In Vitro Anti-Tubulin Activity on MCF10A Cell Line and In Silico Rigid/Semiflexible-Residues Docking, of Two Lignans from Bursera Fagaroides var. Fagaroides.

Podophyllotoxins are natural lignans with known cytotoxic activity on several cell lines. The structural basis for their actions is mainly by the aryltetralin-lignan skeleton. Authors have proposed a cytotoxic mechanism of podophyllotoxins through the topoisomerase-II inhibition activity; however, several studies have also suggested that podophyllotoxins can inhibit the microtubules polymerization. In this work, the two possible mechanisms of action of two previously isolated compounds from the stem bark of Bursera fagaroides var. fagaroides: acetylpodophyllotoxin (1) and 5'-desmethoxydeoxypodophyllotoxin (2), was analyzed. An in vitro anti-tubulin epifluorescence on the MCF10A cell line and enzymatic topoisomerase II assays were performed. The binding affinities of compounds 1 and 2 in the colchicine binding site of tubulin by using rigid- and semiflexible-residues were calculated and compared using in silico docking methods. The two lignans were active by the in vitro anti-tubulin assay but could not inhibit TOP2 activity. In the in silico analysis, the binding modes of compounds into both rigid- and semiflexible-residues of tubulin were predicted, and only for the semiflexible docking method, a linear correlation between the dissociation constant and IC50 previously reported was found. Our results suggest that a simple semiflexible-residues modification in docking methods could provide an in vitro correlation when analyzing very structurally similar compounds.

Anti-inflammatory and antihistaminic activity of triterpenoids isolated from Bursera cuneata (Schldl.) Engl.

AIM OF THE STUDY: To isolate compounds with anti-inflammatory activity from Bursera cuneata by a bioassay-guided fractionation. MATERIALS AND METHODS: Three extracts of different polarities were elaborated by maceration. These extracts were assayed for their inhibitory effects on phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) induced edema in mice. The dichloromethane extract was subjected to activity guided fractionation using successive chromatographic procedures. Additionally, the levels of histamine were determined in the ear samples obtained from the TPA assay, which were determined by high-performance liquid chromatography (HPLC). Effect of moronic Acid on RAW 264.7 stimulated with LPS was evaluated for NO and TNF secretion. RESULTS: The dichloromethane extract had the highest anti-inflammatory effect (89.1 ±â€¯2.2% inhibition) over that of the hexane (53.3 ±â€¯1.2%) and methanolic (77.4 ±â€¯1.8%) extracts at a dose of 0.1 mg/ear. The FS-3 fraction, obtained from the dichloromethane extract, comprised triterpenes ß-sitosterol (1), α-amyrin (2), moronic acid (3), and ursolic acid (4), and all the compounds showed significant activity in comparison with that of indomethacin (41.5 ±â€¯0.6%) at 0.1 mg/mouse ear. However, moronic acid displayed the highest inhibitory effect (68.1 ±â€¯1.3%). Additionally, levels of histamine were determined by HPLC in the treated tissues. moronic acid was the most active (73.3 ±â€¯1.1%, indomethacin 33.8 ±â€¯0.8%). The bio-guided isolation resulted in the identification of moronic acid as the principal anti-inflammatory and antihistaminic compound present in B. cuneata. To confirm a general anti-inflammatory effect, moronic acid was evaluated on the activation of RAW 264.7 cell stimulated with LPS. At 30 and 15 mg/mL a significant reduction of ON was observed (36% and 28% respectively) but had no significant effect on TNFα production. CONCLUSIONS: Our study showed that the organic extracts and isolated compounds from the aerial parts of B. cuneata had topical anti-inflammatory and antihistaminic activities in vivo, but in vitro only modified the production of ON in RAW cells. The results of this study validated the use of B. cuneata in folk medicine for the treatment of inflammatory diseases.

Sessein and isosessein with anti-inflammatory, antibacterial and antioxidant activity isolated from Salvia sessei Benth.

ETHNOPHARMACOLOGICAL RELEVANCE: Salvia sessei Benth, popularly known as "pipilolxochitl" or "sabanito", is a plant utilized in Mexico in traditional medicine for the treatment of erysipela. To date, only one report, to our knowledge, has been found in which a royleanone-type diterpene of the aerial parts of the species was isolated but, again to our knowledge, studies have not been conducted on the pharmacological activity of extracts and compounds isolated from this plant. AIM OF THE STUDY: The objective of the study was to evaluate the anti-inflammatory, antibacterial and antioxidant activity of the organic extracts of the aerial parts of Salvia sessei Benth and sessein and isosessein isomers isolated from this. MATERIALS AND METHODS: Anti-inflammatory activity was evaluated in a model of edema in mouse ear at 1 mg/ear of the isolated extracts and compounds (1 and 2), a dose-response curve was performed on these latter and one-half of the effective dose (ED50) was determined; antibacterial activity was determined through minimal inhibitory concentration (MIC) by microdilution at 100, 50, 25, and 12.5 µg/mL, and antioxidant capacity, by means of DPPH, ABTS, and FRAP assays where, for the first two assays noted, the inhibitory concentration 50% (IC50) was calculated for the extracts as well as for the compounds isolated. RESULTS: The hexanic extracts (40.55 ±â€¯0.5%), dichloromethanic (56.01 ±â€¯1.1%) and methanolic (66.05 ±â€¯0.3%), as well as isolated compounds 1 (79.85 ±â€¯3.5%) and 2 (54.36 ±â€¯1.7%), demonstrated anti-inflammatory activity; the methanolic extract presented the greatest percentage of inhibition, while isolated compounds 1 and 2 did not present a difference in their ED50; additionally, compound 1 exerted a similar effect to that of the drug-of-reference at the same dose (75.24 ±â€¯2.4%). The antibacterial activity of the extracts and compounds was principally against Gram-positive bacteria: the hexanic extract presented activity against Staphylococcus hominis and the methanolic and dichloromethanic extracts, and compound 1 exhibited activity against Staphylococcus haemolyticus, S. hominis, E. faecalis, in addition to that Escherichia coli was sensitive to compound 1, while isomer 2 showed activity against Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus epidermis and Streptococcus pyogenes bacteria related to erysipela. In the three assays, the extract demonstrating greatest antioxidant capacity was the methanolic extract, while that of the isolated compounds was compound 1. CONCLUSIONS: The results show that the three extracts evaluated in the three models presented activity and the chromatographic separation of the dichloromethanic extract permitted the isolation of compounds 1 and 2 royleanone-type isomers, which also presented significant activities such as anti-inflammatory, antibacterial and antioxidant, thus validate the use of this species in traditional medicine.

Anti-inflammatory and antioxidative effects of six pentacyclic triterpenes isolated from the Mexican copal resin of Bursera copallifera.

BACKGROUND: Bursera copallifera (Burseraceae) releases a resin known as "copal ancho" which has been used, since pre-Colombian times, as ceremonially burned incense and to treat tooth ache, tumors, arthritis, cold, cough, and various inflammatory conditions; however, its anti-inflammatory potential is poorly studied. The aim of the present study was to isolate, quantify, and to investigate the anti-inflammatory activity of triterpene compounds isolated from the copal resin of B. copallifera. METHODS: The constituents present in the total resin of B. copallifera were obtained by successive chromatographic procedures, and quantitative analysis was performed by High Performance Liquid Chromatography (HPLC). Anti-inflammatory effects of the isolated triterpenes were investigated to determine their inhibitory effects on phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced edema in mice, viability and nitric oxide (NO) production inhibition on lipopolysaccharide (LPS)-activated RAW 264.7 macrophages, and inhibition of cyclooxygenase (COX)-1, COX-2 and secretory Phospholipase A2 (sPLA2) activities in vitro. RESULTS: Quantitative phytochemical analysis of the copal resin showed the presence of six pentacyclic triterpenes of which, 3-epilupeol (59.75 % yield) and α-amyrin (21.1 % yield) are the most abundant. Among the isolated triterpenes, 3-epilupeol formiate (Inhibitory Concentration 50 % (IC50) = 0.96 µmol), α.amyrin acetate (IC50 = 1.17 µmol), lupenone (IC50 = 1.05 µmol), and 3-epilupeol (IC50 = 0.83 µmol) showed marked inhibition of the edema induced by TPA in mice. α-amyrin acetate and 3-epilupeol acetate, at 70 µM, also inhibited the activity of COX-2 by 62.85 and 73.28 % respectively, while α-amyrin and 3-epilupeol were the best inhibitors of the production of NO in LPS-activated RAW 264.7 cells with IC50 values of 15.5 and 8.98 µM respectively, and did not affected its viability. All compounds moderately inhibited the activity of PLA2. CONCLUSIONS: This work supports the folk use of B. copallifera and provides the basis for future investigations about the therapeutic use of this resin in treating inflammation.

Cytotoxicity, Post-Treatment Recovery, and Selectivity Analysis of Naturally Occurring Podophyllotoxins from Bursera fagaroides var. fagaroides on Breast Cancer Cell Lines.

Despite prevention and treatment options, breast cancer (BC) has become one of the most important issues in the present day. Therefore, the need for more specific and efficient compounds remains paramount. We evaluated four previously isolated aryltetralin lignans: 5'-demethoxy-ß-peltatin-A-methylether (1), acetylpodophyllotoxin (2), 5'-demethoxydeoxypodophyllotoxin (3), and 7',8'-dehydroacetylpodophyllotoxin (4) for cytotoxicity, clonogenicity, and selectivity against three BC cell lines: MCF-7, MDA-MB-231, and BT-549, as well as the non-tumorigenic mammary epithelial cell line MCF-10A. Cytotoxicity was evaluated after 72 h of treatment, and clonogenicity was determined at 72 h post-treatment; experiments were performed using the sulforhodamine B staining assay. Selective-index (SI) was calculated by comparing pure compound IC50 values in MCF-10A cell line against the IC50 of the same compound in cancer cell lines. Structural similarities among lignans and controls (podophyllotoxin and etoposide) were analyzed using the Tanimoto coefficient (Tc). Lignans were cytotoxic against all tested cell lines (0.011-7.22 µM) and clonogenicity testing showed a dose-dependent cytocidality for all lignans (≥0.08 µg/mL); compounds 2 and 3 were more potent (14.1 and 7.6 respectively) than etoposide in BT-549 cell line, while compound 2 displayed selectivity (SI = 28.17) in BT-549 cell line. Tc values of lignans suggested a greater similarity with podophyllotoxin structure.

In vitro COX-1 and COX-2 enzyme inhibitory activities of iridoids from Penstemon barbatus, Castilleja tenuiflora, Cresentia alata and Vitex mollis.

A group of sixteen iridoids isolated from plants used as anti-inflammatory remedies in Mexican folk medicine were evaluated for their potential to inhibit cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes. From these assays, loganic acid (10) was identified as the most promising compound with both COX-1 (36.0 ± 0.6%) and COX-2 (80.8 ± 4.0%) inhibition at 10 µM. Compound 10 shows a better inhibition against the COX-2 enzyme. Other iridoids tested in the present study showed weak or no inhibition against these enzymes. Furthermore, herein are presented key interactions of iridoid 10 with COX-1 and COX-2 enzymes through molecular docking studies. These studies suggest that 10 exhibits anti-inflammatory activity due to COX inhibition.

Chemical constituents and antioxidant activity of extracts obtained from branch bark of Bursera simaruba / Constituyentes químicos y actividad antioxidante de extractos obtenidos de corteza de ramas de Bursera simaruba

The chemical constituents of the hexane and methanol extracts obtained from the branch bark of Bursera simaruba (Burseraceae) grown in Querétaro, Mexico, were investigated by GC-MS, HPLC coupled to DAD, and NMR techniques. Seventeen compounds, including terpenoids, flavonoids, phenolic acids, long-chain fatty acids (FA), methyl esters of FA and sucrose, were identified. In addition, an assessment of the antiradical activity of the methanol extract (ME) was also carried out using DPPH, ABTS, FRAP and DPV assays. The DPPH, ABTS and FRAP assays showed a low antioxidant capacity for the ME. This was in accordance with the relatively low quantities of phenols found in the extract. However, according to the differential pulse voltammetry assay (DVP), this extract exhibited an oxidation potential close to those of quercetin and (+)-catechin, two of the flavonoids with recognized good antioxidant power. This indicated that the ME does contain compounds with good antioxidant capacity and suggested that sometimes the most popular methods commonly used might be underestimating the true antioxidant capacities of plant samples and how the DPV is a valuable complementary tool to be taken into consideration when conducting these in vitro assays...

Los constituyentes químicos de los extractos hexánicos y metanólicos de la corteza de ramas de Bursera simaruba (Burseraceae) recolectada en Querétaro, México, fueron investigados mediante las Cromatografías de Gases acoplada a Espectrometría de masas (GC-MS) y de líquidos de alta resolución (HPLC) acoplada a un detector de arreglo de diodos (DAD) (HPLC-DAD) y mediante RMN. Diecisiete compuestos, incluyendo terpenos, flavonoides, ácidos fenólicos, ácidos grasos de cadena larga (AG), ésteres metílicos de AG y la sacarosa fueron identificados. De manera adicional, se determinó la actividad antioxidante del extracto metanólico utilizando los ensayos de DPPH, ABTS, FRAP y DPV (Voltametría de Pulso Diferencial). Los métodos de DPPH, ABTS y FRAP indicaron una baja capacidad antioxidante para este extracto. Esta observación estuvo de acuerdo con las bajas cantidades de fenólicos encontrados en este extracto. Sin embargo, mediante el método DPV, el extracto tuvo un potencial de oxidación cercano a los de la quercetina y la (+)-catequina, dos de los flavonoides con reconocida buna capacidad antioxidante. Estos resultados indican que el extracto sí contiene metabolitos secundarios con buena capacidad antioxidante y sugieren además que los métodos más comunes pueden subestimar la verdadera capacidad antioxidante de extractos de plantas y resalta la importancia del método DPV como complementario a tener en cuenta en estos tipos de estudios in vitro...

Anti-inflammatory activity of iridoids and verbascoside isolated from Castilleja tenuiflora.

Castilleja tenuiflora (Orobanchaceae) has been used in Mexican traditional medicine as a treatment for cough, dysentery, anxiety, nausea and vomiting as well as hepatic and gastrointestinal diseases. The ethanolic extract of the aerial parts of Castilleja tenuiflora was separated by silica gel column chromatography. The fractions were evaluated using the induced edema acetate 12-O-tetradecanoylphorbol (TPA) anti-inflammatory activity model. The most active fraction was subjected to medium-pressure liquid chromatography (MPLC) with UV detection at 206 and 240 nm. The following iridoids were isolated: geniposidic acid, aucubin, bartioside, 8-epi-loganin, mussaenoside, and the phenylpropanoid verbascoside. The most active iridoid was geniposidic acid, which was more active than the control (indomethacin), and the least active iridoid was mussaenoside. 8-epi-Loganin, and mussaenoside have not been previously reported to be anti-inflammatory compounds. The results of these investigations confirm the potential of Mexican plants for the production of bioactive compounds and validate the ethnomedical use of Castilleja tenuiflora-like anti-inflammatory plants.