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1.
Braz J Microbiol ; 55(1): 557-570, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38265571

ABSTRACT

Mountain biodiversity is under unparalleled pressure due to climate change, necessitating in-depth research on high-altitude plant's microbial associations which are crucial for plant survival under stress conditions. Realizing that high-altitude tree line species of Himalaya are completely unexplored with respect to the microbial association, the present study aimed to elucidate plant growth promoting and secondary metabolite producing potential of culturable endophytic fungi of Himalayan silver birch (Betula utilis D. Don). ITS region sequencing revealed that the fungal isolates belong to Penicillium species, Pezicula radicicola, and Paraconiothyrium archidendri. These endophytes were psychrotolerant in nature with the potential to produce extracellular lytic activities. The endophytes showed plant growth promoting (PGP) traits like phosphorus solubilization and production of siderophore, indole acetic acid (IAA), and ACC deaminase. The fungal extracts also exhibited antagonistic potential against bacterial pathogens. Furthermore, the fungal extracts were found to be a potential source of bioactive compounds including the host-specific compound-betulin. Inoculation with fungal suspension improved seed germination and biomass of soybean and maize crops under net house conditions. In vitro PGP traits of the endophytes, supported by net house experiments, indicated that fungal association may support the growth and survival of the host in extreme cold conditions.


Subject(s)
Betula , Plant Development , Endophytes , Bacteria , Phosphorus/metabolism , Plant Roots/microbiology , Fungi
2.
Toxicol In Vitro ; 73: 105147, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33722738

ABSTRACT

Pulp and paper mill effluent can cause changes in the morphology and energy metabolism in the zebrafish (Danio rerio) testis. Betulin, a naturally occurring triterpene is commonly present in this type of effluent and is suspected of being involved in these effects. The aim of this study was to compare the effects pulp and paper mill effluent and betulin on various aspects of testicular physiology in the zebrafish. This included the in vitro effects of effluent and betulin on testicular lactate content and lactate dehydrogenase (LDH) activity. In addition, the effects of betulin on glucose uptake, glycogen, alanine aminotransferase (ALT), reactive oxygen and nitrogen species formation and oxidative damage in the testes were determined. Furthermore, we compared the effects and mechanism of action of betulin and effluent on calcium homeostasis in testes. In vitro exposure to both effluent and betulin decreased lactate and calcium influx, possibly due to the activation of the sodium­calcium exchanger (NCX) pump. Additionally, betulin-treated testes had higher reactive oxygen species (ROS) and reduced glutathione (GSH) content, as well as increased glutathione transferase (GST) activity and a tendency towards decreased catalase (CAT) activity. Thus, this study shows that alterations in testis physiology caused by the pulp and paper mill effluent in the testis may be due in part to the actions of betulin.


Subject(s)
Testis/drug effects , Triterpenes/toxicity , Water Pollutants, Chemical/toxicity , Animals , Calcium/metabolism , Catalase/metabolism , Glucose/metabolism , Glutathione/metabolism , Glutathione Transferase/metabolism , Glycogen/metabolism , Industrial Waste , L-Lactate Dehydrogenase/metabolism , Lactic Acid/metabolism , Male , Oxidative Stress/drug effects , Paper , Reactive Nitrogen Species/metabolism , Reactive Oxygen Species/metabolism , Superoxide Dismutase/metabolism , Testis/metabolism , Zebrafish
3.
Microorganisms ; 9(2)2021 Feb 04.
Article in English | MEDLINE | ID: mdl-33557150

ABSTRACT

Herein, we evaluated in vitro the anti-leishmanial activity of betulin derivatives in Venezuelan isolates of Leishmania amazonensis, isolated from patients with therapeutic failure. METHODS: We analyzed promastigote in vitro susceptibility as well as the cytotoxicity and selectivity of the evaluated compounds. Additionally, the activity of selected compounds was determined in intracellular amastigotes. Finally, to gain hints on their potential mechanism of action, the effect of the most promising compounds on plasma and mitochondrial membrane potential, and nitric oxide and superoxide production by infected macrophages was determined. RESULTS: From the tested 28 compounds, those numbered 18 and 22 were chosen for additional studies. Both 18 and 22 were active (GI50 ≤ 2 µM, cytotoxic CC50 > 45 µM, SI > 20) for the reference strain LTB0016 and for patient isolates. The results suggest that 18 significantly depolarized the plasma membrane potential (p < 0.05) and the mitochondrial membrane potential (p < 0.05) when compared to untreated cells. Although neither 18 nor 22 induced nitric oxide production in infected macrophages, 18 induced superoxide production in infected macrophages. CONCLUSION: Our results suggest that due to their efficacy and selectivity against intracellular parasites and the potential mechanisms underlying their leishmanicidal effect, the compounds 18 and 22 could be used as tools for designing new chemotherapies against leishmaniasis.

4.
Food Chem Toxicol ; 147: 111922, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33321149

ABSTRACT

Overexpression of P-glycoprotein (P-gp), which is linked to multidrug resistance (MDR), is one of the underlying obstacles to the success of chemotherapy as it reduces the efficacy of anticancer drugs and the side effects of these increase as a result of any increased dose to achieve the therapeutic effect. To identify agents with P-gp inhibitory properties, ethanol extracts from 80 plants were screened for their ability to increase intracellular doxorubicin-associated fluorescence, and the extract of Ligaria cuneifolia was found to be the most effective. Its bioassay-guided isolation yielded the pentacyclic triterpene betulin as active agent. This efficiently inhibited P-gp mediated efflux, as demonstrated by the enhancement of the intracellular accumulation of doxorubicin and rhodamine 123 from 1.56 µM in the P-gp overexpressing MDR leukemia cell, Lucena 1. Betulin was also able to render Lucena 1 sensitive to Dox from 0.39 µM. The docking studies revealed that betulin tightly binds to a key region of the TMDs, with a binding mode overlapping one main site of doxorubicin and, more interestingly, emulating the same contacts as tariquidar, as revealed by the per-residue energetic analysis from molecular dynamics simulations. MTT assay using peripheral blood mononuclear cells and hemolysis assay showed that betulin is devoid of toxicity. These findings provide important evidence that betulin may be a safe and promising entity to be further investigated to develop agents able to overcome P-gp-mediated MDR, resulting in a more effective and less toxic chemotherapy.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B/metabolism , Leukemia/drug therapy , Loranthaceae/chemistry , Plant Extracts/pharmacology , Triterpenes/pharmacology , ATP Binding Cassette Transporter, Subfamily B/genetics , Antibiotics, Antineoplastic/metabolism , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Cell Line, Tumor , Doxorubicin/metabolism , Drug Resistance, Neoplasm , Fluorescent Dyes/metabolism , Gene Expression Regulation, Neoplastic/drug effects , Humans , Molecular Structure , Plant Extracts/chemistry , Rhodamine 123/metabolism , Triterpenes/chemistry
5.
Nat Prod Res ; 34(12): 1702-1711, 2020 Jun.
Article in English | MEDLINE | ID: mdl-30580627

ABSTRACT

Betulin (BE) is a pentacyclic triterpenes, obtained from natural sources and with several biological activities described, such as anti-tumoral and anti-inflammatory activities. The BE esterification at hydroxyl group (C-3 and C-28) resulted in five new ester derivatives with different numbers of carbons or halogens (chlorine and fluorine). Among these BE derivatives, two (2a e 2c) were able to significantly decrease IFN-g (*p = 0.0391; **p = 0.0156) and 2c modulated the expression of COX-2 better than Dexamethasone (DEXA). Regarding to cytotoxic assay, the best results were obtained for BE without modifications, with emphasis on tumoral cell lines Raji and MCF-7. The derivatives 2a and 2c showed immunomodulation activity (for the cytokines IFN-g). The presence of chorine in BE seems to be important for the ability of modulate COX-2 expression, since the ester chloride derivative 2c at 100 µM is more powerful inhibitor of COX-2 than DEXA.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Antineoplastic Agents/pharmacology , Cyclooxygenase 2/metabolism , Interferon-gamma/antagonists & inhibitors , Peptide Fragments/antagonists & inhibitors , Triterpenes/pharmacology , Cell Line, Tumor , Cyclooxygenase 2/drug effects , Cytokines/metabolism , Esters/pharmacology , Halogenation , Humans , MCF-7 Cells , Structure-Activity Relationship , Triterpenes/chemistry
6.
Arch Pharm (Weinheim) ; : e1800108, 2018 Jul 12.
Article in English | MEDLINE | ID: mdl-29999539

ABSTRACT

The human respiratory syncytial virus (hRSV) is a leading cause of hospitalization due to acute lower respiratory infection especially in infants and young children, sometimes causing fatal cases. The monoclonal antibody palivizumab is one of the available options for preventing this virus, and at the moment there are several hRSV vaccine trials underway. Unfortunately, the only drug option to treat hRSV infection is ribavirin, which can be used in severe high-risk cases. For this reason, new medicines are needed and, in this context, the triterpenes and their derivatives are promising alternatives, since many of them have shown important antiviral activity, such as bevirimat. Therefore, we report three series of triterpene (betulin (BE), betulinic acid (BA), and ursolic acid (UA)) derivatives tested against hRSV. The derivatives were synthesized by using commercial anhydrides in an easy and inexpensive step reaction. For the antiviral assay, A549 cells were infected by hRSV and after 96 h of compound or ribavirin (positive control) treatment, the cell viability was tested by MTT assay. DMSO, non-infected cells and infected cells without treatment were used as negative control. The triterpene esterification at the hydroxyl group resulted in 17 derivatives. The 3,28-di-O-acetylbetulin derivative (1a) showed the best results for cell viability, and real-time PCR amplification was performed for 1a treatment. Remarkably, one new anti-hRSV prototype was obtained through an easy synthesis of BE, which shall represent an alternative for a new lead compound for anti-hRSV therapy.

7.
Adv Pharm Bull ; 6(3): 443-447, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27766229

ABSTRACT

Purpose: Betulin is a pentacyclic triterpene found in the outer barks of innumerous plants. This secondary metabolite is easily isolated from plants with the major interest in converting it to betulinic acid, which pharmacological properties were much more exploited than betulin. But, investments in the own betulin have been grown since no chemical step is necessary. In this study we focused the precursor betulin in order to evaluate its mutagenicity by Salmonella/microsome assay (Ames test). Methods: The Ames test was carried out using a commercial betulin exposed to Salmonella typhimurium strains TA98, TA100, TA102, and TA97a, in experiments with (+S9) and without (-S9) metabolic activation. Results: Betulin was unable to increase the number of revertants (+S9 and -S9 metabolic activation) showing the absence of any mutagenic effect by Ames test. Conclusion: This study allowed attribute safety to betulin being important for exploiting its pharmacological uses.

8.
Nat Prod Res ; 30(16): 1885-9, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26395173

ABSTRACT

The hexanic, ethyl acetate and methanolic extracts from branches of Stenocereus stellatus were tested in both the 12-O-tetradecanoylphorbol-13-acetate (TPA) - induced ear oedema model and antimicrobial activity assay. The % of oedema inhibition, the Minimum Inhibitory Concentration (MIC), as well as the polyphenolic and flavonoid content were determined. Also, extracts were analysed by gas chromatography-mass spectrometry (GC-MS). In TPA model, the three extracts showed moderate oedema inhibition. In the antimicrobial activity assay, methanolic extract shows better MIC against all strains. The lowest MICs were for Candida albicans (31 µg/mL) and Rhizopus sp. (15 µg/mL). Also, 50.78 mg eq. of gallic acid/g extract of polyphenol and 115.12 mg eq. of catequine/g extract of flavonoids content were founded in ethyl acetate extract. In the chromatographic analysis, ß-sitosterol, ß-amyrine, betulin and some other molecules were identified. The results show that S. stellatus possess antimicrobial activities against some fungus species.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Cactaceae/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Polyphenols/analysis , Animals , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Antioxidants/chemistry , Cactaceae/metabolism , Candida albicans/drug effects , Disease Models, Animal , Edema/chemically induced , Edema/drug therapy , Flavonoids/analysis , Gas Chromatography-Mass Spectrometry , Male , Microbial Sensitivity Tests , Phorbol Esters/toxicity , Rhizopus/drug effects , Secondary Metabolism , Sitosterols/analysis
9.
Bioorg Med Chem ; 22(21): 6220-6, 2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25240731

ABSTRACT

Leishmaniasis is a public health problem in tropical and subtropical areas of the world, including Venezuela. The incidence of treatment failure and the number of cases with Leishmania-HIV co-infection underscore the importance of developing alternative, economical and effective therapies against this disease. The work presented here analyzed whether terpenoids derived from betulin are active against New World Leishmania parasites. Initially we determined the concentration that inhibits the growth of these parasites by 50% or IC50, and subsequently evaluated the chemotactic effect of four compounds with leishmanicidal activity in the sub-micromolar and micromolar range. That is, we measured the migratory capacity of Leishmania (V.) braziliensis in the presence of increasing concentrations of compounds. Finally, we evaluated their cytotoxicity against the host cell and their effect on the infectivity of L. (V.) braziliensis. The results suggest that (1) compounds 14, 17, 18, 25 and 27 are active at concentrations lower than 10 µM; (2) compound 26 inhibits parasite growth with an IC50 lower than 1 µM; (3) compounds 18, 26 and 27 inhibit parasite migration at pico- to nanomolar concentrations, suggesting that they impair host-parasite interaction. None of the tested compounds was cytotoxic against J774.A1 macrophages thus indicating their potential as starting points to develop compounds that might affect parasite-host cell interaction, as well as being leishmanicidal.


Subject(s)
Antiprotozoal Agents/pharmacology , Host-Parasite Interactions/drug effects , Leishmania braziliensis/drug effects , Leishmaniasis, Cutaneous/drug therapy , Macrophages/parasitology , Triterpenes/pharmacology , Animals , Antiprotozoal Agents/chemistry , Cell Line , Humans , Leishmania braziliensis/physiology , Macrophages/drug effects , Mice , Triterpenes/chemistry
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