High-Throughput Metabolomics for Identification of Metabolic Pathways and Deciphering the Effect Mechanism of Dioscin on Rectal Cancer From Cell Metabolic Profiles Coupled With Chemometrics Analysis

Plant Metabolomics: The Future of Anticancer Drug Discovery

Drug development from medicinal plants constitutes an important strategy for finding natural anticancer therapies. While several plant secondary metabolites with potential antitumor activities have been identified, well-defined mechanisms of action remained uncovered. In fact, studies of medicinal plants have often focused on the genome, transcriptome, and proteome, dismissing the relevance of the metabolome for discovering effective plant-based drugs. Metabolomics has gained huge interest in cancer research as it facilitates the identification of potential anticancer metabolites and uncovers the metabolomic alterations that occur in cancer cells in response to treatment. This holds great promise for investigating the mode of action of target metabolites. Although metabolomics has made significant contributions to drug discovery, research in this area is still ongoing. In this review, we emphasize the significance of plant metabolomics in anticancer research, which continues to be a potential technique for the development of anticancer drugs in spite of all the challenges encountered. As well, we provide insights into the essential elements required for performing effective metabolomics analyses.

Steroidal Saponins: Naturally Occurring Compounds as Inhibitors of the Hallmarks of Cancer

Cancer is a global health burden responsible for an exponentially growing number of incidences and mortalities, regardless of the significant advances in its treatment. The identification of the hallmarks of cancer is a major milestone in understanding the mechanisms that drive cancer initiation, development, and progression. In the past, the hallmarks of cancer have been targeted to effectively treat various types of cancers. These conventional cancer drugs have shown significant therapeutic efficacy but continue to impose unfavorable side effects on patients. Naturally derived compounds are being tested in the search for alternative anti-cancer drugs. Steroidal saponins are a group of naturally occurring compounds that primarily exist as secondary metabolites in plant species. Recent studies have suggested that steroidal saponins possess significant anti-cancer capabilities. This review aims to summarize the recent findings on steroidal saponins as inhibitors of the hallmarks of cancer and covers key studies published between the years 2014 and 2024. It is reported that steroidal saponins effectively inhibit the hallmarks of cancer, but poor bioavailability and insufficient preclinical studies limit their utilization.

A host-specific diaminobutyrate aminotransferase contributes to symbiotic performance, homoserine metabolism, and competitiveness in the Rhizobium leguminosarum/Pisum sativum system

Rhizobium leguminosarum bv. viciae (Rlv) UPM791 effectively nodulates pea and lentil, but bacteroids contain a number of proteins differentially expressed depending on the host. One of these host-dependent proteins (C189) is similar to a diaminobutyrate-2-oxoglutarate aminotransferase (DABA-AT). DABA-AT activity was demonstrated with cell extracts and with purified protein, so C189 was renamed as Dat. The dat gene was strongly induced in the central, active area of pea nodules, but not in lentil. Mutants defective in dat were impaired in symbiotic performance with pea plants, exhibiting reduced shoot dry weight, smaller nodules, and a lower competitiveness for nodulation. In contrast, there were no significant differences between mutant and wild-type in symbiosis with lentil plants. A comparative metabolomic approach using cell-free extracts from bacteroids induced in pea and lentil showed significant differences among the strains in pea bacteroids whereas no significant differences were found in lentil. Targeted metabolomic analysis revealed that the dat mutation abolished the presence of 2,4-diaminobutyrate (DABA) in pea nodules, indicating that DABA-AT reaction is oriented toward the production of DABA from L-aspartate semialdehyde. This analysis also showed the presence of L-homoserine, a likely source of aspartate semialdehyde, in pea bacteroids but not in those induced in lentil. The dat mutant showed impaired growth when cells were grown with L-homoserine as nitrogen source. Inclusion of DABA or L-homoserine as N source suppressed pantothenate auxotropy in Rlv UPM791, suggesting DABA as source of the pantothenate precursor β-alanine. These data indicate that Rlv UPM791 Dat enzyme is part of an adaptation mechanism of this bacterium to a homoserine-rich environment such as pea nodule and rhizosphere.

Dioscin ameliorates cisplatin-induced intestinal toxicity by mitigating oxidative stress and inflammation

Cisplatin is the most widely prescribed drug in chemotherapy, but its gastrointestinal toxicity reduces therapeutic efficacy. Oxidative stress and inflammation are considered to be the main pathogenesis of cisplatin-induced intestinal toxicity. Dioscin is a steroidal saponin with potential anti-cancer, antioxidant, and anti-inflammatory activities. In this study, we established a rat model of intestinal injury by tail vein injection of cisplatin, and intragastrically administered dioscin to evaluate its effect on intestinal injury. Biochemical markers, western blotting, qRT-PCR and histopathological staining were used to analyze intestinal injury according to various molecular mechanisms. The results revealed that dioscin significantly inhibited cisplatin-induced intestinal mucosal damage and decreased DAO levels in rats. Furthermore, dioscin activated the Nrf2/HO-1 pathway to increase the level of antioxidant enzymes and reduce the levels of MDA and H₂O₂. In addition, dioscin pretreatment significantly reduced ileum epithelial NLRP3 inflammasome formation and decreased the levels of inflammatory factors compared with the cisplatin group. In parallel, Nrf2 inhibitor ML385 blocked the therapeutic effect of dioscin in rat with cisplatin-induced intestinal toxicity. In terms of mechanisms, dioscin reversed cisplatin-induced up-regulation of MAPKs and up-regulated p-PI3K and p-AKT levels. Meanwhile, dioscin potently promoted Wnt3A/β-catenin signaling to relieve cisplatin-induced proliferation inhibition. In conclusion, our study suggests that dioscin could ameliorate the cisplatin-induced intestinal toxicity by reducing oxidative stress and inflammation.

Natural saponin and cholesterol assembled nanostructures as the promising delivery method for saponin

The application of saponins has been restricted by problems such as hemolysis, low bioavailability, and poor solubility. So it is imperative to find a strategy to deliver saponins safely and efficiently. Here, through bottom-up technique, we design and prepare two saponin-cholesterol (Cho) nano-complex: dioscin (Dio, steroid saponin)-Cho nanofibers (NFs) and escin Ia (EIa, triterpene saponin)-Cho nanoparticles (NPs). It is found that the hydrophobic force and hydrogen bonding drive the two pairs of molecules to bind in different directions (the 3β-OH of Cho face the sugar chain of EIa and the 22α-O of Dio, respectively) and finally show spherical NPs (EIa-Cho) and fibrous NFs (Dio-Cho). The equimolar saponin-Cho complex, Dio NFs and EIa NPs, reveal potent cytotoxicities against mouse breast cancer cells (4T1) in vitro. In vivo results confirm the antitumor (4T1 mice model) efficacy of PEGylation Dio NFs (10 mg/kg, i.v.) with a tumor inhibition rate of 61%, meanwhile, it does not cause extreme irritation and pain as free Dio does to mice. Moreover, compared with the free drug, the prepared nano-complex can significantly reduce hemolysis and organ toxicity. Our research reduces the toxicity of saponins while retaining their antitumor activity, providing a new strategy for the delivery of saponins.

Dioscin Alleviates Cardiac Dysfunction in Acute Myocardial Infarction via Rescuing Mitochondrial Malfunction

Myocardial infarction is one of the most severe heart diseases, leading to sudden death. Currently, angiography and stenting are widely performed in clinics, yet more effective treatment is still needed. Herein, we presented that dioscin, a natural product, showed protective effect on infarcted hearts via mitochondrial maintenance. Upon dioscin treatment, cardiac dysfunction was alleviated, and remodeling is prevented. Mechanistically, disocin maintains mitochondria function through the maintenance of Kreb's cycle, and suppresion of ROS accumulation. In this way, by targeting mitochondrial dysfunction, dioscin is a potential drug for infarcted hearts.

Unravelling the Anticancer Mechanisms of Traditional Herbal Medicines with Metabolomics

Metabolite profiling of cancer cells presents many opportunities for anticancer drug discovery. The Chinese, Indian, and African flora, in particular, offers a diverse source of anticancer therapeutics as documented in traditional folklores. In-depth scientific information relating to mechanisms of action, quality control, and safety profile will promote their extensive usage in cancer therapy. Metabolomics may be a more holistic strategy to gain valuable insights into the anticancer mechanisms of action of plants but this has remained largely unexplored. This review, therefore, presents the available metabolomics studies on the anticancer effects of herbal medicines commonly used in Africa and Asia. In addition, we present some scientifically understudied ‘candidate plants’ for cancer metabolomics studies and highlight the relevance of metabolomics in addressing other challenges facing the drug development of anticancer herbs. Finally, we discussed the challenges of using metabolomics to uncover the underlying mechanisms of potential anticancer herbs and the progress made in this regard.