Mogrosides regulate tumor metabolism and immune response, revealing dual anticancer mechanism

The monk fruit, a small green gourd native to the mountainous forests of Guangxi province in southern China, has been prized in traditional medicine for centuries and has more recently achieved global recognition as a natural zero-calorie sweetener. But the compounds responsible for its extraordinary sweetness—mogrosides, which are estimated to be hundreds of times more potent than sucrose—may possess biological properties that extend far beyond the palate. A newly published comprehensive review in the journal Cancer Immunology, Immunotherapy presents mechanistic evidence that mogrosides could simultaneously disrupt two interconnected pillars of cancer biology: the metabolic reprogramming that allows tumor cells to proliferate relentlessly, and the immune evasion strategies that shield malignant cells from immunological destruction. Led by Meghna Patial and Dhruv Kumar at the University of Petroleum and Energy Studies in Dehradun, India, alongside collaborators from CSIR-Institute of Himalayan Bioresource Technology, the Forest Research Institute, and Aalto University in Finland, the authors argue that these natural triterpene glycosides deserve serious consideration as multifunctional adjuvant candidates in oncology, capable of targeting both the metabolic and immunological vulnerabilities that define the tumor microenvironment.

Mogrosides belong to a class of molecules known as cucurbitane-type triterpene glycosides, with mogroside V constituting the predominant variant found in the fruit of Siraitia grosvenorii. These compounds have attracted enormous commercial interest as sugar substitutes for individuals managing diabetes, obesity, or metabolic syndrome, given their negligible caloric contribution and minimal impact on blood glucose concentrations. Regulatory agencies including the United States Food and Drug Administration have classified monk fruit extracts as generally recognized as safe, and an acceptable daily intake has been formally established. However, the review’s authors contend that the therapeutic significance of these molecules transcends their role as sweetening agents. Drawing upon accumulated evidence from cell culture experiments, animal models, and molecular signaling studies, they map an intricate network through which mogrosides appear to influence pathways central to cancer initiation, growth, metastasis, and immune surveillance, positioning them as candidates whose relevance extends well beyond the food industry into the domain of integrative oncology.

At the core of the review’s argument lies the phenomenon of metabolic reprogramming, first characterized by Otto Warburg nearly a century ago. Normal differentiated cells primarily generate energy through mitochondrial oxidative phosphorylation, efficiently extracting adenosine triphosphate from glucose in the presence of oxygen. Cancer cells, by contrast, preferentially metabolize glucose through glycolysis even under aerobic conditions—a metabolic signature known as the Warburg effect that enables rapid biosynthesis of the macromolecules required for cell division. This glycolytic shift produces substantial quantities of lactate, which accumulates in the tumor microenvironment and creates an acidic milieu that impairs immune cell function, promotes tissue invasion, stimulates new blood vessel formation, and fosters resistance to both chemotherapy and radiotherapy. The authors compile evidence from multiple preclinical investigations indicating that mogrosides directly counteract this metabolic rewiring. Their analysis indicates that mogrosides activate AMP-activated protein kinase, or AMPK, a highly conserved enzyme that functions as the cell’s primary energy sensor and master metabolic regulator, coordinating a systemic shift away from anabolic biosynthesis and toward catabolic pathways that generate energy through the breakdown of stored macromolecules.

The activation of AMPK by mogrosides initiates a cascade of downstream events with profound implications for tumor biology. AMPK directly phosphorylates and inhibits mechanistic target of rapamycin, abbreviated mTOR, a serine/threonine kinase that integrates growth factor, nutrient, and energy signals to control protein synthesis, lipid metabolism, and cellular growth. The mTOR pathway operates downstream of phosphoinositide 3-kinase and protein kinase B, forming the PI3K/AKT/mTOR signaling axis that is constitutively hyperactivated in the majority of human malignancies. By suppressing this signaling cascade, mogrosides reduce ribosomal biogenesis, cap-dependent translation, and cell cycle progression, thereby constraining the synthetic machinery that rapidly dividing cells require for uncontrolled proliferation. Simultaneously, AMPK phosphorylates acetyl-CoA carboxylase, the rate-limiting enzyme in fatty acid biosynthesis, effectively shutting down de novo lipogenesis. Cancer cells depend heavily on lipid synthesis to construct membranes for daughter cells, generate lipid-derived signaling molecules, and maintain membrane fluidity, and by blocking this pathway, mogrosides deprive tumors of essential structural and regulatory components. The review further documents that mogrosides downregulate hypoxia-inducible factor 1 alpha, a transcription factor that accumulates under the hypoxic conditions characteristic of solid tumors and drives expression of glucose transporters and glycolytic enzymes, thereby reinforcing the metabolic shift that mogrosides oppose.

The suppression of lactate accumulation represents another critical mechanism through which mogrosides may undermine tumor progression and restore immune competence within the tumor microenvironment. Lactate does not merely acidify the extracellular space; it actively recruits macrophages toward a pro-tumor M2 phenotype, inhibits the cytotoxic activity of CD8-positive T cells and natural killer cells, promotes the expansion of immunosuppressive regulatory T cells, and upregulates matrix metalloproteinases that degrade the extracellular matrix and facilitate invasion. By curtailing lactate production through inhibition of glycolytic flux, mogrosides may indirectly reverse multiple immunosuppressive features of the tumor microenvironment. This metabolic intervention could create conditions more favorable for endogenous antitumor immunity and potentially enhance the efficacy of immunotherapeutic approaches that depend upon functional T cell responses. The authors emphasize that this mechanism links the metabolic and immunological effects of mogrosides into a coherent pharmacological profile consistent with their proposed role as bifunctional regulators capable of simultaneously targeting both axes of tumor biology.

Beyond their metabolic effects, mogrosides appear to directly modulate immune signaling pathways that tumors exploit for survival and propagation. The review identifies signal transducer and activator of transcription 3, or STAT3, and nuclear factor kappa B, or NF-κB, as two transcription factors whose persistent activation in tumor cells promotes inflammation, proliferation, angiogenesis, metastasis, and immune evasion. Constitutively phosphorylated STAT3 drives expression of genes encoding pro-inflammatory cytokines including interleukin-6, interleukin-10, and tumor necrosis factor-alpha, which in turn create autocrine and paracrine signaling loops that sustain tumor-promoting inflammation and paracrine suppression of antitumor immunity. NF-κB, another transcription factor frequently hijacked by malignant cells, governs the expression of genes controlling inflammation, resistance to apoptosis, and immune suppression through mechanisms involving inhibitor of kappa B kinase phosphorylation and subsequent transcriptional activation of target genes. Evidence compiled in the review indicates that mogrosides suppress both STAT3 and NF-κB signaling, thereby reducing production of inflammatory mediators and dampening the chronic inflammatory state that characterizes many solid tumors and facilitates disease progression.

Perhaps the most clinically significant immunological finding concerns the downregulation of programmed death-ligand 1, commonly abbreviated PD-L1, a cell surface protein that tumor cells deploy to evade cytotoxic T lymphocyte-mediated destruction. PD-L1 binds to its receptor PD-1 on activated T cells and delivers an inhibitory signal that paralyzes antitumor immune responses. The extraordinary clinical success of immune checkpoint inhibitors such as pembrolizumab and nivolumab, which block this interaction, has validated PD-L1 as a therapeutic target; however, primary and acquired resistance remain formidable obstacles, and many tumors fail to respond or eventually progress despite initial benefit. The review presents evidence that mogrosides reduce PD-L1 expression through suppression of upstream signaling pathways including JAK/STAT3 and PI3K/AKT, suggesting a potential mechanism by which these compounds could sensitize tumors to checkpoint blockade immunotherapy or reduce baseline immunosuppressive pressure within the tumor microenvironment. The authors additionally describe interference with the MAPK/ERK signaling cascade, a mitogen-activated protein kinase pathway that transmits proliferative signals from cell surface growth factor receptors to the nucleus and is hyperactivated in approximately one-third of all human cancers through mutations at various nodes including RAS, RAF, and MEK.

The anti-metastatic properties of mogrosides further encompass inhibition of epithelial-mesenchymal transition, a developmental program that cancer cells appropriate to detach from the primary tumor mass, invade surrounding stromal tissue, intravasate into blood vessels or lymphatic channels, and establish metastatic colonies at distant organs. This process is orchestrated by transcription factors including Snail, Slug, Twist, and zinc finger E-box-binding homeobox factors, whose expression drives loss of epithelial markers such as E-cadherin and acquisition of mesenchymal markers including N-cadherin and vimentin. Studies cited in the review indicate that mogroside treatment reduces the expression of these transition-promoting transcription factors across multiple cancer models, preserving epithelial characteristics and limiting invasive potential. Additionally, mogrosides suppress matrix metalloproteinase-9 and matrix metalloproteinase-2, zinc-dependent endopeptidases that cleave components of the extracellular matrix and basement membrane, clearing the physical barriers that ordinarily contain tumor cells and enabling metastatic dissemination to distant anatomical sites.

The concept of exploiting dietary compounds as therapeutic adjuncts in oncology has gained considerable traction over recent decades, driven partly by recognition that many cancers develop resistance to single-agent targeted therapies and that combination approaches engaging multiple pathways simultaneously may yield more durable clinical responses. Mogrosides, by virtue of their apparent capacity to simultaneously modulate metabolic reprogramming, immune checkpoint expression, inflammatory signaling, and metastatic machinery, exemplify the polypharmacology paradigm in which a single molecular class engages multiple biological targets. The review’s authors frame this dual functionality as the defining characteristic that distinguishes mogrosides from many single-target agents, positioning them as candidates for integration into multimodal treatment regimens alongside surgery, chemotherapy, radiotherapy, or immunotherapy. The exceptionally favorable safety profile of these compounds, established through decades of dietary use and formal toxicological assessment including establishment of an acceptable daily intake, provides a considerable advantage over many synthetic investigational drugs whose inherent toxicity frequently limits the doses patients can tolerate, restricting their therapeutic window.

Despite the mechanistic promise documented throughout the review, the authors temper their conclusions with significant caveats. Most supporting evidence derives from in vitro cell culture experiments and rodent models, which do not always translate predictably to human physiology. Questions surrounding the bioavailability of orally administered mogrosides—specifically whether pharmacologically active concentrations can be achieved in tumor tissue following dietary consumption—remain unresolved. The gut microbiome metabolizes mogrosides into secondary compounds whose pharmacological profiles may differ substantially from the parent molecules, complicating predictions about in vivo efficacy. Furthermore, no clinical trials have yet specifically evaluated mogrosides as anticancer agents in human subjects. The authors call for systematic pharmacokinetic studies, drug interaction assessments, and ultimately well-designed controlled clinical trials to determine whether the molecular mechanisms they have catalogued can be translated into measurable therapeutic benefit for cancer patients. Nevertheless, as understanding of the metabolic and immunological dimensions of malignancy continues to deepen, mogrosides exemplify how molecules initially valued for their sensory properties may harbor deeper biological significance with potential implications for cancer prevention, adjuvant treatment, and improved patient outcomes.