Effects of Dietary Supplementation with Agaricus sylvaticus Schaeffer on Glycemia and Cholesterol after Streptozotocin-Induced Diabetes in Rats

Abstract

This study evaluated the effect of the Agaricus sylvaticus (sun mushroom) on biochemical tests of the plasma and on the morphology of the pancreas in an experimental model of type I diabetes mellitus (DM1) induced by streptozotocin. One gram of dry A. sylvaticus was homogenized and mixed with the chow. Male Wistar rats were allocated as follows: normoglycemic control that received commercial chow; normoglycemic control group that received chow with A. sylvaticus; diabetic group that received commercial chow; and diabetic group that received chow with A. sylvaticus. Weight, food, and water consumption were measured every two days. Blood glucose levels were measured twice a week. After 30 days, the animals were euthanized and blood was collected for the analysis of cholesterol, HDL, triglycerides, blood sugar, glutamic-pyruvic transaminase (GPT), alkaline phosphatase, iron, transferrin, and urea. The pancreas was processed for microscopic analysis. A. sylvaticus modulated the levels of cholesterol, HDL, triglycerides, blood sugar, GPT, alkaline phosphatase, iron, transferrin, and urea to levels similar to those found in the controls and led to compensatory hyperplasia of the islets of Langerhans. A. sylvaticus is potentially beneficial in the control of type 1 diabetes, and it may also prevent pancreas damage.

Figure 1

(a) Spectrophotometer readings of extract of A. sylvaticus at 270 to 600 nm; (b) thin-layer chromatography analysis of 10 μL of extract: R _f (mobility) and area (mm²); BAW reagent (4:1:5 organic phase), standard chlorogenic acid (R _f = 0.48), and p-coumaric acid (R _f = 0.88) absorbed at 340 nm.

Figure 2

Graph: Sephadex G-50 chromatography column and pooled fraction 1 (tubes 3 and 4), fraction 2 (tubes 6 to 8), fraction 3 (tubes 10 to 12), and fraction four (tubes 13 to 16). Table: mg of beta-glucan, protein, and phenols in each fraction.

Figure 3

Body weight of rats submitted to treatments (C: normoglycemic control group having received unaltered commercial chow; CA: normoglycemic control group having received chow with A. sylvaticus; D: diabetic group having received unaltered commercial chow; DA: diabetic group having received commercial chow with A. sylvaticus). Measurements were taken twice a week for four weeks. Weight values are mean of 5 animals. The first measurement is prior to the introduction of Agaricus in the chow but when the diabetic induction had already been done. “∗∗” on lines indicates statistically significant differences among all groups (P < 0.05; ANOVA + Tukey's test).

Figure 4

Food consumption of rats submitted to treatments (C: normoglycemic control group having received unaltered commercial chow; CA: normoglycemic control group having received chow with A. sylvaticus; D: diabetic group having received unaltered commercial chow; DA: diabetic group having received commercial chow with A. sylvaticus). Measurements were taken every two days for 4 weeks. Values are mean of 5 animals. “∗” on lines indicates statistically significant differences between the group and the control (P < 0.05; ANOVA + Tukey's test).

Figure 5

Water consumption of rats submitted to treatments (C: normoglycemic control group having received unaltered commercial chow; CA: normoglycemic control group having received chow with A. sylvaticus; D: diabetic group having received unaltered commercial chow; DA: diabetic group having received commercial chow with A. sylvaticus). Measurements were taken every two days for 4 weeks. Values (mL) are mean of 5 animals. “∗∗”on lines indicates statistically significant differences among all groups (P < 0.05; ANOVA + Tukey's test).

Figure 6

Glicemia in rats submitted to treatments (C: normoglycemic control group having received unaltered commercial chow; CA: normoglycemic control group having received chow with A. sylvaticus; D: diabetic group having received unaltered commercial chow; DA: diabetic group having received commercial chow with A. sylvaticus). Measurements were taken twice a week for 4 weeks. Values are mean of 5 animals. The first measurement is prior to the initiation of the experiment (time zero). “∗∗” on lines indicates statistically significant differences among all groups (P < 0.05; ANOVA + Tukey's test).

Figure 7

Photomicrographs of pancreas samples; (a) control (C/CA) showing normal round islets of Langerhans; (b) diabetic (D) pancreas showing few β-cells and degenerated islets; (c) diabetic animals treated with A. sylvaticus (DA) showing hyperplastic pancreatic islets (hematoxylin and eosin, original magnification: 160x).