Ethnobotanical study of medicinal plants utilized in the management of candidiasis in Northern Uganda.

BACKGROUND: The emergence of resistant Candida species to antifungal drugs has led to resurgence in herbal usage globally. However, little is known about anti-candida plants. This study explored ethnomedicinal plants as treatment option for candidiasis in Pader, Northern Uganda. METHODS: A cross-sectional survey of potential anti-candida plants was conducted using questionnaires, focus group discussions and field observations in March 2022. Sixty-three respondents were selected by snowball technique. The frequencies of respondents/responses were analyzed, associations of respondents' socio-demographics with indigenous knowledge of herbal usage established by Chi-square (χ2) test using SPSS 27. Informant Consensus Factor was computed to establish level of agreement on herbal usage, and thematic analysis done for focus group discussions. RESULTS: Candidiasis is still common and troublesome in Pader. All herbalist had equal chances of receiving and treating candidiasis patients irrespective of herbalist's gender, age, education level, occupation, marital status and religion (p > 0.05). About 39.7% of herbalists received candidiasis patients weekly (p < 0.01). All herbalists had knowledge on candidiasis. Death (56.8%) and discomfort (36.8%) were the major health risks of oropharyngeal candidiasis (OPC) and vulvovaginal candidiasis (VVC), respectively. A total of 32 potential anti-candida plant species in 18 families were identified. Families of Fabaceae (9 species) and Asteraceae (5 species) had most plant species. Trees (50.0%) and herbs (43.8%) were the dominant life forms. The commonest plants by frequency of mention were: Momordica foetida (26), Sansevieria dawei (20), Khaya anthotheca (15), Piliostigma thonningii (10), Clerodendrum umbellatum (7), Hallea rubrostipulata (5) and unidentified plant, 'Agaba/daa layata' in Acholi dialect (5). Plant parts mainly used were roots (56.3%) and stem barks (15.6%) harvested majorly by cutting (46.9%) and uprooting (12.5%). Most respondents (females, 95%) preferred herbal to western medication (p < 0.01) due to its perceived effectiveness. There was high consensus among herbalists on herbal remedies for OPC and VVC (FIC = 0.9). CONCLUSIONS:  Pader communities have diverse indigenous knowledge on candidiasis and prefer herbal medicines to orthodox treatment for candidiasis. However, the herbalists use unsustainable harvesting techniques like uprooting whole plants and cutting main roots. Hence, the need to document such indigenous knowledge before being lost for community usage and scientific validation.

Sodium houttuyfonate enhances the mono-therapy of fluconazole on oropharyngeal candidiasis (OPC) through HIF-1α/IL-17 axis by inhibiting cAMP mediated filamentation in Candida albicans-Candida glabrata dual biofilms.

Candida albicans and Candida glabrata are two common opportunistic fungi that can be co-isolated in oropharyngeal candidiasis (OPC). Hypha is a hallmark of the biofilm formation of C. albicans, indispensable for the attachment of C. glabrata, which is seldom in mycelial morphology. Increasing evidence reveals a hypoxic microenvironment in interior fungal biofilms, reminding of a fact that inflammation is usually accompanied by oxygen deprivation. As a result, it is assumed that the disaggregation of hypha-mediated hypoxia of biofilms might be a solution to alleviate OPC. Based on this hypothesis, sodium houttuyfonate (SH), a well-identified traditional herbal compound with antifungal activity, is used in combination with fluconazole (FLU), a well-informed synthesized antimycotics, to investigate their impact on filamentation in C. albicans and C. glabrata dual biofilms and the underlying mechanism of their combined treatment on OPC. The results show that compared with the single therapy, SH plus FLU can inhibit the hyphal growth in the mixed biofilms in vitro, decrease the fungal burden of oral tissues and internal organs, restore mucosal epithelial integrity and function, and reduce hypoxic microenvironment and inflammation in a mice OPC model. The possible mechanism of the combined therapy of SH plus FLU can be attributed to the regulation of HIF-1α/IL-17A axis through direct abrogation of the dual Candida biofilm formation. This study highlights the role of HIF-1α/IL-17A axis and the promising application of SH as a sensitizer of conventional antifungals in the treatment of OPC.

Paeonol enhances treatment of fluconazole and amphotericin B against oropharyngeal candidiasis through HIF-1α related IL-17 signaling.

Oropharyngeal candidiasis (OPC) is an oral infection mainly caused by Candida albicans, a dimorphic human opportunistic pathogen that can proliferate and invade the superficial oral epithelium using its hyphae. The filamentation of C. albicans is a hallmark of biofilm formation, accompanied by the occurrence of a hypoxic microenvironment. Paeonol (PAE) is a traditional medicine with multiple properties. In a previous study, we demonstrated the synergism of PAE plus Fluconazole (FLU) or Amphotericin B (AmB) against C. albicans in vitro and in vivo. This study aimed to explore the therapeutic mechanisms of drug combinations on OPC. In an established OPC mouse model, the culture of hypoxia was observed by calcofluor white and hypoxyprobe staining. The expression and levels of IL-17 signaling-associated genes and proteins (IL-17A and IL-23) were evaluated in tissue homogenates and EC109 cells. The results show that compared with the single therapy, PAE plus FLU or AmB can decrease fungal burden, restore mucosal integrity, and reduce the hypoxic microenvironment and inflammation in the OPC mice. Relative to infected mice, the drug combinations can also rectify the abnormal expression of hypoxia inducible factor (hif)-1α, il-17a, and il-23 mRNA. Meanwhile, compared with the infected EC109 cells treated with a single drug, PAE plus FLU or AmB significantly inhibited the mRNA and protein expression of HIF-1α, IL-17A, and IL-23. Taken together, the possible mechanism of PAE plus FLU or AmB can be attributed to the regulation of hypoxia-associated IL-17 signaling in OPC treatment.

Perillaldehyde: A promising antifungal agent to treat oropharyngeal candidiasis.

Perillaldehyde (PAE), a natural monoterpenoid agent extracted from Perilla frutescence, PAE has been reported to present various physiological capabilities, such as anti-inflammation, anti-oxidative and anti-fungal. In this study, we show that PAE exhibits strong antifungal activity against Candida albicans (C. albicans). C. albicans, a fungal pathogen with high incidence of antifungal resistance in clinical settings, is the major cause of oropharyngeal candidiasis (OPC). OPC is characterized by inflammatory immunological responses to fungal infections. Our in vitro results show PAE inhibited several virulence attributes of C. albicans including biofilm formation, yeast-to-hyphal transition and secreted aspartic proteinases (SAPs) gene expression. Using an experimental murine model of OPC, we found that PAE inhibited NLRP3 inflammasome assembly, reduced the excessive accumulation of ROS and prevented the p65 transfer in nuclear; processes all leading to reduced inflammation burden in the host. Together, this supports use PAE as a promising new agent to improve OPC.

Chemokine CCL28 Is a Potent Therapeutic Agent for Oropharyngeal Candidiasis.

Candida albicans is a commensal organism that causes life-threatening or life-altering opportunistic infections. Treatment of Candida infections is limited by the paucity of antifungal drug classes. Naturally occurring antimicrobial peptides are promising agents for drug development. CCL28 is a CC chemokine that is abundant in saliva and has in vitro antimicrobial activity. In this study, we examine the in vivo Candida killing capacity of CCL28 in oropharyngeal candidiasis as well as the spectrum and mechanism of anti-Candida activity. In the mouse model of oropharyngeal candidiasis, application of wild-type CCL28 reduces oral fungal burden in severely immunodeficient mice without causing excessive inflammation or altering tissue neutrophil recruitment. CCL28 is effective against multiple clinical strains of C. albicans Polyamine protein transporters are not required for CCL28 anti-Candida activity. Both structured and unstructured CCL28 proteins show rapid and sustained fungicidal activity that is superior to that of clinical antifungal agents. Application of wild-type CCL28 to C. albicans results in membrane disruption as measured by solute movement, enzyme leakage, and induction of negative Gaussian curvature on model membranes. Membrane disruption is reduced in CCL28 lacking the functional C-terminal tail. Our results strongly suggest that CCL28 can exert antifungal activity in part via membrane permeation and has potential for development as an anti-Candida therapeutic agent without inflammatory side effects.

Activities of Nerol, a natural plant active ingredient, against Candida albicans in vitro and in vivo.

Candida albicans invasion is one of the most serious fungal infections in clinical history. In recent years, because of the widespread use of immunosuppressive drugs, chemotherapy drugs, glucocorticoids, and broad-spectrum antibiotics, serious drug resistance has been reported; therefore, a new type of antifungal drug needs to be developed. In this study, we found that Nerol (NEL) had strong antimicrobial activity and 0.77 µL/mL NEL was the minimum inhibitory concentration (MIC) effective against C. albicans. We determined the change of the growth curve of NEL for C. albicans, to identify the trend of NEL activity against C. albicans. Through the determination of the ergosterol content and glucose-induced extracellular fluid acidification of NEL on C. albicans, we found that NEL inhibits the growth of C. albicans by destroying cell membranes. This finding was also supported by the expression of SAP (secreted aspartyl proteinase) involved in cell membrane synthesis. Finally, demonstrations of phenotype investigation, colony-forming unit (CFU) counts, and PAS (periodic acid-Schiff) staining were conducted to prove that NEL had the ability to treated mouse oral C. albicans infection and vaginal C. albicans infection. This research may help us to investigate new antimicrobial agents for treating C. albicans infections. KEY POINTS: • NEL can inhibit the growth of C. albicans. • NEL destroys the cell membrane formation and permeability of C. albicans. • NEL can treat vulvovaginal candidiasis and oropharyngeal candidiasis in mice. • NEL could be used as a possible antifungal agent.

Cinnamaldehyde inhibits Candida albicans growth by causing apoptosis and its treatment on vulvovaginal candidiasis and oropharyngeal candidiasis.

The invasion of Candida albicans is one of the most common fungal infections seen in clinical practice, and serious drug resistance has been reported in recent years. Therefore, new anti-C. albicans drugs must be introduced. In this research, it was demonstrated that cinnamaldehyde (CA) shows strong antimicrobial activity, with 0.26 mg/mL CA being the minimum inhibitory concentration to manage C. albicans. Extraordinarily, we detected that CA accumulated the intracellular reactive oxygen species (ROS) and enhanced the calcium concentration in the cytoplasm and mitochondria through flow cytometry. In addition, we observed that C. albicans cells released Cytochrome c from the mitochondria to the cytoplasm, depolarized the mitochondrial membrane potential, and activated the metacaspase when exposed to 0.065, 0.13, 0.26, and 0.52 mg/mL CA. Furthermore, to confirm that CA introduces the C. albicans apoptosis, we discovered that when the phosphatidylserine was exposed, DNA damage and chromatin condensation occurred, which were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and 4',6-diamidino-2-phenylindole (DAPI) staining. Finally, demonstrations of phenotype investigation, colony-forming unit (CFU) counts, and periodic acid-Schiff (PAS) staining were conducted to prove that CA possessed the ability to treat oropharyngeal candidiasis (OPC) and vulvovaginal candidiasis (VVC). From the above, our research indicates that CA is a promising antifungal candidate when applied to C. albicans infections.

Iranian HIV/AIDS patients with oropharyngeal candidiasis: identification, prevalence and antifungal susceptibility of Candida species.

Oropharyngeal candidiasis is the commonest mucocutaneous infection in HIV-positive individuals. Herein, samples were taken from oral cavities of 150 HIV-infected patients and cultured on Sabouraud-dextrose agar; 89 (59·3%) of 150 patients had positive culture for Candida and presented clinical sign of classical oral candidiasis. Totally, 102 morphologically distinct colonies were isolated from Candida positive cultures and subsequently identified by polymerase chain reaction and sequencing assay, presenting the following frequency: 54 C. albicans (52·9%), 16 C. dubliniensis (15·7%), 12 C. tropicalis (11·8%), 9 C. glabrata (8·8%), 7 C. kefyr (6·9%) and 4 C. africana (3·9%). Additionally, multiple Candida species were co-isolated from 13·5% (12/89) patients. Regarding the antifungal susceptibility test, which was performed by CLSI protocol (M27-A3/M27-S3), all Candida isolates were susceptible to amphotericin B and caspofungin, while some of them were resistant to fluconazole (17·6%; 16 C. albicans, 1 C. dubliniensis and 1 C. glabrata), itraconazole (16·7%; 15 C. albicans, 1 C. dubliniensis and 1 C. tropicalis) and voriconazole (5·9%; 5 C. albicans and 1 C. tropicalis). Collectively, our findings reinforce the urgent necessity to find new therapeutic agents to treat oral candidiasis in HIV-positive patients, especially due to the high incidence of azole-resistant Candida strains and the increased frequency of non-C. albicans species. SIGNIFICANCE AND IMPACT OF THE STUDY: The Candida species recovered from oral cavity of 150 Iranian HIV/AIDS patients and their antifungal susceptibility profiles were reported. Candida albicans was the commonest Candida species, followed by C. dubliniensis, C. tropicalis, C. glabrata, C. kefyr and C. africana. All Candida isolates were susceptible to amphotericin B and caspofungin, while resistance to azoles was detected. The growing drug-resistance profile reported in clinical isolates of C. albicans and non-C. albicans strains is a serious problem in hospitals worldwide. Consequently, the suitable antifungal choice to treat the HIV/AIDS population with oral candidiasis needs to be rethought and new therapeutic options must urgently arise.

Antifungal photosensitive activity of Porophyllum obscurum (Spreng.) DC.: Correlation of the chemical composition of the hexane extract with the bioactivity.

We report Porophyllum obscurum as a source of new photosensitizers with potential use in Photodynamic Therapy as an alternative for oropharyngeal candidiasis treatment. The antifungal photosensitive activity of different extracts from P. obscurum was evaluated by using microdilution and bioautographic assays. The Minimum Fungicidal Concentration for hexanic extract under UV-A irradiation was 0.98µg/mL, but it was inactive in experiments without irradiation. The bioassay-guided fractionation of this extract led to the isolation of four thiophenes responsible for the photosensitive activity: 2,2':5'2″terthiophene, 5-(3-buten-1-ynyl)-2,2'-bithiophene, 5-(4-acetoxy-1-butenyl)-2,2'- bithiophene and 5-(4-hydroxy-1-butenyl)-2,2'- bithiophene, with Minimum Fungicidal Concentrations ranging 0.24-7.81µg/mL under UV-A irradiation. The activity of the hexanic extract was evaluated against 25 clinical strains of Candida spp. isolates as etiological agents of oropharyngeal candidiasis. No differences in susceptibility were observed in strains resistant and susceptible to conventional antifungal drugs. Qualitative and quantitative chemical analyses of seven samples of P. obscurum collected in four different phenological stages were carried out showing that full flowering stage possesses the highest thiophenes content. These data also allowed us to establish a correlation between the thiophene composition of the different extracts and their antifungal photosensitive activity, according to a second order polynomial model with the equation: y=11.2603-0.6831*x+0.0108*x2. The thiophenes isolated were the responsible of antifungal photosensitive activity and can be used for the future standardization of the extract. Results showed that P. obscurum hexanic extract could be potentially developed as an Herbal Medicinal Product to be applied as a photosensitizer in Photodynamic Therapy.

Photodynamic inactivation of oropharyngeal Candida strains.

Oropharyngeal candidiasis (OPC) is an infection frequent in immunocompromised patients. Photodynamic therapy is an alternative to conventional treatments, based on the utilization of compounds that inhibit or kill microorganisms only under the effect of light, process known as Photodynamic Inactivation (PDI). In the present study, PDI of Candida spp. by the natural product α-terthienyl (α-T) was investigated following the guidelines of CLSI M27-A3, under UV-A light irradiation. The optimal values of two variables, exposure irradiation time (ET) and distance to the irradiation source (DIS) were established by employing Design Expert Software (DES). For this purpose, a panel of Candida strains isolated from OPC (C. albicans, C. tropicalis, C. parapsilosis and C. krusei) was employed and optimal values were 5 min (ET) and between 6.06 and 6.43 cm (DIS) with a desirability factor of 0.989. α-T plus UV-A light in the optimal conditions caused a complete reduction in viable cells in 5 min which was demonstrated by viable cells reduction assays and confocal microscopy after vital staining (propidium iodide/fluorescein diacetate). The germ tube formation of C. albicans was inhibited by α-T at sub-inhibitory concentrations. Results showed that α-T plus UV-A light could constitute an alternative for OPC treatments at the optimal conditions determined here.

Susceptibilidad in vitro de candida spp: aisladas de la cavidad oral de pacientes VIH/Sida a itraconazol, clotrimazol y ketoconazol / In vitro susceptibility of candida ssp: isolated fromthe oral cavity of HIV/AIDS patientes to itraconazole, clotrimazole and ketoconazole

La candidiasis orofaríngea (COF) permanece como una de las principales infecciones oportunistas en pacientes infectados con el virus de la inmunodeficiencia humana (VIH) y con el síndrome de inmunodeficiencia adquirida (sida), y aunque su incidencia ha disminuido con la introducción de la terapia antirretroviral de alta eficacia, continúa siendo una afección característica en estos pacientes. En el presente trabajo se realizó un estudio de susceptibilidad in vitro mediante la metodología del CLSI, frente a itraconazol, ketoconazol y clotrimazol de 144 aislamientos clínicos de Candida, aisladas de la cavidad oral de pacientes infectados con el VIH/sida con cuadros clínicos de COF. La identificación de los aislamientos demostró que más del 90% pertenecían a Candida albicans. Al determinar el patrón general de susceptibilidad frente a los azoles estudiados mediante el método de microdilución en caldo del documento M27-A2 del Clinical and Laboratory Standard Institute, C. albicans exhibió valores de concentración mínima inhibitoria (CMI) en un rango de 0,01 a 8µg/mL para el itraconazol y el ketoconazol y de 0,01 a 2 g/mL para el clotrimazol. Sólo el 2,1 % de los aislamientos mostró franca resistencia frente al itraconazol, en tanto que el 3,5 % quedó clasificado dentro de la categoría “susceptible dosis-dependiente” para este triazol. La mayoría de los aislamientos de C. albicans mostraron valores de CMI frente al ketoconazol y al clotrimazol menores a 0.06 g/mL, siendo de un 96,9% (129 aislamientos) y de un 97,7% (129 aislamientos), respectivamente. El clotrimazol tuvo una mejor actividadin vitro comparado con los restantes azoles frente a los aislamientos estudiados. Candida spp. Mostró una elevada sensibilidad in vitro a los azoles estudiados. Se hace necesario continuar realizando estudios epidemiológicos para determinar los patrones de susceptibilidad y tasas de resistencias frente a los agentes...

The oropharyngeal candidiasis (OFC) remains as one of the principal opportunistic infections in patients infected with the human immunodeficiency virus (HIV) and with the acquired immunodeficiency syndrome (aids), and although his incidence has declined with the introduction of the highly active anti-retroviral therapy (HAART), remains as a typical complaint in these patients. A study of antifungal in vitro susceptibility testing, following the CLSI methodology, was realized against itraconazole, ketoconazole and clotrimazole of 144 clinical isolations of Candida, isolated from the oral cavity of patients infected with HIV/aids, with clinical pictures of OFC. The isolation’s identification, demonstrated that more than 90% belonged to Candida albicans. The determination of the general pattern of susceptibility, following the document M27-A2 of the Clinical and Laboratory Standard Institute, against to the studied azoles by means of the method of microdilution in liquid medium, show that the majority of C. albicans isolates showed values of MIC against ketoconazole and clotrimazole lower than 0.06 g/mL, representing a 96,9% (129 isolations) and a 97,7% (129 isolations), respectively. C. albicans exhibited the widest range of minimal inhibitory concentration (MIC). Only 2.1% of the isolations showed resistance against to itraconazole, while 3.5 % remained classified in the category “sensible dose - dependent” for this triazole. The majority of the strains showed values of MIC against ketoconazole and clotrimazole below 0.06 g/mL. The clotrimazole had a better in vitro activity compared with the remaining azoles opposite to the isolations. Candida spp. showed a high in vitro sensibility to the azoles studied. It becomes necessary the maintenance of epidemiologic studies for the determination of susceptibility patterns and of resistances rates against to the antifungal agents