Effects of proanthocyanidin enriched extract from Ligaria cuneifolia on plasma cholesterol and hemorheological parameters. In vivo and In vitro studies.

UNLABELLED: It was demonstrated that Ligaria cuneifolia (Lc) crude extract increased blood viscosity and decreased plasma cholesterol in rats. In the present study, we analyzed the Lc proanthocyanidin enriched fraction (PLc) to determine if it is capable of altering the hemorheological parameters while diminishing the plasma cholesterol. In vivo studies in adult male Wistar rats, randomized in three groups (n = 6 each one) were performed: 1. CONTROL: saline intraperitoneal (i.p.); 2. PLc 0.6 mg/100 g body weight (b.w.) i.p. and 3. PLc 3 mg/100 g b.w. i.p., every 24 hours during 3 days. IN VITRO STUDIES: with blood obtained by cardiac puncture, separated in aliquots and incubated with: 1. Saline solution (Control); 2. PLc 0.1 mg/mL, and 3. PLc 1.0 mg/mL, equivalent to doses in vivo experiments. The results demonstrated that in vivo PLc 0.6 and PLc 3 reduced plasma cholesterol (Cho) and LDL-Cho. Neither blood nor plasma viscosity was altered. Decrease of plasma cholesterol could be due to an increase of cholesterol and bile salts excretion leading to an increase of bile flow. In vitro experiments showed a direct interaction of PLc, at high concentration, with the erythrocyte membrane, inducing a switch from discocyte to stomatocyte. Only, PLc without hepatic metabolism produces hemorheological changes. Thus, PLc in vivo might be a pharmacological agent capable of decreasing plasma cholesterol.

Effect of Ligaria cuneifolia catechin- and quercetin-enriched fractions on hemorheology and plasma cholesterol.

UNLABELLED: We tested the in vivo and the in vitro effects of both Ligaria cuneifolia catechin- and quercetin-enriched fractions on erythrocyte shape and deformability, and on plasma cholesterol level. For in vivo studies, adult male Wistar rats were randomized in three experimental groups which received intraperitoneally, once a day, 3 days: CONTROL: saline solution (C; n = 6); catechin from L. cuneifolia, 0.60 mg/100 g body weight (CLc; n = 6), or quercetin from L. cuneifolia, 2.3 mg/100 g body weight (QLc; n = 6). For in vitro studies, blood samples obtained from male Wistar rats were divided into three fractions, which were incubated with saline solution (C), catechin (CLc; n = 5) and quercetin (QLc; n = 5), in a concentration equivalent to 0.60 mg/100 g body weight, and 2.3 mg/100 g body weight, respectively. CLc significantly reduced the rigidity index due to a diminished mean concentration volume. QLc induced erythrocyte rigidization (less deformability), thus increasing blood viscosity. Neither of the two treatments produced any changes in plasmatic or biliary excretion of cholesterol. Opposite results were observed in rigidity index with CLc and QLc. In vitro studies showed an interaction of both CLc and QLc with the erythrocyte membrane, which induced changes in the erythrocyte shape from discocyte to stomatocyte.

Effect of the vehicle polyvinylpyrolidone and the Methanolic Fraction of Ligaria cuneifolia (Argentine Mistletoe) extract on hemorheological properties and biliary secretion in rats.

Ligaria cuneifolia (R et P) Tiegh. (Loranthaceae) (Lc) aqueous extract-treated rats by via intraperitoneal (i.p.) show increased blood viscosity and decreased plasma cholesterol (Chol) levels. In this work, we analize the effect of the vehicle polyvinylpyrrolidone (PVP) and that of the Methanolic Fraction of the extract of Lc (MFLc) on hemorrheological properties in vivo and in vitro and on biliary excretion. For in vivo conditions, adult male Wistar rats were divided in five experimental groups (n=5 each one) which were injected, every 24 hr during 3 days by via i.p., with: (1) saline solution (Control); (2) PVP 0.47 mg/100 g bw; (3) MFLc 0.95 mg/100 g bw plus PVP 0.47 mg/100 g bw; (4) PVP 12.5 mg/100 g bw; and (5) MFLc 23.0 mg/100 g bw plus PVP 12.5 mg/100 g bw. Intended for in vitro conditions, blood samples obtained by heart puncture were divided into three fractions, which were incubated with: saline solution (Control), PVP 12.5 mg%, and MFLc 25 mg% plus PVP 12.5 mg%. We demonstrated a direct effect of PVP alone and of MFLc "per se" on the erythrocyte membrane resulting in a cell shape change from dyscocyte to spherostomatocyte (MI more negative) as well as a decrease in erythrocyte deformability (increased RI). These changes induce an increase in blood viscosity. Decreased plasma Chol is a consequence of an increased bile salts biliary excretion.