The Fungicidal Effect Of Peritoneal Exudates In Rat Model Infected By Candida Albicans

Objectives: To investigate fungicidal activity in peritoneal exudates from abdominal cavity inflammatory fluid of rat infected by Candida albicans (C. albicans). To provide important information for developing new type of antifungus drugs which is different from the traditional fungicidal drugs.Methods: The model of severe abdominal cavity inflammation was prepared by intraperitoneal administration of C. albicans to rats. The peritoneal exudates were collected in the different stage of abdominal cavity inflammation. The present study was carried out as following. 1. The cells collected in the different stage of severe abdominal cavity inflammation were dyed with Giemsa and were observed and identified by microscopy. 2. The protein concentration in peritoneal exudates collected at 12 hour after intraperitoneal administration of C. albicans was determined by ultraviolet spectrophotometry. 3. The peritoneal exudates, supernatant of peritoneal exudation and cells collected form peritoneal exudates were incubated with C. albicans at 37℃for 2 hour, the mixture were plating and incubated at 37℃for 48hr. The fungicidal activity were determined by comparing the CFU in experiment group with that in the control. In the same way, the fungicidal activity of supernatant of peritoneal exudation collected at 12 hour against other fungus such as Candida tropicalis (C. tropicalis) and Candida glabrate(C. glabrate) were determined. 4. Thermal stability of the fungicidal substance in peritoneal exudation supernatant was determined. 5. The mechanism of anti- Candida albicans activity in peritoneal exudation supernatant was preliminarily elucidated. Results: 1.Abundant peritoneal exudates emerge in rat peritoneal after intraperitoneal administration of C. albicans, the peritoneal exudation volume at 12hr after administration was 4950ul. The numbers of cell was (3.53×10~7/ml) of C. albicans of cells in peritoneal exudates in 12hr afer intraperitoneal administration of C. albicans and 5-fold higher than that in control groups. The predominant cell in peritoneal exudates was neutrophilic granulocytes while control group was mast macrophage. 2. The protein concentration (41.75±2.92mg/ml) in peritoneal exudation supernatant was 2-fold higher than that in the control group and the total amount of protein in peritoneal exudation supernatant was 50-fold higher than that in control group. 3. (1) Peritoneal exudates possessed potent fungicidal activity against C. albicans. Peritoneal exudation supernatant and cells in peritoneal exudates possessed similar activity. (2) Peritoneal exudation supernatant killed C. albicans in concentration-dependent way. The peritoneal exudation supernatant collected at 12 hr possessed the most potent fungicidal activity,e.g. the 0.8% peritoneal exudation supernatant could kill 91.23±6.12% of C. albicans. (3) Peritoneal exudation supernatant could also kill C. glabrate and C. tropicalis. 4. The fungicidal activity(97.6±6.31% in 37℃) of 20% peritoneal exudation supernatant collected at 12 hr was dramatically declined to 9.10±2.56% after incubated in 56℃for 10 mins. 5. C. albicans morphology changed gradually and their color turned dark, their thalline was shrinked and their cell wall was degraded after treated by peritoneal exudation supernatant for 40min, C. albicans color turned dark further, the thalline was smaller further,and then was expired due to disruption lastly.Conclusions: The peritoneal exudates from abdominal cavity inflammation rat models infected by C. albicans possess potent fungicidal activity against C. albicans. The supernatant of imflammatory fluid possess a similar fungicidal activity as imflammatory cells. There were not similar reports about fungicidal activity in peritoneal exudates at present. The substance may be one or more protein molecules. Our study provide some important information for developing new type of fungicidal drugs.