Butyl alcohol extract of Baitouweng Decoction alleviates vulvovaginal candidiasis in mice by downregulating NLRP3 inflammasome and related signal pathways / 中国中药杂志

This study aims to explore the effect of butyl alcohol extract of Baitouweng Decoction(BAEB) on vulvovaginal candidiasis(VVC) in mice and to clarify the mechanism from Toll-like receptors(TLRs)/MyD88 and Dectin-1/Syk signal pathways and NLRP3 inflammasome. To be specific, female KM mice were randomized into control group(i.g., normal saline), model group, fluco-nazole group(i.g., 20 mg·kg~(-1)), and low-dose, medium-dose, and high-dose BAEB groups(i.g., 20, 40, and 80 mg·kg~(-1), respectively). VVC was induced in mice except the control group. After the modeling, administration began and lasted 7 days. The ge-neral conditions and body weight of mice were recorded every day. On the 1 st, 3 rd, 7 th, and 14 th after vaginal infection by Candida albicans, the fungal load in the vaginal lavage fluid of the mice was measured with the plate method, and the morphology of C. albicans in vaginal lavage fluid was observed based on Gram staining. After the mice were killed, vaginal tissues were subjected to hematoxylin-eosin(HE) staining and periodic acid-Schiff(PAS) staining for vaginal histopathological analysis. The content of cytokines in vaginal lavage fluid, such as interleukin(IL)-1β, IL-18, tumor necrosis factor-α(TNF-α), IL-6, and S100 a8, was determined by enzyme-linked immunosorbent assay(ELISA), and content of reactive oxygen species(ROS) in vaginal tissues by tissue ROS detection kit. The protein expression of NLRP3, ASC, caspase-1, Dectin-1, Syk, MyD88, TLR2, TLR4, and nuclear factor-κB(NF-κB) in vaginal tissues was detected by Western blot, and the levels and distribution of NLRP3, Dectin-1, Syk, MyD88, TLR2, and TLR4 in vaginal tissues were determined with the immunohistochemical method. The results show that BAEB can improve the general conditions of VVC mice, reduce the fungal load and C. albicans hyphae in vaginal secretion, decrease ROS content in vaginal tissues and content of cytokines in vaginal lavage fluid, and down-regulate the expression of NLRP3, ASC, caspase-1, Dectin-1, Syk, MyD88, TLR2, TLR4, and NF-κB in vaginal tissues. The above results indicate that BAEB exerts therapeutic effect on VVC mice by down-regulating the key proteins in the TLRs/MyD88 and Dectin-1/Syk signal pathways and NLRP3 inflammasome.

Effect of butyl alcohol extract of Baitouweng Decoction on vaginal mucosal neutrophil chemotaxis in vulvovaginal candidiasis mice / 中国中药杂志

To investigate the effects of butyl alcohol extract of Baitouweng Decoction(BAEB) on neutrophil chemotaxis in vaginal mucosa of mice with vulvovaginal candidiasis(VVC). Seventy-two SPF female Kunming mice were randomly divided into normal control group, model group, fluconazole group, BAEB low-dose group, middle-dose group and high-dose group. Subcutaneous injection of estradiol benzoate was conducted to induce pseudo-estrus, and then 2×10~6 CFU·mL~(-1)of Candida albicans was inoculated into vaginal lumen, followed by drug treatment for 7 days. Gram staining was used to observe the morphological changes of C. albicans in vagina; vaginal fungal load was detected on agar plate. Histological changes of vaginal tissues in mice were observed by HE staining. Lactate dehydrogenase(LDH), interleukin-6(IL-6) and tumor necrosis factor(TNF-α) levels in mouse lavage fluid were detected by enzyme-linked immunosorbent assay(ELISA). Neutrophils in vaginal lavage fluid was observed and counted by using Pap smear. The levels of IL-8 and MIP-2 in vaginal mucosa were detected by ELISA. IL-8 and MIP-2 mRNA levels in vaginal mucosa of mice were detected by qRT-PCR. The results showed that as compared with the normal group, VVC model group had a large number of hyphae and a high level of fungal loadinvagina. The vaginal mucosa was completely destroyed, the number of neutrophils increased, and the protein and mRNA levels of IL-8 and MIP-2 were up-regulated. After BAEB treatment, the hyphae of the treatment group was decreased, the fungal load was decreased, the impaired mucosa showed different degrees of improvement, the inflammatory factors were decreased to varying degrees, and the protein and mRNA levels of chemokine IL-8 and MIP-2 were down-regulated. In conclusion, BAEB may be used to treat VVC by inhibiting vulvovaginal candidiasis via blocking neutrophils recruitment into vagina.

Mechanism of butyl alcohol extract of Baitouweng Decoction (BAEB) on Candida albicans biofilms based on pH signal pathway / 中国中药杂志

This study aimed to investigate the effect of butyl alcohol extract of Baitouweng Decoction( BAEB) on Candida albicans biofilms based on pH signal pathway. The morphology of biofilms of the pH mutants was observed by scanning electron microscope. The biofilm thickness of the pH mutants was measured by CLSM. The biofilm activity of the pH mutants was analyzed by microplate reader.The biofilm damage of the pH mutants was detected by flow cytometry. The expression of pH mutant biofilm-related genes was detected by qRT-PCR. The results showed that the deletion of PHR1 gene resulted in the defect of biofilm,but there were more substrates for PHR1 complementation. BAEB had no significant effect on the two strains. RIM101 gene deletion or complementation did not cause significant structural damage,but after BAEB treatment,the biofilms of both strains were significantly inhibited. For the biofilm thickness,PHR1 deletion or complementation caused the thickness to decrease,after BAEB treatment,the thickness of the two strains did not change significantly. However,RIM101 gene deletion or complementation had little effect on the thickness,and the thickness of the two strains became thinner after adding BAEB. For biofilm activity,PHR1 deletion or complementation and RIM101 deletion resulted in decreased activity,RIM101 complementation did not change significantly; BAEB significantly inhibited biofilm activity of PHR1 deletion,PHR1 complemetation,RIM101 deletion and RIM101 complemetation strains. For the biofilm damage,PHR1 gene deletion or complementation,RIM101 gene deletion or complementation all showed different degrees of damage; after adding BAEB,the damage rate of PHR1 deletion or complementation was not significantly different,but the damage rate of RIM101 deletion or complementation was significantly increased. Except to the up-regulation of HSP90 gene expression,ALS3,SUN41,HWP1,UME6 and PGA10 genes of PHR1 deletion,PHR1 complementation,RIM101 deletion,and RIM101 complementation strains showed a downward expression trend. In a word,this study showed that mutations in PHR1 and RIM101 genes in the pH signaling pathway could enhance the sensitivity of the strains to the antifungal drug BAEB,thus inhibiting the biofilm formation and related genes expression in C. albicans.

Butyl alcohol extract of Baitouweng decoction inhibits Candida albicans cell membrane / 中国中药杂志

To study the inhibitory effect of butyl alcohol extract of Baitouweng decoction(BAEB) on Candida albicans cell membrane. The effects of BAEB on the activity of C. albicans were observed by Spot assay. The changes of intracellular osmotic pressure of C. albicans after BAEB intervention were detected by microtiter plate reader. The effect of BAEB on cell membrane permeability of C. albicans were observed by fluorescence microscopy. The content of ergosterol in C. albicans cell membrane was detected by high performance liquid chromatography, and the expression of ergosterol biosynthesis related genes in cell membrane was detected by qRT-PCR. The results showed that the activity of C. albicans was significantly decreased in 256, 512 and 1 024 mg•L⁻¹ BAEB group. The intracellular glycerol content of C. albicans was significantly increased in 512 and 1 024 mg•L⁻¹ BAEB group(P<0.05). The gene HOG1 associated with intracellular osmotic pressure of C. albicans was down-regulated by 9.1, 9.3 and 5.5 times, respectively. C. albicans with red fluorescent were increased significantly in 512 and 1 024 mg•L⁻¹ BAEB group. The peak area of ergosterol in the 1 024 mg•L⁻¹ BAEB group was 35.884 95, with a significant difference(P<0.05); ERG1, ERG2, ERG3, ERG4, ERG5, ERG6, ERG10, ERG11, ERG13, ERG24, ERG25, ERG251, ERG26 and UPC2 were down-regulated by 6.58, 4.89, 4.15, 9.24,3.41, 9.84, 3.08, 7.50, 5.53, 5.90, 2.45, 3.25,1.98 and 10.07 times respectively in 1 024 mg•L⁻¹ BAEB group. The study indicated that BAEB could inhibit ergosterol and its biosynthesis related genes expression in the cell membrane and inhibit the activity of C. albicans.