Anticancer effect of resibufogenin on gastric carcinoma cells through the phosphoinositide 3-kinase/protein kinase B/glycogen synthase kinase 3β signaling pathway

Resibufogenin: An Emerging Therapeutic Compound with Multifaceted Pharmacological Effects - A Comprehensive Review

Resibufogenin (RBG), a significant bufadienolide compound found in the traditional Chinese medicine Chansu, has garnered increasing attention in recent years for its wide range of pharmacological effects. This compound has shown promising potential in various therapeutic areas, including oncology, cardiology, and respiratory medicine. Among its notable properties, the anticancer effects of RBG are particularly striking, positioning it as a potential candidate for innovative cancer treatments. The mechanism of action of RBG is diverse, impacting various cellular processes. Its anticancer efficacy has been observed in different types of cancer cells, where it induces apoptosis and inhibits cell proliferation. Beyond its oncological applications, RBG also demonstrates substantial anti-inflammatory and antiviral activities. These properties suggest its utility in managing chronic inflammatory disorders and viral infections, respectively. The compound's cardiotonic effects are also noteworthy, providing potential benefits in cardiovascular health, particularly in heart failure management. Additionally, RBG has shown effectiveness in blood pressure regulation and respiratory function improvement, making it a versatile agent in the treatment of hypertension and respiratory disorders. However, despite these promising aspects, systematic reviews focusing specifically on RBG are limited. This article aims to address this gap by comprehensively reviewing RBG's origin, physiological, and pharmacological effects. The review will serve as a crucial reference for clinicians and researchers interested in the therapeutic applications of RBG, highlighting its potential in various medical domains. By synthesizing current research findings, this review will facilitate a deeper understanding of RBG's role in medicine and encourage further investigation into its clinical uses.

Identification of resibufogenin, a component of toad venom, as a novel senolytic compound in vitro and for potential skin rejuvenation in male mice

Senescent cells that accumulate with age have been shown to contribute to age-related diseases and organ dysfunction and have attracted attention as a target for anti-aging therapy. In particular, the use of senescent cell-depleting agents, or senolytics, has been shown to improve the aging phenotype in animal models. Since senescence has been implicated in the skin, particularly in fibroblasts, this study used aged human skin fibroblasts to investigate the effects of resibufogenin. A component of the traditional Chinese medicine toad venom, resibufogenin was investigated for senolytic and/or senomorphic activity. We found that the compound selectively caused senescent cell death without affecting proliferating cells, with a marked effect on the suppression of the senescence-associated secretory phenotype. We also found that resibufogenin causes senescent cell death by inducing a caspase-3-mediated apoptotic program. Administration of resibufogenin to aging mice resulted in an increase in dermal collagen density and subcutaneous fat, improving the phenotype of aging skin. In other words, resibufogenin ameliorates skin aging through selective induction of senescent cell apoptosis without affecting non-aged cells. This traditional compound may have potential therapeutic benefits in skin aging characterized by senescent cell accumulation.

Induction of apoptosis, oxidative stress, hormonal, and histological alterations in the reproductive system of thiamethoxam-exposed female rats

The present study aimed to investigate the oral toxic effects of 1/10 LD50 and 1/5 LD50 of thiamethoxam (TMX), a neonicotinoid insecticide, on the reproductive system of female Wistar rats. Thirty female rats were divided into three groups and supplied orally with either; saline solution, 1/10 LD50 of TMX (156 mg/kg) or 1/5 LD50 of TMX (312 mg/kg). The daily administration was extended for 30 days. Investigating the parameters of oxidative stress, hormonal levels, histopathological alterations, and the apoptotic markers (P53, BAX, BCL-2, and caspase-3) was performed in the uterus and ovary of rats. Results showed significant changes in the body weight gain, and relative weight of the left and right ovaries and uterus. Moreover, luteinizing hormone (LH), estradiol (ED), and progesterone (PG) serum levels were not significantly altered following TMX oral administration. The level of follicle-stimulating hormone in the TMX-exposed group (156 mg/kg) was significantly increased; however, a significant decrease was observed in TMX-exposed animals (312 mg/kg). TMX induced significant oxidative stress in exposed groups by reducing the activities of superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT), and elevating malondialdehyde (MDA) levels. Following hematoxylin and eosin staining, the microscopic examination revealed deteriorated luteal cells with vacuolation in the corpus luteum, a follicle containing a degenerated oocyte and degeneration/necrosis of the circular muscle layer with a high rate of apoptotic cells in TMX-exposed animals. TMX induced transcriptional alterations in apoptosis-related genes shifting towards the activation of the intrinsic apoptotic pathway. Collectively, results suggest the toxic effect of the TMX on the reproductive health of female Wistar rats.

Chemistry and the Potential Antiviral, Anticancer, and Anti-Inflammatory Activities of Cardiotonic Steroids Derived from Toads

Cardiotonic steroids (CTS) were first documented by ancient Egyptians more than 3000 years ago. Cardiotonic steroids are a group of steroid hormones that circulate in the blood of amphibians and toads and can also be extracted from natural products such as plants, herbs, and marines. It is well known that cardiotonic steroids reveal effects against congestive heart failure and atrial fibrillation; therefore, the term "cardiotonic" has been coined. Cardiotonic steroids are divided into two distinct groups: cardenolides (plant-derived) and bufadienolides (mainly of animal origin). Cardenolides have an unsaturated five-membered lactone ring attached to the steroid nucleus at position 17; bufadienolides have a doubly unsaturated six-membered lactone ring. Cancer is a leading cause of mortality in humans all over the world. In 2040, the global cancer load is expected to be 28.4 million cases, which would be a 47% increase from 2020. Moreover, viruses and inflammations also have a very nebative impact on human health and lead to mortality. In the current review, we focus on the chemistry, antiviral and anti-cancer activities of cardiotonic steroids from the naturally derived (toads) venom to combat these chronic devastating health problems. The databases of different research engines (Google Scholar, PubMed, Science Direct, and Sci-Finder) were screened using different combinations of the following terms: “cardiotonic steroids”, “anti-inflammatory”, “antiviral”, “anticancer”, “toad venom”, “bufadienolides”, and “poison chemical composition”. Various cardiotonic steroids were isolated from diverse toad species and exhibited superior anti-inflammatory, anticancer, and antiviral activities in in vivo and in vitro models such as marinobufagenin, gammabufotalin, resibufogenin, and bufalin. These steroids are especially difficult to identify. However, several compounds and their bioactivities were identified by using different molecular and biotechnological techniques. Biotechnology is a new tool to fully or partially generate upscaled quantities of natural products, which are otherwise only available at trace amounts in organisms.

Resibufogenin inhibits the malignant characteristics of multiple myeloma cells by blocking the PI3K/Akt signaling pathway

Resibufogenin (RBG) is an active ingredient of toad venom that also has antitumor potential. The present study aimed to investigate the role of RBG in multiple myeloma (MM) and the underlying action mechanism involving the PI3K/Akt signaling pathway. A human MM cell line, RPMI8226, was treated with RBG and/or insulin-like growth factor 1 (IGF-1; an activator of the PI3K/AKT signaling pathway). Cell viability and apoptosis were detected using Cell Counting Kit-8 and flow cytometry, respectively. Cell migration and invasion were detected using a Transwell assay. In addition, the epithelial-mesenchymal transition (EMT)-associated proteins (E-cadherin, N-cadherin and Vimentin) and the PI3K/AKT pathway-associated proteins [AKT, phosphorylated (p)-AKT, PI3K and p-PI3K] were measured using western blotting. RBG inhibited the viability, migration and invasion, and promoted the apoptosis of RPMI8226 cells in a dose-dependent manner. RBG at concentrations of 4 and 8 µM upregulated E-cadherin, and downregulated N-cadherin and Vimentin in RPMI8226 cells. RBG also decreased the protein expression of p-AKT and p-PI3K in a dose-dependent manner. In addition, the intervention of IGF-1 weakened the inhibitory effects of RBG on the malignant characteristics of MM cells. RBG-induced inhibition of EMT and the PI3K/AKT pathway were also weakened by IGF-1 treatment. In conclusion, RBG inhibited viability, migration, invasion and EMT, and promoted the apoptosis of MM cells by blocking the PI3K/AKT signaling pathway.

Chromogranin A regulates neuroblastoma proliferation and phenotype

Neuroblastoma is a commonly encountered solid tumor in early childhood with high neuroplasticity, and differentiation therapy is hypothesized to lead to tumor mass shrinkage and/or symptom relief. CgA is a tissue specific protein restricted to the diffuse neuroendocrine system, and widely expressed in neuroblastomas. Using knockdown and knockout approaches to deplete CgA levels, we demonstrated that CgA loss inhibits SH-SY5Y cell proliferation and leads to a morphological shift with increased expression of Schwann and extracellular matrix specific molecules, and suppression of chromaffin features. We further confirmed the effects of CgA in a series of neuroblastoma cells with [BE(2)-M17 and IMR-32] and without (SK-N-SH) N-Myc amplification. We demonstrated that CgA depletion reduced IGF-II and IGFBP-2 expression, increased IGFBP-3 levels, and suppresses IGF downstream signaling as evidenced by reduced AKT/ERK pathway activation. This was further supported by an increased anti-proliferative effect of the ERK inhibitor in the CgA depleted cells. In an in vivo xenograft neuroblastoma model, CgA knockdown led to increased S-phenotypic marker expression at both protein and mRNA levels. Together these results suggest that CgA maintains IGF secretion and intracellular signaling to regulate proliferation and differentiation in neuroblastomas.