Effect of Cinnamaldehyde on Systemic Candida albicans Infection in Mice.

OBJECTIVE: To investigate the therapeutic efficacy of cinnamaldehyde (CA) on systemic Candida albicans infection in mice and to provide supportive data for the development of novel antifungal drugs. METHODS: Ninety BALB/c mice were randomly divided into 3 groups according to a random number table: CA treatment group, fluconazole (positive control) group, and Tween saline (negative control) group, with 30 mice in each group. Initially, all groups of mice received consecutive intraperitoneal injections of cyclophosphamide at 200 mg/kg for 2 days, followed by intraperitoneal injection of 0.25 mL C. albicans fungal suspension (concentration of 1.0 × 107 CFU/mL) on the 4th day, to establish an immunosuppressed systemic Candida albicans infection animal model. Subsequently, the mice were orally administered CA, fluconazole and Tween saline, at 240, 240 mg/kg and 0.25 mL/kg respectively for 14 days. After a 48-h discontinuation of treatment, the liver, small intestine, and kidney tissues of mice were collected for fungal direct microscopic examination, culture, and histopathological examination. Additionally, renal tissues from each group of mice were collected for (1,3)- ß -D-glucan detection. The survival status of mice in all groups was monitored for 14 days of drug administration. RESULTS: The CA group exhibited a fungal clearance rate of C. albicans above 86.7% (26/30), significantly higher than the fluconazole group (60.0%, 18/30, P<0.01) and the Tween saline group (30.0%, 9/30, P<0.01). Furthermore, histopathological examination in the CA group revealed the disappearance of inflammatory cells and near-normal restoration of tissue structure. The (1,3)-ß-D-glucan detection value in the CA group (860.55 ± 126.73 pg/mL) was significantly lower than that in the fluconazole group (1985.13 ± 203.56 pg/mL, P<0.01) and the Tween saline group (5910.20 ± 320.56 pg/mL, P<0.01). The mouse survival rate reached 90.0% (27/30), higher than the fluconazole group (60.0%, 18/30) and the Tween saline group (30.0%, 9/30), with a significant difference between the two groups (both P<0.01). CONCLUSIONS: CA treatment exhibited significant therapeutic efficacy in mice with systemic C. albicans infection. Therefore, CA holds potential as a novel antifungal agent for targeted treatment of C. albicans infection.

Effect of Cinnamaldehyde on C. albicans cell wall and (1,3)- ß - D-glucans in vivo.

BACKGROUND: The incidence rate of invasive candidiasis is high, its treatment is difficult, and the prognosis is poor. In this study, an immunosuppressive mouse model of invasive Candida albicans (C. albicans) infection was constructed to observe the effects of cinnamaldehyde (CA) on the C. albicans cell wall structure and cell wall (1,3)-ß-D-glucan contents. This study provides a theoretical basis for CA treatment to target invasive C. albicans infection. METHODS: Immunosuppressed mice with invasive C. albicans infection were given an oral dosage of CA (240 mg.kg- 1.d- 1) for 14 days. Then, mouse lung tissue samples were collected for detection of the levels of (1,3)-ß-D-glucan and transmission electron microscopy observations, using fluconazole as a positive control and 2% Tween 80 saline as a negative control. RESULTS: The immunosuppressive mouse model of invasive C. albicans infection was successfully established. The levels of (1,3)-ß-D-glucan in the CA treatment group, fluconazole positive control group, invasive C. albicans infection immunosuppressive mouse model group, and 2% Tween 80 normal saline control group were 86.55 ± 126.73 pg/ml, 1985.13 ± 203.56 pg/ml, 5930.57 ± 398.67 pg/ml and 83.36 ± 26.35 pg/ml, respectively. Statistically, the CA treatment group, fluconazole positive control group and invasive C. albicans infection immunosuppressive mouse model group were compared with each other (P < 0.01) and compared with the 2% Tween 80 saline group (P < 0.01), showing that the differences were very significant. Comparison of the CA treatment group with the fluconazole positive control group (P < 0.05) displayed a difference as well. Electron microscopy showed that CA destroyed the cell wall of C. albicans, where the outer layer of the cell wall fell off and became thinner and the nuclei and organelles dissolved, but the cell membrane remained clear and intact. CONCLUSION: CA destroys the cell wall structure of C. albicans by interfering with the synthesis of (1,3)-ß-D-glucan to kill C. albicans. However, CA does not affect the cell membrane. This study provides a theoretical basis for CA treatment to target invasive C. albicans infection.

Effect and Safety of Cinnamaldehyde on Immunosuppressed Mice with Invasive Pulmonary Candidiasis.

OBJECTIVE: To evaluate the effect and safety of cinnamaldehyde on immunosuppressed mice with invasive pulmonary candidiasis. METHODS: An immunosuppressed BALB/c mouse model was established by intraperitoneal administration of cyclophosphamide (200 mg/kg) once daily for 2 days. The immunosuppressed mouse with invasive pulmonary candidiasis model was further established by nasal perfusion of Candida albicans suspension. In the cinnamaldehyde treatment group, immunosuppressed mice with invasive pulmonary candidiasis were orally given cinnamaldehyde 240 mg/(kg·d) for 14 consecutive days. Fluconazole and 0.9% saline were used as the positive and negative controls, respectively. The mice in the cinnamaldehyde safety evaluation group were orally administered cinnamaldehyde 480 mg/(kg·d) for 42 days to observe the safety of the drug. Microscopic identification, fungal culture, histopathological examination, and (1,3)-beta-D-glucans detection were conducted to analyze the effect of cinnamaldehyde on C. albicans. RESULTS: The fungal clearance rate in the cinnamaldehyde treatment group was higher than that in the fluconazole control group (80.00% vs. 56.67%, P<0.05). The level of (1,3)-ß-D-glucan in the cinnamaldehyde treatment group was lower than that in the fluconazole positive control group (1160.62 ±89.65 pg/mL vs. 4285.87 ± 215.62 pg/mL, P<0.05). The survival rate of mice in the cinnamaldehyde safety evaluation group was 100%, and no significant pathological changes of kidney, lung and liver were observed. CONCLUSIONS: Cinnamaldehyde was effective and safe in treating immunosuppressed BALB/c mice with invasive pulmonary candidiasis. It would be a potentially novel drug for anti-candidiasis infection.

Mechanisms, clinically curative effects, and antifungal activities of cinnamon oil and pogostemon oil complex against three species of Candida.

The anti-fungus mechanisms and curative effects of cinnamon oil and pogostemon oil complexes towards intestinal Candida infections were investigated. We measured the minimal inhibitory concentration (MIC) values of the complexes against Candida using proportionally-diluted test-tube medium, and examined the evolution of the morphology and structures of Candida albicans using scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). We found that the average MIC values of the complexes against the fungi were 0.064 mg/mL (cinnamon oil), 0.032 mg/mL (pogostemon oil) for Candida albicans, 0.129 mg/ mL (cinnamon oil), 0.064 mg/mL (pogostemon oil) for Candida tropicalis, and 0.129 mg/mL (cinnamon oil), 0.064 mg/mL (pogostemon oil), for Candida krusei. SEM examination over a 24-48 h period showed that the morphology of Candida albicans cells changed significantly. Irregular hollows appeared on the surfaces, inside organelles were destroyed and the cells burst after treatment. TEM examination over a 48 - 72 h period indicated that the cell walls were damaged, organelles were destroyed and most cytoplasms became empty bubbles. Sixty intestinal Candida-infected patients were treated with a capsule containing cinnamon and pogostemon oil. The curative ratio was 71.67% (43/60), and the improvement ratio was 28.33% (17/ 60), giving a total ratio of 100%. Thus, the cinnamon oil and pogostemon oil complexes had strong anti-fungus effects against Candida albicans, Candida tropicalis, and Candida krusei. They impacted the morphology and sub-micro structures of the fungus within 48 - 72 h, and eventually denatured and killed the cells. The complexes have also shown considerable curative effects to intestinal Candida infections.