Search

The pathophysiology of chemotherapy-associated anemia, prevalent in at least 75% of patients, remains difficult to establish. Chemotherapy-related anemia is attributed in part to eryptosis, and it is therefore of considerable interest to interrogate the toxicity of investigative anticancer compounds to red blood cells (RBCs). Beta-lapachone (LAP), an anthraquinone extracted from the bark of Lapacho tree (Tabebuia avellanedae), is effective against a myriad of cancer cells. However, the toxicity of LAP to RBCs remains unexplored. Hemoglobin leakage as a surrogate for hemolysis was photometrically measured, while flow cytometry was employed to capture phosphatidylserine (PS) exposure with Annexin-V- FITC, calcium levels with Fluo4/AM, cell size by forward scatter (FSC), and oxidative stress by H2DCFDA. Our results show that LAP, at antitumor levels (10-30 μM), induces dose-dependent hemolysis secondary to calcium influx from the extracellular space. Moreover, LAP stimulates eryptosis, as evident from PS exposure, which is associated with reduced cell volume and intracellular calcium overload. Importantly, it is also revealed that the cytotoxicity of LAP is mediated through casein kinase 1α. Altogether, this report shows, for the first time, that LAP possesses both hemolytic and eryptotic potential against RBCs that necessitates careful application in chemotherapy. Practical applications: Lapacho is a widely consumed herbal tea with origins in the Tabebuia avellanedae tree endogenous to South America. LAP is one of the active ingredients in lapacho with promising antitumor potential. We show that LAP is cytotoxic to human RBCs by virtue of eryptosis and hemolysis, and we identify associated molecular mechanisms. Given that these two manifestations are known to contribute to chemotherapy-induced anemia, our study provides invaluable insights into the suitability of LAP in cancer management and sheds some light on possible strategies to limit its undesirable side effects. [ABSTRACT FROM AUTHOR]

β-Lapachone (β-lap, 1), an ortho -naphthoquinone natural product isolated from the lapacho tree (Tabebuia avellanedae) in many regions of South America, has received extensive attention due to various pharmacological activities, such as antitumor, anti- Trypanosoma cruzi , anti- Mycobacterium tuberculosis , antibacterial, and antimalarial activities. Related mechanisms of β-lap have been widely investigated for a full understanding of its therapeutic potentials. Numerous derivatives of β-lap have been reported with aims to generate new chemical entities, improve the corresponding biological potency, and overcome disadvantages of its physical and chemical properties and safety profiles. This review will give insight into the pharmacological mechanisms of β-lap and provide a comprehensive understanding of its structural modifications with regard to different therapeutic potentials. The available clinical trials related to β-lap and its derivatives are also summarized. Image 1 • Pharmacological mechanisms of β-lapachone are included. • Various modification strategies toward β-lapachone are provided. • Numerous derivatives of β-lapachone are reviewed and classified. • Derivatives undergoing clinical evaluation are summarized. [ABSTRACT FROM AUTHOR]