Suppressive effects of Vochysia divergens aqueous leaf extract and its 5-methoxyflavone on murine macrophages and lymphocytes.

Abstract Ethnopharmacological relevance Vochysia divergens Pohl (Vochysiaceae), popularly known as "Cambara", is a tree that is resistant to the seasonal floods in the Pantanal, and usually found in monodominant stands called "Cambarazal". The inhabitants of the Pantanal exploit this tree for medicinal uses. Infusions and decoctions of its leaves are taken as teas, particularly for the treatment of asthma, flu and diarrhea, according to the local tradition transmitted empirically through the generations. Aim of the study To evaluate the beneficial health effects related to the ethnomedicinal uses of V. divergens (Vd) by using biomonitored fractionation of an aqueous leaf extract. Materials and methods The aqueous leaf extract was obtained by decoction, and then the extract was fractionated by a combination of separation techniques including precipitation, organic partition and chromatography. Chromatographic analyses of the active samples were carried out using HPLC-DAD-MS. Flavonoid 1 was isolated from the n-BuOH fraction through classic chromatographic techniques. The inhibitory effects and cytotoxicity of the Vd extract, fractions and flavonoid 1 on NO and TNF-α production were assessed in LPS-stimulated RAW 264.7 macrophage cultures. Additionally, suppression on the proliferation of BALB/c lymphocytes was estimated by [3H] thymidine incorporation. The antioxidant activity of the samples was verified by SNP and DPPH assays and the suppression of the iNOS protein expression was evaluated through Western blotting. Results The HPLC-DAD-MS analysis of the Vd extract led to the identification of 5-methoxyluteolin-7-O-β-glucopyranoside (2), rutin (4) and the tannin galloyl-HHDP-glucopyranoside (3), besides the main flavonoid 3′,5-dimethoxyluteolin-7-O-β-glucopyranoside (1), which was biologically evaluated in comparison with luteolin aglycone. The Vd extract, n-BuOH fraction and flavonoid 1 inhibited NO and TNF-α production by LPS-stimulated macrophages. The reduction of NO levels was mediated mainly by suppression of the iNOS expression. In addition, both the Vd extract (IC50 13.6 µg/mL) and flavonoid 1 (IC50 19.8 µg/mL; 41.6 µM) strongly inhibited stimulated lymphocyte proliferation when compared to the immunosuppressive agent cyclosporin A (IC50 43.8 µg/mL; 36.4 µM). The Vd extract also showed a scavenging activity toward DPPH and NO free radicals. This is the first report describing the immunomodulatory potential of V. divergens and its major flavonoid (1). Conclusion Our findings showed that the aqueous leaf extract of V. divergens and its flavonoid reduced the production of excessive pro-inflammatory markers, collaborating with the Pantanal folk medicinal tradition that recommends the tea of cambara leaves for both asthma and flu. In addition, this study contributes to the knowledge of the pharmacological properties of 5-methoxy flavones, a poorly investigated subclass of flavonoids

Antimycobacterial and Nitric Oxide Production Inhibitory Activities of Triterpenes and Alkaloids from Psychotria nuda (Cham. & Schltdl.) Wawra

A phytochemical study of leaves and twigs of Psychotria nuda resulted in 19 compounds, including five indole alkaloids, N,N,N-trimethyltryptamine, lyaloside, strictosamide, strictosidine, and 5α-carboxystrictosidine; two flavonolignans, cinchonain Ia and cinchonain Ib; an iridoid, roseoside; a sugar, lawsofructose; a coumarin, scopoletin; a diterpene, phytol; three triterpenes, pomolic acid, spinosic acid, and rotungenic acid; and five steroids, sitosterol, stigmasterol, campesterol, β-sitosterol-3-O-β-d-glucoside, and β-stigmasterol-3-O-β-d-glucoside. Some compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis and their ability to inhibit NO production by macrophages stimulated by lipopolysaccharide (LPS). The compounds pomolic acid, spinosic acid, strictosidine, and 5α-carboxystrictosidine displayed antimycobacterial activity with minimum inhibitory concentrations ranging from 7.1 to 19.2 µg/mL. These compounds showed promising inhibitory activity against NO production (IC50 3.22 to 25.5 μg/mL). 5α-carboxystrictosidine did not show cytotoxicity against macrophages RAW264.7 up to a concentration of 100 µg/mL. With the exception of strictosamide, this is the first report of the occurrence of these substances in P. nuda

Antimycobacterial and Anti-Inflammatory Activities of Substituted Chalcones Focusing on an Anti-Tuberculosis Dual Treatment Approach

Tuberculosis (TB) remains a serious public health problem aggravated by the emergence of M. tuberculosis (Mtb) strains resistant to multiple drugs (MDR). Delay in TB treatment, common in the MDR-TB cases, can lead to deleterious life-threatening inflammation in susceptible hyper-reactive individuals, encouraging the discovery of new anti-Mtb drugs and the use of adjunctive therapy based on anti-inflammatory interventions. In this study, a series of forty synthetic chalcones was evaluated in vitro for their anti-inflammatory and antimycobacterial properties and in silico for pharmacokinetic parameters. Seven compounds strongly inhibited NO and PGE2 production by LPS-stimulated macrophages through the specific inhibition of iNOS and COX-2 expression, respectively, with compounds 4 and 5 standing out in this respect. Four of the seven most active compounds were able to inhibit production of TNF-α and IL-1β. Chalcones that were not toxic to cultured macrophages were tested for antimycobacterial activity. Eight compounds were able to inhibit growth of the M. bovis BCG and Mtb H37Rv strains in bacterial cultures and in infected macrophages. Four of them, including compounds 4 and 5, were active against a hypervirulent clinical Mtb isolate as well. In silico analysis of ADMET properties showed that the evaluated chalcones displayed satisfactory pharmacokinetic parameters. In conclusion, the obtained data demonstrate that at least two of the studied chalcones, compounds 4 and 5, are promising antimycobacterial and anti-inflammatory agents, especially focusing on an anti-tuberculosis dual treatment approach