species. RESULTS: Phenolic acids, flavonoids and pyrrolizidine alkaloids were the most representative compounds in all comfrey samples. Hierarchical cluster analysis revealed that, within the roots, S. grandiflorum was slightly different from S. ibericum, S. caucasicum and the remaining species. Within the aerial parts, S. caucasicum and S. asperum differed from the other samples. All Symphytum species showed good antioxidant and enzyme inhibitory activities, as evaluated in DPPH (up to 50.17 mg Trolox equivalents (TE) g-1), ABTS (up to 49.92 mg TE g-1), cupric reducing antioxidant capacity (CUPRAC, up to 92.93 mg TE g-1), ferric reducing antioxidant power (FRAP, up to 53.63 mg TE g-1), acetylcholinesterase (AChE, up to 0.52 mg galanthamine equivalents (GALAE) g-1), butyrylcholinesterase (BChE, up to 0.96 mg GALAE g-1), tyrosinase (up to 13.58 mg kojic acid equivalents g-1) and glucosidase (up to 0.28 mmol acarbose equivalents g-1) tests. Pearson correlation analysis revealed potential links between danshensu and ABTS/FRAP/CUPRAC, quercetin-O-hexoside and DPPH/CUPRAC, or rabdosiin and anti-BChE activity. CONCLUSIONS: By assessing for the first time in a comparative manner the phytochemical-biological profile of a considerably high number of Symphytum samples, this study unveils the potential use of less common comfrey species as novel phytopharmaceutical or agricultural raw materials. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Influence of pyrrolizidine alkaloids depletion upon the biological activity of Symphytum officinale L. extracts.

ETHNOPHARMACOLOGICAL RELEVANCE: Comfrey (Symphytum officinale L., Boraginaceae) root preparations are used as both traditional remedies and therapeutic agents in treating pain and inflammation associated with joint, bone, and muscle ailments. Even though numerous phytochemicals contribute to the beneficial effects of comfrey, the presence of toxic pyrrolizidine alkaloids (PAs) overshadows its uses. AIM OF THE STUDY: In this work, different PA-/mucilage-depleted/undepleted comfrey root extracts were subjected to detailed phytochemical characterization and biological evaluation. MATERIALS AND METHODS: The phytochemical profiling was performed by LC-HRMS/MS. The quantification of PAs and major phenolic compounds was carried out by LC-MS/MS and LC-DAD. Antioxidant and enzyme inhibitory activity was determined by in vitro free radical scavenging, ion reducing, metal chelating, cholinesterase, tyrosinase, amylase, and glucosidase assays. Using an ex vivo model of LPS-stimulated neutrophils, their viability (as measured by flow cytometry) and the release of IL-1ß, IL-8, and TNF-α were determined (ELISA assay). RESULTS: 12 phenolic acids, six PAs, three organic acids, two fatty acids, and two sugars were identified in the obtained comfrey extracts. The PA-depleted materials contained PAs levels below 2 ppm, whereas the removal of mucilage increased the content of rosmarinic acid, globoidnan A, globoidnan B, and rabdosiin. PA-depletion did not significantly affect the antioxidant potential. However, the radical scavenging and metal reducing properties were higher in the mucilage-depleted extracts. Neither PA-depletion nor mucilage-depletion had considerable effects on the in vitro inhibitory activity of cholinesterases, tyrosinase, amylase, and glucosidase or release of ex vivo pro-inflammatory cytokines (e.g., IL-1ß, IL-8, and TNF-α) in LPS-stimulated neutrophils. CONCLUSIONS: In light of their superior safety profiles, PA-depleted comfrey extracts can be utilized further in cosmetic and pharmaceutical products.

Safety of medicinal comfrey cream preparations (Symphytum officinale s.l.): The pyrrolizidine alkaloid lycopsamine is poorly absorbed through human skin.

European Union guidelines indiscriminately discuss a permitted daily exposure (PDE) for pyrrolizidine alkaloids (PA) of up to 0.007 µg/kg body weight for oral and for topical exposure to herbal medicinal products. In this study, lycopsamine served as a model substance for measuring the extent of skin permeation of PAs following the application of a spiked comfrey cream (Symphytum officinale s.l.) to abdominal skin from human donors in Franz diffusion cells. PAs could be excluded in the non-spiked cream with a limit of detection of 8 µg/kg. Only small amounts of the applied quantity of lycopsamine had migrated through the skin sample into the receptor cell side of the diffusion cell after 24 h. In five of six diffusion cells, there was no detectable lycopsamine within the skin and only 0.6 ± 0.4% of the applied dose in the receptor fluid. The theoretical skin penetration of 4.9% of the applied quantity of lycopsamine largely resulted from the worst case approach of assuming the presence of at least a quantity corresponding to the limit of detection - the true penetration is probably considerably lower. Even with the worst-case calculation, the currently discussed guidelines on PA overestimate the risk related to topical preparations.

LC-ESI-FT-MSn Metabolite Profiling of Symphytum officinale L. Roots Leads to Isolation of Comfreyn A, an Unusual Arylnaphthalene Lignan.

Preparations of comfrey (Symphytum officinale L.) roots are used topically to reduce inflammation. Comfrey anti-inflammatory and analgesic properties have been proven in clinical studies. However, the bioactive compounds associated with these therapeutic activities are yet to be identified. An LC-ESI-Orbitrap-MSn metabolite profile of a hydroalcoholic extract of comfrey root guided the identification of 20 compounds, including a new arylnaphthalene lignan bearing a rare δ-lactone ring, named comfreyn A. Its structure was determined using extensive 2D NMR and ESI-MS experiments. Additionally, the occurrence of malaxinic acid, caffeic acid ethyl ester, along with the lignans ternifoliuslignan D, 3-carboxy-6,7-dihydroxy-1-(3',4'-dihydroxyphenyl) -naphthalene, globoidnan A and B, and rabdosiin was reported in S. officinale for the first time. These results helped to redefine the metabolite profile of this medicinal plant. Finally, caffeic acid ethyl ester and comfreyn A were found to significantly inhibit E-selectin expression in IL-1ß stimulated human umbilical vein endothelial cells (HUVEC), with EC values of 64 and 50 µM, respectively.

Epidermal Regeneration Induced by Comfrey Extract: A Study by Light and Electron Microscopy.

INTRODUCTION: An accelerated healing of superficial wounds was demonstrated in clinical trials with a topical comfrey preparation (Symphytum × uplandicum Nyman). The effect has previously not been examined in skin models. METHODS: An established in vitro model of epidermal cells with the typical strata was used for the observation of effects of applied substances on skin regeneration. Damage corresponding to a typical abrasion was created on day 1 by punching an opening into the epidermal fine structure down to the stratum basale. Samples were either untreated (controls) or exposed to comfrey cream on days 2, 3, 5, and 6. Tissue samples were taken for light and electron microscopy on days 1, 4, and 7. RESULTS AND CONCLUSIONS: Application of comfrey cream led to a quicker regeneration of skin cells and to an earlier differentiation of the cells towards a normal fine structure with a visible distinction of epidermal strata, keratin, and corneocyte formation within 4-7 days. The study covered the early days of skin regeneration and confirms the benefits observed in published clinical trials and non-interventional studies in patients with abrasions.

Comparative Assessment of Phytochemical Profiles of Comfrey (Symphytum officinale L.) Root Extracts Obtained by Different Extraction Techniques.

In this work a comparative study on phytochemical profiles of comfrey root extracts obtained by different extraction approaches has been carried out. Chemical profiles of extracts obtained by supercritical fluid (SFE), pressurized liquid (PLE), and conventional solid/liquid extraction were compared and discussed. Phytochemical composition was assessed by high-performance liquid chromatography coupled with electrospray time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS) identifying 39 compounds reported for the first time in comfrey root, mainly phenolic acids and fatty acids. The influence of different extraction parameters on phytochemical profiles of S. officinale root was investigated for all applied techniques. PLE and maceration, using alcohol-based solvents (aqueous methanol or ethanol), were shown to be more efficient in the recovery of more polar compounds. Greater numbers of phenolics were best extracted by PLE using 85% EtOH at 63 °C. The use of SFE and 100% acetone for 30 min enabled good recoveries of nonpolar compounds. SFE using 15% EtOH as a cosolvent at 150 bar produced the best recoveries of a significant number of fatty acids. The main compositional differences between extracts obtained by different extraction techniques were assigned to the solvent type. Hence, these results provided comprehensive approaches for treating comfrey root enriched in different phytochemicals, thereby enhancing its bioaccessibility.

Symphytum officinale augments osteogenesis in human bone marrow-derived mesenchymal stem cells in vitro as they differentiate into osteoblasts.

ETHNOPHARMACOLOGICAL RELEVANCE: Mesenchymal stem cells (MSCs) are multipotent stem cells possessing regenerative potential. Symphytum officinale (SO) is a medicinal plant and in homoeopathic literature, believed to accelerate bone healing. AIM OF THE STUDY: This study aimed to determine if homoeopathic doses of SO could augment osteogenesis in MSCs as they differentiate into osteoblasts in vitro. MATERIALS AND METHODS: Bone marrow samples were obtained from patients who underwent bone grafting procedures (n = 15). MSCs were isolated, expanded and characterized by flow cytometry (CD90, CD105). Cytotoxicity of SO was evaluated by MTT assay. Osteogenic differentiation was induced in MSCs with ß-glycerophosphate, ascorbic acid and dexamethasone over 2 weeks. Different homoeopathic doses of SO (MT, 3C, 6C, 12C and 30C) were added to the basic differentiation medium (BDM) and efficiency of MSCs differentiating into osteoblasts were measured by evaluating expression of Osteocalcin using flow cytometry, and alkaline phosphatase activity using ELISA. Gene expression analyses for osteoblast markers (Runx-2, Osteopontin and Osteocalcin) were evaluated in differentiated osteoblasts using qPCR. RESULTS: Flow cytometry (CD90, CD105) detected MSCs isolated from bone marrow (93-98%). MTT assay showed that the selected doses of SO did not induce any cytotoxicity in MSCs (24 hours). The efficiency of osteogenic differentiation (2 weeks) for different doses of Symphytum officinale was determined by flow cytometry (n = 10) for osteoblast marker, Osteocalcin, and most doses of Symphytum officinale enhanced osteogenesis. Interestingly, gene expression analysis for Runx-2 (n = 10), Osteopontin (n = 10), Osteocalcin (n = 10) and alkaline phosphatase activity (n = 8) also showed increased osteogenesis with the addition of Symphytum officinale to BDM, specially mother tincture. CONCLUSIONS: Our findings suggest that homoeopathic dose (specially mother tincture) of Symphytum officinale has the potential to enhance osteogenesis.

Reduction of Pyrrolizidine Alkaloid Levels in Comfrey (Symphytum officinale) Hairy Roots by RNAi Silencing of Homospermidine Synthase.

Comfrey is a medicinal plant, extracts of which are traditionally used for the treatment of painful inflammatory muscle and joint problems, because the plant contains allantoin and rosmarinic acid. However, its medicinal use is limited because of its toxic pyrrolizidine alkaloid (PA) content. PAs encompass more than 400 different compounds that have been identified from various plant lineages. To date, only the first pathway-specific enzyme, homospermidine synthase (HSS), has been characterized. HSS catalyzes the formation of homospermidine, which is exclusively incorporated into PAs. HSS has been recruited several times independently in various plant lineages during evolution by duplication of the gene encoding deoxyhypusine synthase (DHS), an enzyme of primary metabolism. Here, we describe the establishment of RNAi knockdown hairy root mutants of HSS in Symphytum officinale. A knockdown of HSS by 60 - 80% resulted in a significant reduction of homospermidine by ~ 86% and of the major PA components 7-acetylintermedine N-oxide and 3-acetylmyoscorpine N-oxide by approximately 60%. The correlation of reduced transcript levels of HSS with reduced levels of homospermidine and PAs provides in planta support for HSS being the central enzyme in PA biosynthesis. Furthermore, the generation of PA-depleted hairy roots might be a cost-efficient way for reducing toxic by-products that limit the medicinal applicability of S. officinale extracts.

Proliferative and antioxidant activity of Symphytum officinale root extract.

The root of Symphytum officinale L. is commonly used in folk medicine to promote the wound healing, reduce the inflammation and in the treatment of broken bones. The objective of our investigation was to analyse the extract from S. officinale in term of its antioxidant activity and the effect on cell viability and proliferation of human skin fibroblast (HSF). Moreover, the quantification of main phenolics and allantoin was conducted using HPLC-DAD method. Five compounds were found: rosmarinic, p-hydroxybenzoic, caffeic, chlorogenic and p-coumaric acid. DPPH, FRAP and TPC assay showed the high antioxidant activity of the extract. MTT test proved the stimulatory effect on cell metabolism and viability of HSF cells. Moreover, no changes in cytoskeleton structure and cells shape were observed. The obtained results indicate that non-toxic extract from S. officinale root has strong antioxidant potential and a beneficial effect on human skin fibroblasts.

FORMULATION AND TECHNOLOGY DEVELOPMENT OF HERBAL PHENOLIC BIOPOLYMER-CONTAINING FILMS FOR BURN TREATMENT.

Application of phytofilms based on biosolublepolymers is considered as a prospectivemethod for burn treatment . Herbal remedies contain biologically active substances, that are relatively less toxic, do not cause skin irritation or allergic reactions and, importantly, affectstrains of the microorganisms and viruses resistant to antibiotics and synthetic drugs. Nowadays, the advantages are given to such burn healing drugs, which along with high specific efficacy, have analgesic, anti-inflammatory and antimicrobial effects, and don't irritate the tissues. The mentioned peculiarities are characteristic for a new herbal phenolic biopolymer poly[3-(3,4-dihydroxyphenyl) glyceric acid](PDGA), isolated from the roots and stems of different comfrey species . The aim of the study was the development of the formulation and technology of biosoluble films for burn treatment on the basis of PDGA. The optimal content of phytofilm for burn healing was selected on the basis of the biopharmaceutical study results. The impact of the film-former on the quality, adhesion and moisture absorption of the phytofilmhas been studied. The optimal degree of the phytofilm moisture, determining its high adhesive properties,was established. The film prepared on the basis of sodium alginate, with 30.4% humidity, demonstrated the greatest adhesion strength. After investigation of the PDGA release it was found, that the hydrophilic bases such as: sodium carboxymethyl-cellulose (69.2%) andsodium alginate (78,65%) appeared to be optimal among the others. At the same time, taking into consideration the disadvantages of sodium carboxymethyl-cellulose (tautening effect on burnt surface, relatively low stability), a film based on sodium alginate has been chosen. The manufacturing technology for obtaining PDGA-containing phytofilm by casting is proposed. Theshelf-lifeofproposedPDGA-containingphytofilmis 2 years.

DEVELOPMENT OF FORMULATION AND TECHNOLOGY FOR THE POLY[3-(3,4-DIHYDROXYPHENYL)GLYCERIC ACID] GEL.

One of the most actual problems of pharmacy is the development of medication forms for external application with complex effects on (gel, emplastro, aerosol, etc.) skin wounds, burns and inflammatory factors. The centuries-old practice of using phyto-preparations (herbal remedies) proved that they have fewer side effects in comparison with synthetic drugs. Despite the wide application of herbal preparations, in the literature there is a little information about their application in development of wound and burn healing modern dosage forms. Among the medicinal plants with the mentioned pharmacological actions, comfrey (Symphytum L.) should be distinguished. Phenolic polymer poly[3-(3,4-dihydroxyphenyl)glyceric acid] (PDGA) or poly[oxy-1-carboxy-2-(3,4-dihydroxyphenyl)ethylene], amounting approximately 25% of polysaccharides and 1.5-2.5% of dry plant material, were isolated from the roots and stems of Caucasian comfrey species (S. asperum, S. caucasicum). Contrary to polysaccharides this phenolic polymer of Comfrey appeared to have a high immunomodulatory (anticomplement), antioxidative, antilipoperoxidantive, anti-inflammatory and wound-healing efficacy/activities. The aim of the study was development of the composition and technology of PDGA-containing gel. According to the results of complex biopharmaceutical studies PDGA gel optimal composition has been proved. The technological scheme for preparation of PDGA gel has been developed. PDGA gel stability under normal conditions of storage at +40С was studied. The gel has a shelf life (determined expiration date) of 2 year.

Penetration of lycopsamine from a comfrey ointment through human epidermis.

Mutagenic and teratogenic pyrrolizidine alkaloids (PAs) have been identified in several plant species. The industrially most important PA-containing plant is Symphytum officinale (common comfrey). The application of its root is restricted in several countries due to its PA content. In medicines, the daily alkaloid quantity and duration of treatment may be limited even in case of topical application. Due to the confirmed good absorption of PAs from the gastrointestinal tract, the prohibition of oral use is justified, however the limitation of external application is not supported by relevant data. Penetration experiments on human skin are not available to be a rational basis for limitation. The aim of our work was to carry out pharmacokinetic studies on the diffusion and penetration of lycopsamine (a main PA of comfrey) from a Symphytum product through a synthetic membrane and human skin. Investigations were carried out on vertical Franz diffusion cell and lycopsamine was quantified by a validated LC-MS method. The amount of lycopsamine diffused through a synthetic membrane varied between 0.11% and 0.72% (within 24 h). On human epidermis, the rate of penetration was lower (0.04-0.22%). Our results may contribute to the more realistic toxicological assessment of externally applied PA-containing products.

The comparative toxicity of a reduced, crude comfrey (Symphytum officinale) alkaloid extract and the pure, comfrey-derived pyrrolizidine alkaloids, lycopsamine and intermedine in chicks (Gallus gallus domesticus).

Comfrey (Symphytum officinale), a commonly used herb, contains dehydropyrrolizidine alkaloids that, as a group of bioactive metabolites, are potentially hepatotoxic, pneumotoxic, genotoxic and carcinogenic. Consequently, regulatory agencies and international health organizations have recommended comfrey be used for external use only. However, in many locations comfrey continues to be ingested as a tisane or as a leafy vegetable. The objective of this work was to compare the toxicity of a crude, reduced comfrey alkaloid extract to purified lycopsamine and intermedine that are major constituents of S. officinale. Male, California White chicks were orally exposed to daily doses of 0.04, 0.13, 0.26, 0.52 and 1.04 mmol lycopsamine, intermedine or reduced comfrey extract per kg bodyweight (BW) for 10 days. After another 7 days chicks were euthanized. Based on clinical signs of poisoning, serum biochemistry, and histopathological analysis the reduced comfrey extract was more toxic than lycopsamine and intermedine. This work suggests a greater than additive effect of the individual alkaloids and/or a more potent toxicity of the acetylated derivatives in the reduced comfrey extract. It also suggests that safety recommendations based on purified compounds may underestimate the potential toxicity of comfrey.

Quantification of pyrrolizidine alkaloids in North American plants and honey by LC-MS: single laboratory validation.

Pyrrolizidine alkaloids (PAs) are a class of naturally occurring compounds produced by many flowering plants around the World. Their presence as contaminants in food systems has become a significant concern in recent years. For example, PAs are often found as contaminants in honey through pollen transfer. A validated method was developed for the quantification of four pyrrolizidine alkaloids and one pyrrolizidine alkaloid N-oxide in plants and honey grown and produced in British Columbia. The method was optimised for extraction efficiency from the plant materials and then subjected to a single-laboratory validation to assess repeatability, accuracy, selectivity, LOD, LOQ and method linearity. The PA content in plants ranged from1.0 to 307.8 µg/g with repeatability precision between 3.8 and 20.8% RSD. HorRat values were within acceptable limits and ranged from 0.62 to 1.63 for plant material and 0.56-1.82 for honey samples. Method accuracy was determined through spike studies with recoveries ranging from 84.6 to 108.2% from the raw material negative control and from 82.1-106.0 % for the pyrrolizidine alkaloids in corn syrup. Based on the findings in this single-laboratory validation, this method is suitable for the quantitation of lycopsamine, senecionine, senecionine N-oxide, heliosupine and echimidine in common comfrey (Symphytum officinale), tansy ragwort (Senecio jacobaea), blueweed (Echium vulgare) and hound's tongue (Cynoglossum officinale) and for PA quantitation in honey and found that PA contaminants were present at low levels in BC honey.

A Validated, Rapid HPLC-ESI-MS/MS Method for the Determination of Lycopsamine.

The aim of the present work was to develop and validate an HPLC-MS/MS method for the determination of a major pyrrolizidine alkaloid of comfrey (lycopsamine) in aqueous samples as a basis for the development of a method for the determination of absorption of lycopsamine by human skin. A linear calibration curve was established in the range of 1.32-440 ng. The intraday precision during the 3-day validation period ranged between 0.57 and 2.48% while the interday precision was 1.70% and 1.95% for quality control samples. LOD was 0.014 ng and recovery was above 97%. The lycopsamine content of the samples stored for 9 and 25 days at 22 degrees C, 10 degrees C and -25 degrees C did not vary. These results underline the good repeatability and accuracy of our method and allow the analysis of samples with very low lycopsamine content.

Comparative Study of the Biological Activity of Allantoin and Aqueous Extract of the Comfrey Root.

This study investigates the biological activity of pure allantoin (PA) and aqueous extract of the comfrey (Symphytum officinale L.) root (AECR) standardized to the allantoin content. Cell viability and proliferation of epithelial (MDCK) and fibroblastic (L929) cell line were studied by using MTT test. Anti-irritant potential was determined by measuring electrical capacitance, erythema index (EI) and transepidermal water loss of artificially irritated skin of young healthy volunteers, 3 and 7 days after application of creams and gels with PA or AECR. Pure allantoin showed mild inhibitory effect on proliferation of both cell lines at concentrations 40 and 100 µg/ml, but more pronounced on MDCK cells. Aqueous extract of the comfrey root effect on cell proliferation in concentrations higher than 40 µg/ml was significantly stimulatory for L929 but inhibitory for MDCK cells. Pharmaceutical preparations that contained AECR showed better anti-irritant potential compared with PA. Creams showed better effect on hydration and EI compared with the gels that contained the same components. Our results indicate that the biological activity of the comfrey root extract cannot be attributed only to allantoin but is also likely the result of the interaction of different compounds present in AECR. Topical preparations that contain comfrey extract may have a great application in the treatment of skin irritation.

TLC densitometric method for screening of lycopsamine in comfrey root (Symphytum officinale L.) extracts using retrorsine as a reference compound.

Due to severe toxicity of pyrrolizidine alkaloids, their quantification in medicinal products is very important. The idea of this research was to use retrorsine as a surrogate reference compound instead of lycopsamine reference or lycopsamine isolated from comfrey. A method for the analysis of lycopsamine in extracts of comfrey roots was developed and validated, employing thin layer chromatography, derivatisation with Dann-Mattocks reagent followed by densitometric analysis. The new method showed linearity within 0.70 to 7.0 µg of lycopsamine per application of 10 µL of a solution. It has also been proven to be specific and precise (repeatability RSD 2-4 % within the plate). The method was successfully employed for quantification of lycopsamine in comfrey root and comfrey root medicinal products such as ointments.

Sodium-hydrogen exchanger inhibitory potential of Malus domestica, Musa × paradisiaca, Daucus carota, and Symphytum officinale.

BACKGROUND: The involvement of sodium-hydrogen exchangers (NHE) has been described in the pathophysiology of diseases including ischemic heart and brain diseases, cardiomyopathy, congestive heart failure, epilepsy, dementia, and neuropathic pain. Synthetic NHE inhibitors have not achieved much clinical success; therefore, plant-derived phytoconstituents may be explored as NHE inhibitors. METHODS: In the present study, the NHE inhibitory potential of hydroalcoholic and alkaloidal fractions of Malus domestica, Musa × paradisiaca, Daucus carota, and Symphytum officinale was evaluated. The different concentrations of hydroalcoholic and alkaloidal extracts of the selected plants were evaluated for their NHE inhibitory activity in the platelets using the optical swelling assay. RESULTS: Among the hydroalcoholic extracts, the highest NHE inhibitory activity was shown by M. domestica (IC50=2.350 ± 0.132 µg/mL) followed by Musa × paradisiaca (IC50=7.967 ± 0.451 µg/mL), D. carota (IC50=37.667 ± 2.517 µg/mL), and S. officinale (IC50=249.330 ± 1.155 µg/mL). Among the alkaloidal fractions, the highest NHE inhibitory activity was shown by the alkaloidal fraction of Musa × paradisiacal (IC50=0.010 ± 0.001 µg/mL) followed by D. carota (IC50=0.024 ± 0.002 µg/mL), M. domestica (IC50=0.031 ± 0.005 µg/mL), and S. officinale (IC50=4.233 ± 0.379 µg/mL). The IC50 of alkaloidal fractions was comparable to the IC50 of synthetic NHE inhibitor, EIPA [5-(N-ethyl-N-isopropyl)amiloride] (IC50=0.033 ± 0.004 µg/mL). CONCLUSIONS: It may be concluded that the alkaloidal fractions of these plants possess potent NHE inhibitory activity and may be exploited for their therapeutic potential in NHE activation-related pathological complications.

[Efficacy and safety of symphytum herb extract cream in the treatment of pressure ulcers]. / Therapieergebnisse und Anwendungssicherheit von Symphytum-Herba-Extrakt-Creme in der Behandlung von Dekubitus.

In an open, prospective use study, 161 patients with 198 decubitus ulcers (pressure ulcers, ITT population) in stages II and III were treated with the topical preparation symphytum herb extract cream. The bandages with the cream were changed every 2-3 days. The primary parameters evaluated were the area of the sore and the depth of the wound (planimetrically in mm). In all, 151 patients with a total of 184 pressure sores (PP population) were included and received treatment over a period of 4 weeks in order to evaluate the treatment results. Complete healing of the pressure sores within 4 weeks was observed in 85.9 % (PP population)/79.8 % (ITT population) of the treated ulcers. Over a treatment duration of 25-30 days, a 89.2 % reduction of the total decubitus area was observed. The same result was found for the depth of the pressure ulcer with a reduction of 88 %. The overall treatment success was from both the perspective of the physician and the patient considered successful in 90.4 % (5-point scale) of cases and 87.9% (100 mm VAS, PP population). Two cases of local irritation were observed after 25/30 days (1.2 % of the patients with exposure), thus showing very good skin compatibility. The efficacy of symphytum herb extract cream is surprisingly good in the treatment of pressure ulcers.

[Development of technology for the substance of poly[3-(3,4-dihydroxyphenyl) glyceric acid] from Symphytum asperum].

Comfrey (Symphytum L.) is used to treat bone fractures, tendon injuries, ulcer lesions of gastrointestinal tract. It promotes wound healing, accelerates exudates resorption in lungs and reduces joints' inflammation. In Georgian folk medicine, herbal remedies from comfrey are used to accelerate regeneration processes. Comfrey contains hepatotoxic and carcinogenic pyrrolizidine alkaloids, besides the main active ingredient is poly [3 - (3,4-dihydroxyphenyl) glyceric acid] (PDPGA). The aim of present work was to develop a technology for the substance - poly [3-(3,4dihydroxyphenyl) glyceric acid] (PDPGA) from comfrey stems, free of toxic pyrrolizidine alkaloids. During the investigation the optimal conditions for extraction and purification have been established: on the first stage pyrrolizidine alkaloids were removed from plant material by supercritical extraction; then the crude polysaccharides' fraction was obtained by water extraction (raw materials/extragent ratio was 1:15 at 90oC, the procedure was carried twice for 60 and 90 minutes). The isolation of the final product - PDPGA from crude polysaccharides' fraction was carried out by ultrafiltration on membrane filters. Based on the results of the investigation the technological scheme for the substance has been developed.