Characterization and cytotoxic activity of sulfated derivatives of polysaccharides from Agaricus brasiliensis

Abstract

Agaricus brasiliensis cell-wall polysaccharides isolated from fruiting body (FR) and mycelium (MI) and their respective sulfated derivatives (FR-S and MI-S) were chemically characterized using elemental analysis, TLC, FT-IR, NMR, HPLC, and thermal analysis. Cytotoxic activity was evaluated against A549 tumor cells by MTT and sulforhodamine assays. The average molecular weight (Mw) of FR and MI was estimated to be 609 and 310 kDa, respectively. FR-S (127 kDa) and MI-S (86 kDa) had lower Mw, probably due to hydrolysis occurred during the sulfation reaction. FR-S and MI-S presented ~14 % sulfur content in elemental analysis. Sulfation of samples was characterized by the appearance of two new absorption bands at 1253 and 810 cm−1 in the infrared spectra, related to S=O and C-S-O sulfate groups, respectively. Through 1H and 13C NMR analysis FR-S was characterized as a (1→6)-(1→3)-β-D-glucan fully sulfated at C-4 and C-6 terminal and partially sulfated at C-6 of (1→3)-β-D-glucan moiety. MI-S was shown to be a (1→3)-β-D-gluco-(1→2)-β-D-mannan, partially sulfated at C-2, C-3, C-4, and C-6, and fully sulfated at C-6 of the terminal residues. The combination of high degree of sulfation and low molecular weight was correlated with the increased cytotoxic activity (48 h of treatment) of both FR-S (EC50=605.6 μg/mL) and MI-S (EC50=342.1 μg/mL) compared to the non-sulfated polysaccharides FR and MI (EC50>1500 μg/mL).

In Vivo Anti-Herpes Simplex Virus Activity of a Sulfated Derivative of Agaricus brasiliensis Mycelial Polysaccharide

“…In addition, we have recently determined that MI-S is a sulfated ␤-(1¡2)-gluco-␤-(1¡3)-mannan ( Fig. 1) (18). Considering the economically feasible biotechnological production of A. brasiliensis mycelial biomass and the promising in vitro antiherpetic activity of MI-S, the goal of this study was to characterize the anti-HSV spectrum of activity of MI-S, using different viral strains, as well as to assess its in vivo anti-HSV-1 and anti-HSV-2 activity in murine models of herpes ocular, cutaneous, and genital infections.…”

Antiherpetic Mechanism of a Sulfated Derivative of <b><i>Agaricus brasiliensis</i></b> Fruiting Bodies Polysaccharide

“…They also found anti-HSV-1 activity for the PLS-sulfated derivative (SPLS), but unlike our findings there was not much improvement on antiviral activity after sulfation in the simultaneous treatment (EC 50 = 346 μg/ml), while no activity was detected for SPLS during postinfection treatment. These discrepant results are likely due not only to the disparity in chain configuration, but also to other chemical features, such as protein content [ours: FR = 1.76% (w/w), FR-S = not detected; Yamamoto et al: PLS = 25.3%, SPLS = not mentioned], molecular weight (ours: FR = 609 kDa, FR-S = 127 kDa; Yamamoto et al: PLS = 97.7 kDa, SPLS = not mentioned), and probably the degree of substitution of sulfated groups (ours: FR-S = 1.88; Yamamoto et al: SPLS = not mentioned) [8,15,26]. …”

“…In this work, attempts were made to study the antiherpetic activity of a (1→6)-(1→3)-β- D -glucan isolated from A. brasiliensis fruiting bodies (FR) and its corresponding sulfated derivative (FR-S) [8] . …”

“…A. brasiliensis cell-wall polysaccharide was obtained and sulfated as we reported previously [8]. Briefly, 50 g of lyophilized fruiting bodies were extracted with water at 100° (3 h), precipitated with ethanol, and centrifuged (1,100 g , 10 min).…”

“…In the present study, we demonstrate the antiherpetic activity and mechanism of action of the sulfated derivative of a polysaccharide isolated from A. brasiliensis fruiting bodies chemically characterized as a sulfated (1→6)-(1→3)-β- D -glucan [8]. In previous studies, we demonstrated the in vitro and in vivo anti-HSV-1 and -HSV-2 activities of a sulfated derivative of a polysaccharide obtained from A. brasiliensis mycelia [9,10].…”