Vitamin C Inhibits Lipopolysaccharide-Induced Hyperinflammatory State of Chronic Myeloid Leukemia Cells through Purinergic Signaling and Autophagy.

Background: Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the overproduction of white blood cells, leading to symptoms such as fatigue, infections, and other complications. CML patients must take measures to prevent infections to mitigate the exacerbation of cancer cell proliferation and comorbidities. Methods: This study investigated whether vitamin C can suppress the hyperinflammatory activation of K-562 cells induced by lipopolysaccharide (LPS) and whether purinergic signaling (ATP and P2X7 receptor) and autophagy play a role in it. Two different doses of vitamin C (5 µg/mL and 10 µg/mL) were employed, along with the lysosome inhibitor chloroquine (CQ; 100 µM), administered 2 h prior to LPS stimulation (10 ng/mL) for a duration of 22 h in K-562 cells (3 × 105 cells/mL/well). Results: Both doses of vitamin C reduced the release of interleukin-6 (IL-6) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) and tumor necrosis factor (TNF) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) induced by LPS. Furthermore, in LPS + CQ-stimulated cells, vitamin C at a concentration of 10 µg/mL inhibited the expression of LC3-II (p < 0.05). Conversely, both doses of vitamin C led to the release of the anti-inflammatory cytokine interleukin-10 (IL-10) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01), while only the 10 µg/mL dose of vitamin C induced the release of Klotho (10 µg/mL, p < 0.01). In addition, both doses of vitamin C reduced the accumulation of ATP (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) and decreased the expression of the P2X7 receptor at the mRNA level. Conclusions: Vitamin C inhibits the hyperinflammatory state induced by LPS in K-562 cells, primarily by inhibiting the ATP accumulation, P2X7 receptor expression, and autophagy signaling.

Rosmarinus officinalis L. (rosemary) extract has antibiofilm effect similar to the antifungal nystatin on Candida samples.

Candida spp. are naturally opportunistic and can promote infections. These yeasts can form biofilm, after penetration and adhesion to the biotic or abiotic surfaces. Preexisting diseases, treatments with drugs and radiation therapy, medical procedures, and parafunctional habits favor the installation of a fungal infection. Increased resistance to the available antifungals has become a concern. Therefore, alternative methods to control them have been evaluated, including the use of plant substances. In this study, the antibiofilm effect of R. officinalis L. extract was analyzed on C. albicans, C. dubliniensis, C. glabrata, C. krusei, and C. tropicalis. A phytochemical analysis of the extract was performed. Biofilms were formed for 48 h and exposed to the different concentrations of the extract (50, 100, and 200 mg/mL) for 5 min or 24 h. The effect of the plant extract was compared to the antifungal nystatin. Rosmarinus officinalis L. extract was constituted of phenols and flavonoids, highlighting the presence of chlorogenic acid derivatives in its composition. Biofilm reductions were observed after exposure to the plant extract for both periods. The plant extract provided a reduction similar to the antifungal. Thus, R. officinalis L. extract showed antibiofilm effect on Candida spp. comparable to the nystatin.