Unveiling the antibacterial and antioxidant potential of Hedera helix leaf extracts: recent findings.

Hedera helix L., a member of the Araliaceae family, is a commonly known decorative plant with recognized medicinal activities. In this study, the ethanolic extract from H. helix leaves was investigated for its total polyphenolic and flavonoid contents, as well as its antioxidant and antibacterial properties. The aim was to evaluate its potential for controlling certain infections by screening its antibacterial activity against selected pathogenic bacteria. The total phenolic and flavonoid contents of the extract were determined using colorimetric methods. The antioxidant activity was assessed through two assay methods: the 1, 1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging activity and the reducing power ferric reducing/antioxidant power (FRAP). The antibacterial activity against different pathogenic bacteria, including Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa, was evaluated using the well diffusion method. The total phenolic and flavonoid contents of the H. helix extract were found to be 134.3 ± 4.9 mg gallic acid/g and 42.4 ± 3.6 mg catechin/g, respectively. The extract exhibited antioxidant activity, with a reducing power represented by an FRAP value of 9.5 ± 0.9 mmol Fe+2/g DW and a percentage inhibition of DPPH of 64.7 ± 3.8 at 80 µg/mL. The extract demonstrated antibacterial activity, inhibiting the growth of K. pneumoniae and S. aureus with zone of inhibition values of 18.5 and 23.2 mm, respectively, using 25 mg/well. However, E. coli and P. aeruginosa exhibited resistance to the extract. The findings of this study highlight the antibacterial and antioxidant properties of the ethanolic extract from H. helix leaves. The extract exhibited significant phenolic and flavonoid contents, as well as antioxidant activity. It also demonstrated antibacterial activity against selected pathogenic bacteria, suggesting its potential for controlling certain infections. Further research is warranted to identify the active compounds responsible for these activities and to explore their mechanisms of action.

Functional Identification of HhUGT74AG11-A Key Glycosyltransferase Involved in Biosynthesis of Oleanane-Type Saponins in Hedera helix.

Hedera helix is a traditional medicinal plant. Its primary active ingredients are oleanane-type saponins, which have extensive pharmacological effects such as gastric mucosal protection, autophagy regulation actions, and antiviral properties. However, the glycosylation-modifying enzymes responsible for catalyzing oleanane-type saponin biosynthesis remain unidentified. Through transcriptome, cluster analysis, and PSPG structural domain, this study preliminarily screened four candidate UDP-glycosyltransferases (UGTs), including Unigene26859, Unigene31717, CL11391.Contig2, and CL144.Contig9. In in vitro enzymatic reactions, it has been observed that Unigene26859 (HhUGT74AG11) has the ability to facilitate the conversion of oleanolic acid, resulting in the production of oleanolic acid 28-O-glucopyranosyl ester. Moreover, HhUGT74AG11 exhibits extensive substrate hybridity and specific stereoselectivity and can transfer glycosyl donors to the C-28 site of various oleanane-type triterpenoids (hederagenin and calenduloside E) and the C-7 site of flavonoids (tectorigenin). Cluster analysis found that HhUGT74AG11 is clustered together with functionally identified genes AeUGT74AG6, CaUGT74AG2, and PgUGT74AE2, further verifying the possible reason for HhUGT74AG11 catalyzing substrate generalization. In this study, a novel glycosyltransferase, HhUGT74AG11, was characterized that plays a role in oleanane-type saponins biosynthesis in H. helix, providing a theoretical basis for the production of rare and valuable triterpenoid saponins.

Diversity and plant growth-promoting potential of (un)culturable bacteria in the Hedera helix phylloplane.

BACKGROUND: A diverse community of microbes naturally exists on the phylloplane, the surface of leaves. It is one of the most prevalent microbial habitats on earth and bacteria are the most abundant members, living in communities that are highly dynamic. Today, one of the key challenges for microbiologists is to develop strategies to culture the vast diversity of microorganisms that have been detected in metagenomic surveys. RESULTS: We isolated bacteria from the phylloplane of Hedera helix (common ivy), a widespread evergreen, using five growth media: Luria-Bertani (LB), LB01, yeast extract-mannitol (YMA), yeast extract-flour (YFlour), and YEx. We also included a comparison with the uncultured phylloplane, which we showed to be dominated by Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes. Inter-sample (beta) diversity shifted from LB and LB01 containing the highest amount of resources to YEx, YMA, and YFlour which are more selective. All growth media equally favoured Actinobacteria and Gammaproteobacteria, whereas Bacteroidetes could only be found on LB01, YEx, and YMA. LB and LB01 favoured Firmicutes and YFlour was most selective for Betaproteobacteria. At the genus level, LB favoured the growth of Bacillus and Stenotrophomonas, while YFlour was most selective for Burkholderia and Curtobacterium. The in vitro plant growth promotion (PGP) profile of 200 isolates obtained in this study indicates that previously uncultured bacteria from the phylloplane may have potential applications in phytoremediation and other plant-based biotechnologies. CONCLUSIONS: This study gives first insights into the total bacterial community of the H. helix phylloplane, including an evaluation of its culturability using five different growth media. We further provide a collection of 200 bacterial isolates underrepresented in current databases, including the characterization of PGP profiles. Here we highlight the potential of simple strategies to obtain higher microbial diversity from environmental samples and the use of high-throughput sequencing to guide isolate selection from a variety of growth media.

Ivy leaf (Hedera helix) for acute upper respiratory tract infections: an updated systematic review.

PURPOSE: Acute cough due to viral upper respiratory tract infections (URTIs) and bronchitis is a common reason for patients to seek medical care. Non-antibiotic over-the-counter cough medications such as ivy leaf extract are frequently used but their efficacy is uncertain. Our purpose was to update our previous systematic review and evaluate the effectiveness and tolerability of ivy leaf in the treatment of acute URTIs in adult and pediatric populations. METHODS: We searched MEDLINE, EMBASE, the Cochrane Library, and clinical trial registries from December 2009 to January 2020. Randomized controlled trials (RCTs), controlled clinical trials (CCTs), and observational studies (OSs) investigating ivy leaf mono- or combination preparations were included. Two independent reviewers assessed records for eligibility and risk of bias and performed data extraction. RESULTS: Six RCTs, 1 CCT, and 4 OSs were identified. Since the publication of our previous review, the number of RCTs has increased. All studies concluded that ivy leaf extract is an effective and safe option for the treatment of cough due to URTIs and bronchitis. Three RCTs reported a more rapid reduction in cough severity and/or frequency under ivy leaf treatment. The clinical significance of these effects appears to be minimal. No serious adverse effects were reported. The overall quality of reporting was low and the risk of bias was high. CONCLUSIONS: Ivy leaf preparations are safe for use in cough due to acute URTIs and bronchitis. However, effects are minimal at best and of uncertain clinical importance.

The Effects of Ivy (Hedera helix) on Respiratory Problems and Cough in Humans: A Review.

Hedera helix (ivy) belongs to the genus Hedera of the Araliaceae family. The leaf of this plant has several active ingredients with medicinal uses. The active constituents of H. helix include monodesmoside α-hederin, hederacoside B, hederacoside C, and hederacoside D.H. helix leave have been used for the treatment of cough and respiratory problems, and now, other uses have emerged. As a medicinal plant, H. helix has been approved by the German Commission E due to its antispasmodic, spasmolytic, antimicrobial, anti-inflammatory, anthelmintic, antioxidative, antitumor, and antileishmanial activities. It comes with several formulations, including tablets, liquids, and topical ointments. In this review, we focus on the respiratory effects of tablet and liquid forms of H. helix.

Branching morphology and biomechanics of ivy (Hedera helix) stem-branch attachments.

PREMISE: Hedera helix is a striking example of a plant with morphological traits and growth habits that vary between juvenile and adult phases. The present study focuses on its branching morphology and variations with age and change in growth habit, based on conspicuous stem-branch attachments previously described in related Araliaceae species. METHODS: We decorticated and morphologically analyzed 300 samples of ramifications from prostrate, climbing and self-supporting axes of H. helix. For bending experiments, 103 specimens with the self-supporting growth habit were collected. RESULTS: Ramifications of H. helix exhibited a so-called "finger-like" branching morphology with abaxial branch lobes and varying degrees of fusion of woody strands. Three categories of woody strand coalescence were defined. Biomechanical experiments in which the branches of stem-branch attachments were bent revealed two main modes of failure, breaking failure in (1) the attachment region and (2) the side branch. CONCLUSIONS: Coalescence of woody strands in H. helix ramifications results from accumulation of secondary xylem with age, influenced by mechanical stimuli causing specific loading situations during different growth habits. Mechanical experiments showed the tendency toward failure in the side branch with increasing fusion of woody strands, affected by the diameter ratio of the side branch to the main axis. Of specific interest is the comparison of H. helix branching with tropical Araliaceae, which do not show the described coalescence of woody strands to this extent. Fracture toughness of self-supporting H. helix axes with merged stem-branch attachment regions are comparable to other self-supporting plant species, despite anatomical and ontogenetic differences.

Anti-inflammatory effects of ivy leaves dry extract: influence on transcriptional activity of NFκB.

EA 575® is an ivy leaves dry extract (DER 5-7.5:1, 30% ethanol) used against diseases of the lower respiratory tract associated with productive cough. EA 575® improves symptoms associated with chronic inflammatory bronchial conditions. Compared to its bronchospasmolytic and secretolytic properties, the anti-inflammatory effects of EA 575® are mostly untried. Therefore, we addressed the question of whether the anti-inflammatory effect of EA 575® is due to an impact on the NFκB pathway. NFκB nuclear translocation was visualized by immunofluorescence in J774.2 as well as HEK293 cells. In the latter, a luciferase-based reporter was used to monitor NFκB transcriptional activity. Phosphorylation of RelA and its inhibitor IκB was measured by Western blot analysis. Additionally, changes in the stability of NFκB:IκB complex were shown by protein fragment complementation. Decreased transcriptional activity of NFκB under treatment with EA 575® was also shown for a human monocytic as well as a human lung epithelial cell line. EA 575® is able to inhibit NFκB transcriptional activity by partially inhibiting its translocation to the nucleus after stimulation with TNFα. Furthermore, phosphorylation of IκBα is reduced while phosphorylation of RelA is enhanced after pre-incubation with EA 575®, leading to an enhanced stability of NFκB:IκBα complex. EA 575® has an regulatory impact on the NFκB pathway, possibly by switching specificity of IKK from IκBα to RelA, resulting in enhanced stability of NFκB:IκBα complex and reduced RelA translocation into the nucleus.

Hederagenin and α-hederin promote degradation of proteins in neurodegenerative diseases and improve motor deficits in MPTP-mice.

Pathogenesis of neurodegenerative diseases such as Parkinson's disease (PD) and Huntington's disease (HD) are closely related to the formation of protein aggregates and inclusion body. For instance, active autophagic components from Chinese herbal medicines (CHMs) are highlighted to modulate neurodegeneration via degradation of disease proteins. In this study, the neuroprotective effect of the purified Hedera helix (HH) fraction containing both hederagenin and α-hederin, is confirmed by the improvement of motor deficits in PD mice model. Furthermore, hederagenin and α-hederin derived from HH are confirmed as novel autophagic enhancers. Both compounds reduce the protein level of mutant huntingtin with 74 CAG repeats and A53T α-synuclein, and inhibit the oligomerization of α-synuclein and inclusion formation of huntingtin, via AMPK-mTOR dependent autophagy induction. Both hederagenin and α-hederin induce autophagy and promote the degradation of neurodegenerative mutant disease proteins in vitro, suggesting the therapeutic roles of HH in neurodegenerative disorders.

Time-dependent Inhibition of CYP2C8 and CYP2C19 by Hedera helix Extracts, A Traditional Respiratory Herbal Medicine.

The extract of Hedera helix L. (Araliaceae), a well-known folk medicine, has been popularly used to treat respiratory problems, worldwide. It is very likely that this herbal extract is taken in combination with conventional drugs. The present study aimed to evaluate the effects of H. helix extract on cytochrome P450 (CYP) enzyme-mediated metabolism to predict the potential for herb-drug interactions. A cocktail probe assay was used to measure the inhibitory effect of CYP. H. helix extracts were incubated with pooled human liver microsomes or CYP isozymes with CYP-specific substrates, and the formation of specific metabolites was investigated to measure the inhibitory effects. H. helix showed significant inhibitory effects on CYP2C8, CYP2C19 and CYP2D6 in a concentration-dependent manner. In recombinant CYP2C8, CYP2C19 and CYP2D6 isozymes, the IC50 values of the extract were 0.08 ± 0.01, 0.58 ± 0.03 and 6.72 ± 0.22 mg/mL, respectively. Further investigation showed that H. helix extract has a positive time-dependent inhibition property on both CYP2C8 and CYP2C19 with IC50 shift value of 2.77 ± 0.12 and 6.31 ± 0.25, respectively. Based on this in vitro investigation, consumption of herbal medicines or dietary supplements containing H. helix extracts requires careful attention to avoid any CYP-based interactions.

Chemical composition and antifungal activity of Hedera helix leaf ethanolic extract.

The 50% ethanol extract obtained from Hedera helix leaves was investigated regarding the presence and quantity of polyphenols, sterols and in vitro antifungal activity against phytopathogenic fungi. The chemical analysis revealed the presence of rutin, quercetin and kaempferol in the non-hydrolysed sample and quercetin and kaempferol in the hydrolysed sample and stigmasterol in the ivy leaf extract (nonhydrolysed sample). The antifungal activity against phytopathogenic fungi (Aspergillus niger, Botrytis cinerea, B. tulipae, Fusarium oxysporum f. sp. tulipae, Penicillium gladioli, and Sclerotinia sclerotiorum) was assessed using an agar dilution assay. The results are expressed as the minimum inhibitory concentration (MIC = 10-14%) and were compared to a synthetic antifungal drug - fluconazole (MIC = 8-30%). This report presents the first screening of the antifungal activity of the ivy leaf extract on these plant pathogenic fungi species, aiming to use the ivy leaf extract for controlling different diseases of vegetables and ornamental plants, in addition to human disorders.

efficacy of dry extract of ivy leaves in the treatment of productive cough.

OBJECTIVE: Introduction: Coughing is a physiological, spontaneous defense mechanism against irritants that stimulate respiratory mucosa. Productive cough should be not suppressed; instead, mucus-dissolving agents are recommended. One of the expectorants, which increases the excretion volume, is the herbal medicine derived from ivy leaves. The ivy extract contains triterpene saponins, which have secretory properties. The aim of this study was to determine the effectiveness and safety of the treatment with the medicinal product Hedussin®, containing dry ivy extract, in the therapy of productive cough in the course of the respiratory tract infection. PATIENTS AND METHODS: Material and methods:This was a non-randomized, non-interventional, multicenter, open-label, post-authorization effectiveness study (PAES). The study group consisted of 464 patients aged 2-12 years with productive cough. The study was supported by a questionnaire that included: the type of cough etiological factor, Bronchitis Severity Score (BSS), temperature, and prescription of antibiotic therapy. Effectiveness and safety of the therapy with Hedussin® was assessed at the follow-up visit. RESULTS: Results and conclusion: Improvement in cough was reported in 93.3% subjects; improvement in chest pain on coughing was reported in 84.7%, in wheezing - in 90.0%, in dyspnoea - in 88.7%, and in auscultation changes - in 94.8%. In addition, decline or normalization of body temperature was found in 96.0% of subjects. No adverse drug reactions were reported in the study population. The non-antibiotic treated group showed similar proportions. The results of this study support the efficacy of Hedussin® prescribed for the treatment of productive cough in the course of respiratory tract infections. Hedussin® was well tolerated by sick children aged 2-12 years.

Pharmacokinetic parameters of three active ingredients hederacoside C, hederacoside D, and ɑ-hederin in Hedera helix in rats.

In Hedera helix hederacoside C, hederacoside D, and ɑ-hederin are three major bioactive saponins and play pivotal roles in the overall biological activity. In this study, a specific and sensitive ultra-high performance liquid chromatography with tandem mass spectrometry method has been developed and validated for the quantification of three major bioactive saponins in rat plasma. Chromatographic separation was performed on a reversed-phase Thermo Hypersil GOLD C18 column (2.1 mm × 50 mm, 1.9 µm) using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid. The assay was successfully applied to study the pharmacokinetic behavior of the three analytes in rats after oral and intravenous administration of a mixture of saponins (hederacoside C, hederacoside D, and ɑ-hederin). Further research was performed to compare the pharmacokinetic behavior of the three analytes after the oral administration of a mixture of saponins and an extract of saponins from Hedera helix, and results showed that double peaks were evident on concentration-time profile for each of the three saponins. The difference in the pharmacokinetic characteristics of three saponins between a mixture of saponins and an extract of saponins from Hedera helix was found in rat, which would be beneficial for the preclinical research and clinical use of Hedera helix.

Contact dermatitis as an adverse reaction to some topically used European herbal medicinal products - part 2: Echinacea purpurea-Lavandula angustifolia.

This review focuses on contact dermatitis as an adverse effect of a selection of topically used herbal medicinal products for which the European Medicines Agency has completed an evaluation up to the end of November 2013 and for which a Community herbal monograph has been produced. Part 2: Echinacea purpurea Moench-Lavandula angustifolia Mill.

Efficacy and tolerability of SEDIFLÙ in treating dry or productive cough in the pediatric population (SEPEDIA): A pilot, randomized, double-blind, placebo-controlled, multicenter clinical trial.

The aim of this trial was to assess the effectiveness of Sediflù, a medical device containing active herbal ingredients, on nocturnal and diurnal persistent coughs in children, with a duration of 3 to 7 days. Children with a dry and/or productive cough were enrolled in this prospective, interventional, multicenter, placebo-controlled, double-blind, randomized clinical study. Clinical efficacy was assessed through the evaluation of the soothing action of Sediflù against dry and/or productive coughing, both at night and during the day, and other effects of coughing associated with quality of sleep: frequency, child's quality of sleep, parental quality of sleep and severity. Treatment with Sediflù improved both night-time and day-time cough scores from day 2. The diurnal score also improved significantly in the Sediflù group at days 3 and 7. Sediflù syrup can be considered a valid treatment for cough management in younger children with upper respiratory tract infections, shortening the cough duration.

The genome sequence of common ivy, Hedera helix L., 1753.

We present a genome assembly from a specimen of Hedera helix (common ivy; Streptophyta; Magnoliopsida; Apiales; Araliaceae). The genome sequence is 1,199.4 megabases in span. Most of the assembly is scaffolded into 24 chromosomal pseudomolecules. The mitochondrial and plastid genomes have also been assembled and are 609.2 and 162.2 kilobases in length respectively.

Optimization and characterization of antileukemic L-asparaginase produced by Fusarium solani endophyte.

L-asparaginase is an antileukemic enzyme that hydrolyzes L-asparagine into L-aspartic acid and ammonia, causing cell starvation and apoptosis in susceptible leukemic cell populations. Currently, L-asparaginase obtained from bacterial sources is constrained by several issues, including lesser productivity, stability, selectivity, and higher toxicity. The goal of this study is to provide fungal L-asparaginase with in-vitro effectiveness towards different human carcinomas. L-asparaginase from endophytic Fusarium solani (Gene Bank accession number MW209717) isolated from the roots of the medicinal plant Hedera helix L. was characterized and optimized experimentally for maximum L-asparaginase production in addition to evaluating its subsequent cytotoxicity towards acute monocytic leukemia and human skin fibroblast cell lines. The enzyme production was maximized using potato dextrose media (15.44 IU/ml/hr) at the 5th and 6th days of fermentation with incubation temperature 30 °C, 3% asparagine, 150-180 rpm agitation rate and a 250 ml flask. Enzyme characterization studies revealed that the enzyme maintained its thermal stability with temperatures up to 60 °C. However, its optimal activity was achieved at 35 °C. On measuring the enzymatic activity at various temperatures and different pH, maximum enzyme activity was recorded at 40 °C and pH 8 using 0.1 M asparagine concentration. Results also revealed promising cytotoxic activity against acute monocytic leukemia with IC50 = 3.66 µg/ml and low cytotoxicity against tested normal human skin fibroblast cell line which suggested that it might have selective toxicity, and consequently it could be used as a less toxic alternative to the current formulations.

Modified Hederagenin Derivatives Demonstrate Ex Vivo Anthelmintic Activity against Fasciola hepatica.

Infection with Fasciola hepatica (liver fluke) causes fasciolosis (or fascioliasis) and poses a considerable economic as well as welfare burden to both the agricultural and animal health sectors. Here, we explore the ex vivo anthelmintic potential of synthetic derivatives of hederagenin, isolated in bulk from Hedera helix. Thirty-six compounds were initially screened against F. hepatica newly excysted juveniles (NEJs) of the Italian strain. Eleven of these compounds were active against NEJs and were selected for further study, using adult F. hepatica derived from a local abattoir (provenance unknown). From these eleven compounds, six demonstrated activity and were further assessed against immature liver flukes of the Italian strain. Subsequently, the most active compounds (n = 5) were further evaluated in ex vivo dose response experiments against adult Italian strain liver flukes. Overall, MC042 was identified as the most active molecule and the EC50 obtained from immature and adult liver fluke assays (at 24 h post co-culture) are estimated as 1.07 µM and 13.02 µM, respectively. When compared to the in vitro cytotoxicity of MDBK bovine cell line, MC042 demonstrated the highest anthelmintic selectivity (44.37 for immature and 3.64 for adult flukes). These data indicate that modified hederagenins display properties suitable for further investigations as candidate flukicides.

Phytochemical and Bioactivity Studies on Hedera helix L. (Ivy) Flower Pollen and Ivy Bee Pollen.

Bee pollen, known as a 'life-giving dust', is a product of honeybees using flower pollen grains and combining them with their saliva secretions. Thus, flower pollen could be an indicator of the bee pollen botanical source. Identification of bee pollen sources is a highly crucial process for the evaluation of its health benefits, as chemical composition is directly related to its pharmacological activity. In this study, the chemical profiles, contents of phenolic marker compounds and pharmacological activities of Hedera helix L. (ivy) bee pollen samples from Türkiye and Slovenia, as well as ivy flower pollen grains, were compared. High-performance thin-layer chromatography (HPTLC) analyses revealed that pollen samples, regardless of where they were collected, have similar chemical profiles due to the fact that they have the same botanical origins. Marker compounds afzelin, platanoside and quercetin-3-O-ß-glucopyranosyl-(1→2)-ß-galactopyranoside, common to both bee pollen and flower pollen, were isolated from bee pollen, and their structures were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS). These three compounds, as well as chlorogenic acid and 3,5-dicaffeoylquinic acid (found in flower pollen), were quantified using high-performance liquid chromatography (HPLC) analyses. In vitro tests and effect-directed analyses were used to evaluate the xanthine oxidase inhibition and antioxidant activity of the marker compounds and extracts from flower pollen and bee pollen. This is the first report comparing chemical profiles and related bioactivities of the flower pollen and bee pollen of the same botanical origin, as well as the first report of the chemical profile and related bioactivities of ivy flower pollen.

Assessment of subchronic toxicity and toxicokinetics of AG NPP709 in Sprague-Dawley rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Hedera helix L. (HH) leaves and Coptidis rhizoma (CR) have traditionally been used to treat respiratory conditions. AG NPP709, which is formulated using extracts of both these herbs, has been developed as an expectorant and antitussive. AIM OF THE STUDY: The objective was to evaluate the subchronic toxicity and toxicokinetic characteristics of AG NPP709 in laboratory rats. MATERIALS AND METHODS: AG NPP709 was orally administered to rats at doses of up to 2.0 g/kg/day for a duration of 13 weeks. Various health parameters were measured throughout the treatment period. At the end of the treatment, a necropsy was conducted and additional parameters were analyzed. Toxicokinetic analyses were also performed on hederacoside C and berberine, the active components of HH leaves and CR, respectively, in the plasma of rats treated with AG NPP709. RESULTS: AG NPP709-treated rats exhibited several health issues, such as reduced feed intake, altered differential white blood cell (WBC) count, increased plasma Alb/Glo ratio in females, and reduced kidney weight in males. However, these changes appeared to be incidental and fell within the typical range for healthy animals of this species. Additionally, toxicokinetic analysis of hederacoside C and berberine showed no accumulation in the plasma of rats during the repeated treatments with AG NPP709. CONCLUSIONS: Our study demonstrates that AG NPP709 does not have any harmful effects on rats under experimental conditions. Based upon these findings, the no observed adverse effect level of AG NPP709 can be estimated to be 2.0 g/kg/day in rats.