Molecular Docking Analysis of Siddha Formulation Parangipattai Chooranam Against Vaginal Candidiasis

Vulvovaginal candidiasis called by its name Vellai Noi as per Siddha terminology is considerably the second most common cause of vaginal inflammation in the women of middle-aged group. Candida albicans are prioritised top among other pathogens in mediating vaginal inflammation and its related symptoms. Candida albicans exerts its virulence by secreting the enzyme known as secreted aspartyl proteinases (SAP) which allows hassle-free adherence and growth of the opportunistic pathogen. Hence, drugs that selectively inhibit this enzyme may act as a novel candidate drug in halting the growth and invasion of Candida albicans. Siddha formulations have century's old credit of managing infectious pathogens. The greater ideology of siddha practice is to adequately strengthen the host immunity and resistance towards infections. In the present investigation, about twelve phytocompounds have been retrieved from the siddha formulation Parangipattai Chooranam and the same were subjected to molecular docking analysis against SAP enzyme target along with standard fluconazole. Results of the present in silico investigation signify that the compounds such as beta-sitosterol, afzelin, apigenin, quercetin and rosmarinic acid ranked first by demonstrating potential binding affinity with active amino acid residues by occupying the respective binding sites (Asp 32, 83 Lys, Asp86, Gly220, Thr221 and Thr222) in comparison with standard drug fluconazole. Similar binding behaviour was exhibited by other compounds like kaempferol, carnosic acid and engeletin (Asp 32, Gly85, Asp86, Asp218, Gly220, Thr221 and Thr222) against the target amino acids. Vicenin exhibited best binding affinity of - 12.07 kcal/mol followed by beta-sitosterol (- 9.29 kcal/mol), engeletin (- 9.04 kcal/mol), afzelin (- 8.07 kcal/mol) and 4-O-caffeoylquinic acid (- 7.85 kcal/mol) in comparison with fluconazole (- 7.32 kcal/mol). From the results of the present study, it was concluded that the phytochemicals present in the siddha formulation Parangipattai Chooranam reveal significant antifungal activity by inhibiting the target enzyme (SAP) and thereby considered an excellent drug of choice for the clinical management of vaginal candidiasis.