Anticandidal effect of cinnamic acid characterized from Cinnamomum cassia bark against the fluconazole resistant strains of Candida

Abstract

Candida spp., causes invasive fungal infections, especially in immune-compromised patients and the propensity of antifungal resistance against azole-based drugs need to be addressed. This study is thus aimed to characterize the anticandidal effect of the cinnamic acid extracted from the barks of Cinnamomum cassia. Five species of Fluconazole-resistant Candida sp. were retrieved from the department repertoire. The extraction of CA was performed by three different methods followed by silica gel column chromatography. Eluant was subjected to FTIR and XRD analysis for confirmation. The anticandidal activity of the CA was checked by the agar disc diffusion method and the MIC and MFC were determined. The anti-biofilm effect of CA was assessed using the CLSM technique followed by the biocompatibility check using MTT assay in normal HGF cell lines. CA was best extracted with the hot maceration method using ethanol with a maximum yield of 6.73 mg. Purification by column chromatography was achieved using benzene, acetic acid, and water (6:7:3) mobile phase. CA was confirmed by FTIR with absorption peaks and by XDR based on strong intensity. CA was found to possess promising anticandidal activity at 8 µg/mL with MIC and MFC values determined as 0.8 µg/mL and 0.08 µg/mL respectively. Antibiofilm activity by CLSM analysis revealed biofilm inhibition and was biocompatible at 8.5 µg/ml concentrations in HGF cell lines until 24 h. The study findings conclude that CA is the best alternative to treat candidal infection warranting further experimental preclinical studies.

Keywords: C. Cassia; Candida; Antifungal; Biocompatible; Cinnamic acid; Health.

Fig. 1

Fourier Transform Infrared (FTIR) spectrum illustrating the chemical structures of cinnamic acid isolated from C. cassia bark, showing the distinctive functional groups and molecular structures

Fig. 2

X-ray diffraction (XRD) spectrum depicting the crystalline structure of purified cinnamic acid, providing insights into its molecular arrangement and characteristics

Fig. 3

Evaluation of the anticandidal activity of cinnamic acid using the agar disk diffusion method against various Candida species: A C. albicans, B C. glabrata, C C. tropicalis, D C. krusei, E C. parapsilosis

Fig. 4

Determination of the Minimum Inhibitory Concentration (MIC) of cinnamic acid extracted from C. cassia against the Candida species under study based on the percentage of growth inhibition

Fig. 5

Assessment of cell viability in normal human gingival fibroblast cells at increasing concentrations of cinnamic acid, showing high biocompatibility with least cytotoxicity

Fig. 6

Determination of time period showing maximum biofilm formation at day 3 by C. albicans, C. glabrata, C. tropicalis, C. krusei, and C. parapsilosis

Fig. 7

Confocal Laser Scanning Microscopy (CLSM) images of the control and CA treated tooth samples (biofilm models). Channel 1 (ch1) displays live cells, Channel 2 (ch2) shows dead cells, and the combined image illustrates both live and dead cells