Discovery of Polyoxypregnane Derivatives From Aspidopterys obcordata With Their Potential Antitumor Activity

The bioassay-guided phytochemical study of an ethnic medicinal plant Aspidopterys obcorda ta Hemsl. var. obcordata results in the isolation of eight new polyoxypregnane derivatives, named aspidatasides A–H (1–8), along with ten known analogs (9–18). The series polyoxypregnane derivatives were screened for their cytoxic activity against HL-60 cells, and compound 2 showed the highest potency with an IC50 8.03 μM. Preliminary structure–activity relationship studies displayed that the sugar chain and double bond could notably impact their biological activity.

The Potential Mechanisms by which Artemisinin and Its Derivatives Induce Ferroptosis in the Treatment of Cancer

Artemisinin (ART) is a bioactive molecule derived from the Chinese medicinal plant Artemisia annua (Asteraceae). ART and artemisinin derivatives (ARTs) have been effectively used for antimalaria treatment. The structure of ART is composed of a sesquiterpene lactone, including a peroxide internal bridge that is essential for its activity. In addition to their well-known antimalarial effects, ARTs have been shown recently to resist a wide range of tumors. The antineoplastic mechanisms of ART mainly include cell cycle inhibition, inhibition of tumor angiogenesis, DNA damage, and ferroptosis. In particular, ferroptosis is a novel nonapoptotic type of programmed cell death. However, the antitumor mechanisms of ARTs by regulating ferroptosis remain unclear. Through this review, we focus on the potential antitumor function of ARTs by acting on ferroptosis, including the regulation of iron metabolism, generation of reactive oxygen species (ROS), and activation of endoplasmic reticulum stress (ERS). This article systematically reviews the recent progress in ferroptosis research and provides a basis for ARTs as an anticancer drug in clinical practice.

Impact of Diabetes and Metformin Use on Enteropancreatic Neuroendocrine Tumors: Post Hoc Analysis of the CLARINET Study

The prognostic role of diabetes mellitus (DM) in advanced enteropancreatic neuroendocrine tumors (NETs) is unclear. Progression free survival (PFS) was assessed in post-hoc analyses of the 96-week, phase III, double-blind, placebo-controlled CLARINET study of lanreotide 120 mg in patients with advanced non-functional enteropancreatic NETs with DM (with/without metformin) and without DM. Of 204 patients, there were 79 with DM (lanreotide, n = 42 {metformin, n = 14}; placebo, n = 37 {metformin, n = 10}) and 125 without DM (lanreotide, n = 59; placebo, n = 66). Median PFS was 96.0 and 98.0 weeks with and without DM, respectively (hazard ratio 1.20 {95% confidence interval 0.79 to 1.82}; p = 0.380). No difference in PFS was observed in lanreotide-treated patients with/without DM (p = 0.8476). In the placebo group, median PFS was numerically shorter with versus without DM (p = 0.052) and was significantly longer in patients with DM and metformin (85.7 weeks) versus without metformin (38.7 weeks; p = 0.009). Multivariable Cox analyses showed that DM at baseline was not associated with PFS (p = 0.079); lanreotide was significantly associated with lower disease progression risk (p = 0.017). Lanreotide efficacy was confirmed in patients with advanced enteropancreatic NETs, regardless of diabetic status; DM was not a negative prognostic factor. A potential antitumor effect of metformin was observed in patients receiving placebo.

Cytotoxic Potential of Industrial Hemp Extracts

Industrial hemp (Cannabis sativa L.) is a source of fibers, oil and valuable secondary metabolites. Regarding phenolic compounds, it has to be noted that the plant biosynthesizes molecules with various pharmacological benefits. The aim of this study was to prove the cytotoxic potential of hemp polar and non-polar fractions against two cancer cell lines (BT-20 and U87). The study revealed the potential antitumor activity of industrial hemp selective fractions but a correlation between polyphenols content and the cytotoxic effect could not be established.

Identification of Spiro-Fused Pyrrolo[3,4-a]pyrrolizines and Tryptanthrines as Potential Antitumor Agents: Synthesis and In Vitro Evaluation

A series of heterocyclic compounds containing a spiro-fused pyrrolo[3,4-a]pyrrolizine and tryptanthrin framework have been synthesized and studied as potential antitumor agents. Cytotoxicity of products was screened against human erythroleukemia (K562) and human cervical carcinoma (HeLa) cell lines. Among the screened compounds. 4a, 4b and 5a were active against human erythroleukemia (K562) cell line, while 4a and 5a were active against cervical carcinoma (HeLa) cell line. In agreement with the DNA cytometry studies, the tested compounds have achieved significant cell-cycle perturbation with higher accumulation of cells in G2/M phase and induced apoptosis. Using confocal microscopy, we found that with 4a and 5a treatment of HeLa cells, actin filaments disappeared, and granular actin was distributed diffusely in the cytoplasm in 76–91% of cells. We discovered that HeLa cells after treatment with compounds 4a and 5a significantly reduced the number of cells with filopodium-like membrane protrusions (from 63 % in control cells to 29% after treatment) and a decrease in cell motility.