In vitro and in situ antiyeast activity of Gracilaria changii methanol extract against Candida albicans.
OBJECTIVE
The Gracilaria (G.) sp are widely used in the traditional medicine in Malaysia. The methanol extract of Gracilaria changii B.M. Xia & I.A. Abbott (Gracilariaciae) was evaluated for antiyeast activity against Candida albicans (Berkhout).


METHODS
The antiyeast activities were studied by using disc diffusion method and broth dilution method. The effect of the extract on the growth profile of the yeast was also examined via time-kill assay. In addition, the in situ antiyeast activity was studied by microscopic observations using scanning electron microscopy (SEM), transmission electron microscopy (TEM) to determine the major alterations in the microstructure of Candida (C.) albicans.


CONCLUSIONS
The extract showed a favourable antimicrobial activity against C albicans with a minimum inhibitory concentration (MIC) value of 1.56 mg/mL. The main abnormalities noted from the SEM and TEM studies were the internal shrinkage of cell, disorganization within the cell cytoplasm and complete collapse of the yeast cells after 36 h of exposure to the extract. The time-kill assay suggested that the G. changii extract significantly inhibited C. albicans growth and it also exhibited prolonged antiyeast activity against the C albicans.


CONCLUSIONS
The extract has shown in vitro fungicidal properties against C. albicans and should be investigated for its therapeutic potential.
Institute for Research in Molecular Medicine (INFORMM), University Sains Malaysia, Minden, Penang, Malaysia. srisasidharan@yahoo.com
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Sasidharan
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Darah
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Jain
D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D052978:Disk Diffusion Antimicrobial Tests; D044724:Gracilaria / Q000737:chemistry; D000432:Methanol / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D012997:Solvents / Q000737:chemistry*; D013997:Time Factors
D000935:Antifungal Agents; D012997:Solvents; D000432:Methanol