Mexican Coccoloba uvifera L. Leaf and Fruit Extracts: Identification of Pentacyclic Triterpenes and Volatile Profile by GC-MS.

Mexican Coccoloba uvifera fruit contains polyphenols, flavonoids, and anthocyanins, while in the leaves, lupeol, α- and ß-amyrin have been previously identified by HPLC. However, the low resolution by HPLC of pentacyclic triterpenes (PTs) is a limitation. Moreover, the volatile profile of C. uvifera fruit is still unknown. Therefore, this study aimed to identify PTs in C. uvifera leaf and fruit extracts by CG-MS analysis and to determine the volatile profile of C. uvifera pulp by headspace solid-phase microextraction. The results showed trimethylsilylated compounds of standards lupeol, α- and ß-amyrin, indicating that the silylation reaction was suitable. These trimethylsilylated compounds were identified in leaf and fruit extracts. The fruit volatile profile revealed the presence of 278 esters, 20 terpenes, 9 aldehydes, 5 alcohols, and 4 ketones. The fruit showed a high content of esters and terpenes. Due to their flavour properties, esters are essential for the food, cosmetics, and pharmaceutics industries. Moreover, terpenes in the fruit, such as menthone, ß-elemene, junipene, and ß-caryophyllene have the potential as anticancer and phytopathogen agents. The results indicated that GC-MS is an alternative to HPLC approaches for identifying PTs. Besides, identifying volatile compounds in the fruit will increase the value of this plant and expand its application. Identifying PTs and volatile compounds in Mexican C. uvifera leads to a better understanding of the potential benefits of this plant. This would increase the consumption of Mexican C. uvifera fresh or as functional ingredients in nutraceutical or pharmaceutical products.

Pentacyclic triterpene-loaded emulsion stabilized by Agaricus blazei Murill polysaccharides: Factorial design and cytoprotection study.

In this study, pentacyclic triterpene-loaded emulsions were stabilized by polysaccharides from Agaricus blazei Murill mushroom (PAb). The drug-excipient compatibility results by Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) showed the absence of physicochemical incompatibilities. The use of these biopolymers at 0.75 % led to obtaining emulsions with droplets smaller than 300 nm, moderate polydispersity, and ζ-potential >30 mV in modulus. The emulsions presented high encapsulation efficiency, suitable pH for topical application, and absence of macroscopic signs of instability during 45 days. Morphological analysis suggested the deposition of thin layers of PAb around the droplets. The encapsulation of pentacyclic triterpene in emulsions, stabilized by PAb, improved the cytocompatibility of this drug against PC12 and murine astrocyte cells. There was a reduction in cytotoxicity, which resulted in a lower accumulation of intracellular reactive oxygen species and maintenance of the mitochondrial transmembrane potential. Based on these results, it is estimated that PAb are promising biopolymers for the emulsions' stabilization by improving their physicochemical and biological properties.

Celastrol: A lead compound that inhibits SARS-CoV-2 replication, the activity of viral and human cysteine proteases, and virus-induced IL-6 secretion.

The global emergence of coronavirus disease 2019 (COVID-19) has caused substantial human casualties. Clinical manifestations of this disease vary from asymptomatic to lethal, and the symptomatic form can be associated with cytokine storm and hyperinflammation. In face of the urgent demand for effective drugs to treat COVID-19, we have searched for candidate compounds using in silico approach followed by experimental validation. Here we identified celastrol, a pentacyclic triterpene isolated from Tripterygium wilfordii Hook F, as one of the best compounds out of 39 drug candidates. Celastrol reverted the gene expression signature from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected cells and irreversibly inhibited the recombinant forms of the viral and human cysteine proteases involved in virus invasion, such as Mpro (main protease), PLpro (papain-like protease), and recombinant human cathepsin L. Celastrol suppressed SARS-CoV-2 replication in human and monkey cell lines and decreased interleukin-6 (IL-6) secretion in the SARS-CoV-2-infected human cell line. Celastrol acted in a concentration-dependent manner, with undetectable signs of cytotoxicity, and inhibited in vitro replication of the parental and SARS-CoV-2 variant. Therefore, celastrol is a promising lead compound to develop new drug candidates to face COVID-19 due to its ability to suppress SARS-CoV-2 replication and IL-6 production in infected cells.

Synthesis, biological evaluation, molecular docking studies and In-silico ADMET evaluation of pyrazines of pentacyclic triterpenes.

The semisynthesis of novel derivatives of lupeyl palmitate and 3ß-palmitoyloxy-olean-12-ene by introduction of a pyrazine at C-2 / C-3 and modifications of the relatively unexplored C-30 position of lupeol derivatives was conducted, and their cytotoxic and anti-inflammatory activities were evaluated. The derivatives 7, 10 and 11 significantly inhibited the tumor cell lines U251, K562, HCT-15, MCF-7 and SKLU-1, and compounds 7 and 11 were more active (IC50 25.4 ± 2.0 µM and 7.1 ± 0.4 µM, respectively) than the positive control (etoposide (IC50 31.5 ± 2.2 µM) in the tumor line PC-3. Introduction of the pyrazine at C-2 / C-3 in compounds 1 and 2 or modification at C-30 of compound 1 decreased the anti-inflammatory activity in the TPA-induced mouse ear edema. Following the results of the PASS online evaluation of the potential biological activity of the natural compounds and their derivatives, the inhibition of pNF-κB translocation to the prostate cancer (PC-3) cell nucleus was investigated and the binding mode of compounds 7, 10 and 11 with the human NF-κB receptor was explored by a molecular docking study. These derivatives bound directly or close to the amino acids that form the DNA recognition site. The ADMET physicochemical parameters of the fifteen compounds were further analyzed in silico using Molinspiration calculations indicating the potential of compounds 7, 10 and 11 for further investigation.

Pentacyclic Triterpenoids Isolated from Celastraceae: A Focus in the 13C-NMR Data.

The Celastraceae family comprises about 96 genera and more than 1.350 species, occurring mainly in tropical and subtropical regions of the world. The species of this family stand out as important plant sources of triterpenes, both in terms of abundance and structural diversity. Triterpenoids found in Celastraceae species display mainly lupane, ursane, oleanane, and friedelane skeletons, exhibiting a wide range of biological activities such as antiviral, antimicrobial, analgesic, anti-inflammatory, and cytotoxic against various tumor cell lines. This review aimed to document all triterpenes isolated from different botanical parts of species of the Celastraceae family covering 2001 to 2021. Furthermore, a compilation of their 13C-NMR data was carried out to help characterize compounds in future investigations. A total of 504 pentacyclic triterpenes were compiled and distinguished as 29 aromatic, 50 dimers, 103 friedelanes, 89 lupanes, 102 oleananes, 22 quinonemethides, 88 ursanes and 21 classified as others.

Toxicological and pharmacological effects of pentacyclic triterpenes rich fraction obtained from the leaves of Mansoa hirsuta.

Mansoa hirsuta is a medicinal plant native to the Brazilian semi-arid region. This approach aimed to investigate the in vitro and in vivo toxicity and anti-inflammatory and analgesic actions of the M. hirsuta fraction (MHF). In vitro cell viability was assessed in 3T3 cells. In vivo, the acute toxicity test, a single dose of the MHF was administered. For the subchronic toxicity test, three doses of were administered for 30 days. Locomotion and motor coordination were assessed using open field and rota-rod. The anti-inflammatory activity was evaluated in carrageenan-induced paw edema and zymosan-induced air-pouch models. Myeloperoxidase (MPO) and total proteins were also measured. The antinociceptive activity MHF was determined using acid acetic-induced abdominal writhing and formalin models. In the cytotoxicity assay, MHF showed no significative impairment of cell viability and in the acute toxicity study, did not cause mortality or signs of toxicity. Repeated exposure to MHF did not cause relevant toxicological changes. The evaluation in the open field test showed that the MHF did not alter the locomotor activity and there was no change in motor coordination and balance of animals. MHF significantly reduced edema, MPO production, the migration of leukocytes and protein leakage. In addition, MHF reduced abdominal writhing and significantly inhibited the first and second stage of the formalin test. The results of this study indicated that MHF has an anti-inflammatory and analgesic potential without causing acute or subchronic toxic effects and it can be a promising natural source to be explored.

The Methionine 549 and Leucine 552 Residues of Friedelin Synthase from Maytenus ilicifolia Are Important for Substrate Binding Specificity.

Friedelin, a pentacyclic triterpene found in the leaves of the Celastraceae species, demonstrates numerous biological activities and is a precursor of quinonemethide triterpenes, which are promising antitumoral agents. Friedelin is biosynthesized from the cyclization of 2,3-oxidosqualene, involving a series of rearrangements to form a ketone by deprotonation of the hydroxylated intermediate, without the aid of an oxidoreductase enzyme. Mutagenesis studies among oxidosqualene cyclases (OSCs) have demonstrated the influence of amino acid residues on rearrangements during substrate cyclization: loss of catalytic activity, stabilization, rearrangement control or specificity changing. In the present study, friedelin synthase from Maytenus ilicifolia (Celastraceae) was expressed heterologously in Saccharomyces cerevisiae. Site-directed mutagenesis studies were performed by replacing phenylalanine with tryptophan at position 473 (Phe473Trp), methionine with serine at position 549 (Met549Ser) and leucine with phenylalanine at position 552 (Leu552Phe). Mutation Phe473Trp led to a total loss of function; mutants Met549Ser and Leu552Phe interfered with the enzyme specificity leading to enhanced friedelin production, in addition to α-amyrin and ß-amyrin. Hence, these data showed that methionine 549 and leucine 552 are important residues for the function of this synthase.

Betulinic acid exerts antigenotoxic and anticarcinogenic activities via inhibition of COX-2 and PCNA in rodents.

Phytochemicals have been suggested as an effective strategy for cancer prevention. Within this context, triterpene betulinic acid (BA) exhibits several biological properties but its chemopreventive effect has not been fully demonstrated. The present study investigated the antigenotoxic potential of BA against doxorubicin (DXR)-induced genotoxicity using the mouse peripheral blood micronucleus assay, as well as its anticarcinogenic activity against 1,2dimethylhydrazine (DMH)-induced colorectal lesions in rats. Micronuclei (MN) assay and aberrant crypt foci assay were used to assess the antigenotoxic and the anticarcinogenic potential, respectively. The molecular mechanisms underlying the anticarcinogenic activity of BA were evaluated by assessing anti-inflammatory (COX-2) and antiproliferative (PCNA) pathways. The results demonstrated that BA at the dose of 0.5 mg/kg bodyweight exerted antigenotoxic effects against DXR, with a reduction of 70.2% in the frequencies of chromosomal damage. Animals treated with BA showed a 64% reduction in the number of preneoplastic lesions when compared to those treated with the carcinogen alone. The levels of COX-2 and PCNA expression in the colon were significantly lower in animals treated with BA and DMH compared to those treated with the carcinogen alone. The chemopreventive effect of BA is related, at least in part, to its antiproliferative and anti-inflammatory activity, indicating a promising potential of this triterpene in anticancer therapies, especially for colorectal cancer.

α-amyrin-loaded nanocapsules produce selective cytotoxic activity in leukemic cells.

INTRODUCTION: Amyrins are triterpenes that have attractive pharmacological potential; however, their low water solubility and erratic stomach absorption hinders their use as a drug. The aim of this paper was to develop a novel α-amyrin-loaded nanocapsule for intestinal delivery and evaluate, preliminarily, its cytotoxic ability against leukemic cells. MATERIAL AND METHODS: Five nanocapsule formulations were designed by the solvent displacement-evaporation method. Poly-ε-caprolactone, Eudragit® E100, and Kollicoat® Mae 100 P were used as film-former materials. Particle size, polydispersity index (PdI), zeta potential, and the pH of all formulations were measured. The cytotoxic potential of the nanocapsules was evaluated in vitro using different leukemic lineages RESULTS: Nanocapsules coated with Kollicoat® Mae 100 P presented the smallest particle size (130 nm), the lowest zeta-potential (-38 mV), and the narrowest size distribution (PdI = 0.100). The entrapment efficiency was 65.47%, while the loading capacity was 2.40%. Nanocapsules release 100% of α-amyrin in 40 min (pH 7.4), by using a possible mechanism of swelling-diffusion. The formulation showed excellent on-shelf physicochemical stability during one year. Additionally, nanocapsules produced a selective cytotoxic effect on a human leukemia lineage Kasumi-1, an acute myeloid leukemia cell line, and produced cell death by apoptosis CONCLUSION: α-amyrin-loaded nanocapsules appear to be a promising nanoformulation that could be used against leukemia.

Bioassay-Guided Identification of the Antiproliferative Compounds of Cissus trifoliata and the Transcriptomic Effect of Resveratrol in Prostate Cancer Pc3 Cells.

The bioassay-guided fractionation of a CHCl3-MeOH extract from the stems of Cissus trifoliata identified an active fraction against PC3 prostate cancer cells. The treatment for 24 h showed an 80% reduction in cell viability (p ≤ 0.05) by a WST-1 assay at a concentration of 100 µg/mL. The HPLC-QTOF-MS analysis of the fraction showed the presence of coumaric and isoferulic acids, apigenin, kaempferol, chrysoeriol, naringenin, ursolic and betulinic acids, hexadecadienoic and octadecadienoic fatty acids, and the stilbene resveratrol. The exposure of PC3 cells to resveratrol (IC25 = 23 µg/mL) for 24 h induced significant changes in 847 genes (Z-score ≥ ±2). The functional classification tool of the DAVID v6.8 platform indicates that the underlying molecular mechanisms against the proliferation of PC3 cells were associated (p ≤ 0.05) with the process of differentiation and metabolism. These findings provide experimental evidence suggesting the potential of C. trifoliata as a promising natural source of anticancer compounds.

Virtual screening of plant-derived compounds against SARS-CoV-2 viral proteins using computational tools.

The new SARS-CoV-2, responsible for the COVID-19 pandemic, has been threatening public health worldwide for more than a year. The aim of this work was to evaluate compounds of natural origin, mainly from medicinal plants, as potential SARS-CoV-2 inhibitors through docking studies. The viral spike (S) glycoprotein and the main protease Mpro, involved in the recognition of virus by host cells and in viral replication, respectively, were the main molecular targets in this study. Molecular docking was performed using AutoDock, which allowed us to select the plant actives with the highest affinity towards the viral targets and to identify the interaction molecular sites with the SARS-CoV2 proteins. The best energy binding values for S protein were, in kcal/mol: -19.22 for glycyrrhizin, -17.84 for gitoxin, -12.05 for dicumarol, -10.75 for diosgenin, and -8.12 for delphinidin. For Mpro were, in kcal/mol: -9.36 for spirostan, -8.75 for N-(3-acetylglycyrrhetinoyl)-2-amino-propanol, -8.41 for α-amyrin, -8.35 for oleanane, -8.11 for taraxasterol, and -8.03 for glycyrrhetinic acid. In addition, the synthetic drugs umifenovir, chloroquine, and hydroxychloroquine were used as controls for S protein, while atazanavir and nelfinavir were used for Mpro. Key hydrogen bonds and hydrophobic interactions between natural compounds and the respective viral proteins were identified, allowing us to explain the great affinity obtained in those compounds with the lowest binding energies. These results suggest that these natural compounds could potentially be useful as drugs to be experimentally evaluated against COVID-19.

Related Pentacyclic Triterpenes Have Immunomodulatory Activity in Chronic Experimental Visceral Leishmaniasis.

Leishmaniasis is a neglected tropical disease caused by the flagellated protozoa of the genus Leishmania that affects millions of people around the world. Drugs employed in the treatment of leishmaniasis have limited efficacy and induce local and systemic side effects to the patients. Natural products are an interesting alternative to treat leishmaniasis, because some purified molecules are selective toward parasites and not to the host cells. Thus, the aim of the present study was to compare the in vitro antileishmanial activity of the triterpenes betulin (Be), lupeol (Lu), and ursolic acid (UA); analyze the physiology and morphology of affected organelles; analyze the toxicity of selected triterpenes in golden hamsters; and study the therapeutic activity of triterpenes in hamsters infected with L. (L.) infantum as well as the cellular immunity induced by studied molecules. The triterpenes Lu and UA were active on promastigote (IC50 = 4.0 ± 0.3 and 8.0 ± 0.2 µM, respectively) and amastigote forms (IC50 = 17.5 ± 0.4 and 3.0 ± 0.2 µM, respectively) of L. (L.) infantum, and their selectivity indexes (SI) toward amastigote forms were higher (≥13.4 and 14, respectively) than SI of miltefosine (2.7). L. (L.) infantum promastigotes treated with Lu and UA showed cytoplasmic degradation, and in some of these areas, cell debris were identified, resembling autophagic vacuoles, and parasite mitochondria were swelled, fragmented, and displayed membrane potential altered over time. Parasite cell membrane was not affected by studied triterpenes. Studies of toxicity in golden hamster showed that Lu did not alter blood biochemical parameters associated with liver and kidney functions; however, a slight increase of aspartate aminotransferase level in animals treated with 2.5 mg/kg of UA was detected. Lu and UA triterpenes eliminated amastigote forms in the spleen (87.5 and 95.9% of reduction, respectively) and liver of infected hamster (95.9 and 99.7% of reduction, respectively); and UA showed similar activity at eliminating amastigote forms in the spleen and liver than amphotericin B (99.2 and 99.8% of reduction). The therapeutic activity of both triterpenes was associated with the elevation of IFN-γ and/or iNOS expression in infected treated animals. This is the first comparative work showing the in vitro activity, toxicity, and therapeutic activity of Lu and UA in the chronic model of visceral leishmaniasis caused by L. (L.) infantum; additionally, both triterpenes activated cellular immune response in the hamster model of visceral leishmaniasis.

Pentacyclic Triterpene Profile and Its Biosynthetic Pathway in Cecropia telenitida as a Prospective Dietary Supplement.

Promising research over the past decades has shown that some types of pentacyclic triterpenes (PTs) are associated with the prevention of type 2 diabetes (T2D), especially those found in foods. The most abundant edible sources of PTs are those belonging to the ursane and oleanane scaffold. The principal finding is that Cecropia telenitida contains abundant oleanane and ursane PT types with similar oxygenation patterns to those found in food matrices. We studied the compositional profile of a rich PT fraction (DE16-R) and carried out a viability test over different cell lines. The biosynthetic pathway connected to the isolated PTs in C. telenitida offers a specific medicinal benefit related to the modulation of T2D. This current study suggests that this plant can assemble isobaric, positional isomers or epimeric PT. Ursane or oleanane scaffolds with the same oxygenation pattern are always shared by the PTs in C. telenitida, as demonstrated by its biosynthetic pathway. Local communities have long used this plant in traditional medicine, and humans have consumed ursane and oleanane PTs in fruits since ancient times, two key points we believe useful in considering the medicinal benefits of C. telenitida and explaining how a group of molecules sharing a closely related scaffold can express effectiveness.

Chemical Strategies towards the Synthesis of Betulinic Acid and Its More Potent Antiprotozoal Analogues.

Betulinic acid (BA, 3ß-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic triterpene acid present predominantly in Betula ssp. (Betulaceae) and is also widely spread in many species belonging to different plant families. BA presents a wide spectrum of remarkable pharmacological properties, such as cytotoxic, anti-HIV, anti-inflammatory, antidiabetic and antimicrobial activities, including antiprotozoal effects. The present review first describes the sources of BA and discusses the chemical strategies to produce this molecule starting from betulin, its natural precursor. Next, the antiprotozoal properties of BA are briefly discussed and the chemical strategies for the synthesis of analogues displaying antiplasmodial, antileishmanial and antitrypanosomal activities are systematically presented. The antiplasmodial activity described for BA was moderate, nevertheless, some C-3 position acylated analogues showed an improvement of this activity and the hybrid models-with artesunic acid-showed the most interesting properties. Some analogues also presented more intense antileishmanial activities compared with BA, and, in addition to these, heterocycles fused to C-2/C-3 positions and amide derivatives were the most promising analogues. Regarding the antitrypanosomal activity, some interesting antitrypanosomal derivatives were prepared by amide formation at the C-28 carboxylic group of the lupane skeleton. Considering that BA can be produced either by isolation of different plant extracts or by chemical transformation of betulin, easily obtained from Betula ssp., it could be said that BA is a molecule of great interest as a starting material for the synthesis of novel antiprotozoal agents.

Natural and Semisynthetic Pentacyclic Triterpenes for Chronic Myeloid Leukemia Therapy: Reality, Challenges and Perspectives.

Chronic myeloid leukemia (CML) is a neoplasm characterized by BCR-ABL1, an oncoprotein with vital role in leukemogenesis. Its inhibition by tyrosine kinase inhibitors represents the main choice of treatment. However, therapeutic failure is worrying given the lack of pharmacological options. Pentacyclic triterpenes are phytochemicals with outstanding antitumoral properties and have also been explored as a basis for the design of potential leads. In this review, we have gathered and discuss data regarding both natural and semisynthetic pentacyclic triterpenes applied to CML cell treatment. We found consistent evidence that the class of pentacyclic triterpenes in general exerts promising pro-apoptotic and antiproliferative activities in sensitive and resistant CML cells, and thus represents a rich source for drug development. We also analyze the predicted drug-like properties of the molecules, discuss the structural changes with biological implications and show the great opportunities this class represents, as well as the perspectives they provide on drug discovery for CML treatment.

Ursolic and betulinic semisynthetic derivatives show activity against CQ-resistant Plasmodium falciparum isolated from Amazonia.

ACT's low levels of Plasmodium parasitemia clearance are worrisome since it is the last treatment option against P. falciparum. This scenario has led to investigations of compounds with different mechanisms of action for malaria treatment. Natural compounds like ursolic acid (UA) and betulinic acid (BA), distinguished by their activity against numerous microorganisms, including P. falciparum, have become relevant. This study evaluated the antiplasmodial activity of imidazole derivatives of UA and BA against P. falciparum in vitro. Eight molecules were obtained by semisynthesis and tested against P. falciparum strains (NF54 and CQ-resistant 106/cand isolated in Porto Velho, Brazil); 2a and 2b showed activity against NF54 and 106/cand strains with IC50  < 10 µM. They presented high selectivity indexes (SI > 25) and showed synergism when combined with artemisinin. 2b inhibited the parasite's ring and schizont forms regardless of when the treatment began. In silico analysis presented a tight bind of 2b in the topoisomerase II-DNA complex. This study demonstrates the importance of natural derivate compounds as new candidates for malarial treatment with new mechanisms of action. Semisynthesis led to new triterpenes that are active against P. falciparum and may represent new alternatives for malaria drug development.

Antiophidic activity of the secondary metabolite lupeol isolated from Zanthoxylum monogynum.

Previous studies have demonstrated the potential antiophidic activity of Zanthoxylum monogynum A.St.-Hil. a tree from the Rutaceae family native to South America. In this present contribution, we demonstrate the activity of the metabolite lupeol, a triterpenoid isolated from the stem bark of Z. monogynum against the harmful effects of the Bothrops alternatus venom. We investigated the antiophidic properties of lupeol, for this purpose, and use crude venom (Pb) incubated with lupeol in different concentrations, testing in vitro experiments and inoculated in mice for inhibitory evaluations in vivo. Besides, we tried to elucidate through the molecular dynamics the mechanism of action of lupeol with the bothropic thrombin-like toxin Jararacussin-I; the acidic phospholipase A2 toxin BthA-I from Bothrops jararacussu and the metalloproteinase toxin BmooMP-I from Bothrops moojeni. In our results, we demonstrated the potential inhibitory effect upon coagulant, phospholipasic and myotoxic activities of the bothropic venom, previously incubated with lupeol. We found that lupeol triterpenoid was able to partially inhibit local and systemic damage caused by snake venom toxins. Our in silico results demonstrate that lupeol is capable of interacting and altering the activity of the thrombin-like toxin Jararacussin-I, and capable of interacting with the BthA-I acidic PLA2, both toxins present in Bothrops snakes venom, thus demonstrating the pharmacological potential of this compound for the treatment of bothropic accidents.

Influence of Asiatic acid on cell proliferation and DNA damage in vitro and in vivo systems.

Asiatic acid (AA) is a triterpene with promising pharmacological activity. In the present study, in vitro and in vivo assays were conducted to understand the effect of AA on cell proliferation and genomic instability. AA was cytotoxic to human tumor cell lines (M059J, HeLa, and MCF-7), with IC50 values ranging from 13.91 to 111.72 µM. In the case of M059J, AA exhibited selective cytotoxicity after 48 h of treatment (IC50 = 24 µM), decreasing the percentage of cells in the G0/G1 phase, increasing the percentage of cells in the S phase, and inducing apoptosis. A significant increase in chromosomal damage was observed in V79 cell cultures treated with AA (40 µM), revealing genotoxic activity. In contrast, low concentrations (5, 10, and 20 µM) of AA significantly reduced the frequencies of micronuclei induced by the mutagens doxorubicin (DXR), methyl methanesulfonate, and hydrogen peroxide. A reduction of DXR-induced intracellular free radicals was found in V79 cells treated with AA (10 µM). The antigenotoxic effect of AA (30 mg/kg) was also observed against DXR-induced chromosomal damage in Swiss mice. Significant reductions in p53 levels were verified in the liver tissue of these animals. Taken together, the data indicate that AA exerted antiproliferative activity in M059J tumor cells, which is probably related to the induction of DNA damage, leading to cell cycle arrest and apoptosis. Additionally, low concentrations of AA exhibited antigenotoxic effects and its antioxidant activity may be responsible, at least in part, for chemoprevention.

Quantitative determination of pentacyclic triterpenic acids in Amazonian species Eugenia punicifolia DC by ATR-FTIR.

Leaf extracts from Eugenia punicifolia are rich in pentacyclic triterpenic acids (PTAs), especially barbinervic acid (BA), which is an important biomarker of the species. Dichloromethane extracts of E. punicifolia leaf samples harvested in Amazonian summer and winter seasons were analysed by infrared spectroscopy using ATR-FTIR technique aiming to evaluate barbinervic acid (BA) and its PTAs equivalent contents. A validated HPLC-DAD quantification method was also performed to compare the relationship between BA and PTAs contents in E. punicifolia extracts with ATR-FTIR technique. The use of ATR-FTIR allowed a rapid, efficient and environment-friendly quantification method for total PTAs equivalent content, showing a significant statistical difference (p< 0.05) in the production of these metabolites (38.66 µg/mL, summer; 13.62 µg/mL, winter). A mathematical correction factor between the HPLC-DAD and ATR-FTIR quantification methods was established.

Anti-leukemic activity of semisynthetic derivatives of lupeol.

In our previous work, lupeol was isolated from aerial parts of V. scorpioides and modified by semisynthetic approach. The purpose of this study was to investigate the cytotoxicity of lupeol and its derivatives previously prepared on the human K562 acute myeloid leukemia cell and human Jurkat acute lymphoid leukemia cell in vitro. Compounds 3ß-hydroxylup-20(29)-en-30-al (2), lup-20(30)-en-3ß,29-diol (3), 3ß-acetoxylup-20(29)-en-30-al (5) and 3ß-acetoxy-30-hydroxylup-20(29)-ene (6) presented cytotoxicity with IC50 ranging from 11.72 to 56.15 µM at 24 h of incubation for both cell lines. Most of the active compounds (3, 5 and 6) were selective to leukemia cells, in compare with healthy cells. The hemolysis assay showed high blood compatibility of the cytotoxic lupeol derivatives which makes possible an intravenous administration of these compounds aiming to the potential to development of anti-leukemic drugs.