title: Ocimum sanctum essential oil inhibits virulence attributes in Candida albicans.
abstract: Candida albicans is an opportunistic human fungal pathogen which causes disease mainly in immunocompromised patients. Activity of hydrolytic enzymes is essential for virulence of C. albicans and so is the capacity of these cells to undergo transition from yeast to mycelial form of growth. Ocimum sanctum is cultivated worldwide for its essential oil which exhibits medicinal properties. This work evaluates the anti-virulence activity of O. sanctum essential oil (OSEO) on 22 strains of C. albicans (including a standard strain ATCC 90028) isolated from both HIV positive and HIV negative patients. Candida isolates were exposed to sub-MICs of OSEO. In vitro secretion of proteinases and phospholipases was evaluated by plate assay containing BSA and egg yolk respectively. Morphological transition from yeast to filamentous form was monitored microscopically in LSM. For genetic analysis, respective genes associated with morphological transition (HWP1), proteinase (SAP1) and phospholipase (PLB2) were also investigated by Real Time PCR (qRT-PCR). Results were analyzed using Student's t-test. OSEO inhibits morphological transition in C. albicans and had a significant inhibitory effect on extracellular secretion of proteinases and phospholipases. Expression profile of respective selected genes associated with C. albicans virulence by qRT-PCR showed a reduced expression of HWP1, SAP1 and PLB2 genes in cells treated with sub-inhibitory concentrations of OSEO. This work suggests that OSEO inhibits morphological transition in C. albicans and decreases the secretion of hydrolytic enzymes involved in the early stage of infection as well as down regulates the associated genes. Further studies will assess the clinical application of OSEO and its constituents in the treatment of fungal infections.
authors.affiliation: Medical Mycology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi, India.
authors.forename: Amber
authors.initials: A
authors.lastname: Khan
authors.affiliation: Department of Pharmaceutical Sciences, Tshwane University of Technology, Arcadia Campus, Pretoria 0001, South Africa.
authors.forename: Aijaz
authors.initials: A
authors.lastname: Ahmad
authors.affiliation: Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Immaculata
authors.initials: I
authors.lastname: Xess
authors.affiliation: Medical Mycology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi, India.
authors.forename: Luqman A
authors.initials: LA
authors.lastname: Khan
authors.affiliation: Medical Mycology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi, India. Electronic address: nikhatmanzoor@yahoo.co.in.
authors.forename: Nikhat
authors.initials: N
authors.lastname: Manzoor
mesh_terms: D000935:Antifungal Agents / Q000032:analysis* / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification / Q000472:pathogenicity; D015870:Gene Expression / Q000187:drug effects; D015658:HIV Infections / Q000382:microbiology; D006801:Humans; D025301:Hyphae / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D031339:Ocimum / Q000737:chemistry*; D009822:Oils, Volatile / Q000494:pharmacology*; D010447:Peptide Hydrolases / Q000032:analysis; D010740:Phospholipases / Q000032:analysis
chemical_list: D000935:Antifungal Agents; D009822:Oils, Volatile; D010740:Phospholipases; D010447:Peptide Hydrolases
keywords: Candida albicans; Essential oil; Morphological transition; Ocimum sanctum; Phospholipase; Proteinase; Virulence