Physalin F is a natural blocker of CaV2.3 (R-type) and CaV2.2 (N-type) voltage-gated calcium channels.It is a secosteroid with potent anti-inflammatory and immunomodulatory activities. Physalin F induces apoptosis of PBMC, decreasing the spontaneous proliferation and cytokine production caused by Human T-lymphotropic virus type 1 (HTLV-1) infection

METHODS: Three renal cancer cell lines (A498, ACHN, and UO-31) were treated with physalin F (0, 0.3, 1, 3, and 10 μg/mL, 24 h), and cell viability was determined by MTT assay.
RESULTS Physalin F inhibited cell viability in human renal cancer cell lines A498, ACHN, and UO-31 in a concentration-dependent manner with IC50 values ​​of 1.40 μg/mL, 2.18 μg/mL, and 2.81 μg/mL, respectively. [3]
METHODS: A498 cells were incubated in the absence or presence of physalin F (10 μg/mL, 6, 12, 18, 24 hours) for the indicated time, and the cells were harvested and prepared for detection of (A) mitochondrial membrane potential using FACScan analysis; A498 cells were incubated in the presence of physalin F (10 μg/mL, 3, 6, 8, 12, 18, 24 hours) for the indicated time, and the cells were harvested and prepared for detection of pro-caspase-8, 9, caspase-3, PARP, and p53, p21 expression using Western blotting.
RESULTS The expression of Bcl-2 protein family including Bcl-2 and Bcl-xL was decreased after treatment with physalin F, and physalin F induced apoptosis of A498 cells through a mitochondria-dependent pathway; physalin F induced apoptosis by inducing p53 and p21 proteins, followed by cleavage of caspase-8/-9/-3 and PARP. [3]

Physalin F is a secosteroid with potent anti-inflammatory and immunomodulatory activities.?A concentration-dependent inhibition of spontaneous proliferation of PBMC from HAM/TSP subjects was observed in the presence of physalin F, as evaluated by (3)H-thymidine uptake.?The IC50 for physalin F was 0.97 0.11 μM.?Flow cytometry analysis using Cytometric Bead Array (CBA) showed that physalin F (10 μM) significantly reduced the levels of IL-2, IL-6, IL-10, TNF-α and IFN-γ, but not IL-17A, in supernatants of PBMC cultures.?Next, apoptosis induction was addressed by using flow cytometry to evaluate annexin V expression.?Treatment with physalin F (10 μM) increased the apoptotic population of PBMC in HAM/TSP subjects.?Transmission electron microscopy analysis of PBMC showed that physalin F induced ultrastructural changes, such as pyknotic nuclei, damaged mitochondria, enhanced autophagic vacuole formation, and the presence of myelin-like figures.?In conclusion, physalin F induces apoptosis of PBMC, decreasing the spontaneous proliferation and cytokine production caused by HTLV-1 infection.