Comparison of Pouzolzia indica methanolic extract and Virkon against cysts of Acanthamoeba spp.

The present study was conducted to investigate the morphological and structural changes of Acanthamoeba cysts after being treated with various concentrations of Pouzolzia indica methanolic extract fraction 3 (methanol eluted) and Virkon solution. Changes in the Acanthamoeba cysts were detected by light microscopy, scanning electron microscopy and transmission electron microscopy. The results show Acanthamoeba cysts were killed by Pouzolzia indica methanolic extract fraction 3 at a concentration of 1:8 and by Virkon solution at a concentration of 0.25%, with a minimal cysticidal concentration (MCC) by 24 hours. Both agents caused similar structural damage to Acanthamoeba cysts in the same sequence. Step by step structural alterations occurred within the cyst. First, the cyst shrank, collapsed and had clumping of cytoplasmic stuctures inside the cyst walls. Second, the cysts began to bulge, swell, have a decrease in wrinkles in the cyst walls and spill the cytoplasmic contents into the environment. Finally, the cyst walls broke into small pieces. This study may be beneficial to compare with future studies of pharmaceutical agents against Acanthamoeba keratitis.

Pouzolzia indica methanolic extract fraction 2 and povidone-iodine induced changes in the cyst of Acanthamoeba spp.: light and electron microscopic studies.

OBJECTIVE: To compare the minimal cysticidal concentration (MCC) between Pouzolzia indica methanolic extract fraction 2 and Povidone-lodine (PVP-I) on the Acanthamoeba cyst and to illustrate the morphological changes of the cyst after being treated by light and electron microscopies. MATERIAL AND METHOD: Acanthamoeba spp were isolated from patients with Acanthamoeba keratitis and cultured on a non-nutrient agar plate (NNA) seeded with heat killed Escherichia coli (NNA-E.coli) at 37 degrees C for 7 days, adjusted to a final concentration of 10(4) cysts/ml. Several concentrations of PVP-I and fraction 2 of Pouzolzia indica methanolic extract were tested to find the minimal cysticidal concentrations (MCC) of both agents, at these concentrations there was no viable cyst which was confirmed by no excystment after further incubation for 7 days. The cysts were prepared for routine transmission and scanning electron microscopic studies. RESULTS: Structural damages of the treated cysts by MCC of PVP-I and fraction 2 of Pouzolzia indica methanolic extract showed a series of damages. Starting from shrinkage, destruction or rupture of the cyst walls and opercula, withdrawal of the cytoplasm or edema cyst by the outside solution passed through the damaged wall caused a decrease in wrinkle ridges of the ectocyst. Then the cyst was ripped and torn into small pieces CONCLUSION: MCC of PVP-I solution and the fraction 2 of Pouzolzia indica methanolic extract were 0.04% and 1:4, respectively. The structural damages were somewhat similar, such as the shrinkage, ruptured cyst wall and opercula, edema and end by breaking up of the cyst wall and degeneration of the inside cytosol. Pouzolzia indica may be modified as an effective disinfectant solution for a contact lens case if the active ingredients are more purified.