UMNSAH/DF-1

Enrofloxacin Induces Apoptosis and Reduces Viability of UMNSAH/DF-1 Cells

Enrofloxacin belongs to the fluoroquinolone category and has been used to treat bacterial infections in poultry since 1989. Current findings indicate that enrofloxacin potentially triggers apoptosis in multiple eukaryotic cell types which raises safety issues. Grabowski et al. examined its apoptotic effects on UMNSAH/DF-1 chicken cells, exploring the mitochondrial pathway as a potential mechanism. Methods include assessing changes in mitochondrial morphology, apoptosome formation, and caspase activation.

Researchers measured UMNSAH/DF-1, HEK-293, and PC3 cell viability using the MTT assay after treating them with enrofloxacin concentrations ranging from 2.5 to 40 µg/mL over time periods of 24 to 72 hours while comparing results to 10% DMSO (positive control) and medium (negative control). The experimental findings demonstrated that metabolic activity decreased over time in each tested cell line (Fig. 1). Further analysis with Annexin V and Dead Cell Assay at 10 µg/mL enrofloxacin showed increased apoptosis over time only in UMNSAH/DF-1 cells (Fig. 2A), corresponding to a typical veterinary dose for poultry. No significant apoptosis was noted in HEK-293 and PC3 lines, which retained a high number of live cells (Fig. 2B-C).

Fig. 1. Effects of enrofloxacin on viability of UMNSAH/DF-1 (panel A), HEK (panel B), and PC3 (panel C) cells after 24 h, 48 and 72 h of incubation, as assessed by the MTT test (Grabowski Ł, Choszcz M, et al., 2024)

Fig. 2. Fractions of live, early-apoptotic, late-apoptotic and dead cells of the UMNSAH/DF-1 (panel A), HEK (panel B), and PC3 (panel C) cells after incubation in DMEM medium (negative control), DMEM with enrofloxacin (10 µg/mL), and DMEM with 10% DMSO (positive control) for 24 h, 48 h, 72 h (Grabowski Ł, Choszcz M, et al., 2024).

PGPSt Alleviated Cr(VI)-Induced Mitochondrial Damage of DF-1 Cells

The heavy metal hexavalent chromium (Cr(VI)) has been acknowledged as a human carcinogen and both short-term and long-term exposure results in damage to organs. The compound PGPS originates from the Chinese herb Platycodon grandiflorus and displays multiple pharmacological properties. Therefore, Zhang's team investigated the role of PGPSt in Cr(VI)-induced apoptosis in chicken embryo fibroblast cell lines (DF-1 cells).

The roles of PGPSt in decreasing Cr(VI)-induced apoptosis in DF-1 cells were determined by analyzing oxidative stress and mitochondrial damage levels. The DF-1 cells underwent pretreatment with 150 μM Cr(VI) for a duration of 8 hours. Western blotting was used to examine Drp1 protein which plays an essential role in mitochondrial fission. As shown in Figure 3A, Drp1 expression increased significantly in the Cr(VI) group, indicating mitochondrial division. PGPSt treatment reduced Drp1 levels compared to the Cr(VI) group. Additionally, ROS, which activates Drp1, was measured. Figure 3B shows a significant ROS increase in the Cr(VI) group, reduced by PGPSt. MMP, an indicator of mitochondrial health, decreased in the Cr(VI) group but improved with PGPSt (Fig. 3C). These findings suggest Cr(VI) induces mitochondrial damage, while PGPSt mitigates it.

Fig. 3. PGPSt alleviated Cr(VI)-induced mitochondrial damage (Zhang Z, Zheng P, et al., 2022).