Isolation of indole alkaloids and a new norneolignan of hydroethanol extract from the stem barks of Aspidosperma nitidum Benth: Preclinical evaluation of safety and anti-inflammatory and healing properties

ETHNOPHARMACOLOGICAL RELEVANCE

Aspidosperma nitidum Benth (Apocynaceae) is a tree found in Brazil especially in the Amazonia region, known as "carapanaúba", being used by indigenous and cabloco population in folk medicine in the treatment of malaria, leprosy, rheumatism, cancer, diabetes and inflammatory disorders. However, there are no scientific reports, up to now, to evidence its popular use as anti-inflammatory and healing agent.

AIM OF THE STUDY

This study aimed to isolate indole alkaloids, as well as investigate the safety, anti-inflammatory and healing properties of hydroethanol extract from the stem barks of Aspidosperma nitidum Benth (An).

MATERIAL AND METHODS

The compounds were isolated using diverse chromatographic methodologies and the structures were determined by extensive spectroscopic analyses. The safety was evaluated in vitro through 3-methyl-[4-5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay using murine fibroblast (3T3) and monkey kidney (Vero E6) cell lines and by the hemolytic assay, as well as, in vivo, through acute toxicity model, which the mice received a single dose of 2000 mg/kg of An, by intra-gastric (i.g.) route, and behavioral, hematological and biochemical parameters were evaluated. The anti-edematogenic effect was monitored through carrageenan-induced paw edema model, in which the rodents were treated with 50, 100 and 200 mg/kg of An by i. g., the percentage of edema (0-4 h), myeloperoxidase (MPO) and pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) levels were quantified. The anti-inflammatory activity was demonstrated through the zymosan-air-pouch model, in which the animals were treated with 50, 100 and 200 mg/kg of An by i. g, and the leukocytes number, MPO, total protein and cytokines levels were determined. In addition, the healing potential was evaluated through a skin wound model, in which the mice received 50, 100 and 200 mg/mL of An in wound area, and the wound skins were photographed and the area calculated.

RESULTS

In total, five compounds were isolated in the An, being a new 8,9-dinorneolignan glucoside and four known indole alkaloids. The MTT and hemolytic assays, in all concentrations of the extract, demonstrated not be cytotoxic. Acute toxicity model also evidenced no sign of toxicity or significant changes on the behavior, biochemical and hematological parameters after use of the extract. In the edematogenic model, the An reduced significantly the percentage of edema, as well as, the MPO and pro-inflammatory cytokines levels. The same form, An revealed to be efficient in decreasing the leukocytes migration (mainly polymorphonuclears), total proteins, MPO and cytokines concentrations in the zymosan-air-pouch assay. Moreover, the An revealed a healing effect, reducing the area of the skin wound.

CONCLUSION

Ours results evidence in the first time, the anti-inflammatory and healing property of An, justifying its use in traditional medicine. Moreover, include cytotoxicity in vitro and acute toxicity in vivo tests, which indicate the safety of use of the extract.

In vitro and in vivo anti-inflammatory and antiophidic effects of the extract and fraction of Eugenia uniflora

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia uniflora Linn, popularly known as 'pitanga', is a native plant endemic to Brazil that belongs to the Myrtaceae family. Its traditional use (leaves infusion) has been reported for the treatment of different diseases, including hypertension, inflammation, and as a diuretic agent. Considering the snakebite problem and the rich molecule repertoire of this herbal species, studies that evaluate its antiophidic potential are relevant for a broad social impact.

AIM OF THE STUDY

This approach aims to evaluate the anti-inflammatory and antiophidic potential in vitro and in vivo of the extract (aqueous) and a fraction (ethyl acetate) of E. uniflora leaves against Bothrops leucurus and Bothrops brazili venoms.

MATERIALS AND METHODS

Extract and fraction from E. uniflora leaves were obtained by turbo-extraction and partitioning. The cytotoxicity was assayed on normal cell lines (Vero E6 and 3T3) using the 3-methyl-[4-5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide method. The anti-inflammatory activity of the aqueous extract was analyzed in vivo in the zymosan-induced air pouch model, and the leukocytes migration and other molecular inflammatory mediators quantified (myeloperoxidase, total protein, pro-inflammatory cytokine, malondialdehyde, and glutathione). In vitro, the antiophidic effect was evaluated by the ability of the E. uniflora extract and fraction to inhibit the enzymatic action (proteolytic, phospholipase A2, and hyaluronidase) of B. leucurus and B. brazili venoms. In addition, the antiophidic action in vivo was investigated after treatment with E. uniflora extract and fraction (50, 100, and 200 mg/kg) in the B. leucurus venom-induced paw edema with an evaluation of the antiedematogenic effect and quantification of myeloperoxidase (MPO) and pro-inflammatory cytokine levels.

RESULTS

The E. uniflora leaves extract (7.8-125 mg/mL) revealed no toxicity in cell culture, but reduced MTT by 47% at the highest concentration (250 mg/mL) in Vero E6 cells. In contrast, the E. uniflora fraction (7.8-250 mg/mL) showed no cytotoxicity for both cell lines. In the air pouch model, E. uniflora leaves extract demonstrated anti-inflammatory activity, reducing cell migration, MPO activity, protein, malondialdehyde, and proinflammatory cytokines, and increased glutathione levels. Evaluating the antiophidic action in vitro, E. uniflora extract and fraction inhibited the proteolytic, phospholipase, and hyaluronidase effects of B. leucurus and B. brazili venoms at low concentrations. In addition, the extract and fraction also demonstrated in vivo antiophidic activity by reducing edema in the first 0.5 h after treatment, besides reducing MPO and pro-inflammatory cytokines levels.

CONCLUSION

E. uniflora leaves extract showed cytotoxicity only at the highest concentration while the fraction revealed no toxic effect in vitro. This approach showed for the first time that the aqueous extract and ethyl acetate fraction of E. uniflora leaves has similar antiophidic action in vitro and in vivo, with antiedematogenic and anti-inflammatory effects and the ability to inhibit the enzymatic action of B. leucurus and B. brazili venoms. Therefore, this study points to the presence of bioactive components in the leaves of E. uniflora useful for the treatment of inflammatory disorders and ophidian accidents, expanding the therapeutic potential of this herbal species.

Phytochemical analysis and preclinical toxicological, antioxidant, and anti-inflammatory evaluation of hydroethanol extract from the roots of Harpalyce brasiliana Benth (Leguminosae)

ETHNOPHARMACOLOGICAL RELEVANCE

Harpalyce brasiliana Benth (Leguminosae) is a shrub endemic to Brazil, popularly known as "snake's root." This species is used in folk medicine for the treatment of inflammation and snakebites. However, up to now there is no scientific research to justify its popular use. The study aimed to characterize the phytochemical profile of the hydroethanol extract from the roots of H. brasiliana (Hb), to evaluate its antioxidant and anti-inflammatory potential, as well as to investigate its cytotoxicity and acute toxicity.

MATERIALS AND METHODS

The extract was obtained by maceration method using a solution of ethanol:water (70: 30, v/v). The phytochemical profile was obtained by liquid chromatography coupled to mass spectrometry. The cytotoxicity of extract (31-2000 μg/mL) was evaluated in vitro, by the 3-methyl-[4-5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method using murine macrophage and fibroblast cell lines (RAW 247.6 and 3T3, respectively) and by the hemolytic assay. For the in vivo acute toxicity, the extract (2000 mg/kg) was administered and after 14 days the weight (body and organs) and hematological and biochemical parameters were analyzed. Chemical free radical scavenging effect of the extract (125-2000 μg/mL) was investigated through diphenylpicryl hydrazine reduction, total antioxidant capacity, reducing power, hydroxyl radical scavenging, and iron and copper chelating assays. In vitro anti-inflammatory effect of the extract (125, 500, and 2000 μg/mL) was demonstrated through of nitric oxide (NO) analyzed in lipopolysaccharides stimulated RAW 264.7 cells. In vivo anti-inflammatory activities were evaluated in carrageenan-induced paw edema and zymosan-air-pouch models, with gavage administration (post-treatment) of extract at 100, 200, and 400 mg/kg. For the first animal model, the anti-edematogenic activity and myeloperoxidase (MPO) levels were investigated, while in the zymosan-air-pouch model the leukocyte number, MPO, total protein and pro-inflammatory cytokine (IL-1β, IL-6, and TNF-α) levels were quantified. In addition, the oxidative parameters such as malondialdehyde (MDA) and reduced glutathione (GSH) were determined.

RESULTS

The phytochemical profile revealed the presence of 20 compounds, mainly prenylated and geranylated pterocarpans. The extract demonstrated no cytotoxicity in erythrocytes, macrophages and fibroblasts cells at the tested concentrations, as well as no sign of toxicity and mortality or significant alterations on the hematological and biochemical parameters in the acute toxicity model. The extract was also able to neutralize chemical free radicals, with copper and iron chelating effect. For the NO dosage, the extract evidenced the reduction of expression of NO after the administration of the extract (500 and 2000 μg/mL). The edematogenic model revealed a decrease in paw edema and MPO level, while the zymosan-air-pouch model evidenced a reduction of leukocyte number (especially of polymorphornuclears), MPO production, and total protein and cytokine levels, and demonstrated the antioxidant effect through a decrease in MDA and increase in GSH parameters.

CONCLUSION

This approach demonstrates for the first time that Hb is not cytotoxic, has low acute toxicity, and possesses antioxidant and anti-inflammatory properties in preclinical analyses, corroborating its popular use.