Effects of geographical origin and post-harvesting processing on the bioactive compounds and sensory quality of Brazilian specialty coffee beans.

Specialty coffee beans are those produced, processed, and characterized following the highest quality standards, toward delivering a superior final product. Environmental, climatic, genetic, and processing factors greatly influence the green beans' chemical profile, which reflects on the quality and pricing. The present study focuses on the assessment of eight major health-beneficial bioactive compounds in green coffee beans aiming to underscore the influence of the geographical origin and post-harvesting processing on the quality of the final beverage. For that, we examined the non-volatile chemical profile of specialty Coffea arabica beans from Minas Gerais state, Brazil. It included samples from Cerrado (Savannah), and Matas de Minas and Sul de Minas (Atlantic Forest) regions, produced by two post-harvesting processing practices. Trigonelline, theobromine, theophylline, chlorogenic acid derivatives, caffeine, caffeic acid, ferulic acid, and p-coumaric acid were quantified in the green beans by high-performance liquid chromatography with diode array detection. Additionally, all samples were roasted and subjected to sensory analysis for coffee grading. Principal component analysis suggested that Cerrado samples tended to set apart from the other geographical locations. Those samples also exhibited higher levels of trigonelline as confirmed by two-way ANOVA analysis. Samples subjected to de-pulping processing showed improved chemical composition and sensory score. Those pulped coffees displayed 5.8% more chlorogenic acid derivatives, with an enhancement of 1.5% in the sensory score compared to unprocessed counterparts. Multivariate logistic regression analysis pointed out altitude, ferulic acid, p-coumaric acid, sweetness, and acidity as predictors distinguishing specialty coffee beans obtained by the two post-harvest processing. These findings demonstrate the influence of regional growth conditions and post-harvest treatments on the chemical and sensory quality of coffee. In summary, the present study underscores the value of integrating target metabolite analysis with statistical tools to augment the characterization of specialty coffee beans, offering novel insights for quality assessment with a focus on their bioactive compounds.

LC-MS/DIA-based strategy for comprehensive flavonoid profiling: an Ocotea spp. applicability case.

We introduce a liquid chromatography - mass spectrometry with data-independent acquisition (LC-MS/DIA)-based strategy, specifically tailored to achieve comprehensive and reliable glycosylated flavonoid profiling. This approach facilitates in-depth and simultaneous exploration of all detected precursors and fragments during data processing, employing the widely-used open-source MZmine 3 software. It was applied to a dataset of six Ocotea plant species. This framework suggested 49 flavonoids potentially newly described for these plant species, alongside 45 known features within the genus. Flavonols kaempferol and quercetin, both exhibiting O-glycosylation patterns, were particularly prevalent. Gas-phase fragmentation reactions further supported these findings. For the first time, the apigenin flavone backbone was also annotated in most of the examined Ocotea species. Apigenin derivatives were found mainly in the C-glycoside form, with O. porosa displaying the highest flavone : flavonol ratio. The approach also allowed an unprecedented detection of kaempferol and quercetin in O. porosa species, and it has underscored the untapped potential of LC-MS/DIA data for broad and reliable flavonoid profiling. Our study annotated more than 50 flavonoid backbones in each species, surpassing the current literature.

Evaluation of the anti-inflammatory activity of Acacia polyphylla and identification of a new apigenin-3-C- glycosylated type flavonoid.

Owing to the potentially harmful adverse effects of current anti-inflammatory drugs, there is a need to identify new alternative substances. Thus, this study aimed to perform a phytochemical analysis of A. polyphylla to identify compounds responsible for its anti-inflammatory activity. Several fractions of the A. polyphylla extract were obtained and evaluated in an ex vivo anti-inflammatory assay using fresh human blood. Among the evaluated fractions, the BH fraction displayed the highest percentage of PGE2 inhibition (74.8%) compared to the reference drugs dexamethasone and indomethacin, demonstrating its excellent potential for anti-inflammatory activity. Astragalin (P1), a known 3-O-glucoside of kaempferol, was isolated from the A. polyphylla extract for the first time. In addition, a new compound (P2) was isolated and identified as the apigenin-3-C-glycosylated flavonoid. Astragalin showed moderate PGE2 activity (48.3%), whereas P2 was not anti-inflammatory. This study contributes to the phytochemical studies of A. polyphylla and confirms its anti-inflammatory potential.

Chemical Composition, Anthelmintic Activity, and Mechanism of Action of Lippia dominguensis Mold. Essential Oil on Haemonchus contortus.

Gastrointestinal nematode parasitism is a major burden to small ruminant production globally, compounded by increasing anthelmintic resistance. Previous studies have identified essential oils (EOs) from the Lippia genus with antiprotozoal and anthelmintic effects. Lippia dominguensis Moldenke (Ld), an endemic specie from the Dominican Republic, has similar popular uses, however, is chemically and pharmacologically yet uncharacterized. Here, we investigated the in vitro anthelmintic activity of LdEO and its ultrastructural effects on eggs and adult nematodes of Haemonchus contortus multidrug-resistant isolated. The GC/MS analysis showed linalool (33.85 %), 1,8-cineole (30.88 %), and δ-terpineol (10.61 %) as the main EO constituents. The LdEO showed an IC50 =0.523 mg/mL in the egg hatch test, and the motility in the adult worm motility test was 95.8 % at 1 mg/mL. The confocal scanning laser microscopy of eggs indicated permeabilization or disruption of egg cell membranes as the possible mechanism of action of LdEO. The scanning electron microscopy of adult worms showed wrinkling, undulations, and cuticular disruptions. The LdEO displayed significant in vitro anthelmintic activity on eggs and adult worms of H. contortus. Additionally, the LdEO showed low oral toxicity in mice at 2,000 mg/kg. Thus, additional in vivo studies are justified to determine its anthelmintic efficacy in small ruminants.

Immunological Modulation and Control of Parasitaemia by Ayahuasca Compounds: Therapeutic Potential for Chagas's Disease.

Ayahuasca is a psychoactive and psychedelic decoct composed mainly of Banisteriopsis caapi and Psychotria viridis plant species. The beverage is rich in alkaloids and it is ritualistically used by several indigenous communities of South America as a natural medicine. There are also reports in the literature indicating the prophylaxis potential of Ayahuasca alkaloids against internal parasites. In the present study, Ayahuasca exhibited moderate in vitro activity against Trypanosoma cruzi trypomastigotes (IC50 95.78 µg/mL) compared to the reference drug benznidazole (IC50 2.03 µg/mL). The ß-carboline alkaloid harmine (HRE), isolated from B. caapi, was considered active against the trypomastigotes forms (IC50 6.37), and the tryptamine N, N-dimethyltryptamine (DMT), isolated from P. viridis was also moderately active with IC50 of 21.02 µg/mL. Regarding the in vivo evaluations, no collateral effects were observed. The HRE alone demonstrated the highest trypanocidal activity in a dose-responsive manner (10 and 100 mg/kg). The Ayahuasca and the association between HRE and DMT worsened the parasitaemia, suggesting a modulation of the immunological response during the T. cruzi infection, especially by increasing total Immunoglobulin (IgG) and IgG1 antibody levels. The in silico molecular docking revealed HRE binding with low energy at two sites of the Trypanothione reductase enzyme (TR), which are absent in humans, and thus considered a promissory target for drug discovery. In conclusion, Ayahuasca compounds seem to not be toxic at the concentrations of the in vivo evaluations and can promote trypanocidal effect in multi targets, including control of parasitaemia, immunological modulation and TR enzymatic inhibition, which might benefit the treatments of patients with Chagas' disease. Moreover, the present study also provides scientific information to support the prophylactic potential of Ayahuasca against internal parasites.

Anti-Inflammatory Markers of Hops Cultivars (Humulus lupulus L.) Evaluated by Untargeted Metabolomics Strategy.

Hops (Humulus lupulus L.) are edible flowers commonly used to add flavour and aroma to beer, besides they have rich chemical diversity and medicinal potential. In this work, an ex vivo anti-inflammatory assay via the LPS-induced signalling pathway and metabolomics approaches were performed to evaluate the ability of hops to inhibit the production of prostaglandin E2 (PGE2) inflammatory mediator and analyze which metabolites produced by the nine different hop cultivars are potential anti-inflammatory markers. Columbus, Chinook and Hallertau Mittelfrüh hop cultivars yielded extracts with PGE2 release inhibition rates of 86.7, 92.5 and 73.5 %, respectively. According to the multivariate statistical analysis, the majority of the metabolites correlated with the activity were prenylated phloroglucinol and phenolic homologs. These results suggest promissory anti-inflammatory hop metabolites.

In vivo anti-inflammatory activity of Fabaceae species extracts screened by a new ex vivo assay using human whole blood.

INTRODUCTION: Plants have been considered a promising source for discovering new compounds with pharmacological activities. The Fabaceae family comprises a large variety of species that produce substances with diverse therapeutic potential, including anti-inflammatory activity. The limitations of current anti-inflammatories generate the need to research new anti-inflammatory structures with higher efficacy as well as develop methods for screening multiple samples, reliably and ethically, to assess such therapeutic properties. OBJECTIVE: Validate and apply a quantification method for prostaglandin E2 (PGE2 ) production from an ex vivo assay in human blood in order to screen anti-inflammatory activity present in many Fabaceae species extracts. METHODS: Human blood was incubated with extracts from 47 Fabaceae species. After lipopolysaccharide (LPS)-induced inflammation, PGE2 was quantified in the plasma by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The extracts that presented PGE2 production inhibition were further assessed through in vivo assay and then chemically characterised through an analysis of ultra-performance liquid chromatography electrospray ionisation quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-QTOF-MS2 ) data. RESULTS: The new ex vivo anti-inflammatory assay showed that five out of the 47 Fabaceae species inhibited PGE2 production. Results from an in vivo assay and the metabolic profile of the active extracts supported the anti-inflammatory potential of four species. CONCLUSION: The quantification method for PGE2 demonstrated fast, sensitive, precise, and accurate results. The new ex vivo anti-inflammatory assay comprised a great, reliable, and ethical approach for the screening of a large number of samples before an in vivo bioassay. Additionally, the four active extracts in both ex vivo and in vivo assays may be useful for the development of more efficient anti-inflammatory drugs.

Confirmation of ethnopharmacological anti-inflammatory properties of Ocotea odorifera and determination of its main active compounds.

ETHNOPHARMACOLOGICAL RELEVANCE: Ocotea odorifera (Vell.) Rohwer has been used in traditional medicine in the south of Brazil for the treatment of inflammatory-related conditions, such as rheumatism. However, there is not any scientific evidence for popular use. AIMS OF THE STUDY: To investigate the O. odorifera anti-inflammatory potential and identification of the main active compounds through metabolomic approaches. MATERIALS AND METHODS: In order to in vivo evaluate the inhibition of the main inflammatory pathways, the leaf decoction, leaf extract, its fractions and the essential oils from leaves and branches were submitted to the ear oedema and the neutrophils recruitment assays. The samples were chemically investigated by UHPLC-HRMS or GC-MS. The multivariate statistical analysis (PLS-DA) was used to determine the substances correlated with the anti-inflammatory properties. RESULTS: The in vivo studies indicated a promissory anti-inflammatory effect on both oedema and neutrophil recruitment for some samples including the decoction; hydroethanolic, ethyl acetate, and chloroform fractions; and the essential oils. According to the PLS-DA, the S-(+)-reticuline was evidenced as one of the three compounds of the plant most correlated with both anti-inflammatory mechanisms. Thus, S-(+)-reticuline was isolated and the anti-inflammatory activity was confirmed. Moreover, for the first time, the dual inhibition of oedema and neutrophil recruitment was uncovered and reported. Another compound positively correlated with the anti-inflammatory activity is likely to be a new compound since zero hit on the comprehensive mass database were encountered. The compounds found in the essential oils also showed significant anti-inflammatory activity, and thus indeed the plant has different classes of active substances. CONCLUSIONS: The decoction of O. odorifera and different fractions from its ethanolic extract demonstrated anti-inflammatory activity through dual inhibition of oedema and neutrophil recruitment. Thus, corroborating the popular medicinal use of the decoction of leaves from O. odorifera as an anti-inflammatory medicine. Besides, reticuline, one of the main active compounds, was isolated and proved to display the dual mechanism of action, indicating the O. odorifera as a promising source of active compounds for the treatment of inflammatory conditions.

Impact of sesquiterpene lactones on the skin and skin-related cells? A systematic review of in vitro and in vivo evidence.

Although anti-inflammatory properties are attributed to sesquiterpene lactones (SL), cutaneous hypersensitivity reactions are proposed as limitations for SL-based therapies. Thus, the impact of SL on the skin and skin-related cells was systematically reviewed. Studies indexed in electronic databases were screened from the PRISMA strategy. The risk of bias in all studies was verified from the SYRCLE's tool. Thirty original studies were recovered and analyzed. Mice and guinea pig, keratinocytes and fibroblasts were predominantly investigated from in vivo and in vitro studies, respectively. In vivo studies indicated that most SL induced contact dermatitis associated with edema, erythema, and inflammatory infiltrate. Conversely, in vitro evidence was consistent with a dose-dependent anti-inflammatory effect of SL in response to reduced cytokines, 5-LOX, and COX-2 levels or activity in keratinocytes, fibroblasts, macrophages and dendritic cells; which are events potentially triggered by downregulation of gene expression and/or inhibition of the NF-κB signaling pathway. In vivo studies presented uncertain to high-risk of bias mainly associated with underreporting of randomization and experimental blinding. The current evidence supports potent cutaneous immunomodulatory properties of SL. Although in vitro and in vivo studies indicate opposite anti- or proinflammatory effects, this contradiction exhibits a dose-dependent component. In addition, the anti-inflammatory pathways activated by SL are better understood from in vitro evidence. However, additional studies are required to elucidating specific anti-inflammatory and proinflammatory mechanisms triggered by SL in vivo. Thus, controlling the sources of bias described in this review can contribute to improving the quality of the evidence in further investigations.

Tagitinin F has anti-inflammatory, anti-nociceptive and anti-matrix metalloproteinase properties: An in silico, in vitro and in vivo study.

Sesquiterpene lactones (SL) are natural bioactive molecules indicated as potential scaffolds for anti-inflammatory and analgesic drug design. However, their anti-inflammatory applicability remains underestimated since the impact of SL on inflammatory nociception and tissue repair are overlooked. Thus, we used an integrated in silico, in vitro and in vivo framework to investigate the impact of tagitinin F (TAG-F) on lipopolysaccharide (LPS)-challenged macrophages, excisional skin wounds, and carrageenan-induced paw edema and mechanical hyperalgesia in mice. RAW 264.7 macrophages in culture were challenged with LPS and treated with TAG-F (5, 10, 50 and 100 µM). The paw of BALB/c mice was injected with carrageenan and treated with 0.5% and 1% TAG-F. Excisional wounds were also produced in BALB/c mice and treated with 0.5% and 1% TAG-F. Our results indicated a consistent concentration-dependent downregulation in 5-lipoxygenase, cyclooxygenase 1 and 2 (COX-1 and COX-2), matrix metalloproteinase 1 and 2 (MMP-1 and MMP-2) activities; as well as attenuation in prostaglandin E2 (PGE2), leukotriene B4 (LTB4) and tumor necrosis factor-α (TNF-α) production in both in vitro and in vivo models. In vivo, TAG-F also attenuated carrageenan-induced paw edema and mechanical hyperalgesia in mice. From the excisional skin wound, TAG-F was still effective in reducing neutrophils and macrophages infiltration and stimulating collagen deposition in the scar tissue, accelerating tissue maturation. Together, our findings indicate that the anti-inflammatory effect of TAG-F is more comprehensive than previously suggested, exerting a significant impact on the control of edema, inflammatory pain and modulating central metabolic processes linked to skin wound healing.

Fast and Efficient Method to Obtain Tagitinin F by Photocyclization of Tagitinin C.

There is some evidence in the literature of the photocyclization reaction of Tagitinin C (1) to Tagitinin F (2). Compound 2 has high pharmacological potential, but it is not easy to obtain, while compound 1 is easily obtained from a widespread plant, Tithonia diversifolia. Among different reaction conditions monitored, one was found that allowed the cyclization of 1 into 2 in <15 min in a photo-dependent reaction. Scaling-up the photocyclization of the pure compound 1 into 2 demonstrated 100% yield, and the isolation of 2 from a UV-irradiated extract was eight-fold higher than the quantity isolated from the non-UV-irradiated extract. We were also able to better understand the process of photoconversion and determine methods to isolate and quantify these compounds, which are known for their important antitumoral activities among other important pharmacological properties.

A strategy for the identification of patterns in the biosynthesis of nonribosomal peptides by Betaproteobacteria species.

Nonribosomal peptides have an important pharmacological role due to their extensive biological properties. The singularities in the biosynthesis of these natural products allowed the development of genome-mining strategies which associate them to their original biosynthetic gene clusters. Generally, these compounds present complex architectures that make their identification difficult. Based on these evidences, genomes from species of the class Betaproteobacteria were studied with the purpose of finding biosynthetic similarities among them. These organisms were applied as templates due to their large number of biosynthetic gene clusters and the natural products isolated from them. The strategy for Rapid Identification of Nonribosomal Peptides Portions (RINPEP) proposed in this work was built by reorganizing the data obtained from antiSMASH and NCBI with a product-centered way. The verification steps of RINPEP comprehended the fragments of existent compounds and predictions obtained in silico with the purpose of finding common subunits expressed by different genomic sequences. The results of this strategy revealed patterns in a global overview of the biosynthesis of nonribosomal peptides by Betaproteobacteria.

The Correlation between Chemical Structures and Antioxidant, Prooxidant, and Antitrypanosomatid Properties of Flavonoids.

Flavonoids have demonstrated in vivo and in vitro leishmanicidal, trypanocidal, antioxidant, and prooxidant properties. The chemotherapy of trypanosomiasis and leishmaniasis lacks efficacy, presents high toxicity, and is related to the development of drug resistance. Thus, a series of 40 flavonoids were investigated with the purpose of correlating these properties via structure and activity analyses based on integrated networks and QSAR models. The classical groups for the antioxidant activity of flavonoids were combined in order to explain the influence of antioxidant and prooxidant activities on the antiparasitic properties. These analyses become useful for the development of efficient treatments for leishmaniasis and trypanosomiasis. Finally, the dual activity of flavonoids presenting both anti- and prooxidant activities revealed that the existence of a balance between these two features could be important to the development of adequate therapeutic strategies.

In vitro evaluation of the schistosomicidal effect of the extracts, fractions and major 3-hydroxy-2,6-dialkyl-substituted piperidine alkaloids from the flowers of Senna spectabilis (Fabaceae).

In this work, we present the in vitro schistosomicidal activity evaluation of the most active dichloromethane fraction (FDm) (ED50=83.5µg/mL) and of a mixture of the major alkaloids ((-)-cassine/(-)-spectaline, C/E) (ED50=37.4µg/mL) from the flowers of Senna spectabilis against adult worms and cercariae. We also demonstrate other toxic effects including paralysis of the adult worms, inhibition of the secretory activity, tegument lesions and cercaricidal activity. In the association test of Praziquantel (PZQ)-C/E, we observed up to 80% mortality of Schistosoma mansoni in comparison to PZQ monotherapy. Due to the diversity of the toxic effects, the schistosomicidal activity of C/E is likely a result of a multitarget mechanism involving the tegument, secretory system and neuromotor action.

Importance and Implications of the Production of Phenolic Secondary Metabolites by Endophytic Fungi: A Mini-Review.

In the natural products research, a valuable approach is the prospection of uncommon sources and unexplored habitat. Special attention has been given to endophytic fungi because of their ability to produce new and interesting secondary metabolites, which have several biological applications. The endophytes establish exclusive symbiotic relationships with plants and the metabolic interactions may support the synthesis of some similar valuables compounds. Among secondary metabolites, phenol-derived structures are responsible for several bioactivities such as antioxidant, cytotoxic, antimicrobial, among others. Phenolic compounds might be biosynthesized from the shikimate pathway. Although shikimic acid is a common precursor in plants, it is described as rare in microorganisms. To the best of our knowledge, this is the first review about phenolic compounds produced by endophytic fungi and a comparison has been made with those produced by the plant host. This review covers 124 phenolic secondary metabolites produced by endophytic fungi. Considering the data analyzed by us, only seven of such compounds were isolated from fungi and from their hosts. These observations claim for more attention to phenolic compounds produced by endophytic fungi with a view to understand the real importance of these compounds to endophytes survival.

Outstanding Anti-inflammatory Potential of Selected Asteraceae Species through the Potent Dual Inhibition of Cyclooxygenase-1 and 5-Lipoxygenase.

Cyclooxygenase and 5-lipoxygenase are enzymes that catalyze important inflammatory pathways, suggesting that dual cyclooxygenase/lipoxygenase inhibitors should be more efficacious as anti-inflammatory medicines with lower side effects than the currently available nonsteroidal anti-inflammatory drugs. Many plants from the family Asteraceae have anti-inflammatory activities, which could be exerted by inhibiting the cyclooxygenase-1 and 5-lipoxygenase enzymes. Nevertheless, only a small number of compounds from this family have been directly evaluated for their ability to inhibit the enzymes in cell-free assays. Therefore, this study systematically evaluated 57 Asteraceae extracts in vitro in enzyme activity experiments to determine whether any of these extracts exhibit dual inhibition of cyclooxygenase-1 and 5-lipoxygenase. The chemical profiles of the extracts were obtained by the high-performance liquid chromatography-ultraviolet-diode array detector method, and their major constituents were dereplicated. Of the 57 tested extracts, 13 (26.6 %, IC50 range from 0.03-36.2 µg/mL) of them displayed dual inhibition. Extracts from known anti-inflammatory herbs, food plants, and previously uninvestigated species are among the most active. Additionally, the extract action was found to be specific with IC50 values close to or below those of the standard inhibitors. Thus, the active extracts and active substances of these species are potent inhibitors acting through the mechanism of dual inhibition of cyclooxygenase-1 and 5-lipoxygenase. The extracts were prepared for this study using nontoxic extraction solvents (EtOH-H2O), requiring only a small amount of plant material to carry out the bioassays and the phytochemical analyses. In summary, this study demonstrated the potential of the investigated species as dual inhibitors, revealing their potential as pharmaceuticals or nutraceuticals.

Prediction of Anti-inflammatory Plants and Discovery of Their Biomarkers by Machine Learning Algorithms and Metabolomic Studies.

Nonsteroidal anti-inflammatory drugs are the most used anti-inflammatory medicines in the world. Side effects still occur, however, and some inflammatory pathologies lack efficient treatment. Cyclooxygenase and lipoxygenase pathways are of utmost importance in inflammatory processes; therefore, novel inhibitors are currently needed for both of them. Dual inhibitors of cyclooxygenase-1 and 5-lipoxygenase are anti-inflammatory drugs with high efficacy and low side effects. In this work, 57 leaf extracts (EtOH-H2O 7 : 3, v/v) from Asteraceae species with in vitro dual inhibition of cyclooxygenase-1 and 5-lipoxygenase were analyzed by high-performance liquid chromatography-high-resolution-ORBITRAP-mass spectrometry analysis and subjected to in silico studies using machine learning algorithms. The data from all samples were processed by employing differential expression analysis software coupled to the Dictionary of Natural Products for dereplication studies. The 6052 chromatographic peaks (ESI positive and negative modes) of the extracts were selected by a genetic algorithm according to their respective anti-inflammatory properties; after this procedure, 1241 of them remained. A study using a decision tree classifier was carried out, and 11 compounds were determined to be biomarkers due to their anti-inflammatory potential. Finally, a model to predict new biologically active extracts from Asteraceae species using liquid chromatography-mass spectrometry information with no prior knowledge of their biological data was built using a multilayer perceptron (artificial neural networks) with the back-propagation algorithm using the biomarker data. As a result, a new and robust artificial neural network model for predicting the anti-inflammatory activity of natural compounds was obtained, resulting in a high percentage of correct predictions (81 %), high precision (100 %) for dual inhibition, and low error values (mean absolute error = 0.3), as also shown in the validation test. Thus, the biomarkers of the Asteraceae extracts were statistically correlated with their anti-inflammatory activities and can therefore be useful to predict new anti-inflammatory extracts and their anti-inflammatory compounds using only liquid chromatography-mass spectrometry data.

Repeated-dose toxicological studies of Tithonia diversifolia (Hemsl.) A. gray and identification of the toxic compounds.

ETHNOPHARMACOLOGICAL RELEVANCE: Tithonia diversifolia (Hemsl.) A. Gray has been commonly used in folk medicine to treat abscesses, microbiological infections, snake bites, malaria and diabetes. Both anti-inflammatory and anti-malarial properties have been identified using appropriate assays, but the effective doses have demonstrated toxic effects for the experimental animals. Most of the pharmacological activities have been attributed to sesquiterpene lactones (STLs) and some chlorogenic acid derivatives (CAs) in the leaves of this species. This work aimed to evaluate the repeated-dose toxicity of an aqueous extract (AE) from Tithonia diversifolia leaves and to compare the results with an extract rich in STLs (LRE) and a polar extract (PE) without STLs but rich in CAs. The purpose of this work was to provide insights into the identity of the compounds responsible for the toxic effects of Tithonia diversifolia. MATERIALS AND METHODS: The major classes of compounds were confirmed in each extract by IR spectra and HPLC-UV-DAD profiling using previously isolated or standard compounds. The toxicity of each extract was evaluated in a repeated-dose toxicity study in Wistar rats for 90 days. RESULTS: The AE is composed of both STLs and CAs, the LRE is rich in STLs, and the PE is rich in CAs. The AE caused alterations in haematological parameters but few alterations in biochemical parameters and was relatively safe at doses lower than 100mg/kg. However, the PE and LRE demonstrated several adverse effects by damaging the liver and kidneys, respectively. CONCLUSION: STLs and CAs can be toxic in prolonged use at higher doses in extracts prepared from Tithonia diversifolia by affecting the kidneys and liver.

Chlorogenic acids from Tithonia diversifolia demonstrate better anti-inflammatory effect than indomethacin and its sesquiterpene lactones.

ETHNOPHARMACOLOGICAL RELEVANCE: T. diversifolia (Hemsl.) A. Gray (Asteraceae) has been used in the traditional medicine in several countries as anti-inflammatory and against other illnesses. It is important to evaluate the anti-inflammatory activity of extracts from the leaves of this species, including an infusion, to identify the main constituents of the extracts, observe their effects and correlate them with the anti-inflammatory activity. MATERIALS AND METHODS: An infusion, a leaf rinse extract (LRE) and a polar extract from the rinsed leaves (PE) were obtained and analysed by HPLC-UV-DAD and infrared spectroscopy. The major compounds of these extracts were quantified. The three obtained extracts were evaluated for their anti-inflammatory activities using the paw oedema and croton oil ear oedema assays in mice. Furthermore, neutrophil migration was measured by evaluating myeloperoxidase activity. RESULTS: The PE consists primarily of chlorogenic acids (CAs) and lacks sesquiterpene lactones (STLs). The LRE is rich in STLs and includes a few flavonoids. The infusion is chemically similar to the PE but also contains very low amounts of STLs. The PE and LRE have better mechanisms of action than non-steroidal anti-inflammatory drugs (NSAIDs). Unlike NSAIDs, both the PE and LRE inhibit oedema and neutrophil migration. The pool of CAs from the PE of T. diversifolia has an additional mechanism of action, and its anti-inflammatory effect was greater than what is described in the literature for this class of compounds using the same evaluation models. The similar chemical compositions observed for the infusion and the PE, contrasted with the different activities observed, suggests the presence of antagonist compounds produced during the extraction procedure (infusion); the infusion did not inhibit oedema, however it inhibited neutrophil migration. It suggests that although the great majority of plants present CAs, the category of anti-inflammatory effect of their extracts depends on a suitable pool of compounds and an absence of antagonists, among other factors. CONCLUSIONS: CAs from T. diversifolia comprise a good pool of anti-inflammatory compounds with better activity mechanisms than NSAIDs, other active compounds from the leaf extracts (STLs and flavonoids) and CAs from other plant sources. Thus, the PE of T. diversifolia has high potential for the development of new anti-inflammatory phytomedicines. The infusion probably contains antagonists, and therefore it can be useful to treat inflammation processes where neutrophil recruitment is involved and oedema is not.