Abstract:
We have reported the anti-inflammatory activity of Pleurotus ostreatus using
carrageenan induced rat paw edema model. This study evaluates anti-histamine
and membrane stabilization potentials of acetone extract (AE) of P. ostreatus.
Rats were assigned to three groups, and fur on the left posterior lateral side was
removed. After 24 hours, rats were treated with AE (500mg/kg),
chlorpheniramine (0.67mg/kg) and distilled water respectively. After 1 hour,
histamine (50μLof 200μg/mL) was subcutaneously injected to the shaven area
and the area of the wheal formed was determined after 2 minutes. A ten-fold
dilution series ranging from 0.001 to 1000μg/mL of AE and aspirin was made
using phosphate buffered saline (PBS) whereas PBS was the control. The vials
containing rat blood and different concentrations of AE, aspirin and PBS (1mL
each) were incubated at 37°C and centrifuged. The supernatants were removed
and the cells were resuspended in PBS and incubated at 54°C, centrifuged and
optical density (OD) of supernatants was measured at 540 nm. Percent inhibition
of haemolysis was calculated with respect to the controls. Oral treatment with P.
ostreatus and chlorpheniramine significantly (p<0.0001) reduced the area of
wheal formed (52.1±1.1% and 57.9±1.5% respectively) on the skin. All
dilutions of P. ostreatus except 0.001μg/mL (lowest) significantly inhibited the
heat-induced haemolysis of rat erythrocytes in vitro indicating membrane
stabilizing activity. Protection against heat-induced lysis of RBC is often
extrapolated to stabilization of lysosomal membranes, and used as a measure of
anti-inflammatory activity. Therefore, the ability of P. ostreatus to protect RBC
against heat-induced lysis indicates its ability to stabilize the lysosomal
membrane and thereby inhibit the inflammation. Therefore, anti-histamine and
membrane stabilizing activities may contribute as possible mechanisms of anti-inflammatory activity of P. ostre
