Synergistic anti-candidal activity of tetrandrine on ketoconazole: an experimental study.

With the widespread use of azoles, drug resistant Candida albicans strains are increasing. The study examined the synergism of tetrandrine (TET) on ketoconazole (KCZ) candidacidal activity. The protocol M27-A2 of the Clinical and Laboratory Standards Institute (CLSI) was adopted and the minimum inhibitory concentrations (MICs) were determined for KCZ alone and in combination with a TET level that was noncytotoxic for C. albicans strains CA-1 through CA-17, with no CA-10. Colony counting techniques were used to construct time-kill curves. CA-15 was used to build the mouse candidal vaginitis model. After randomization, drugs were administered vaginally once daily from days 3-10 (both KCZ and TET were 26 mg/kg/day and 13 mg/kg/day, respectively, administered in different combinations). Mouse vaginal lavage fluid was obtained at days 2, 6, and 11 after inoculation for fungal load analysis, and vaginal tissue was obtained for pathological examination. MICs of KCZ alone and combined with 30 microg/mL TET for the C. albicans strains were 1-32 microg/mL and 0.0038-0.2500 microg/mL, respectively ( T = 24.624, p = 0.000). Time-kill curves showed that at 48 h the viable cell counts of strains treated with KCZ + TET were at least 2 log(10) CFU/mL lower compared to strains treated with corresponding doses of KCZ (p = 0.000). At day 6, the fungal load in the KCZ 26 mg/kg/day + TET 26 mg/kg/day mice was significantly lower than the KCZ 26 mg/kg/day mice (1.17 +/- 1.17 x 10(4) CFU/mL and 9.33 +/- 3.08 x 10(4) CFU/mL, respectively, p = 0.000). Mucosal and submucosal fungal clearances were complete and vaginal mucosal edema was slight with minimal inflammatory cell infiltration. We conclude that noncytotoxic doses of TET synergistically enhance KCZ candidacidal activity in vitro and in vivo.

Mechanism of action of tetrandrine, a natural inhibitor of Candida albicans drug efflux pumps.

Synergistic effects have previously been observed for a natural compound, tetrandrine (TET), with fluconazole (FLC) in vitro and in the treatment of Candida albicans-infected mice. To investigate the mechanisms of these synergistic effects, 16 strains of C. albicans from the same parent but with different FLC sensitivities were examined using flow cytometry and fluorescent spectrophotometry. Rhodamine 123 (Rh123)-positive cells and intracellular Rh123 fluorescence intensity were determined in accumulation/efflux experiments involving no or a noncytotoxic dose of TET. Total RNA extracted from each strain was used to compare the expressions of drug efflux pump genes in FLC-susceptible, -susceptible dose-dependent, and -resistant strains before and 24 h after TET administration. Accumulation experiments determined that mean percentages of Rh123-positive cells were 26.65% (TET-free) and 70.99% (TET 30 microg/ml), and mean respective intracellular Rh123 fluorescence intensities were 11.34 and 18.00. Efflux experiments showed that percentages of Rh123-positive cells were 1.79% (TET free) and 42.57% (TET 30 microg/ml), respectively, and respective mean intracellular Rh123 fluorescence intensities were 0.74 and 2.19. Differences in MDR1, FLU1, CDR1, and CDR2 expression levels in the absence of TET were statistically significant (p<0.05) between FLC-susceptible, -susceptible dose-dependent, and -resistant strains. Compared with TET-free conditions, 24 h TET-treated strains showed statistically different (p<0.05) expression of MDR1 (FLC-resistant strain), FLU1 (FLC-susceptible dose-dependent and -resistant strains), and CDR1 and CDR2 (FLC-susceptible, -susceptible dose-dependent, and -resistant strains). Thus TET can inhibit the C. albicans drug efflux system and reduce drug efflux. Its mechanism of action is related to the inhibition of expression of the drug efflux pump genes MDR1, FLU1, CDR1, and CDR2.

Risk factors for sebaceous gland diseases and their relationship to gastrointestinal dysfunction in Han adolescents.

Sebaceous gland diseases are a group of common dermatological diseases with multiple causes. To date, a systematic report of the risk factors for sebaceous gland diseases in adolescents has not been published. The aim of this study was to assess the prevalence and risk factors for certain sebaceous gland diseases (seborrhea, seborrheic dermatitis, acne, androgenetic alopecia and rosacea) and their relationship to gastrointestinal dysfunction in adolescents. From August-October, 2002-2005, a questionnaire survey was carried out to obtain epidemiological data about sebaceous gland diseases. Using random cluster sampling, 13 215 Han adolescents aged 12-20 years were recruited from four countries or districts (Macau; Guangzhou, China; Malaysia; and Indonesia). The statistical software SPSS ver. 13.0 was used to analyze the data. The prevalence of seborrhea, seborrheic dermatitis, acne, androgenetic alopecia and rosacea was 28.27%, 10.17%, 51.03%, 1.65% and 0.97%, respectively. Based on multivariate logistic regression analysis, the risk factors for sebaceous gland diseases included: age; duration of local residency; halitosis; gastric reflux; abdominal bloating; constipation; sweet food; spicy food; family history of acne; late night sleeping on a daily basis; excessive axillary, body and facial hair; excessive periareolar hair; and anxiety. There was a statistically significant difference in the prevalence of gastrointestinal symptoms (halitosis; gastric reflux; abdominal bloating; constipation) between patients with and without sebaceous gland diseases (chi(2) = 150.743; P = 0.000). Gastrointestinal dysfunction is an important risk factor for diseases of the sebaceous glands and is correlated with their occurrence and development.