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Propolis is a natural product widely used in folk medicine. Among its various applications, its antiparasitic properties stand out. Due to its great biodiversity, Brazil is a major producer of several types of propolis. This study proposes to evaluate the leishmanicidal properties of the hydroalcoholic extract of propolis collected in the southern region of Brazil (Brown propolis – HEBP) and its main isolated compounds: abietic acid (1), 13-epi-cupressic acid (2), 13-epi-torulosol (3), dehydroabietic acid (4), cis-communic acid (5) and ent-agatic acid (6). In general, the diterpenes did not show activity against the promastigotes of Leishmania (Leishmania) amazonensis at the evaluated concentrations. However, the HEBP was very active with an inhibition concentration of 50% at 8.32 µg/mL. Moreover, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) assays showed morphological and structural alterations in promastigote forms of L. (L.) amazonensis when incubated with HEBP. [ABSTRACT FROM AUTHOR]

Background/Objectives: Brazilian red propolis has attracted attention for its pharmacological properties. However, signs of toxicity were recently observed in long-term studies using the hydroalcoholic extract of red propolis (RPHE), likely due to polyprenylated benzophenones. This study aimed to develop a benzophenone-free red propolis extract (BFRP) and validate an HPLC-PDA method to quantify its main constituents: isoliquiritigenin, vestitol, neovestitol, medicarpine, and 7-O-methylvestitol. Methods: BFRP's toxicity was assessed in zebrafish larvae through a vibrational startle response assay (VSRA) and morphological analysis. Genotoxicity was evaluated using the micronucleus test in rodents, and the extract's effects on chemically induced preneoplastic lesions in rat colon were studied. An HPLC-PDA method was used to quantify BFRP's main compounds. Results: BFRP primarily contained vestitol (128.24 ± 1.01 μg/mL) along with isoliquiritigenin, medicarpin, neovestitol, and 7-O-methylvestitol. Zebrafish larvae exposed to 40 µg/mL of BFRP exhibited toxicity, higher than the 10 µg/mL for RPHE, though no morphological differences were found. Fluorescent staining in the notochord, branchial arches, and mouth was observed in larvae treated with both BFRP and RPHE. No genotoxic or cytotoxic effects were observed up to 2000 mg/kg in rodents, with no impact on hepatotoxicity or nephrotoxicity markers. Chemoprevention studies showed a 41.6% reduction in preneoplastic lesions in rats treated with 6 mg/kg of BFRP. Conclusions: These findings indicate that BFRP is a safe, effective propolis-based extract with potential applications for human health, demonstrating reduced toxicity and chemopreventive properties. [ABSTRACT FROM AUTHOR]

The search for new antibacterial agents and a better comprehension of substances with antimicrobial behavior is mandatory nowadays due to the serious public health problem of infection diseases. In the present work, 30 diterpenes were studied, with 2 natural derivatives, named ent-16-kauren-19-oic acid and ent-pimara-8(14), 15-dien-19-oic acid, and 28 semisynthetic derivatives. The natural diterpenes were isolated from Mikania glomerata and Viguiera arenaria, respectively. All diterpenes were submitted to antimicrobial assays against six different Gram-positive microorganisms to better understand the structure-activity relationship of antimicrobial diterpenes. The semi-synthetic derivatives were all obtained from the two natural derivatives by structural modifications, mainly esterification reactions. Both natural derivatives, together with the derivative ent-8(14)-pimaren-19-oic acid, displayed the most relevant antibacterial activities, with minimal inhibitory concentration (MIC) values that were less than 10 [micro]gm[L.sup.-1] for most pathogens; thus, they were considered promising antimicrobial agents. Moreover, in light of the hypothesis of Urzua and colleagues, several considerations about the structure-activity relationship of antimicrobial diterpenes could be stated. Key words: kaurane diterpenes, pimarane diterpenes, antibacterial activity, semisynthetic derivatives, structure-activity relationship. La recherche de nouveaux agents antibacteriens et d'une meilleure comprehension du comportement des substances antimicrobiennes est maintenant devenue un devoir en raison du grave probleme de sante publique que constituent les maladies infectieuses. Dans le cadre des presents travaux, nous avons etudie trente diterpenes, dont deux naturels, a savoir l'acide ent-16-kauren-19-oique et l'acide ent-pimara-8(14), 15-dien-19-oique, et 28 derives semi-synthetiques. Les diterpenes naturels ont ete isoles a partir des especes Mikania glomerata et Viguiera arenaria, respectivement. Nous avons d'abord soumis tous les diterpenes a des essais antimicrobiens contre six differents microorganismes a Gram positif, puis nous avons tente de mieux comprendre la relation structure-activite de ceux qui montraient une activite antimicrobienne. Les derives semi-synthetiques ont tous ete obtenus a partir des deux molecules naturelles par modifications structurales, principalement des reactions d'esterification. Les deux produits naturels ainsi que le derive acide ent-8(14)-pimaren-19-oique ont montre les activites antibac-teriennes les plus interessantes, soit des concentrations minimales inhibitrices (CMI) inferieures a 10 [micro]gm[L.sup.-1] contre laplupart des pathogenes, et sont donc consideres comme des agents antimicrobiens prometteurs. Par ailleurs, a la lumiere de l'hypothese d'Urzua et ses collaborateurs, nous avons pu formuler plusieurs considerations concernant la relation structure-activite des diterpenes antimicrobiens. [Traduit par la Redaction] Mots-cles : diterpenes a base de kaurane, diterpenes a base de pimarane, activite antibacterienne, derives semi-synthetiques, relation structure-activite., Introduction Natural products (NPs) are undoubtedly an impressive source of drugs, as stated by Newman and Cragg's reviews. (1) As an example, 49% of the approved small molecules by the [...]

Propolis is a natural product of great economic and pharmacological importance. The flora surrounding the bee communities is a determining factor in the composition of propolis and therefore in its biological and medicinal properties. Brown propolis is one of the most important types of propolis in Brazil, produced in the southeastern region. The ethanolic extract of a brown propolis sample from Minas Gerais state was chemically characterized for the subsequent development of a RP‐HPLC method, validated according to the standards of regulatory agencies. The leishmanicidal activity of this extract was assessed. The brown propolis was characterized by the presence of chemical markers reported on green propolis such as ferulic acid, coumaric acid, caffeic acid, cinnamic acid, baccharin, artepillin and drupanin, indicating a probable origin on Baccharis dracunculifolia. The developed method agreed with the parameters established by the validation guidelines, then proved to be reliable for the analysis of this type of propolis. The brown propolis displayed significant activity against Leishmania amazonensis with IC50 values of 1.8 and 2.4 μg/ml against the promastigote and amastigote forms, respectively. The studied propolis exhibited promising evidence for use as a natural source against L. amazonensis. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Red propolis is synthetized from exudates of Dalbergia ecastophyllum (L) Taub. and Symphonia globulifera L.f. presents isoflavones, guttiferone E, xanthochymol, and oblongifolin B and has anti-inflammatory, antioxidant, and antiproliferative activities. OBJECTIVES: This study aimed to evaluate the antigenotoxic and anticarcinogenic potential of red propolis hydroalcoholic extract (RPHE) in rodents. METHODS: The influence of RPHE in doxorubicin (DXR)-induced genotoxicity was investigated through the micronucleus test in Swiss mice. Blood samples were also collected to investigate oxidative stress, hepatotoxicity, and nephrotoxicity. Was investigated the influence of RPHE in 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci, as well as its influence in prolifera ting cell nuclear antigen (PCNA) and the cyclooxygenase-2 (COX-2) expression in colon of rats, by immunohistochemistry. RESULTS: The results showed that RPHE (48 mg/kg) reduced DXR-induced genotoxicity. Animals treated with DXR showed significantly lower GSH serum levels in comparison to the negative control. RPHE treatments did not attenuated significantly the DXR-induced GSH depletion. No difference was observed in cytotoxicity parameters of mice hematopoietic tissues between the treatment groups, as well as the biochemical parameters of hepatotoxicity and nephrotoxicity. RPHE (12 mg/kg) reduced the DMH-induced carcinogenicity and toxicity, as well as DMH-induced PCNA and COX-2 expression in colon tissue. CONCLUSION: Therefore, was observed that the RPHE has chemopreventive effect, associated to antiproliferative and anti-inflammatory activities. [ABSTRACT FROM AUTHOR]

Context:Solanum lycocarpumA. St.-Hil. (Solanaceae), popularly known as ‘fruta-do-lobo’ (wolf fruit), ‘lobeira’ and ‘jurubebão’, is commonly used by native people of Central Brazil in powder form or as a hydroalcoholic extract for the management of diabetes and obesity and to decrease cholesterol levels.Objective:The present study determines the possible cytotoxic, genotoxic and antigenotoxic activities of hydroalcoholic extract of theS. lycocarpumfruits (SL). Materials and methods:The clonogenic efficiency assay was used to determine the cytotoxicity. Three concentrations of SL (16, 32 and 64 μg/mL) were used for the evaluation of its genotoxic and antigenotoxic potential on V79 cells using the micronucleus and comet assays. In the antigenotoxicity assays, the cells were treated simultaneously with SL and the alkylating agent methyl methanesulphonate (MMS, 44 μg/mL for the micronucleus assay and 22 μg/mL for the comet assay) as an inducer of micronuclei and DNA damage. Results:The results showed that SL was cytotoxic at concentrations up to 64 μg/mL. No significant differences in the rate of chromosome or DNA damage were observed between cultures treated with SL and the control group. In addition, the frequencies of micronuclei and DNA damage induced by MMS were significantly reduced after treatment with SL. The damage reduction percentage ranged from 68.1% to 79.2% and 12.1% to 16.5% for micronucleus and comet assays, respectively. Discussion and conclusion:SL exerted no genotoxic effect and exhibited chemopreventive activity against both genomic and chromosome damage induced by MMS. [ABSTRACT FROM AUTHOR]

ABSTRACT The Copaifera species (Leguminoseae) are popularly known as 'copaíba' or 'copaíva' and are grown in the states of Amazonas, Pará and Ceará in northern Brazil. The oleoresins obtained from these species have been extensively used owing to their pharmacological potential and their application in cosmetic and pharmaceutical preparations. In the present study, the development and validation of a novel, rapid and efficient RP-HPLC methodology for the analysis of the diterpene (−)-copalic acid (CA), pointed out as the only chemical marker of the Copaifera genus, are described. The regression equation ( Y = 26,707 x − 29,498) was obtained with good linearity ( r2 = 0.9993) and the limits of quantification and detection were 9.182 and 3.032 µg/mL, respectively. The precision and the accuracy of the method were adequate (lower than 4%). Finally, the validation parameters evaluated were satisfactorily met, so the developed method represents a suitable tool for application in the quality control of such natural products. Further studies aiming to develop analytical methodologies for each Copaifera species using a more representative number of chemical markers should be performed. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The in vitro activity of the crude hydroalcoholic extract of the aerial parts of Miconia langsdorffii Cogn. was evaluated against the promastigote forms of L. amazonensis, the causative agent of cutaneous leishmaniasis in humans. The bioassayguided fractionation of this extract led to identification of the triterpenes ursolic acid and oleanolic acid as the major compounds in the fraction that displayed the highest activity. Several ursolic acid semi-synthetic derivatives were prepared, to find out whether more active compounds could be obtained. Among these ursolic acid-derived substances, the C-28 methyl ester derivative exhibited the best antileishmanial activity. [ABSTRACT FROM AUTHOR]