Effect of Brazilian copaiba oils on Leishmania amazonensis

Brazilian Amazon Traditional Medicine and the Treatment of Difficult to Heal Leishmaniasis Wounds with Copaifera

The present study describes the use of the traditional species Copaifera for treating wounds, such as ulcers scarring and antileishmanial wounds. It also relates phytochemical studies, evaluation of the leishmanicidal activity, and toxicity. The species of Copaifera with a higher incidence in the Amazon region are Copaifera officinalis, Copaifera reticulata, Copaifera multijuga Hayne. The copaiba oil is used in the Amazon's traditional medicine, especially as anti-inflammatory ingredient, in ulcers healing, and in scarring and for leishmaniasis. Chemical studies have shown that these oils contain diterpenes and sesquiterpenes. The copaiba oil and terpenes isolated have antiparasitic activity, more promising in the amastigote form of L. amazonensis. This activity is probably related to changes in the cell membrane and mitochondria. The oil showed low cytotoxicity and genotoxicity. Furthermore, it may interfere with immune response to infection and also has a healing effect. In summary, the copaiba oil is promising as leishmanicidal agent.

In vitro and in vivo antimalarial potential of oleoresin obtained from Copaifera reticulata Ducke (Fabaceae) in the Brazilian Amazon rainforest

BACKGROUND

In view of the wide variety of the flora of the Amazon region, many plants have been studied in the search for new antimalarial agents. Copaifera reticulata is a tree distributed throughout the Amazon region which contains an oleoresin rich in sesquiterpenes and diterpenes with β-caryophyllene as the major compound. The oleoresin has demonstrated antiparasitic activity against Leishmania amazonensis. Because of this previously reported activity, this oleoresin would be expected to also have antimalarial activity.

PURPOSE

In this study we evaluated the in vitro and in vivo antimalarial potential of C. reticulata oleoresin.

METHODS

In vitro assays were done using P. falciparum W2 and 3D7 strains and the human fibroblast cell line 26VA Wi-4. For in vivo analysis, BALB/c mice were infected with approximately 10⁶ erythrocytes parasitized by P. berghei and their parasitemia levels were observed over 7 days of treatment with C. reticulata; hematological and biochemical parameters were analyzed at the end of experiment.

RESULTS

The oleoresin of C. reticulata containing the sesquiterpenes β-caryophyllene (41.7%) and β-bisabolene (18.6%) was active against the P. falciparum W2 and 3D7 strains (IC₅₀ = 1.66 and 2.54 µg/ml, respectively) and showed low cytotoxicity against the 26VA Wi-4 cell line (IC₅₀ > 100 µg/ml). The C. reticulata oleoresin reduced the parasitemia levels of infected animals and doses of 200 and 100 mg/kg/day reached a rate of parasitemia elimination resembling that obtained with artemisinin 100 mg/kg/day. In addition, treatment with oleoresin improved the hypoglycemic, hematologic, hepatic and renal parameters of the infected animals.

CONCLUSION

The oleoresin of C. reticulata has antimalarial properties and future investigations are necessary to elucidate its mechanism of action.

Essential oils: in vitro activity against Leishmania amazonensis, cytotoxicity and chemical composition

BACKGROUND

The current chemotherapy for cutaneous leishmaniosis (CL) has a series of drug limitations such as toxic side effects, long duration, high costs and drug resistance, which requires the development of new drugs or effective alternatives to the CL treatment. Essential oils (EOs) are complex mixtures of secondary metabolites from various plants. It has been shown that several EOs, or their constituents, have inhibitory activity against protozoa. Thus, this study aims to evaluate the biological activity of different essential oils (EOs) on Leishmania (L.) amazonensis promastigotes forms, as well as their cytotoxicity on mammalian cells and chemical composition.

METHODS

Sixteen EOs were evaluated by mean of IC50/24 h and cytotoxicity against L6 cells (CC50/24 h) using Resazurin assay. Only those EOs that presented better results for IC50/24 h were submitted to GC-MS analysis to determine their chemical constitution.

RESULTS

The EO from Cinnamodendron dinisii, Matricaria chamomilla, Myroxylon peruiferum, Salvia sclarea, Bulnesia sarmientoi, Ferula galbaniflua, Siparuna guianensis and Melissa officinalis were the most active against L. amazonensis with IC50/24 h ranging from 54.05 to 162.25 μg/mL. Analysis of EOs by GC-MS showed mainly the presence of β-farnesene (52.73 %) and bisabolol oxide (12.09 %) for M. chamomilla; α-copaene (13.41 %), safrole (8.35 %) and δ-cadinene (7.08 %) for M. peruiferum; linalool (28.80 %) and linalyl acetate (60.08 %) for S. sclarea; guaiol (48.29 %) and 2-undecanone (19.49 %) for B. sarmientoi; ethyl phthalate (13.09 %) and methyl-8-pimaren-18-oate (41.82 %) for F. galbaniflua; and neral (37.18 %) and citral (5.02 %) for M. officinalis.

CONCLUSION

The EO from F. galbaniflua showed to be effective against L. amazonensis promastigotes forms and presented low cytotoxic activity against L6 cells. Thus, it represents a strong candidate for future studies aiming its molecular activity on these pathogenic parasites.

Copaifera reticulata oleoresin: Chemical characterization and antibacterial properties against oral pathogens

Oral infections such as periodontitis and tooth decay are the most common diseases of humankind. Oleoresins from different copaifera species display antimicrobial and anti-inflammatory activities. Copaifera reticulata is the commonest tree of this genus and grows abundantly in several Brazilian states, such as Pará, Amazonas, and Ceará. The present study has evaluated the chemical composition and antimicrobial potential of the Copaifera reticulata oleoresin (CRO) against the causative agents of tooth decay and periodontitis and has assessed the CRO cytotoxic potential. Cutting edge analytical techniques (GC-MS and LC-MS) aided the chemical characterization of CRO. Antimicrobial assays included determination of the Minimum Inhibitory Concentration (MIC), determination of the Minimum Bactericidal Concentration (MBC), determination of the Minimum Inhibitory Concentration of Biofilm (MICB50), Time Kill Assay, and Checkerboard Dilution. Conduction of XTT assays on human lung fibroblasts (GM07492-A cells) helped to examine the CRO cytotoxic potential. Chromatographic analyses revealed that the major constituents of CRO were β-bisabolene, trans-α-bergamotene, β-selinene, α-selinene, and the terpene acids ent-agathic-15-methyl ester, ent-copalic acid, and ent-polyalthic acid. MIC and MBC results ranged from 6.25 to 200 μg/mL against the tested bacteria. The time-kill assay conducted with CRO at concentrations between 50 and 100 μg/mL showed bactericidal activity against Fusobacterium nucleatum (ATCC 25586) and Streptococcus mitis (ATCC 49456) after 4 h, Prevotella nigrescens (ATCC 33563) after 6 h, Porphyromonas gingivalis (ATCC 33277) and Lactobacillus casei (clinical isolate) after 12 h, and Streptococcus salivarius (ATCC 25975) and Streptococcus mutans (ATCC 25175) after 18 h. The fractional inhibitory concentration indexes (FICIs) revealed antagonistic interaction for Lactobacillus casei (clinical isolate), indifferent effect for Porphyromonas gingivalis (ATCC 33277), Fusobacterium nucleatum (ATCC 25586), Prevotella nigrescens (ATCC 33563), and Streptococcus salivarius (ATCC 25975), and additive effect for Streptococcus mutans (ATCC 25175) and Streptococcus mitis (ATCC 49456). Treatment of GM07492-A cells with CRO demonstrated that concentrations up to 39 μg/mL significantly reduced cell viability as compared to the negative control, being IC50 equal to 51.85 ± 5.4 μg/mL. These results indicated that CRO plays an important part in the search for novel sources of agents that can act against oral pathogens.

Antileishmanial activity of the essential oil from Tetradenia riparia obtained in different seasons

The herbaceous shrub Tetradenia riparia has been traditionally used to treat inflammatory and infectious diseases. Recently, a study showed that T. riparia essential oil (TrEO) obtained in summer has antileishmanial effects, although these results could be influenced by seasonal variation. This study evaluated the activity of the TrEO obtained in different seasons against Leishmania (Leishmania) amazonensis, in vitro and in vivo. The compounds in the TrEO were analysed by gas chromatography-mass spectrometry; terpenoids were present and oxygenated sesquiterpenes were the majority compounds (55.28%). The cytotoxicity and nitric oxide (NO) production were also tested after TrEO treatment. The TrEO from all seasons showed a 50% growth inhibitory concentration for promastigotes of about 15 ng/mL; at 30 ng/mL and 3 ng/mL, the TrEO reduced intracellular amastigote infection, independently of season. The TrEO from plants harvested in summer had the highest 50% cytotoxic concentration, 1,476 ng/mL for J774.A1 macrophages, and in spring (90.94 ng/mL) for murine macrophages. NO production did not change in samples of the TrEO from different seasons. The antileishmanial effect in vivo consisted of a reduction of the parasite load in the spleen. These results suggest that the TrEO has potential effects on L. (L.) amazonensis, consonant with its traditional use to treat parasitic diseases.

Synthesis and biological evaluation of polyalthic acid derivatives for the treatment of neglected diseases

Polyalthic acid is a naturally occurring diterpene found in copaiba oil, one of the most popular natural medicines in the Amazon. Based on the reported antileishmanial activity of copaiba oil, a series of amides and diols derivatives of polyalthic acid were synthesized and tested against Leishmania donovani and Trypanosoma brucei. Polyalthic acid was active in both assays with IC50 ranging from 3.87 to 8.68 μg/mL. The compound with best antileishmanial activity was 2 h (IC50=3.84 μg/mL) and compound 2c showed the best antitrypanosomal activity with an IC50 of 2.54 μg/mL.

Effects of the extract and glycoalkaloids of Solanum lycocarpum St. Hill on Giardia lamblia trophozoites

Background:

Solanum lycocarpum has great importance for food and medicinal traditional use. Recently, it was also evidenced that extracts of S. lycocarpum St. Hill (Solanaceae) and its glycoalkaloids, solamargine (Sg) and solasonine (Sn), are active against flagellated protozoa.

Objective:

The aim was to assess the effects of the extract of S. lycocarpum and its glycoalkaloids, Sn, and Sg, on Giardia lamblia trophozoites.

Materials and Methods:

A crude extract (96%ethanol) (EB) of fruits of S. lycocarpum was prepared and fractionated by partition with 40%ethanol and n-hexane: Ethyl acetate. Glycoalkaloids, Sn, and Sg were recognized in the ethanol fraction (EF) and further isolated by column chromatography. EB, EF, the isolated Sn and Sg and a mixture (1:1) of both glycoalkaloids were tested on cultures of G. lamblia trophozoites and macrophages.

Results:

EB, EF and glycoalkaloids of S. lycocarpum showed activity against Giardia (95.0 < Inhibitory concentration 50 [IC₅₀] ≤120.3 μg/mL). The mixture of glycoalkaloids (1:1) was more active (IC₅₀ = 13.23 μg/mL) than each one individually, suggesting a synergic effect. Moreover, the mixture is nontoxic to macrophage cells.

Conclusion:

Results are optimistic concerning the anti-Giardia potential of the mixture Sn + Sg. Further studies, in vitro and in vivo, will be required to consolidate the usefulness of the mixture of Sn + Sg in view of a new therapeutic strategy for giardiasis.

Synergistic enhancement of parasiticidal activity of amphotericin B using copaiba oil in nanoemulsified carrier for oral delivery: an approach for non-toxic chemotherapy

BACKGROUND AND PURPOSE

The aim of this study was to devise a nanoemulsified carrier system (CopNEC) to improve the oral delivery of amphotericin B (AmB) by increasing its oral bioavailability and synergistically enhance its antileishmanial activity with copaiba oil (Cop).

EXPERIMENTAL APPROACH

The AmB encapsulated NEC (CopNEC-AmB) comprised of Cop, d-α-tocopheryl polyethylene glycol 1000 succinate and phosphatidylcholine was prepared by high-pressure homogenization method. Stability study of CopNEC-AmB was carried out in simulated gastric fluid and simulated intestinal fluid. The CopNEC-AmB and plain AmB were compared as regards their in vitro antileishmanial activity, pharmacokinetics, organ distribution and toxicity.

KEY RESULTS

The optimal CopNEC-AmB had a small globule size, low polydispersity index, high ζ potential and encapsulation efficiency. The high resolution transmission electron microscopy illustrated spherical particle geometry with homogeny in their sizes. The optimal CopNEC-AmB was found to be stable in gastrointestinal fluids showing insignificant changes in globule size and encapsulation efficiency. The AUC0-48 value of CopNEC-AmB in rats was significantly improved showing 7.2-fold higher oral bioavailability than free drug. The in vitro antileishmanial activity of CopNEC-AmB was significantly higher than that of the free drug as Cop synergistically enhanced the antileishmanial effect of AmB by causing drastic changes in the morphology of Leishmania parasite and rupturing its plasma membrane. The CopNEC-AmB showed significantly less haemolytic toxicity and cytotoxicity and did not change the histopathology of kidney tissues as compared with AmB alone.

CONCLUSIONS AND IMPLICATIONS

This prototype CopNEC formulation showed improved bioavailability and had a non-toxic synergistic effect on the antileishmanial activity of AmB.

Kaurenoic Acid Possesses Leishmanicidal Activity by Triggering a NLRP12/IL-1β/cNOS/NO Pathway

Leishmania amazonensis (L. amazonensis) infection can cause severe local and diffuse injuries in humans, a condition clinically known as American cutaneous leishmaniasis (ACL). Currently, the therapeutic approach for ACL is based on Glucantime, which shows high toxicity and poor effectiveness. Therefore, ACL remains a neglected disease with limited options for treatment. Herein, the in vitro antiprotozoal effect and mechanisms of the diterpene kaurenoic acid [ent-kaur-16-en-19-oic acid] (KA) against L. amazonensis were investigated. KA exhibited a direct antileishmanial effect on L. amazonensis promastigotes. Importantly, KA also reduced the intracellular number of amastigote forms and percentage of infected peritoneal macrophages of BALB/c mice. Mechanistically, KA treatment reestablished the production of nitric oxide (NO) in a constitutive NO synthase- (cNOS-) dependent manner, subverting the NO-depleting escape mechanism of L. amazonensis. Furthermore, KA induced increased production of IL-1β and expression of the inflammasome-activating component NLRP12. These findings demonstrate the leishmanicidal capability of KA against L. amazonensis in macrophage culture by triggering a NLRP12/IL-1β/cNOS/NO mechanism.

Therapeutic switching: from antidermatophytic essential oils to new leishmanicidal products

This study examined whether the antidermatophytic activity of essential oils (EOs) can be used as an indicator for the discovery of active natural products against Leishmania amazonensis. The aerial parts of seven plants were hydrodistilled. Using broth microdilution techniques, the obtained EOs were tested against three strains of dermatophytes (Trichophyton mentagrophytes, Microsporum gypseum and Microsporum canis). To compare the EOs antifungal and antiparasitic effects, the EOs activities against axenic amastigotes of L. amazonensis were concurrently evaluated. For the most promising EOs, their antileishmanial activities against parasites infecting peritoneal macrophages of BALB/c mice were measured. The most interesting antifungal candidates were the EOs from Cymbopogon citratus, Otacanthus azureus and Protium heptaphyllum, whereas O. azureus, Piper hispidum and P. heptaphyllum EOs exhibited the lowest 50% inhibitory concentration (IC₅₀) values against axenic amastigotes, thus revealing a certain correspondence between both activities. The P. hispidum EO was identified as the most promising product in the results from the infected macrophages model (IC₅₀: 4.7 µg/mL, safety index: 8). The most abundant compounds found in this EO were sesquiterpenes, notably curzerene and furanodiene. Eventually, the evaluation of the antidermatophytic activity of EOs appears to be an efficient method for identifying new potential drugs for the treatment of L. amazonensis.

Syzygium cumini (L.) Skeels essential oil and its major constituent α-pinene exhibit anti-Leishmania activity through immunomodulation in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Syzygium cumini (L.) Skeels (Myrtaceae), commonly known as "jambolão" in Brazil is widely used in folk medicine against leishmaniasis, inflammation, chronic diarrhea, and ulcers. It is one of the most commonly used plants for the treatment of diabetes worldwide. In previous studies, Syzygium cumini was shown to possess antihyperlipidemic and anti-allergic properties, and to exhibit good performance as an antimicrobial agent against bacteria, fungi, and protozoa parasites of the genus Leishmania and Trypanosoma. This study was aimed at evaluating the effects of S. cumini essential oil (ScEO) and its major component α-pinene on Leishmania (Leishmania) amazonensis, as well as their cytotoxicity and possible mechanisms of action.

MATERIALS AND METHODS

To evaluate the anti-proliferative effect on Leishmania, effects on promastigote and axenic amastigote forms were assessed using tetrazolium salt (MTT) assay. The intramacrophagic amastigotes were exposed to ScEO and α-pinene to determine the survival index. To gain insight into the mechanism of action involved in the effect on the samples, we evaluated the modulation of macrophage activation state by observing structural (phagocytic and lysosomal activities) and cellular (nitric oxide increase) changes. To assess the safety profile of ScEO and α-pinene, murine macrophages and human red blood cells were treated with ScEO and α-pinene and the selectivity index was calculated for each treatment.

RESULTS

α-Pinene was effective against Leishmania amazonensis promastigote forms, with a half-maximal inhibitory concentration (IC50) value of 19.7µg/mL. α-Pinene was more active (IC50 values of 16.1 and 15.6µg/mL against axenic and intracellular amastigotes, respectively) than ScEO (IC50 values of 43.9 and 38.1µg/mL against axenic and intracellular amastigotes, respectively). Our results showed that the anti-Leishmania effects were mediated by immunomodulatory activity, as evidenced by the observed increases in both phagocytic and lysosomal activity, and the elevated NO levels. ScEO and α-pinene exhibited low cytotoxicity against murine macrophages and human erythrocytes. The 50% cytotoxicity concentration (CC50) values for the macrophages in the MTT assay were 614.1 and 425.2µg/mL for ScEO and α-pinene, respectively, while the corresponding half-maximal hemolytic concentration (HC50) values were 874.3 and 233.3µg/mL.

CONCLUSIONS

Taken together, the results demonstrate that ScEO and its major constituent α-pinene have significant anti-Leishmania activity, modulated by macrophage activation, with acceptable levels of cytotoxicity in murine macrophages and human erythrocytes. Further work is warranted, involving more in-depth mechanistic studies and in vivo investigations.

In vitro efficacy of Coriandrum sativum, Lippia sidoides and Copaifera reticulata against Leishmania chagasi

The increased incidence of visceral leishmaniasis (VL) in Brazil is due to a lack of effective disease control measures. In addition to that, no effective treatment exists for canine VL in response to synthetic drugs. Thus, the objective of this study was to evaluate the effect of the essential oils of Coriandrum sativum and Lippia sidoides, and oleoresin from Copaifera reticulata, on Leishmania chagasi promastigotes and amastigotes. We also examined the toxicity of these treatments on the murine monocyte cell line RAW 264.7. To determine the IC50 a MTT test (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was performed on promastigotes, and an in situ ELISA assay was conducted on amastigotes. Here, we demonstrate that oleoresin from C. reticulata was effective against both promastigotes (IC50 of 7.88 µg.mL-1) and amastigotes (IC50 of 0.52 µg.mL-1), and neither of the two treatments differed significantly (p > 0.05) from pentamidine (IC50 of 2.149 µg.mL-1) and amphotericin B (IC50 of 9.754 µg.mL-1). Of the three plant oils tested, only oleoresin showed no toxicity toward monocyte, with 78.45% viability after treatment. Inhibition of promastigote and amastigote growth and the lack of cytotoxicity by C. reticulata demonstrate that oleoresin may be a viable option for analyzing the in vivo therapeutic effects of leishmanicidal plants.

Antileishmanial activity of diterpene acids in copaiba oil

Leishmaniasis is a neglected tropical disease. According to the World Health Organization, there are approximately 1.5-two million new cases of cutaneous leishmaniasis each year worldwide. Chemotherapy against leishmaniasis is based on pentavalent antimonials, which were developed more than a century ago. The goals of this study were to investigate the antileishmanial activity of diterpene acids in copaiba oil, as well as some possible targets of their action against Leishmania amazonensis. Methyl copalate and agathic, hydroxycopalic, kaurenoic, pinifolic and polyaltic acids isolated from Copaifera officinales oleoresins were utilised. Ultrastructural changes and the specific organelle targets of diterpenes were investigated with electron microscopy and flow cytometry, respectively. All compounds had some level of activity against L. amazonensis. Hydroxycopalic acid and methyl copalate demonstrated the most activity against promastigotes and had 50% inhibitory concentration (IC50) values of 2.5 and 6.0 µg/mL, respectively. However, pinifolic and kaurenoic acid demonstrated the most activity against axenic amastigote and had IC50 values of 3.5 and 4.0 µg/mL, respectively. Agathic, kaurenoic and pinifolic acid caused significant increases in plasma membrane permeability and mitochondrial membrane depolarisation of the protozoan. In conclusion, copaiba oil and its diterpene acids should be explored for the development of new antileishmanial drugs.

In vitro leishmanicidal and cytotoxic activities of the glycoalkaloids from Solanum lycocarpum (Solanaceae) fruits

Leishmaniasis is an infection caused by a protozoan parasite of the genus Leishmania and is the second most prevalent parasitic protozoal disease after malaria in the world. We report the in vitro leishmanicidal activity on promastigote forms of Leishmania amazonensis and cytotoxicity, using LLCMK2 cells, of the glycoalkaloids from the fruits of Solanum lycocarpum, determined by colorimetric methods. The alkaloidic extract was obtained by acid-base extraction; solamargine and solasonine were isolated by silica-gel chromatography, followed by reversed-phase HPLC final purification. The alkaloidic extract, solamargine, solasonine, as well as the equimolar mixture of the glycoalkaloids solamargine and solasonine displayed leishmanicidal activity against promastigote forms of L. amazonensis, whereas the aglycone solasodine was inactive. After 24 and 72 h of incubation, most of the samples showed lower cytotoxicities (IC50 6.5 to 124 μM) as compared to leishmanicidal activity (IC50 1.1 to 23.6 μM). The equimolar mixture solamargine/solasonine was the most active with an IC50 value of 1.1 μM, after 72 h. Likewise, solamargine was the most active after 24 h with an IC50 value of 14.4 μM, both in comparison with the positive control amphotericin B.

Effects of Copaifera duckei Dwyer oleoresin on the cell wall and cell division of Bacillus cereus

The aim of this work was to evaluate the antibacterial activity of Copaifera duckei oleoresin and to determine its possible mechanism of action against bacteria of clinical and food interest. The antibacterial activity was determined by agar diffusion and dilution methods; the mechanism of action by transmission electron microscopy and by SDS-PAGE; the bioactive compounds by bioautography; and the chemical analysis by GC/MS. Oleoresin showed activity against nine of the 11 strains of bacteria tested. Bacillus cereus was the most sensitive, with a MIC corresponding to 0.03125 mg ml−1 and with a bactericidal action. Oleoresin acted on the bacterial cell wall, removing proteins and the S-layer, and interfering with the cell-division process. This activity probably can be attributed to the action of terpenic compounds, among them the bisabolene compound. Gram-negative bacteria tested were not inhibited. C. duckei oleoresin is a potential antibacterial, suggesting that this oil could be used as a therapeutic alternative, mainly against B. cereus.

Trans- β -Caryophyllene: An Effective Antileishmanial Compound Found in Commercial Copaiba Oil (Copaifera spp.)

This study investigated the leishmanicidal activity against Leishmania amazonensis of four commercial oils from Copaifera spp. named as C1, C2, C3, and C4, the sesquiterpene and diterpene pools obtained from distilling C4, and isolated β-caryophyllene (CAR). Copaiba oils chemical compositions were analyzed by gas chromatography and correlated with biological activities. Diterpenes-rich oils C2 and C3 showed antipromastigote activity. Sesquiterpenes-rich C1 and C4, and isolated CAR presented a dose-dependent activity against intracellular amastigotes, with IC_50s of 2.9 µg/mL, 2.3 µg/mL, and 1.3 µg/mL (6.4 µM), respectively. Based on the highest antiamastigote activity and the low toxicity to the host cells, C4 was steamdistillated to separate pools of sesquiterpenes and diterpenes. Both pools were less active against L. amazonensis and more toxic for the macrophages than the whole C4 oil. The leishmanicidal activity of C3 and C4 oils, as well as C4 fractions and CAR, appears to be independent of nitric oxide production by macrophages. This study pointed out β-caryophyllene as an effective antileishmanial compound and also to its role as potential chemical marker in copaiba oils or fractions derived thereof, aiming further development of this rainforest raw material for leishmaniasis therapy.

BnSP-7 toxin, a basic phospholipase A2 from Bothrops pauloensis snake venom, interferes with proliferation, ultrastructure and infectivity of Leishmania (Leishmania) amazonensis

This paper reports the effects of BnSP-7 toxin, a catalytically inactive phospholipase A2 from Bothrops pauloensis snake venom, on Leishmania (Leishmania) amazonensis. BnSP-7 presented activity against promastigote parasite forms both in the MTT assay, with IC50 of 58·7 μg mL−1 of toxin, and a growth curve, inhibiting parasite proliferation 60–70% at concentrations of 50–200 μg mL−1 of toxin 96 h after treatment. Also, the toxin presented effects on amastigotes, reducing parasite viability by 50% at 28·1 μg mL−1 and delaying the amastigote–promastigote differentiation process. Ultrastructural studies showed that BnSP-7 caused severe morphological changes in promastigotes such as mitochondrial swelling, nuclear alteration, vacuolization, acidocalcisomes, multiflagellar aspects and a blebbing effect in the plasma membrane. Finally, BnSP-7 interfered with the infective capacity of promastigotes in murine peritoneal macrophages, causing statistically significant infectivity-index reductions (P < 0·05) of 20–35%. These data suggest that the BnSP-7 toxin is an important tool for the discovery of new parasite targets that can be exploited to develop new drugs for treating leishmaniasis.

Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action

Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), γ -elemene (14.25%), and trans- β -elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04  μ g·mL(-1)) and amastigotes (IC50, 1.92  μ g·mL(-1)) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400  μ g·mL(-1)); however, there appeared to be no toxicity at 50  μ g·mL(-1). While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity.

Chemopreventive effect of Copaifera langsdorffii leaves hydroalcoholic extract on 1,2-dimethylhydrazine-induced DNA damage and preneoplastic lesions in rat colon

BACKGROUND

Natural antioxidants present in common foods and beverages have drawn great attention to cancer prevention due to its health benefits, remarkable lack of toxicity and side effects. Copaifera langsdorffii, known as "copaiba", "capaiva", or "pau-de-óleo", belongs to the Leguminosae family and occurs in fields and grasslands in the northern and northeastern parts of Brazil. Biological studies of Copaifera corroborate its widespread use by the population. This paper describes the effects of C. langsdorffii leaves hydroalcoholic extract on the 1,2-dimethylhydrazine (DMH)-induced DNA damage and aberrant crypt foci (ACF) in the colon of male Wistar rats.

METHODS

The hydroalcoholic extract of C. langsdorffii was administered to rats by gavage at daily doses of 20, 40 and 80 mg/kg body weight. To evaluate DNA damage by the comet assay, animals received the C. langsdorffii extract for seven days and a single subcutaneous injection (sc) of 1,2-dimethylhydrazine (DMH) at a dose of 40 mg/kg on day 7. Animals were sacrificed 4 h after injection of DMH, to assess DNA damage. For the ACF assay, animals were acclimatized for one week (week 1) and then treated with the C. langsdorffii extract five times a week for four weeks (weeks 2 to 5). The rats received sc injections of DMH (40 mg/kg) on days 2 and 5 of weeks 2 and 3, to induce ACF. Animals were euthanized at week 5; i.e., four weeks after the first DMH treatment.

RESULTS

Animals treated with different doses of the C. langsdorffii extract combined with DMH had significantly lower frequency of DNA damage as compared with the positive control (animals treated with DMH only). The percentage of reduction in the frequency of DNA damage ranged from 14.30% to 38.8%. The groups treated with 40 and 80 mg/kg C. langsdorffii extract during and after DMH treatment presented significantly lower numbers of ACF and aberrant crypts compared with the control.

CONCLUSION

The C. langsdorffii extract significantly reduced the extent of DNA damage and ACF induced by DMH, suggesting that the extract has a protective effect against colon carcinogenesis.

Changes in the volume and histology of endometriosis foci in rats treated with copaiba oil (Copaiferalangsdorffii)

PURPOSE

The aim of this study was to analyze the changes that occur in rats with experimental endometriosis after treatment with copaiba oil.

METHODS

Experimental endometriosis was induced in rats. The experimental group received copaiba oil (Copaiferalangsdorffii) orally (0.63 mg/day), and the control group received a 0.9% sodium chloride solution orally (1 ml/100 g of body weight/day). Both groups were treated with gavage for 14 days. After this period, the animals were euthanized, and the implant volume was calculated. The autologous transplants were removed, dyed with hematoxylin-eosin, and analyzed by light microscopy.

RESULTS

The average final volumes were significantly different between the groups (p=0.007). There was a significant increase (p=0.012) between the initial and final volumes in the control group, whereas treatment with Copaiferalangsdorffii caused a marked reduction in endometrial growth over time (p=0.016). Histologically, 6/11 (55.00%) rats in the experimental group had a well-preserved epithelial layer, and 3 (45.00%) had mildly preserved epithelium. The control group had seven cases (58.30%) of well-preserved epithelial cells and five cases (41.70%) of mildly preserved epithelial cells (p>0.05).

CONCLUSION

Copaiba oil (Copaiferalangsdorffii) appears to be a promising alternative treatment for endometriosis.

Beta-carboline-3-carboxamide derivatives as promising antileishmanial agents

Leishmaniasis has an overwhelming impact on global public health especially in tropical and subtropical countries and the currently available antileishmanial drugs have serious side effects and low efficacy. Natural and synthetic compounds have been tested in the past few years against Leishmania and the beta-carboline class of compounds have shown great results in antiparasitic chemotherapy. In the present study, three 1-substituted beta-carboline-3-carboxamides (3-5) and 1-substituted beta-carboline-3-carboxylic acid (2) were synthesized and screened for in vitro activity against L. amazonensis. Compound 5 (N-benzyl 1-(4-methoxy)phenyl-9H-beta-carboline-3-carboxamide) had the best activity against promastigote and axenic amastigote forms with IC(50) of 2·6 and 1·0 μM, respectively. Its CC(50) on macrophages cell line was higher than 2457·0 μM with an SI ratio of 930·2. Against intracellular amastigote forms, it had a dose-dependent relationship with a 50% growth inhibitory concentration of 1·0 μM. Through morphological and ultrastructure analysis of promastigote forms treated with compound 5, alterations on cell shape and number of flagella and nuclear membrane damage were observed. For this, compound 5 supports the idea for more in vitro and in vivo studies.

Terpenes from Copaifera demonstrated in vitro antiparasitic and synergic activity

To discover new possible therapies for Chagas' disease, we evaluated against all Trypanosoma cruzi life stages the in vitro trypanocidal and synergistic activity of terpenes isolated from Copaifera oleoresins collected in the Amazon and investigated their possible mechanism of action. Seven acid diterpenes and one sesquiterpene were tested. Terpenes promoted changes in oxidative metabolism followed by autophagic processes in the parasite cell leading to selective death. Furthermore, they were more effective against replicative forms, in particular amastigotes. A synergistic effect occurred. Cytotoxicity to erythrocytes and nucleated cells was moderate. This is the first study showing synergic activity between two terpenes against T. cruzi. Combinations of natural compounds can show high activity and may lead to new alternative treatments in the future.

Chemistry and biological activities of terpenoids from copaiba (Copaifera spp.) oleoresins

Copaiba oleoresins are exuded from the trunks of trees of the Copaifera species (Leguminosae-Caesalpinoideae). This oleoresin is a solution of diterpenoids, especially, mono- and di-acids, solubilized by sesquiterpene hydrocarbons. The sesquiterpenes and diterpenes (labdane, clerodane and kaurane skeletons) are different for each Copaifera species and have been linked to several reported biological activities, ranging from anti-tumoral to embriotoxic effects. This review presents all the substances already described in this oleoresin, together with structures and activities of its main terpenoids.

Copaiba oil-resin treatment is neuroprotective and reduces neutrophil recruitment and microglia activation after motor cortex excitotoxic injury

The oil-resin of Copaifera reticulata Ducke is used in the Brazilian folk medicine as an anti-inflammatory and healing agent. However, there are no investigations on the possible anti-inflammatory and neuroprotective roles of copaiba oil-resin (COR) after neural disorders. We have investigated the anti-inflammatory and neuroprotective effects of COR following an acute damage to the motor cortex of adult rats. Animals were injected with the neurotoxin N-Methyl-D-Aspartate (NMDA) (n = 10) and treated with a single dose of COR (400 mg/kg, i.p.) soon after surgery (Group 1) or with two daily doses (200 mg/kg, i.p.) during 3 days (Group 2) alter injury. Control animals were treated with vehicle only. COR treatment induced tissue preservation and decreased the recruitment of neutrophils and microglial activation in the injury site compared to vehicle animals. The results suggest that COR treatment induces neuroprotection by modulating inflammatory response following an acute damage to the central nervous system.

Tropically stable novel oral lipid formulation of amphotericin B (iCo-010): biodistribution and toxicity in a mouse model

Background

The purpose of this study was to evaluate the biodistribution and toxicity of amphotericin B (AmB) following multiple oral administrations of a novel tropically stable lipid-based formulation (iCo-010).

Methods

BALB/c mice were allocated into six groups: oral iCo-010 twice daily for 5 days in the dose of 20, 10, 5 and 2.5 mg/kg; vehicle control; and intravenous boluses of Fungizone^® 2 mg/kg once daily for 5 days. The animals were sacrificed 12 h following the last administration and blood and tissues were collected.

Results

The plasma concentrations of AmB were similar to previously reported after administration of iCo-009. Somewhat lower concentrations of AmB were detected in reticulo-endothelial system in the case of iCo-010 when compared with iCo-009. The concentration in kidney was higher with iCo-010 than with iCo-009. The creatinine levels in all oral treatment groups were in a normal range as in the case of iCo-009. Administration of Fungizone^® resulted in elevated plasma creatinine levels. Histopathology analysis detected no GI, liver or kidney toxicity following multiple dose oral administration of iCo-010. Fungizone^® treatment induced necrotic changes in hepatic and kidney tissues.

Conclusions

Given the tropical stability of iCo-010, near identical activity against visceral leishmaniasis and significant concentrations in target organs this formulation has a potential to become a treatment of choice in tropical developing countries.

Leishmania amazonensis: effects of oral treatment with copaiba oil in mice

Leishmaniasis is a severe public-health problem, with high rates of morbidity and mortality. Efforts to find new, effective and safe oral agents for the treatment of leishmaniasis have been ongoing for several decades, in order to avoid the problems with the currently used antimonials. In the present study, we found that a copaiba oil oral treatment (Group IV) caused a significant reduction in the average lesion size (1.1±0.4mm) against Leishmania amazonensis lesions compared with untreated mice (Group I) (4.4±1.3mm). To prove the safety of the oil, the toxicity and genotoxicity were also determined. Histopathological evaluation did not reveal changes in the copaiba oil-treated animals compared to the control animals. In the mutagenicity evaluation, (micronucleus test) the dose tested (2000mg/kg) showed no genotoxic effects. Morphological and ultrastructural analyses demonstrated notable changes in parasite cells treated with this oleoresin. The main ultrastructural effect was mitochondrial swelling. We also demonstrated that in vitro copaiba oil treatment of L. amazonensis led to an increase in plasma membrane permeability, and depolarization in the mitochondrial membrane potential in parasite cells. Although the mechanism of action of the oleoresin is still unclear, these findings indicate that copaiba oil is a possible new drug, which would provide a safer, shorter, less-expensive, and more easily administered treatment for leishmaniasis.

Copaiba Oil: An Alternative to Development of New Drugs against Leishmaniasis

Leishmaniasis is a neglected disease that is increasing globally at an alarming rate. Glucantime has been the therapy of choice for more than 50 years. A recent study reported the antileishmanial activity of copaiba oil against Leishmania amazonensis. These results led us to investigate morphological and ultrastructural changes in L. amazonensis treated with copaiba oil, using electron microscopy and flow cytometry to assess specific organelles as targets for copaiba oil. In the promastigote and axenic amastigote forms, this copaiba oil caused notable morphological and ultrastructural changes, including extensive mitochondrial damage and denaturation of the plasma membrane. Copaiba oil treatment also induced a decrease in Rh123 fluorescence, suggesting interference with the mitochondrial membrane potential and loss of cell viability with an increase in plasma membrane permeability, as observed by flow cytometry after staining with propidium iodide. In conclusion, copaiba oil could be exploited for the development of new antileishmanial drugs.

Recent advances in leishmaniasis treatment

About 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis occur each year around the world. For over half a century, the clinical forms of the disease have been treated almost exclusively with pentavalent antimonial compounds. In this review, we describe the arsenal available for treating Leishmania infections, as well as recent advances from research on plants and synthetic compounds as source drugs for treating the disease. We also review some new drug-delivery systems for the development of novel chemotherapeutics. We observe that the pharmaceutical industry should employ its modern technologies, which could lead to better use of plants and their extracts, as well as to the development of synthetic and semi-synthetic compounds. New studies have highlighted some biopharmaceutical technologies in the design of the delivery strategy, such as nanoparticles, liposomes, cochleates, and non-specific lipid transfer proteins. These observations serve as a basis to indicate novel routes for the development and design of effective anti-Leishmania drugs.

The production of the sesquiterpene β-caryophyllene in a transgenic strain of the cyanobacterium Synechocystis

The plant secondary metabolite, β-caryophyllene, is a ubiquitous component of many plant resins that has traditionally been used in the cosmetics industry to provide a woody, spicy aroma to cosmetics and perfumes. Clinical studies have shown it to be potentially effective as an antibiotic, anesthetic, and anti-inflammatory agent. Additionally, there is significant interest in engineering phototrophic microorganisms with sesquiterpene synthase genes for the production of biofuels. Currently, the isolation of β-caryophyllene relies on purification methods from oleoresins extracted from large amounts of plant material. An engineered cyanobacterium platform that produces β-caryophyllene may provide a more sustainable and controllable means of production. To this end, the β-caryophyllene synthase gene (QHS1) from Artemisia annua was stably inserted, via double homologous recombination, into the genome of the cyanobacterium Synechocystis sp. strain PCC6803. Gene insertion into Synechocystis was confirmed through PCR assays and sequencing reactions. Transcription and expression of QHS1 were confirmed using RT-PCR, and synthesis of β-caryophyllene was confirmed in the transgenic strain using GC-FID and GC-MS analysis.

Thiophene derivatives with antileishmanial activity isolated from aerial parts of Porophyllum ruderale (Jacq.) Cass

Porophyllum ruderale (Jacq.) Cass. is a plant native to Brazil and in the northwest region of the state of Paraná, Brazil, aerial parts of P. ruderale have been used popularly in the treatment of lesions caused by Leishmania sp.. In this study the antileishmanial and cytotoxic activities of the crude extract, fractions, and isolated compounds from aerial parts of P. ruderale was evaluated. The dichloromethane extract was submitted to chromatography to yield compounds active against Leishmania amazonensis. Their structures were established by comparison of their spectroscopic data with literature values. The activities of crude extract against promastigote and axenic amastigote forms of L. amazonensis (IC₅₀) were 60.3 and 77.7 μg/mL, respectively. Its cytotoxic activity against macrophage cells (CC₅₀) was 500 μg/mL. The thiophene derivatives isolated were: 5-methyl-2,2′:5′,2″-terthiophene (compound A) and 5′-methyl–[5–(4–acetoxy-1–butynyl)]–2,2′-bithiophene (compound B). The activity of compound A against promastigote and axenic amastigote forms were 7.7 and 19.0 μg/mL and of compound B were 21.3 and 28.7 μg/mL, respectively. The activity of the isolated compounds against promastigote and axenic amastigote forms was better than that of the crude extract and more selective against protozoa than for macrophage cells.

Developmental toxicity of copaiba tree (Copaifera reticulata Ducke, Fabaceae) oleoresin in rat

The oleoresin of the copaiba tree (Copaifera sp., Fabaceae) is traditionally used in Brazilian herbal medicine to treat a variety of illnesses and symptoms. This study, conducted according to the OECD Guideline 414, provides data on the developmental toxicity of oleoresin from C. reticulata (COPA-R) in rats. Pregnant Wistar rats (25 per dose group) were treated by gavage with COPA-R (0, 500, 1000 and 1250 mg/kg bw/day) on gestation days (GD) 6-19 and Caesarean sections performed on GD20. Implantations, living and dead fetuses and resorptions were recorded. Half of the fetuses from each litter were examined for visceral abnormalities and the remaining were cleared and stained for skeleton evaluation. COPA-R was maternally toxic (reduced food intake and weight gain) and embryotoxic (lower fetal body weight and increased occurrence of fetal skeleton variations) at the two highest doses, but did not cause embryo deaths or fetal malformations at any dose level. The study derived an oral no-observed-adverse-effect-level (NOAEL) for maternal and developmental toxicity induced by COPA-R of 500 mg/kg bw/day. The results suggest that copaiba oleoresin does not pose a health risk to pregnant women when used according to the recommended doses (up to five drops, three times a day).

Chemistry, cytotoxicity and antileishmanial activity of the essential oil from Piper auritum

Leishmaniasis is one of the most important parasitic infections, but current treatments are unsatisfactory due to their toxicity, cost and resistance. Therefore, the development of new antileishmanial compounds is imperative. Many people who live in endemic areas use plants as an alternative to treat the disease. In this paper, we characterised the essential oil from Piper auritum, evaluated its cytotoxicity and determined its antileishmanial activity. The chromatogram obtained by gas chromatography revealed 60 peaks and we found that safrole was the most abundant compound, composing 87% of the oil. The oil was active against the promastigotes of Leishmania major, Leishmania mexicana, Leishmania braziliensis and Leishmania donovani with a favourable selectivity index against peritoneal macrophages from BALB/c mice. The Piper-oil inhibited the growing of intracellular amastigotes of L. donovani with an IC50 value of 22.3 +/- 1.8 microg/mL. This study demonstrates the usefulness of the essential oils as a promising alternative to treat leishmaniasis.

Acute effect of Copaifera reticulata Ducke copaiba oil in rats tested in the elevated plus-maze: an ethological analysis

Objectives

Copaiba oil oleoresin exuded from Copaifera reticulata Ducke (CRD) is commonly used in anti-inflammatory, healing and anti-tumoral folk medicines. The purpose of this study was to investigate the putative anxiolytic effect of acute administration of CRD.

Methods

CRD was administered (100, 400 and 800 mg/kg, p.o.) to male Wistar rats submitted to the elevated plus-maze model of anxiety using an ethopharmacological analysis.

Key findings

In comparison with control rats, CRD increased the percentage of entries in the open arms over the entire dose range tested (vehicle, 33.6 ± 4.5; CRD 100 mg/kg, 44.67 ± 3.68; CRD 400 mg/kg, 47.2 ± 2.3; CRD 800 mg/kg, 50.7 ± 2.2) and the percentage of time spent in the open arms of the elevated plus-maze at the highest dose (800 mg/kg) (vehicle, 26.4 ± 5.7; CRD 800 mg/kg, 52.0 ± 2.7). A standard anxiolytic, diazepam (3 mg/kg, p.o.), was used as a positive control. In a similar way, diazepam increased the percentage of entries and time spent in the open arms when compared with vehicle (% open entries: vehicle, 45.4 ± 1.3; diazepam, 50.7 ± 1.9; % time spent in open arms: vehicle, 28.2 ± 0.9; diazepam, 38.9 ± 1.2). Regarding ethological measures, CRD at the highest dose (800 mg/kg) reduced peeping out (anxiety-related behaviour) (vehicle, 3.1 ± 0.6; CRD, 0.9 ± 0.2) and increased end-arm activity (vehicle, 0.2 ± 0.2; CRD, 2.0 ± 0.4), indicating an enhanced tendency of the rats to explore actively the potentially dangerous areas of the maze. Diazepam decreased peeping out (vehicle, 3.3 ± 0.3; diazepam, 1.0 ± 0.2) and flat-back approach (vehicle, 0.8 ± 0.2; diazepam, 0.2 ± 0.1) and increased end-arm activity (vehicle, 0.3 ± 0.1; diazepam, 2.5 ± 0.3) and head-dipping (vehicle, 8.2 ± 0.4; diazepam, 12.0 ± 0.5).

Conclusions

These data showed, for the first time, that acute treatment with CRD copaiba oil produced a dose-dependent anxiolytic-like effect over the dose range tested, on conventional and ethological parameters, without adversely affecting general activity levels.