Trypanocidal activity of triterpenes from Arrabidaea triplinervia and derivatives

Anticoccidial activity of the secondary metabolites in alpine plants frequently ingested by wild Japanese rock ptarmigans

The Japanese rock ptarmigan (Lagopus muta japonica) is an herbivorous species of partridges that inhabits only alpine zones. Alpine plants are their main source of food. These alpine plants contain toxic compounds to deter herbivores from consuming them. A previous analysis of the alpine plants frequently consumed by Japanese rock ptarmigans revealed the presence of a unique mixture of secondary metabolites and a novel compound. Additionally, wild Japanese rock ptarmigans are often infected by two species of Eimeria parasites. When these parasites were experimentally administered to Svalbard rock ptarmigans (Lagopus muta hyperborean), which do not feed on alpine plants, the birds exhibited symptoms, such as diarrhea and depression, and in some cases, they died. Although little is known about the pathogenesis of these parasites in wild Japanese rock ptarmigans, it was hypothesized that compounds found in alpine plants, their main food source, may reduce the pathogenicity of Eimeria parasites. In the present study, we evaluated the anticoccidial activity of the compounds derived from alpine plants in vitro using Eimeria tenella, which infects chickens belonging to the same pheasant family, as an experimental model. Twenty-seven natural components were extracted from eight alpine plants. The natural components were added to E. tenella sporozoites and incubated for 24 h to evaluate their direct effect. Additionally, Madin-Darby bovine kidney cells were incubated with sporozoites and natural components for 24 h to evaluate the inhibitory effect of the components on sporozoite cell invasion. Six compounds from four alpine plants decreased sporozoite viability by up to 88.3%, and two compounds inhibited sporozoite invasion into the cells. Although further studies are needed to evaluate the effects of these components against Eimeria infections in vivo, our findings suggest that these alpine plants may reduce the degree of infection by decreasing the number of sporozoites in the intestinal tract.

Administration of Ethanolic Extract of Spinacia oleracea Rich in Omega-3 Improves Oxidative Stress and Goblet Cells in Broiler Chickens Infected with Eimeria tenella

This study investigated the anticoccidial activity of spinach (Spinacia oleracea) whole-plant extract against Eimeria tenella, both in vitro and in vivo. For this purpose, one hundred 8-day-old broiler chicks of both sexes were divided into four groups (n = 25 in each group). Chicks in the first group served as the negative control (non-treated-non-infected). Chicks in the second group were challenged at 18 days old with 5 × 104E. tenella sporulated oocysts. The third group was challenged with 5 × 104 sporulated E. tenella oocysts at 18 days old after receiving spinach extract at a dose of 50 mg/kg at 8 days old. The fourth group received 0.2 mg/kg diclazuril (Coxiril® 0.2%) in their diet two days before being orally infected with 5 × 104 sporulated E. tenella oocysts and this continued till day 10 post-infection (PI). The growth performance, clinical symptoms, oocyst shedding, histological findings, and biochemical parameters were used to evaluate the efficacy on day 8 PI when the infection was at its peak. A gas chromatography examination revealed that omega-3 fatty acids were the main constituents of the spinach extract, followed by oleic acid, palmitic acid, and phytol, with amounts of 23.37%, 17.53%, 11.26%, and 7.97%, respectively. The in vitro investigation revealed that the spinach extract at concentrations of 10% and 5% inhibited the oocyst sporulation by 52.1% and 45.1%, respectively. The 5% concentration was selected for the in vivo trial based on the results of the in vitro study. The infected-untreated group showed high levels of OPG; lower body weight; a greater number of parasite stages; few goblet cells; decreased SOD, CAT, and GPX levels; and increased MDA and NO levels. The spinach-treated group, on the other hand, showed a significant decrease in oocyst output per gram of feces (OPG), increased body weight, decreased parasitic stages, and a nearly normal number of goblet cells. Additionally, it reduced malondialdehyde (MDA) and nitric oxide (NO), while increasing superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX). In conclusion, spinach produced significant antioxidant effects, increased body weight, reduced the number of oocysts and parasite stages in the caecum, and restored the number of goblet cells relative to those of an uninfected control. Furthermore, spinach extract inhibits the sporulation percentage of E. tenella oocysts. The ethanolic extract of S. oleracea (whole plant) contained high concentrations of fatty acids, palmitic acid, Phytol, betulin, and ursolic aldehyde, all of which are known to regulate the antioxidant pathway and modulate inflammatory processes and may be the main reason for its anticoccidial activity.

The Free Radical Scavenging Property of the Leaves, Branches, and Roots of Mansoa hirsuta DC: In Vitro Assessment, 3D Pharmacophore, and Molecular Docking Study

In this work, a metabolic profile of Mansoa hirsuta was investigated, and in vitro assays and theoretical approaches were carried out to evaluate its antioxidant potential. The phytochemical screening detected saponins, organic acids, phenols, tannins, flavonoids, and alkaloids in extracts of leaves, branches, and roots. Through LC-MS analysis, the triterpenes oleanolic acid (m/z 455 [M-H]⁻) and ursolic acid (m/z 455 [M-H]⁻) were identified as the main bioactive components. The extracts of the leaves, branches, and roots revealed moderate antioxidant potential in the DPPH test and all extracts were more active in the ABTS test. The leaf extracts showed better antioxidant capacity, displaying IC₅₀ values of 43.5 ± 0.14, 63.6 ± 0.54, and 56.1 ± 0.05 µg mL⁻¹ for DPPH, ABTS, and kinetics assays, respectively. The leaf extract showed higher total flavonoid content (TFC) (5.12 ± 1.02 mg QR/g), followed by branches (3.16 ± 0.88 QR/g) and roots (2.04 ± 0.52 QR/g/g). The extract of the branches exhibited higher total phenolic content (TPC) (1.07 ± 0.77 GAE/g), followed by leaves (0.58 ± 0.30 GAE/g) and roots (0.19 ± 0.47 GAE/g). Pharmacophore and molecular docking analysis were performed in order to better understand the potential mechanism of the antioxidant activity of its major metabolites.

A Review of the Phytochemistry and Pharmacological Properties of the Genus Arrabidaea

The genus Arrabidaea, consisting of ~170 species, belongs to the family Bignoniaceae, distributed around the Neotropics and temperate zone. The center of diversity of the family is in Brazil, where 56 genera and about 340 species exist. Most species of the genus Arrabidaea are traditionally utilized as diuretics and antiseptics, as well as for treating intestinal colic, diarrhea, kidney stones, rheumatoid arthritis, wounds, and enterocolitis. The genus is chemically diverse with different substance classes; most of them are triterpenes, phenolic acids, and flavonoids, and they exhibit valuable pharmacological properties, such as antitumor, antioxidant, leishmanicidal, trypanocidal, anti-inflammatory, and healing properties. This review presents information on the chemical constituents isolated from seven Arrabidaea species, and the pharmacological activities of the extracts, fractions and pure substances isolated since 1994, obtained from electronic databases. The various constituents present in the different species of this genus demonstrate a wide pharmacological potential for the development of new therapeutic agents, however its potential has been underestimated.

In Vitro Anti-Inflammatory Activity in Arthritic Synoviocytes of A. brachypoda Root Extracts and Its Unusual Dimeric Flavonoids

Arrabidaea brachypoda is a plant commonly used for the treatment of kidney stones, arthritis and pain in traditional Brazilian medicine. Different in vitro and in vivo activities, ranging from antinociceptive to anti-Trypanosoma cruzi, have been reported for the dichloromethane root extract of Arrabidaea brachypoda (DCMAB) and isolated compounds. This work aimed to assess the in vitro anti-inflammatory activity in arthritic synoviocytes of the DCMAB, the hydroethanolic extract (HEAB) and three dimeric flavonoids isolated from the DCMAB. These compounds, brachydin A (1), B (2) and C (3), were isolated both by medium pressure liquid and high-speed counter current chromatography. Their quantification was performed by mass spectrometry on both DCMAB and HEAB. IL-1β activated human fibroblast-like synoviocytes were incubated with both extracts and isolated compounds to determine the levels of pro-inflammatory cytokine IL-6 by enzyme-linked immunosorbent assay (ELISA). DCMAB inhibited 30% of IL-6 release at 25 µg/mL, when compared with controls while HEAB was inactive. IC₅₀ values determined for 2 and 3 were 3-fold higher than 1. The DCMAB activity seems to be linked to higher proportions of compounds 2 and 3 in this extract. These observations could thus explain the traditional use of A. brachypoda roots in the treatment of osteoarthritis.

Natural Products: Key Prototypes to Drug Discovery Against Neglected Diseases Caused by Trypanosomatids

BACKGROUND

Neglected tropical diseases are a group of infections caused by microorganisms and viruses that affect mainly poor regions of the world. In addition, most available drugs are associated with long periods of treatment and high toxicity which limits the application and patient compliance. Investment in research and development is not seen as an attractive deal by the pharmaceutical industry since the final product must ideally be cheap, not returning the amount invested. Natural products have always been an important source for bioactive compounds and are advantageous over synthetic compounds when considering the unique structural variety and biological activities. On the other hand, isolation difficulties and low yields, environmental impact and high cost usually limit their application as drug per se.

OBJECTIVE

In this review, the use of natural products as prototypes for the semi-synthesis or total synthesis, as well as natural products as promising hits is covered, specifically regarding compounds with activities against trypanosomatids such as Trypanosoma spp. and Leishmania spp.

METHODS

Selected reports from literature with this approach were retrieved.

CONCLUSION

As summary, it can be concluded that natural products are an underestimated source for designing novel agents against these parasites.

2-furyl(phenyl)methanol isolated from Atractilis gummifera rhizome exhibits anti-leishmanial activity

We report for the first time the isolation of 2-furyl(phenyl)methanol (5) from the chloroform extracts of the Atractylis gummifera roots. A. gummifera is a thistle belonging to the Asteraceae family that produces the ent-kaurane diterpenoid glycoside atractyloside (ATR). ATR (1) was isolated and chemically modified to obtain its aglycone atractyligenin (2) and the methylated derivatives ATR-OMe (3) and genine-OMe (4). The compounds 1-5 were structurally characterised and evaluated against the intracellular amastigote, cultured within macrophages, and the extracellular promastigote of Leishmania donovani, the protozoan parasite responsible for the highly infective disease visceral leishmaniasis, which is fatal if untreated. The 2-furyl(phenyl)methanol 5 exhibited notable activity against the promastigote.

Fridericia platyphylla (Cham.) L.G. Lohmann root extract exerts cytotoxic and antiproliferative effects on gastric tumor cells and downregulates BCL-XL, BIRC5, and MET genes

Fridericia platyphylla (Cham.) L.G. Lohmann (FP) has cytotoxic, anti-inflammatory, and analgesic properties. We aimed to characterize the cytotoxic and antiproliferative effects of FP extract on normal (GAS) and tumor-derived (ACP02 and HepG2) cell lines. The effective concentrations (EC50s) by tetrazolium bromide assay (MTT) were 56.16, 43.68, and 42.57 µg mL−1 and 69.38, 41.73, and 52.39 µg mL−1 by neutral red assay for GAS, ACP02, and HepG2 cells, respectively. The extract decreased nuclear division indices, which was not reflected in cell proliferation curves. Flow cytometric analyses showed that even 30 µg mL−1 extract (shown to be noncytotoxic by MTT assay) increased the sub-G1 population, indicating cell death due to apoptosis and necrosis. A cytokinesis-block micronucleus cytome assay showed that 30 µg mL−1 of the extract increased the frequency of nuclear buds in tumor cells. Real-time quantitative polymerase chain reaction showed CCND1 upregulation in doxorubicin-treated GAS cells and BCL-XL, BIRC5, and MET downregulation in 5 or 30 µg mL−1 in FP extract-treated ACP02 cells. In conclusion, FP extract modulated apoptosis- and cell cycle-related genes and presented selective cytotoxicity toward tumor cells that deserves further investigation by testing other cell types. Our results demonstrated that even medicinal plants exert adverse effects depending on the extract concentrations used and tissues investigated.

Antileishmanial Activity of Dimeric Flavonoids Isolated from Arrabidaea brachypoda

Leishmaniasis are diseases caused by parasites belonging to Leishmania genus. The treatment with pentavalent antimonials present high toxicity. Secondary line drugs, such as amphotericin B and miltefosine also have a narrow therapeutic index. Therefore, there is an urgent need to develop new drugs to treat leishmaniasis. Here, we present the in vitro anti-leishmanial activity of unusual dimeric flavonoids purified from Arrabidaea brachypoda. Three compounds were tested against Leishmana sp. Compound 2 was the most active against promastigotes. Quantifying the in vitro infected macrophages revealed that compound 2 was also the most active against intracellular amastigotes of L. amazonensis, without displaying host cell toxicity. Drug combinations presented an additive effect, suggesting the absence of interaction between amphotericin B and compound 2. Amastigotes treated with compound 2 demonstrated alterations in the Golgi and accumulation of vesicles inside the flagellar pocket. Compound 2-treated amastigotes presented a high accumulation of cytoplasmic vesicles and a myelin-like structure. When administered in L. amazonensis-infected mice, neither the oral nor the topical treatments were effective against the parasite. Based on the high in vitro activity, dimeric flavonoids can be used as a lead structure for the development of new molecules that could be useful for structure-active studies against Leishmania.

Bauerenol Acetate, the Pentacyclic Triterpenoid from Tabernaemontana longipes, is an Antitrypanosomal Agent

The Latin American plant Tabernaemontana longipes was studied in this work as a potential source of antiparasitic agents. The chloroform extract of T. longipes leaves was separated into several fractions, and tested for antitrypanosomal activity. One of the fractions displayed significant growth inhibitory activity against Trypanosoma brucei. The active principle in the fraction was isolated, purified, and characterized by NMR and mass spectrometry. The antitrypanosomal agent in the CHCl₃ extract of T. longipes leaves is the pentacyclic triterpenoid bauerenol acetate. A metabolite profiling assay suggest that the triterpenoid influences cholesterol metabolism. The molecular target(s) of bauerenol and its acetate, like many other antiparasitic pentacyclic triterpenoids is/are unknown, but they present privileged structural scaffolds that can be explored for structure-based activity optimization studies using phenotypic assays.

Juglans regia L. protects against UVB induced apoptosis in human epidermal keratinocytes

The present study was aimed to investigate the photoprotective effect of the male flower of J. regia L. (MEJR) against ultraviolet-B induced apoptosis in human skin cells. Human skin epidermal keratinocytes were pretreated with the MEJR (80 µg/ml, has been selected after MTT assay), prior to 30 min UVB-irradiation at a dose of 20 mJ/cm². Mitochondrial membrane potential was evaluated using Rhodamine-123 staining; the % apoptosis by Hoechst staining and acridine orange staining; DNA damage was measured by comet assay. The levels of p53, Bax, Bcl-xL, Bcl-2, Cytochrome c, Caspase-9 and Caspase-3 expression in HaCaT cells were analyzed by western blotting and RT-PCR. Pretreatment with MEJR 80 µg/ml prior to UVB-irradiation significantly prevents apoptotic characteristics, DNA damage and loss of mitochondrial membrane potential. Thus, MEJR protects UVB-mediated human skin cells, by modulating the expression of apoptotic markers and UVB-induced DNA damage in HaCaT cells.

Plants of Brazilian restingas with tripanocide activity against Trypanosoma cruzi strains

Chagas disease is caused by the Trypanosoma cruzi affecting millions of people, and widespread throughout Latin America. This disease exhibits a problematic chemotherapy. Benznidazole, which is the drug currently used as standard treatment, lamentably evokes several adverse reactions. Among other options, natural products have been tested to discover a novel therapeutic drug for this disease. A lot of plants from the Brazilian flora did not contain studies about their biological effects. Restinga de Jurubatiba from Brazil is a sandbank ecosystem poorly studied in relation to plant biological activity. Thus, three plant species from Restinga de Jurubatiba were tested against in vitro antiprotozoal activity. Among six extracts obtained from leaves and stem parts and 2 essential oils derived from leave parts, only 3 extracts inhibited epimastigote proliferation. Substances present in the extracts with activity were isolated (quercetin, myricetin, and ursolic acid), and evaluated in relation to antiprotozoal activity against epimastigote Y and Dm28 Trypanosoma cruzi strains. All isolated substances were effective to reduce protozoal proliferation. Essentially, quercetin and myricetin did not cause mammalian cell toxicity. In summary, myricetin and quercetin molecule can be used as a scaffold to develop new effective drugs against Chagas's disease.

Effects of astaxanthin in mice acutely infected with Trypanosoma cruzi

During Trypanosoma cruzi infection, oxidative stress is considered a contributing factor for dilated cardiomyopathy development. In this study, the effects of astaxanthin (ASTX) were evaluated as an alternative drug treatment for Chagas disease in a mouse model during the acute infection phase, given its anti-inflammatory, immunomodulating, and anti-oxidative properties. ASTX was tested in vitro in parasites grown axenically and in co-culture with Vero cells. In vivo tests were performed in BALB/c mice (4-6 weeks old) infected with Trypanosoma cruzi and supplemented with ASTX (10 mg/kg/day) and/or nifurtimox (NFMX; 100 mg/kg/day). Results show that ASTX has some detrimental effects on axenically cultured parasites, but not when cultured with mammalian cell monolayers. In vivo, ASTX did not have any therapeutic value against acute Trypanosoma cruzi infection, used either alone or in combination with NFMX. Infected animals treated with NFMX or ASTX/NFMX survived the experimental period (60 days), while infected animals treated only with ASTX died before day 30 post-infection. ASTX did not show any effect on the control of parasitemia; however, it was associated with an increment in focal heart lymphoplasmacytic infiltration, a reduced number of amastigote nests in cardiac tissue, and less hyperplasic spleen follicles when compared to control groups. Unexpectedly, ASTX showed a negative effect in infected animals co-treated with NFMX. An increment in parasitemia duration was observed, possibly due to ASTX blocking of free radicals, an anti-parasitic mechanism of NFMX. In conclusion, astaxanthin is not recommended during the acute phase of Chagas disease, either alone or in combination with nifurtimox.

Gastroprotective effects of hydroethanolic root extract of Arrabidaea brachypoda: Evidences of cytoprotection and isolation of unusual glycosylated polyphenols

The hydroethanolic root extract of Arrabidaea brachypoda, from Bignoniaceae family, a Brazilian medicinal plant, demonstrated significant in vivo gastroprotective effects using different in vivo assays. The activity was evaluated in several models of experimental gastric ulcer in rats (absolute ethanol, glutathione depletion, nitric oxide depletion, non-steroidal anti-inflammatory drugs, pylorus ligation and acetic acid). Using 300 mg/kg (p.o.) the extract significantly reduced gastric injury in all models. In depth phytochemical investigation of this extract led to the isolation of two previously undescribed phenylethanoid glycosides derivatives and seven unusual glycosylated dimeric flavonoids. The structures were elucidated using UV, NMR and HRMS analysis. Absolute configuration of the dimeric flavonoids was performed by electronic circular dichroism (ECD) spectroscopy.

Evaluation of anti-inflammatory, antiangiogenic and antiproliferative activities of Arrabidaea chica crude extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Arrabidaea chica (Bignoniacea) has been used in popular medicine in Brazil to treat inflammation, skin diseases and leukemia. This work aimed to investigate the anti-inflammatory and antitumoral activities of the A. chica aqueous (AE) and ethanol (EE) extracts.

MATERIALS AND METHODS

The murine sponge model was used to evaluate the anti-inflammatory and antiangiogenic activities of AE and EE. Accumulation of neutrophil and macrophage in the implants were determined by assaying myeloperoxidase and N-acetyl-glucosaminidase activities and the neovascularization evaluated by the amount of hemoglobin present in the implant using the Drabkin method. The antitumoral activity was evaluated using the MTT colorimetric method against Jurkat, HL60 and MCF-7 cells. Semi-purified fractions F1-F4 from the EE extract were obtained by a liquid-liquid solvent extraction method and their in vitro anti-proliferative effects were also investigated.

RESULTS

Ethanol and aqueous extracts of A. chica decreased neutrophil accumulation and hemoglobin content in the sponge implants without altering the level of cytokines (IL-2, IL- 4, IL-5, IFN-γ, TNF-α and VEGF) and the albumin/globulin ratio in the serum of treated animals. There was no sign of toxicity (clinical, laboratory or histopathology). The ethanol extract presented antiproliferative activity (IC50 21.5-36.3 µg/mL) against HL60 and Jurkat cell lineages and proapoptotic activity at 50 µg/mL in HL60 cells. The fraction F1 also demonstrated significant antiproliferative activity (IC50 38.5 µg/mL) and proapoptotic activity against HL60 cells in a dose dependent manner.

CONCLUSIONS

Aqueous and ethanol extracts of A. chica attenuate the inflammatory and angiogenic components of the subcutaneous fibrovascular tissue induced by the synthetic matrix in mice. In addition, the ethanol extract from Arrabidaea chica and its fraction F1 presented in vitro antiproliferative activity and could be useful for developing potential chemopreventive substances.

Dimeric flavonoids from Arrabidaea brachypoda and assessment of their anti-Trypanosoma cruzi activity

The nonpolar fraction of an aqueous ethanol extract of the roots of Arrabidaea brachypoda, a Brazilian medicinal plant, demonstrated significant in vitro activity against Trypanosoma cruzi, the parasite responsible for Chagas disease. Targeted isolation of the active constituents led to the isolation of three new dimeric flavonoids (1-3), and their structures were elucidated using UV, NMR, and HRMS analysis, as well as by chemical derivatization. The anti-T. cruzi activity and cytotoxicity toward mammalian cells were determined for these substances. Compound 1 exhibited no activity toward T. cruzi, while flavonoids 2 and 3 exhibited selective activity against these trypomastigotes. Compounds 2 and 3 inhibited the parasite invasion process and its intracellular development in host cells with similar potencies to benznidazole. In addition, compound 2 reduced the blood parasitemia of T. cruzi-infected mice. This study has revealed that these two dimeric flavonoids represent potential anti-T. cruzi lead compounds for further drug development.

Arrabidaea chica hexanic extract induces mitochondrion damage and peptidase inhibition on Leishmania spp

Currently available leishmaniasis treatments are limited due to severe side effects. Arrabidaea chica is a medicinal plant used in Brazil against several diseases. In this study, we investigated the effects of 5 fractions obtained from the crude hexanic extract of A. chica against Leishmania amazonensis and L. infantum, as well as on the interaction of these parasites with host cells. Promastigotes were treated with several concentrations of the fractions obtained from A. chica for determination of their minimum inhibitory concentration (MIC). In addition, the effect of the most active fraction (B2) on parasite's ultrastructure was analyzed by transmission electron microscopy. To evaluate the inhibitory activity of B2 fraction on Leishmania peptidases, parasites lysates were treated with the inhibitory and subinhibitory concentrations of the B2 fraction. The minimum inhibitory concentration of B2 fraction was 37.2 and 18.6 μg/mL for L. amazonensis and L. infantum, respectively. Important ultrastructural alterations as mitochondrial swelling with loss of matrix content and the presence of vesicles inside this organelle were observed in treated parasites. Moreover, B2 fraction was able to completely inhibit the peptidase activity of promastigotes at pH 5.5. The results presented here further support the use of A. chica as an interesting source of antileishmanial agents.

Antimicrobial activity of synthetic bornyl benzoates against Trypanosoma cruzi

We report here for the first time the in vitro effects of (1S,2R,4S)-1,7,7-trimethyl-bicyclo[2·2·1]heptan-2-yl-3',4',5'-trimethoxy benzoate (1) and (1S,2R,4S)-1,7,7-trimethyl-bicyclo[2·2·1]heptan-2-yl benzoate (2) on the growth and ultrastructure of Trypanosoma cruzi. These two synthetic compounds exerted an antiproliferative effect on the epimastigote forms of the parasite. The ICs(50/72h) of two synthetic L-bornyl benzoates, 1 and 2, was 10·1 and 12·8 μg/ml, respectively. Both compounds were more selective against epimastigotes than HEp-2 cells. Ultrastructural analysis revealed intense cytoplasmic vacuolization and the appearance of cytoplasmic materials surrounded by membranes. The treatment of peritoneal macrophages with compounds 1 and 2 caused a significant decrease in the number of T. cruzi-infected cells. L-Bornyl benzoate derivatives may serve as a potential source for the development of more effective and safer chemotherapeutic agents against T. cruzi infections.

Evaluation of the mutagenicity and genotoxicity of Arrabidaea chica Verlot (Bignoneaceae), an Amazon plant with medicinal properties

Arrabidaea chica Verlot (Bignoniaceae) is an important folk medicine plant native to the Amazon region and used to treat anemia, hemorrhage, inflammation, intestinal colic, hepatitis, and skin affections. Although studies showed its therapeutic properties, little knowledge regarding genotoxic properties of this plant is available. The aim of this study was to determine the potential mutagenic and genotoxic/antigenotoxic effects of an A. chica chloroformic fraction (Ac-CF) obtained from leaves containing bioactive metabolites. The mutagenic effects were evaluated using the Salmonella mutagenicity assay, with TA98, TA97a, TA100, TA102, and TA1535 strains, with and without metabolic activation. In vivo mutagenic and genotoxic/antigenotoxic effects were investigated using the micronucleus (MN) test in bone marrow and alkaline comet assay in blood and liver after administration of 100, 500, or 1000 mg/kg Ac-CF in CF-1 mice by gavage (once a day for 3 d). In vitro antioxidant potential was evaluated using DPPH and xanthine/hypoxanthine assays. Ac-CF was not mutagenic in any of the Salmonella typhimurium strains tested and showed negative responses for mutagenicity and genotoxicity in mice. Further, Ac-CF displayed antigenotoxic effects by decreasing the oxidative DNA damage induced by hydrogen peroxide by greater than 50% in blood and liver. The antioxidant action detected in the in vitro assays demonstrated IC50 of 0.838 mg/ml in the xanthine/hypoxanthine assay and IC50 of 28.17 μg/ml in the DPPH assay. In conclusion, Ac-CF did not induce mutagenic and genotoxic effects and was able to protect DNA against oxidative damage in vivo, suggesting that this fraction may not pose genetic risks, although further toxicology assays are necessary.

In vitro and in vivo studies of the trypanocidal activity of four terpenoid derivatives against Trypanosoma cruzi

Four terpenoid derivatives were examined for their activity against Trypanosoma cruzi. Our results show that two compounds were very active in vitro against both extra- and intracellular forms. These compounds, non-toxic for the host cells, are more effective than the reference drug benznidazole. The capacity to infect cells was negatively affected and the number of amastigotes and trypomastigotes was reduced. A wide range of ultrastructural alterations was found in the epimastigote forms treated with these compounds. Some metabolic changes occurred presumably at the level of succinate and acetate production, perhaps caused by the disturbance of the enzymes involved in sugar metabolism inside the mitochondria. In vivo results were consistent with those observed in vitro. The parasitic load was significantly lower than in the control assay with benznidazole. The effects of these products showed the reduction of the anti-T. cruzi antibodies level during the chronic stage.

Trypanocide, cytotoxic, and antifungal activities of Momordica charantia

CONTEXT

Chagas disease, caused by Trypanosoma cruzi, is a public health problem. Currently, chemotherapy is the only available treatment for this disease, and the drugs used, nifurtimox and benzonidazol, present high toxicity levels. An alternative for replacing these drugs are natural extracts from Momordica charantia L. (Cucurbitaceae) used in traditional medicine because of their antimicrobial and biological activities.

OBJECTIVE

In this study, we evaluated the extract of M. charantia for its antiepimastigote, antifungal, and cytotoxic activities.

MATERIALS AND METHODS

An ethanol extract of leaves from M. charantia was prepared. To research in vitro antiepimastigote activity, T. cruzi CL-B5 clone was used. Epimastigotes were inoculated at a concentration of 1 × 10(5) cells/mL in 200 µl tryptose-liver infusion. For the cytotoxicity assay, J774 macrophages were used. The antifungal activity was evaluated by microdilution using strains of Candida albicans, Candida tropicalis, and Candida krusei.

RESULTS

The effective concentration capable of killing 50% of parasites (IC(50)) was 46.06 µg/mL. The minimum inhibitory concentration (MIC) was ≤ 1024 µg/mL. Metronidazole showed a potentiation of its antifungal effect when combined with an extract of M. charantia.

CONCLUSIONS

Our results indicate that M. charantia could be a source of plant-derived natural products with antiepimastigote and antifungal-modifying activity with moderate toxicity.

Clinically useful anticancer, antitumor, and antiwrinkle agent, ursolic acid and related derivatives as medicinally important natural product

Medicinal plants are becoming an important research area for novel and bioactive molecules for drug discovery. Novel therapeutic strategies and agents are urgently needed to treat different incurable diseases. Many plant derived active compounds are in human clinical trials. Currently ursolic acid is in human clinical trial for treating cancer, tumor, and skin wrinkles. This review includes the clinical use of ursolic acid in various diseases including anticancer, antitumor, and antiwrinkle chemotherapies, and the isolation and purification of this tritepernoid from various plants to update current knowledge on the rapid analysis of ursolic acid by using analytical methods. In addition, the chemical modifications of ursolic acid to make more effective and water soluble derivatives, previous and current information regarding, its natural and semisynthetic analogs, focusing on its anticancer, cytotoxic, antitumor, antioxidant, anti-inflammatory, anti-HIV, acetyl cholinesterase, α-glucosidase, antimicrobial, and hepatoprotective activities, briefly discussion is attempted here for its research perspectives. This review article contains fourteen medicinally important ursolic acid derivatives and 351 references.

Natural products and Chagas' disease: a review of plant compounds studied for activity against Trypanosoma cruzi

Here, we review studies that have investigated the activity of plant-derived compounds against Trypanosoma cruzi, the etiologic agent of Chagas’ disease. In the last decade, more than 300 species belonging to almost 100 families have been evaluated for activity, and here we describe the compounds isolated; 85 references are cited.

Anti-inflammatory and antinociceptive effects of Arrabidaea brachypoda (DC.) Bureau roots

AIM OF THE STUDY

Arrabidaea brachypoda (DC.) Bureau has been used to relieve general pain, painful joints and kidney stones in Brazilian folk medicine. Nevertheless, scientific information regarding this species is scarce; there are no reports related to its possible analgesic and anti-inflammatory effects. This study was aimed at evaluating the traditional use of Arrabidaea brachypoda root using in vivo inflammatory and nociceptive models.

MATERIALS AND METHODS

Carrageenan-induced paw edema, peritonitis and fibrovascular tissue growth induced by s.c. cotton pellet implantation were used to investigate the anti-inflammatory activity of Arrabidaea brachypoda roots ethanolic extract (AbEE) in rats. Formalin and acetic acid-induced writhing tests were used to investigate the antinociceptive activity in mice. High-performance liquid chromatography (HPLC) was used to determine the fingerprint chromatogram of AbEE.

RESULTS

The AbEE at test doses of 30-300 mg/kg p.o. demonstrated anti-inflammatory effects. AbEE reduced paw edema induced by carrageenan, inhibited leukocyte recruitment into the peritoneal cavity and, in the model of chronic inflammation using the cotton pellet-induced fibrovascular tissue growth in rats, significantly inhibited the formation of granulomatous tissue. The extracts at test doses of 30-300 mg/kg p.o. clearly demonstrated antinociceptive activity, except during the first phase of the formalin test. The presence of quercetin and phenolic compounds in the extract Arrabidaea brachypoda was confirmed using HPLC.

CONCLUSION

Arrabidaea brachypoda ethanol extract markedly demonstrated anti-inflammatory action in rats and antinociceptive activity in mice, which supports the previous claims of traditional use.

Current and developing therapeutic agents in the treatment of Chagas disease

Chagas disease must be treated in all its stages: acute, indeterminate, chronic, and initial and middle determinant chronic, due to the fact that DNA of the parasite can be demonstrated by PCR in chronic cases, where optical microscopy does not detect parasites. Nifurtimox (NF) and benznidazole (BNZ) are the drugs accepted to treat humans based upon ethical considerations and efficiency. However, both the drugs produce secondary effects in 30% of the cases, and the treatment must be given for at least 30-60 days. Other useful drugs are itraconazole and posaconazole. The latter may be the drug to treat Chagas disease in the future when all the investigations related to it are finished. At present, there is no criterion of cure for chronic cases since in the majority, the serology remains positive, although it may decrease. In acute cases, 70% cure with NF and 75% with BNZ is achieved. In congenital cases, 100% cure is obtained if the treatment is performed during the first year of life. In chronic acquired cases, 20% cure and 50% improvement of the electrocardiographic changes are obtained with itraconazole.

Trypanocidal activity and acute toxicity assessment of triterpene acids

The present study evaluates the in vitro and in vivo trypanocidal activity of ursolic acid and oleanolic acid against the Bolivia strain of Trypanosoma cruzi. Their acute toxicity is also assessed on the basis of median lethal dose (DL50) determination and quantification of biochemical parameters. Ursolic acid is the most active compound in vitro, furnishing IC50 of 25.5 microM and displaying 77% of trypomastigote lysis at a concentration of 128 microM. In agreement with in vitro assays, the results obtained for the in vivo assay reveals that ursolic acid (at a dose of 20 mg/Kg/day) provides the most significant reduction in the number of parasites at the parasitemic peak. Results concerning the LD50 assay and the biochemical parameters evaluated in the present study demonstrate that these substances can be safely used on an experimental basis.

Endothelium-dependent vasorelaxation in rat thoracic aorta by Mansoa hirsuta D.C

The vasodilator effect of the ethanolic extract of Mansoa hirsuta leaves (EEF) was assayed in rat aortic rings. EEF produced a concentration-dependent vasodilatation (pIC(50)=5.1+/-0.2), which was absent in endothelium-denuded vessels. The vasodilator effect of EEF was similar to a standardized ethanolic extract of Hancornia speciosa Gomes (pIC(50)=5.1+/-0.1). The endothelium-dependent vasodilatation induced by EEF was abolished by L-NAME (100 microM), a nitric oxide (NO) synthase inhibitor, but not by indomethacin (10 microM; pIC(50)=4.9+/-0.2), a cyclooxygenase inhibitor. The concentration-response curve of EEF was not modified by the addition of superoxide dismutase (SOD; 300 U/ml). In addition, EEF (50 microg/ml) displaced the 3-morpholino-sidnonimine (SIN-1; p<0.05) concentration-effect curve to the left, as well as SOD (300 U/ml). These findings lead us to conclude that EEF induces a NO- and endothelium-dependent vasodilatation in rat aortic preparations, and that this effect is, at least in some extent, due to an increase in the NO bioavailability as consequence of its antioxidant activity. The HPLC-DAD profile recorded for EEF indicates the presence of four major peaks with close retention times, exhibiting similar UV spectra with wavelength maxima compatible with heterogeneous proanthocyanidins.

Antioxidant C-glucosylxanthones from the leaves of Arrabidaea patellifera

Chemical investigation of the methanol extract from the leaves of Arrabidaea patellifera, a Bignoniaceae from Panama, afforded mangiferin, isomangiferin, and six new derivatives (3'-O-p-hydroxybenzoylmangiferin, 3'-O-trans-coumaroylmangiferin, 6'-O-trans-coumaroylmangiferin, 3'-O-trans-cinnamoylmangiferin, 3'-O-trans-caffeoylmangiferin, and 3'-O-benzoylmangiferin). All these compounds had antioxidant and radical-scavenging activities, and four of them were relatively active in vitro against Plasmodium falciparum. The structures were determined by spectrometric and chemical methods, including 1D and 2D NMR experiments and MS analysis.