Antifungal Activity of Plant Extracts against Candida Species from Oral Lesions

Seventy five patients with oral lesions attending the different departments of Rajah Muthiah Medical College and Hospital, Annamalai University were screened for Candida. Forty six (61.3%) Candida strains were isolated from the oral lesions. Of the 46 Candida strains, Candida albicans accounted for 35 (76.08%), Candida glabrata for 5 (10.86%), Candida tropicalis and Candida krusei for 2 (4.34%) each and Candida parapsilosis and Candida guilliermondii for one (2.17%) each. Antifungal activity of ethanol extracts of five plant species that included Syzygium jambolanum, Cassia siamea, Odina wodier, Momordica charantia and Melia azedarach and two algal species, Sargassum wightii and Caulerpa scalpelliformis were tested against 25 isolated strains by disc diffusion method. Antifungal activity was observed at 100 mg/ml for Syzygium jambolanum, Cassia siamea and Caulerpa scalpelliformis and at 10 mg/ml for Sargassum wightii.

Candidiasis is an acute or chronic, superficial or deep infection with a very wide clinical spectrum. Candidiasis occurs mostly in patients who are predisposed to an overgrowth of their own yeast flora. Oropharyngeal candidiasis occurs in patients with diabetes mellitus, those receiving antibacterial antibiotics and those infected with HIV 1 or HIV 2 1 .
Either nystatin suspension or the clotrimazole douches is the drug of choice in candidiasis for nonimmunosuppressed adults. Patients with advanced HIV infection or other immunosuppressed disorders may not respond to clotrimazole and may require systemic therapy with ketoconazole, given 200 mg once daily or ß uconazole given 100 mg once daily 1 .
Traditional herbal cures for superÞ cial candidiasis is topical application using calendula and commiphora 2 . The antifungal properties of various phytoalexins that are naturally occurring antimycotic secondary metabolites are well researched but mainly for crop plants 3,4 and relatively little work has been done on their medical applications. In a study carried out to determine the antifungal activity of the marine algae of the French Mediterranean Coast it was found that of the thirty one species investigated, eight species exhibited antifungal activity 5  Candidiasis is an opportunistic infectious disease caused by the genus Candida, which includes eight species. The most common species of the Candida is C. albicans. The preponderance of isolation of Candida from the oral lesions in our study was C. albicans (76.08%) and our study conforms with the isolation of the C. albicans by the different investigators. People with poor oral hygiene may have a higher rate of oral yeast carriage. Also oral yeast carriage rates are generally higher in the patients receiving medical attention 1 . The patient population of the study is exclusively those who have come to our hospital for some ailment or the other.
HIV is an important predisposing factor for oral candidiasis. It was observed that candidiasis was as high as 87.5% among HIV patients. Though the number studied was small, the isolation rate of Candida was still considerable. In advanced HIV infection, the appearance of oropharyngeal candidiasis is a predictor of clinical progression to AIDS 9 . Moreover, nearly all patients who progress to clinical AIDS have oral candidiasis at some time 10 .
As per our study candidiasis has been associated with 58.2% of patients with diabetes mellitus. Diabetes mellitus is an important predisposing factor for candidiasis 11 . Other predisposing factors for candidiasis are AIDS, preceding surgery, iatrogenic immunosuppression, intravenous catheters, prolonged administration of antimicrobial agents, cytoreductive chemotherapy, neutropenia, hematologic malignant diseases, burns and intravenous drug abuse 1 .
We have observed that S. jambolanum and C. siamea have exhibited anticandidial activity at 100 mg/ml and O. wodier at 500 mg/ml ( Table 1). Extracts of M. charantia and M. azedarach have not exhibited any activity and so their activity has not been shown in the table. The algal extracts of S. wightii and C. scalpelliformis have also exhibited anticandidial activity at 10 and 100 mg/ml, respectively ( Table 1) Table 1).
The zone of inhibition recorded at 500 mg/ml concentration was higher than that of 250, 100, 10 mg/ml concentration for all the extracts. As the amount of the extract increased, the inhibitory effect has also increased. Similar Þ ndings were observed by Perumalsamy et al. 12 Candida is a difÞ cult organism to establish standards of therapeutic activity. The problem is compounded for plant extracts in which variation may be expected between samples depending on genotype, area of cultivation, time of harvesting, processing methods, dilution etc. The extracts in our study are crude and that may be the reason for the antifungal activity of these extracts up to 100 mg/ml for the S. jambolanum, C. siamea and C. scalpelliformis.
Probably, a more refined preparation would have antifungal activity at a lower concentration. Further experimental and clinical trials should be carried out and if these antifungals are effective they could be used as therapeutic agents.