Abstract
Purpose :
Experimental studies have shown that extracts of Pleurotus tuberregium caused a decrease in intraocular pressure in steroid induced ocular hypertension in feline animal models and a contractile effect on isolated bovine iris. There is therefore an emerging interest in the extract of Pleurotus tuberregium as a potential antiglaucoma drug. In this study, a comparative chromatographic analysis and pharmacodynamic study of the activity of aqueous extract of Pleurotus tuberregium of various concentrations with known antiglaucoma drugs (0.5% betaxolol, 0.5% timolol maleate, 2% pilocarpine, and 0.005% latanoprost) was carried out.
Methods :
Graded concentrations (5mg/ml, 10mg/ml, 20mg/ml and 40mg/ml) of the extracts were spotted along with the drugs on prepared glass plates. Silica type 60 gel served as the stationary phase while a solvent system of 50ml chloroform and 50ml absolute ethanol was used as the solvent system. On completion, comparison was made between the extracts and the drugs based on their migration speeds and retardation factors. Further analytic studies were carried out on the filtrates gotten from thin layer chromatography with an Ultraviolet-Visible spectrophotometer.
Results :
Thin layer chromatographic (TLC) analysis showed that the extracts compared favourably with the drugs under study, particularly with timolol maleate and latanoprost, as they had similar migration distances and retardation factors. A plot of the absorption spectrum of the extract was obtained and compared with the known absorption spectrum of the antiglaucoma drugs under study based on the wavelength at which absorption was maximum. Spectrophotometric studies on the extract revealed that it has an absorption spectrum within the ultra-violet wavelength range with a λmax of 260nm and was compared with the absorption spectra of antiglaucoma drugs under study as determined by previous literatures.
Conclusions :
The similarities in the RF values of the extract and the known anti glaucoma drug has been used as a first tier structure activity relationship of the plant extract. There appear therefore to be a promise in the use of the aqueous extract of pleurotus tuberregium in lowering intra ocular pressure. Results are presented in tables, and graphs.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.