Investigation of polysaccharide extracts from Iranian and French strains of Agaricus subrufescens against enzymes involved in Alzheimer's disease / Investigación de extractos de polisacáridos de cepas iraníes y francesas de Agaricus subrufescens contra enzimas relevantes para la enfermedad de Alzheimer

In this work, the inhibitory activity of a wide range of polysaccharide extracts from two Iranian and French strains of Agaricus subrufescens were evaluated toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Among them, two extracts S9 and S'7 obtained from Iranian and French strains under different extraction conditions showed selective AChE inhibitory activity with IC50 values of 154.63 and 145.43 µg/mL, respectively. It should be noted that all extracts from both strains demonstrated no BChE inhibitory activity. S9 and S'7 were also tested for their effect on amyloid beta (Aß) aggregation, antioxidant activity, and neuroprotectivity. Their activity against Aß aggregation was comparable to that of donepezil as the reference drug but they induced moderate antioxidant activity by DPPH radical scavenging activity and negligible neuroprotectivity against Aß-induced damage.

En este trabajo, se evaluó la actividad inhibitoria de acetilcolinesterasa (AChE) y butirilcolinesterasa (BChE) para varios extractos de polisacáridos de dos cepas iraníes y francesas de Agaricus subrufescens. Los extractos más potentes mostraron valores de IC50 de 154,63 y 145 µg/ml para las cepas iraní (S9) y francesa (S'7), respectivamente, las cuales se obtuvieron de diferentes condiciones de extracción; sin embargo, todos los extractos no mostraron actividad inhibitoria de BChE. Además, S9 y S'7 se probaron para determinar su efecto sobre la agregación de beta-amiloide (Aß), así como su actividad antioxidante y neuroprotectora. Su actividad inhibitoria de la agregación de Aß fue comparable con donepezil, fármaco de referencia, pero indujeron una actividad antioxidante moderada, medida mediante la captación de radicales DPPH, y una neuroprotectora insignificante contra el daño inducido por Aß.

Cytotoxic diterpenoids from the roots of Salvia lachnocalyx

ABSTRACT Salvia lachnocalyx Hedge, Lamiaceae, is an endemic sage which grows naturally in the Fars Province of Iran. The phytochemical analyses of the roots of S. lachnocalyx led to the isolation of five known diterpenoids: ferruginol (1), taxodione (2), sahandinone (3), 4-dehydrosalvilimbinol (4) and labda-7,14-dien-13-ol (5). Their chemical structures were elucidated using one (1H and 13C) and two dimensional (COSY, HSQC and HMBC) NMR spectroscopic data as well as electron impact mass spectra. The cytotoxicity of the purified compounds was evaluated against three human cancer cell lines; MOLT-4 (acute lymphoblastic leukemia), HT-29 (colorectal adenocarcinoma) and MCF7 (breast adenocarcinoma) and all of the isolated compounds showed considerable cytotoxic activity against these cell lines. Compounds 2 and 3 (IC50 range: 0.41-3.87 µg/ml) with endocyclic α,β-unsaturated carbonyl functional group, exhibited the highest cytotoxic activities compared to the other compounds (IC50 range: 6.85-17.23 µg/ml). In conclusion, compounds 2 and 3 are presented as compounds that deserve further investigation of their biological activities.

Bioassay guided purification of cytotoxic natural products from a red alga Dichotomaria obtusata

ABSTRACT Different solvent extracts of Dichotomaria obtusata (J. Ellis & Solander) Lamark, Galaxauraceae, a red algae collected from the coast of Bushehr in the Persain Gulf, was investigated for its cytotoxic properties and chemical constituents. The fresh alga, after extraction with methanol and dichloromethane were combined and partitioned between water, dichloromethane and ethyl acetate. The above fractions were then tested against MOLT-4 (human lymphoblastic leukemia) cancer cell line. The IC50 values of the dichloromethane and ethyl acetate layers of the crude extract were 29.8 ± 3.1 and 30.6 ± 7.9 µg/ml against MOLT-4 cells, respectively, while the water layer showed a week activity with IC50 > 50 µg/ml. After fractionation of the active extracts using open column chromatography over silica gel and preparative thin layer chromatography purification, two terpenoid derived compounds, trans-phytol palmitate and γ-tocopherol were isolated from the dichloromethane and ethyl acetate extracts. The structures of the compounds were elucidated using different spectral data including 1H NMR, 13C NMR, HSQC, HMBC and EI-MS. The IC50 values of compounds trans-phytol palmitate, γ-tocopherol and an undetermined mixture of compounds (F-13-14) were determined as 43.4 ± 1.6, – and 20.3 ± 6.2 µg/ml against LS180 (human colon adenocarcinoma); 53.2 ± 9.3, >100 and 27.6 ± 6.9 µg/ml against MCF-7 (human breast adenocarcinoma) and 40.0 ± 4.1, 48.8 ± 1.8 and 15.9 ± 0.3 µg/ml against MOLT-4 cell lines, respectively, which were comparable to the IC50 values of standard anticancer agent, cisplatin against the same cell lines. The red algae collected from the Persian Gulf contained substances that could inhibit the growth of human cancer cell lines and may represent a natural source for the discovery of novel anticancer agents.