In Vivo And In Vitro Antifungi Acitivity Study Of Active Ingredient Of Pogostemon Cablin (Blanco) Benth

Objects:As one of the four noted Lingnan herbal drugs, Pogostemon cablin (Blanco) Benth is commonly applied in the treatment of gastrointestinal function disorder and microorganism infection based on its remedy efficacy including damp resolution, appetite whetting, vomit arrest, exterior release and summer-dampness expelling. Although it has been revealed that P. cablin owned antifungi activity according to some researches, there are still few studies on the antifungi activity, antifungi spectrum and mechanisms underling this property of the characteristic ingredients of P. cablin, patchouli alcohol (PA) and pogostone (PO). Hence, against the dermatophytes and Candida, the pathogenic bacterium for superficial and deep fungi infection, this study was performed to assess the antifungi activities of pogostone and patchouli alcohol in vitro, as well as the in vivo antifungi experiment specifically against Candida albicans.Methods:1. Antifungi experiment in vitro. The minmun inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC) of PO and PA against11common dermatophytes and28Candidas were determined by microdilution.2. Antifungi experiment in vivo. The C. albicans infection model was established by female Kunming mice, which were under pseudoestrus induced by subcutaneous injection of estrodial, being infected with20μl of3.5×106CFU/mL C. albicans solution. After that the infected mice were administrated with PO by gavage and vagina applyment and were subjected to fungi load counting and vagina histopathology observation by PAS stain at each time point. Results:1. The MICs of PO against the11drug-resistant dermatophytes (Fluconazole and itraconazole resistant, both MICs were over1560μg/ml) ranged from24.38to195μg/ml. Specifically, the MICs of PO against Trichophyton gypseum, Trichophyton mentagrophytes, Microsporum camis, Microsporum lanosum were lower than or equal to that of ketoconazole. Additionally, the MFCs of PO against Trichophyton gypseum, Trichophyton tonsurans, Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, Epidermophyton floccosum were all lower than ketoconazole. But MICs of PA against these dermatophytes were all over1560μg/ml.2. The MIC of PO against C. albicans standard bacterial strain was12.5μg/ml, while that of voriconazole was6.25μg/ml. Against the16C. albicans clinical strains, MICs of PO ranged from3.13to50u g/ml, some of which were even lower than or equal to those of voriconazole, and4strains of them were sensitive to PO and8strains of them exhibited dose-dependant sensitivities to PO. Moreover, PO displayed sterilization activity on all the C. albicans strains with MFC ranging from100to400μg/ml, while voriconazole (400μg/ml) only on2of them. Against other candida strains, PO had lower MICs than voriconazle ranging from12.5to400μg/ml, but rare sterilization was observed. However, MICs of PA against these candidas were all over1560μg/ml.3. The data of vagina fungi load counting indicated that oral administration of PO (20～80mg/Kg) could decreased the fungi load significantly since the11th day after infection when being compared with the model group (P<0.05), but this potency was weaker than that of voriconazole (40mg/Kg). On the hand, vagina applyment of PO (1～4mg/Kg) could markedly reduced the fungi load (P<0.05) since7th day. Moreover, the high dose group (PO of4mg/Kg) had an extremely lower fungi load than the voriconazole group (4mg/Kg).4. Vagina histopathology observation results showed that the vagina of all subject mice exhibited fungi infection to various degrees except the third day after infection. It could be seen that the epithelial cell of vagina mucous membrane in model group displayed significant hornification with increasing endospore and pseudohypha of C. albicans as time went by. Spore and hypha were seen gradually decrease by treatment of vagina applyment of PO since7lh day after infection while the amount of spore and hypha of oral administration began decrease since11th day.Conclusion:PO exhibited evident inhibition on the drug-resistant dermatophytes (fluconazole and itraconazole resistant). Although the antibacterial activity of PO against dermatophytes was equal to or a bit weaker than that of ketoconazole, sterilizing activity of PO was more potent than ketoconazole. Meanwhile, PO had a stronger antifungi property than voriconazole. Moreover, both oral administration and vagina applyment of PO could restrain the growth of C. albicans, and the inhibition of the latter treatment was better than voriconazole. However, PA had no growth restrain on any fungi in our test.