Antiparasitic Activity of Plumbago auriculata Extracts and Its Naphthoquinone Plumbagin against Trypanosoma cruzi.

Chagas disease (CD) caused by the protozoan Trypanosoma cruzi affects more than six million people worldwide. Treatment is restricted to benznidazole (Bz) and nifurtimox (Nf) that display low activity in the later chronic stage besides triggering toxic events that result in treatment abandonment. Therefore, new therapeutic options are necessary. In this scenario, natural products emerge as promising alternatives to treat CD. In the family Plumbaginaceae, Plumbago sp. exhibits a broad spectrum of biological and pharmacological activities. Thus, our main objective was to evaluate, in vitro and in silico, the biological effect of crude extracts of root and of aerial parts of P. auriculata, as well as its naphthoquinone Plumbagin (Pb) against T. cruzi. The phenotypic assays revealed potent activity of the root extract against different forms (trypomastigote and intracellular forms) and strains (Y and Tulahuen), with a compound concentration that reduced 50% of the number of the parasite (EC50) values ranging from 1.9 to 3.9 µg/mL. In silico analysis showed that Pb is predicted to have good oral absorption and permeability in Caco2 cells, besides excellent probability of absorption by human intestinal cells, without toxic or mutagenic potential effects, not being predicted as a substrate or inhibitor of P-glycoprotein. Pb was as potent as Bz against intracellular forms and displayed a superior trypanosomicidal effect (about 10-fold) in bloodstream forms (EC50 = 0.8 µM) as compared to the reference drug (8.5 µM). The cellular targets of Pb on T. cruzi were evaluated using electron microscopy assays and the findings on bloodstream trypomastigotes showed several cellular insults related to the autophagic process. Regarding toxicity in mammalian cells, the root extracts and the naphthoquinone present a moderate toxic profile on fibroblasts and cardiac cell lines. Then, aiming to reduce host toxicity, the root extract and Pb were tested in combination with Bz, and the data showed additive profiles with the sum of the fractional inhibitory concentration indexes (ΣFICIs) being 1.45 and 0.87, respectively. Thus, our work reveals the promising antiparasitic activity of Plumbago auriculata crude extracts and its purified naphthoquinone Plumbagin against different forms and strains of Trypanosoma cruzi in vitro.

In vitro activity of Schinus terebinthifolius extract and fractions against Sporothrix brasiliensis.

BACKGROUND: Sporothrix brasiliensis is the causative agent of zoonotic cases of sporotrichosis in Brazil and is associated with atypical and severe presentations in cats, dogs, and humans. Sporotrichosis treatment is usually time- and cost-consuming, sometimes with poor response and host toxicity. Schinus terebinthifolius has proven efficacy against bacteria and fungi of clinical interest. OBJECTIVE: To determine the in vitro activity of S. terebinthifolius against S. brasiliensis. METHODS: Five S. brasiliensis isolates and three reference strains were subjected to a hydroethanol extract derived from the leaves of S. terebinthifolius and its fractions. The minimal inhibitory concentration (MIC) was determined using the broth microdilution method according to the M38-A2 CLSI guidelines. Also, the fungicidal/fungistatic activity of the extract and fractions was studied. FINDINGS: The crude extract of S. terebinthifolius inhibited the growth of S. brasiliensis (MIC: 0.5-1.0 µg/mL), while the partitioned extracts dichloromethane, ethyl acetate, and butanol demonstrated growth inhibition at 8 µg/mL due to a fungistatic activity. MAIN CONCLUSIONS: Due to its in vitro efficacy against S. brasiliensis and its known pharmacological safety, S. terebinthifolius is a candidate to be tested using in vivo models of sporotrichosis.

In vitro activity of Schinus terebinthifolius extract and fractions against Sporothrix brasiliensis

BACKGROUND Sporothrix brasiliensis is the causative agent of zoonotic cases of sporotrichosis in Brazil and is associated with atypical and severe presentations in cats, dogs, and humans. Sporotrichosis treatment is usually time- and cost-consuming, sometimes with poor response and host toxicity. Schinus terebinthifolius has proven efficacy against bacteria and fungi of clinical interest. OBJECTIVE To determine the in vitro activity of S. terebinthifolius against S. brasiliensis. METHODS Five S. brasiliensis isolates and three reference strains were subjected to a hydroethanol extract derived from the leaves of S. terebinthifolius and its fractions. The minimal inhibitory concentration (MIC) was determined using the broth microdilution method according to the M38-A2 CLSI guidelines. Also, the fungicidal/fungistatic activity of the extract and fractions was studied. FINDINGS The crude extract of S. terebinthifolius inhibited the growth of S. brasiliensis (MIC: 0.5-1.0 µg/mL), while the partitioned extracts dichloromethane, ethyl acetate, and butanol demonstrated growth inhibition at 8 µg/mL due to a fungistatic activity. MAIN CONCLUSIONS Due to its in vitro efficacy against S. brasiliensis and its known pharmacological safety, S. terebinthifolius is a candidate to be tested using in vivo models of sporotrichosis.

An overview of anticancer activity of Garcinia and Hypericum.

Cancer is one of the leading causes of death worldwide (approximately 8.2 million cases/year) and, over the next two decades, a 70% increase in new cancer cases is expected. Through analysis of the available drugs between the years of 1930 and 2014, it was found that 48% were either natural products or their derivatives. This proportion increased to 66% when semi-synthetic products were included. The family Clusiaceae Juss. (Malpighiales) includes approximately 1000 species distributed throughout all tropical and temperate regions. The phytochemical profile of this family includes many chemicals with interesting pharmacological activities, including anticancer activities. This study includes an overview of the in vitro and in vivo anticancer activity of secondary metabolites from Garcinia and Hypericum and the mechanisms involved in this activity. Hypericum no longer belong to Clusiaceae family, but was considered in the past by taxonomists, due to similarities with this family. Research in the area has shown that several compounds belonging to different chemical classes exhibit activity in several tumor cell lines in different experimental models. This review shows the significant antineoplasic activity of these compounds, in particular of these two genera and validates the importance of natural products in the search for anticancer drugs.

Chemical profile and antinociceptive efficacy of Rheedia longifolia leaf extract.

Different species of the family Clusiaceae, including Rheedia longifolia, are used in folk medicine to treat inflammatory diseases. This family is largely distributed in tropical and subtropical areas of Brazil, but their chemical and pharmacological properties have been the subject of a few studies. In previous studies, we found that the aqueous extract from R. longifolia leaves presented important anti-inflammatory and analgesic activity. We investigated the chemical profile of R. longifolia and characterized the pharmacological effect of different chemically identified fractions in pharmacological models of neurogenic and inflammatory nociception. The pharmacological tests showed that oral treatment with aqueous crude extract and fractions of methanol extract of R. longifolia leaf induced a significant antinociceptive effect using von Frey filaments. In addition, the most polar fractions presented antinociceptive activity in a neurogenic model of nociception (capsaicin model). The chromatographic analysis indicated the presence of bisflavonoids in the fractions obtained from the methanol extract. These results suggest that bisflavonoids found in methanol-extracted fractions are involved in the inhibition of inflammatory and neurogenic nociception. It is important that the R. longifolia aqueous extract treatment inhibited ulcer formation induced by indomethacin, suggesting an anti-ulcerogenic activity closely associated with its analgesic effect.

Effect of Rheedia longifolia leaf extract and fractions on the P2X7 receptor in vitro: novel antagonists?

Recently, the P2X(7) receptor has been reported to be associated with chronic inflammatory and neuropathic pain. Because Rheedia longifolia extract has analgesic and anti-inflammatory activity, we evaluated the in vitro inhibitory potential of methanol extract and fractions from its leaves on the P2X(7) purinergic receptor. The activity of P2X(7) was studied with a dye uptake assay and with the whole-cell patch clamp technique in mouse peritoneal macrophages treated with methanol extract of R. longifolia leaves and fractions. The dye uptake was evaluated by flow cytometry and fluorescence microscopy. The R. longifolia extract and some fractions showed an inhibitory effect on the P2X(7) purinergic receptor in a dose-dependent manner. The ethyl acetate fraction exhibited the most potent inhibitory effects. The methanol extract and the butanol fraction showed the same inhibitory effects, despite their lower potency compared with the other fractions. The R. longifolia extract and some of its fractions may be anti-inflammatory because of their inhibitory effect on the P2X(7) receptor. Further investigation is needed to determine the pattern of inhibition and selectivity. Chromatographic analysis indicated the presence of bisflavonoids in the methanol extract fractions. A member of this chemical family is the most probable active compound responsible for the P2X(7) inhibitory effects present in the R. Longifolia extract and fractions.

Analgesic and anti-inflammatory activity of the aqueous extract of Rheedia longifolia Planch & Triana.

Rheedia longifolia Planch et Triana belongs to the Clusiaceae family. This plant is widely distributed in Brazil, but its chemical and pharmacological properties have not yet been studied. We report here that leaves aqueous extract of R. longifolia (LAE) shows analgesic and anti-inflammatory effects. Oral or intraperitoneal administration of this extract dose-dependently inhibited the abdominal constrictions induced by acetic acid in mice. The analgesic effect and the duration of action were similar to those observed with sodium diclofenac, a classical non-steroidal analgesic. In addition to the effect seen in the abdominal constriction model, LAE was also able to inhibit the hyperalgesia induced by lipopolysaccharide from gram-negative bacteria (LPS) in rats. We also found that R. longifolia LAE inhibited an inflammatory reaction induced by LPS in the pleural cavity of mice. Acute toxicity was evaluated in mice treated with the extract for seven days with 50 mg/kg/day. Neither death, nor alterations in weight, blood leukocyte counts or hematocrit were noted. Our results suggest that aqueous extract from R. longifolia leaves has analgesic and anti-inflammatory activity with minimal toxicity and are therefore endowed with a potential for pharmacological control of pain and inflammation.

Analgesic and anti-inflammatory activity of the aqueous extract of Rheedia longifolia Planch & Triana

Rheedia longifolia Planch et Triana belongs to the Clusiaceae family. This plant is widely distributed in Brazil, but its chemical and pharmacological properties have not yet been studied. We report here that leaves aqueous extract of R. longifolia (LAE) shows analgesic and anti-inflammatory effects. Oral or intraperitoneal administration of this extract dose-dependently inhibited the abdominal constrictions induced by acetic acid in mice. The analgesic effect and the duration of action were similar to those observed with sodium diclofenac, a classical non-steroidal analgesic. In addition to the effect seen in the abdominal constriction model, LAE was also able to inhibit the hyperalgesia induced by lipopolysaccharide from gram-negative bacteria (LPS) in rats. We also found that R. longifolia LAE inhibited an inflammatory reaction induced by LPS in the pleural cavity of mice. Acute toxicity was evaluated in mice treated with the extract for seven days with 50 mg/kg/day. Neither death, nor alterations in weight, blood leukocyte counts or hematocrit were noted. Our results suggest that aqueous extract from R. longifolia leaves has analgesic and anti-inflammatory activity with minimal toxicity and are therefore endowed with a potential for pharmacological control of pain and inflammation.