1 Introduction

Cordyceps, like Cordyceps sinensis and Cordyceps militaris, have been used in traditional Asian medicine for hundreds of years. People value them for many health benefits, such as boosting the immune system, reducing inflammation, and fighting tumors (Zhang et al., 2019; Jędrejko et al., 2021; Liu et al., 2022). One of the main helpful parts in Cordyceps is its polysaccharides. These sugars seem to play a big role in health effects. They can help the body by turning on immune cells, making cancer cells die, and changing the tumor environment to slow down its growth (Bi et al., 2018; 2020; Qi et al., 2020). Because of these effects, Cordyceps polysaccharides are now being added to health foods and are also being looked at as possible support drugs in cancer treatment (Zhang et al., 2019; Miao et al., 2022; Chatnarin and Thirabunyanon, 2023).

Cordyceps polysaccharides come in many forms. They can be very different in size, sugar types (like glucose, mannose, or galactose), how the sugars are linked, and how the chains are branched (Jing et al., 2014; Miao et al., 2022; Dai et al., 2024b; Zhu et al., 2024; Li et al., 2025). These differences in structure matter a lot. They can change how well the polysaccharides boost the immune system, kill cancer cells, or stop tumors from growing (Jing et al., 2015; Miao et al., 2022). In recent years, better lab tools have made it easier for scientists to study these structures in more detail. This has helped them understand how the shape of a polysaccharide is linked to what it can do—especially in fighting cancer (Miao et al., 2022; Zhao et al., 2023).

Although Cordyceps polysaccharides exhibit good biological activity, their application in clinical tumor treatment still faces many limitations, mainly manifested in large molecular weight, poor water solubility and low bioavailability (Xie et al., 2020; Zhu et al., 2024). These factors affect its absorption, distribution and ability to target tumor tissues in the body, reducing its actual therapeutic potential (Xie et al., 2020; Zhu et al., 2024).

To overcome these obstacles, researchers have developed a series of chemical modification strategies, such as sulfation, phosphorylation, selenization, and acetylation, to improve the physicochemical properties and biological activities of Cordyceps polysaccharides (Liu et al., 2017; Sun et al., 2018; Xie et al., 2020; Zhao et al., 2023). These chemical modifications can improve their solubility, stability, and tumor targeting ability, thereby enhancing their anti-tumor effects and expanding their application prospects in cancer treatment.

This study looked at how to change Cordyceps polysaccharides using different chemical methods. It focused on how these changes in structure can affect their ability to fight tumors. By comparing different ways to modify them, the goal was to make these natural compounds work better. The results offer useful information for making new anti-tumor drugs from Cordyceps. These drugs could become a safer and more effective choice for treating cancer in the future.

2 Extraction, Purification, and Characterization of Cordyceps Polysaccharides

2.1 Extraction and purification techniques for Cordyceps polysaccharides

Hot water extraction is still the most commonly used method for isolating Cordyceps polysaccharides, usually supplemented by an alcohol precipitation step to concentrate and preliminarily purify the crude extract. In order to improve the yield and extraction efficiency of polysaccharides, enzymatic extraction and enzyme-assisted ultrasonic extraction have also been used in recent years. The optimized extraction conditions can effectively improve the recovery rate and biological activity of polysaccharides (Wang et al., 2024; Yao et al., 2024; Li et al., 2025). These extraction strategies are applicable to the fruiting bodies and mycelium of Cordyceps, whether they are wild or cultivated, or cultivated under fermentation conditions (Zhang et al., 2019; Wu et al., 2024).

In the subsequent purification process, column chromatography techniques, such as ion exchange chromatography (such as DEAE-cellulose) and gel filtration chromatography (such as Sephadex G-100, G-150), are often used to effectively separate polysaccharide components by differences in charge and molecular size (Cheong et al., 2016; Luo et al., 2017; Shi et al., 2020; Yao et al., 2024; Li et al., 2025). In addition, membrane separation techniques, such as ultrafiltration, are also widely used to separate polysaccharide components in a specific molecular weight range and remove impurities (Liu et al., 2017).

2.2 Structural characterization of Cordyceps polysaccharides

Cordyceps polysaccharides are usually heteropolysaccharides, composed of monosaccharides such as glucose, mannose, and galactose in different proportions. Their molecular weight ranges from thousands of daltons to millions of daltons, and this structural diversity has an important impact on their biological activity (Cheong et al., 2016; Shi et al., 2020; Zhang et al., 2020; Yao et al., 2024; Li et al., 2025). In order to determine its monosaccharide composition and molecular weight distribution, analytical techniques such as high performance liquid chromatography (HPLC) and gel permeation chromatography are often used.

More in-depth structural analysis relies on advanced methods such as nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR), and gas chromatography-mass spectrometry (GC-MS). These methods can reveal the type of glycosidic bonds, branching patterns, and conformational characteristics, thus providing important evidence for studying the relationship between its structure and function (Cheong et al., 2016; Zhang et al., 2020).

2.3 Biological properties of native Cordyceps polysaccharides

Native Cordyceps polysaccharides have immunomodulatory effects, promoting the proliferation of lymphocytes and macrophages, enhancing phagocytic function, and stimulating the secretion of multiple cytokines, like nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) (Zhang et al., 2020; Yao et al., 2024; Li et al., 2025). At the same time, they also show strong antioxidant capacity, can scavenge free radicals and protect cells from oxidative stress damage, and their antioxidant effects are comparable to those of conventional antioxidants (Shi et al., 2020; Wang et al., 2024).

Previous animal experiments have shown that Cordyceps polysaccharides can inhibit tumor cell proliferation, induce cell apoptosis, and regulate immune responses in tumor-bearing models. These results support the potential application of Cordyceps polysaccharides as natural anti-tumor active substances and functional food ingredients (Xu et al., 2021; Dai et al., 2024a).

3 Chemical Modification Strategies for Cordyceps Polysaccharides

3.1 Sulfation, phosphorylation, and carboxymethylation of Cordyceps polysaccharides

Sulfonation, phosphorylation and carboxymethylation are the most commonly studied chemical modification methods for Cordyceps polysaccharides, which change the physicochemical properties and biological activities of native polysaccharides by introducing specific functional groups. These methods each use different reagents and reaction conditions. Sulfonation usually uses the chlorosulfonic acid-pyridine method to introduce sulfonic acid groups into the polysaccharide backbone, and the modification effect can be confirmed by chemical analysis and infrared spectroscopy (IR) (Jing et al., 2015). Phosphorylation is often carried out using phosphoric acid or phosphorus oxychloride, while carboxymethylation is completed using monosodium chloroacetate under alkaline conditions (Xie et al., 2020; Zhao et al., 2023). These reactions mainly act on the hydroxyl groups of sugar residues to produce derivatives with a high degree of substitution and altered molecular conformation.

After the introduction of sulfonic acid, phosphate or carboxyl groups, the polysaccharide chains gain enhanced water solubility and impart negative charges to them, thereby improving their dispersibility and ability to interact with biological targets (Xie et al., 2020; Zhao et al., 2023). For example, sulfonated Cordyceps polysaccharides have higher solubility and stronger antitumor activity than unmodified forms, and the optimal degree of sulfonation (DS 1.2-1.5) is positively correlated with in vitro antitumor effects (Jing et al., 2015). Carboxylmethylation and phosphorylation can also improve their solubility and may enhance their biological activity by promoting cellular uptake and enhancing immunomodulatory effects.

3.2 Acetylation and selenization of Cordyceps polysaccharides

Acetylation is the process of introducing an acetyl group, usually at the C-2, C-3 or C-6 position of the sugar residue, with acetic anhydride or acetic acid as the reaction reagent (Zhao et al., 2023). Selenization, as a newer modification method, introduces selenium into the polysaccharide structure through biotransformation or reaction with sodium selenite to produce selenium-rich polysaccharide derivatives (Liu et al., 2017; Sun et al., 2018; Zhang et al., 2023). The success of these modifications can be confirmed by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and elemental analysis, thereby revealing the introduction of new functional groups and changes in molecular conformation (Sun et al., 2018; Zhao et al., 2023; Zhang et al., 2023).

Both acetylation and selenization can significantly affect the biological activity of Cordyceps polysaccharides. In particular, selenized derivatives show enhanced antitumor effects, such as inducing cancer cell apoptosis through mitochondrial pathways and death receptor-mediated pathways, while their antioxidant capacity is also significantly improved (Liu et al., 2017; Sun et al., 2018; Zhang et al., 2023). Acetylation may also modulate its antioxidant activity, although its effect depends on the degree of substitution and the different substitution sites (Zhao et al., 2023). These two modifications generally improve free radical scavenging ability, enhance immune activation, and more effectively inhibit tumor cell proliferation (Zhao et al., 2023; Zhang et al., 2023).

3.3 Grafting and nanoparticle-based modifications of Cordyceps polysaccharides

Grafting and conjugation strategies refer to the covalent attachment of bioactive molecules or drugs to Cordyceps polysaccharides to construct derivatives with multiple functions to enhance their therapeutic potential (Guan et al., 2020; Wang et al., 2024). For example, acetic acid-modified Cordyceps polysaccharides can be made into nanoparticles for encapsulation and delivery of docetaxel, which has shown advantages in drug loading rate, sustained release performance and anti-tumor effect compared with traditional drug formulations (Guan et al., 2020). Such modifications can also be further integrated with targeting ligands or imaging probes to expand the application range of Cordyceps polysaccharides in drug delivery systems (Wang et al., 2024).

Nanotechnology-based modification methods are also emerging, including the construction of selenium nanoparticles or black phosphorus nanosheets and the loading of cordyceps polysaccharides on them. These methods provide new strategies for targeted drug delivery and synergistic anticancer therapy (Zhang et al., 2023; Wang et al., 2024). Such nanocarriers can not only improve cellular uptake efficiency and bioavailability, but also achieve the synergistic delivery of multiple therapeutic factors. For example, selenium nanoparticle complexes exhibited potent antitumor activity by activating intrinsic and extrinsic apoptosis pathways, while black phosphorus-cordyceps polysaccharide nanocomposites showed significant synergistic effects in photothermal therapy and immunotherapy models.

4 Structure-Activity Relationship of Modified Cordyceps Polysaccharides

4.1 Effects of modification degree and substitution pattern

The effects of Cordyceps polysaccharides vary greatly depending on how they are modified. Sulfonation is one of the commonly used methods. Studies have found that when the degree of sulfonation (DS) is between 1.2-1.5, the anti-tumor activity is the strongest. Exceeding this range may backfire and affect structural stability (Jing et al., 2015). Selenization is similar. Adding an appropriate amount can indeed enhance the ability to induce apoptosis, but too much selenium may destroy the original structure of the polysaccharide (Liu et al., 2017; Sun et al., 2018; Zhang et al., 2023). Acetylation is characterized by "too much is as bad as too little". Only when it is controlled within the appropriate range can it play a positive role (Qi et al., 2020; Zhao et al., 2023).

In addition to “how much to add”, “where” to add is also critical. For example, substitution at the C-6 position is more likely to affect the three-dimensional configuration of the polysaccharide, improve its ability to bind to the receptor, and thus enhance the immunomodulatory effect (Qiao et al., 2019; Li et al., 2025). Some polysaccharides with structural advantages, such as highly branched, low-molecular-weight galactoglucomannan, not only have strong immune activity, but are also particularly suitable for use as drug delivery carriers (Jing et al., 2014; Bi et al., 2018). Choosing the right structure and combining it with moderate modification will make the activity performance more stable.

4.2 Role of molecular weight and conformational features

Molecular weight is an important factor that affects the bioavailability and function of Cordyceps polysaccharides. Low molecular weight polysaccharides (like 2-20 kDa) are usually easier for cells to take in. They also dissolve better in water and show stronger immune-regulating effects. Because of this, they are often used as drug carriers or adjuvants (Jing et al., 2014; Shi et al., 2020; Dai et al., 2024a; b; Li et al., 2025). On the other hand, high molecular weight polysaccharides (over 100 kDa) may have stronger immune-boosting and direct anti-tumor effects. But their bioavailability in the body is lower, and they don’t move through tissues as easily (Tan et al., 2023; He et al., 2019; Zhu et al., 2024).

By adjusting extraction and processing methods—like changing the temperature, using ultrasound, or adding enzymes—we can control the molecular weight and improve the anti-tumor effects of Cordyceps polysaccharides (Zhu et al., 2014; 2016; Nurmamat et al., 2018). For example, Nurmamat et al. (2018) looked into how extracting at different temperatures (4 °C and 80 °C) changes the chemical structure and anti-tumor activity of Cordyceps polysaccharides. They found that the polysaccharide called CMPs-4, which was extracted at low temperature (4 °C), had a molecular weight around 188 kDa, was rich in glucose, and had a more stable triple-helix structure. In contrast, CMPs-80, extracted at high temperature (80 °C), had a higher molecular weight (about 308 kDa) and was richer in rhamnose and galactose. Lab tests showed that CMPs-4 was much better at causing human esophageal cancer Eca-109 cells to undergo apoptosis. It also had a stronger concentration-dependent effect when compared with CMPs-80 (Figure 1).

Structural features like the triple-helix shape and highly branched chains are closely linked to stronger biological activity. The triple-helix structure helps the polysaccharide resist enzyme breakdown and makes it more stable. At the same time, highly branched or porous chain structures can create more surface area to interact with immune receptors, which helps activate immune cells (Jing et al., 2014; Bi et al., 2018; Li et al., 2025). For instance, a low molecular weight galactoglucomannan with a net-like, porous, and highly branched chain structure showed great potential for boosting immunity and fighting tumors (Li et al., 2025). These structural features are usually confirmed through Congo red binding tests and scanning electron microscopy (SEM).

4.3 Synergistic modifications in Cordyceps polysaccharides

Many studies have found that the combination of several chemical modifications, such as sulfonation and carboxymethylation or selenization, is often more effective than a single modification (Zhao et al., 2023; Zhang et al., 2023; Dai et al., 2024a). This type of double-modified Cordyceps polysaccharide performs better in solubility, charge distribution and molecular interactions, and is more likely to exhibit stronger antioxidant and anti-tumor activities (Zhao et al., 2023; Dai et al., 2024a). Of course, the order and combination of modifications cannot be messed up. Proper combination can activate potential, but if the polysaccharide skeleton is destroyed, the original biological function may be lost.

In recent years, a new approach has emerged: the use of synergistic modification and nanotechnology together. For example, using modified Cordyceps polysaccharides as carriers to encapsulate selenium nanoparticles or acetic acid-modified nanoparticles has shown better targeting in certain tumor models. The experimental results of Guan et al. (2020), Zhang et al. (2023) and Wang et al. (2024) all mentioned that these systems can improve cellular uptake efficiency, prolong circulation time, and deliver drug efficacy to tumor tissues more concentratedly. Overall, synergistic modification not only enhances activity, but also makes Cordyceps polysaccharides more promising in the field of drug delivery.

5 Antitumor Activity of Modified Cordyceps Polysaccharides

5.1 In vitro antitumor effects on cancer cell lines

Chemically modified Cordyceps polysaccharides, such as selenization, acetylation, and nanoparticle encapsulation, have shown significant toxic effects on a variety of tumor cell lines in experiments. These cells include liver cancer (HepG2), lung cancer (A549), ovarian cancer (SKOV-3), colon cancer (HCT116), and tongue cancer (CAL-27) (Liu et al., 2017; Sun et al., 2018; Guan et al., 2020; Li et al., 2022). Many studies have shown that these modified polysaccharides can induce tumor cell death by activating the mitochondrial apoptosis pathway (intrinsic) and the death receptor pathway (exogenous). For example, common changes include increased levels of pro-apoptotic proteins such as Bax, caspase-3, caspase-9, and p53, while decreased levels of anti-apoptotic proteins such as Bcl-2 (Qi et al., 2020; Zheng et al., 2020; Zhang et al., 2023; Chen et al., 2024).

These mechanisms do not occur in isolation, and sometimes occur together with cell cycle arrest, mainly concentrated in the G1 or S phase, which just limits the proliferation of tumor cells (Jing et al., 2014; Liu et al., 2019; Xu et al., 2021; Dai et al., 2024a; b). Of course, not all toxicity relies solely on apoptotic mechanisms. Some studies have also pointed out that modified Cordyceps polysaccharides can also induce ROS (reactive oxygen species) accumulation and enhance cytotoxicity by blocking autophagic flux, which is also one of the important means for them to exert anti-tumor effects (Li et al., 2022).

More importantly, these compounds seem to have a certain degree of selectivity in killing tumor cells. In other words, they are effective against cancer cells, but relatively less toxic to normal cells (Liu et al., 2017; Chen et al., 2024). For example, selenium-enriched Cordyceps polysaccharides and acetylated nanoparticles show very low toxicity on normal endothelial cells or other animal cells, which is a positive signal for subsequent drug development (Liu et al., 2017; Qi et al., 2020). Some cordycepin derivatives also show good selectivity - they can effectively inhibit the growth of tumor cells, but have little effect on normal cells (Cui et al., 2024).

5.2 In vivo tumor suppression in animal models

The anti-tumor effect of modified Cordyceps polysaccharides is not only determined by in vitro experiments, but also empirically supported by studies on animal models. Selenized polysaccharides and high molecular weight polysaccharides have performed well in a variety of tumor models. Whether it is xenografted SKOV-3 ovarian cancer, HepG2 liver cancer, Lewis lung cancer, or homografted S180 sarcoma and H22 liver cancer, there are obvious tumor inhibition responses (Liu et al., 2017; Bi et al., 2020; Shi et al., 2020; Liu et al., 2022; Li et al., 2022; Zhu et al., 2024; Sui et al., 2025). In most experiments, the tumor inhibition rate can be stabilized at more than 30% to 45%. Some are even close to the effectiveness of standard chemotherapy drugs, but with much fewer toxic side effects (Jing et al., 2014; Liu et al., 2017; Sui et al., 2025).

Combination therapy is also a highlight. The combination of modified Cordyceps polysaccharides and conventional chemotherapy drugs such as cyclophosphamide and cisplatin not only enhances the anti-tumor effect, but also reduces the toxic burden of chemotherapy (Sui et al., 2025). In contrast, this combination treatment regimen appears to be milder but not ineffective in animal experiments. The histological results are also quite convincing. The number of apoptotic cells in the tumor tissues of the treated animals increased, while the proliferation activity weakened. The indexes of immune organs such as the spleen and thymus have rebounded, indicating that the immune status has improved (Tan et al., 2023; Dai et al., 2024a; b; Zhu et al., 2024).

Further immunological tests found that the expression of pro-apoptotic proteins (such as TNF-α, IL-2, and IFN-γ) was enhanced, and the activity of macrophages and lymphocytes was also greatly improved, indicating that it does not fight alone, but fights tumors by activating the immune system (Bi et al., 2018; He et al., 2019; Dai et al., 2024a). Some studies have also mentioned that modified Cordyceps polysaccharides can also inhibit the formation of tumor angiogenesis and optimize the tumor microenvironment. Although this part of the mechanism is still under study, it has shown its multi-pathway potential (Lu et al., 2024).

5.3 Pharmacokinetic properties and biodistribution

If the therapeutic effects of modified Cordyceps polysaccharides are noteworthy, their performance in vivo cannot be ignored. In particular, with the help of nanotechnology, such as acetic acid-modified Cordyceps polysaccharide nanoparticles and selenium nanocomplexes, these new forms have shown obvious pharmacokinetic advantages (Guan et al., 2020; Qi et al., 2020; Wang et al., 2024). The drug is not only released more slowly and more stable in the body, but also stays in the blood longer, which is helpful for reducing the frequency of dosing and extending the efficacy window, making it more suitable for clinical use.

More importantly, these modified nanocarriers have another advantage - they are easier to aggregate in tumor tissues. In animal experiments, nanoparticles showed good targeting ability, which not only improved the utilization rate of active ingredients, but also reduced systemic toxicity (Qi et al., 2020; Chen et al., 2024; Wang et al., 2024). In other words, the drug cures the disease while causing less damage to normal tissues.

Other studies have attempted to use black phosphorus nanosheets to carry cordyceps polysaccharides to build a more targeted delivery system. This system can not only achieve tumor localization, but also adapt to the needs of photothermal therapy, and even show a certain synergistic effect in activating immune responses (Wang et al., 2024). This type of combined strategy shows that Cordyceps polysaccharides are not only auxiliary, but can also play a more core role in modern anti-tumor treatment.

6 Mechanisms of Antitumor Action of Cordyceps Polysaccharides

6.1 Immune activation pathways induced by Cordyceps polysaccharides

Cordyceps polysaccharides can strongly activate the innate immune system, especially by activating macrophages and natural killer cells (NK cells) to exert anti-tumor effects. These polysaccharides not only enhance the phagocytic activity of macrophages, but also induce tumor-associated macrophages (TAMs) to transform from the immunosuppressive M2 phenotype to the cytotoxic M1 phenotype, and enhance the cytotoxic ability of NK cells against tumor cells (Bi et al., 2020; Wan et al., 2023; Wang et al., 2024). Mechanistically, this immune activation is mediated by the recognition of pattern recognition receptors (such as TLR2 and Dectin-1), activating downstream signaling pathways such as p38, Akt, NF-κB and Syk, thereby enhancing the activity of immune cells and promoting tumor cell clearance (Bi et al., 2020; Wan et al., 2023). Animal experiments have confirmed that these immune effects can effectively inhibit tumor growth and have better safety than traditional chemotherapy drugs (Bi et al., 2020; Wang et al., 2024).

Cordyceps polysaccharides also modulate the tumor microenvironment by enhancing the secretion of key cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-2 (IL-2), interleukin-6 (IL-6), and interferon-gamma (IFN-γ) (Dai et al., 2024a; Li et al., 2025). This cytokine upregulation boosts both innate and adaptive immune responses, promoting T cell proliferation, dendritic cell maturation, and overall antitumor immunity (Li et al., 2025). The increased cytokine milieu not only supports direct tumor cell killing but also helps reset immune cell phenotypes, overcoming tumor-induced immunosuppression (Liu et al., 2022; Deng et al., 2022; Wan et al., 2023; Zhu et al., 2024).

Cordyceps polysaccharides further modulate the tumor microenvironment by promoting the secretion of key cytokines such as TNF-α, IL-2, IL-6, and IFN-γ (Dai et al., 2024a; Li et al., 2025). The upregulation of these cytokines can enhance innate and adaptive immune responses, promote T cell proliferation, and dendritic cell maturation, thereby enhancing overall anti-tumor immunity (Li et al., 2025). Increased cytokine levels not only help to directly eliminate tumor cells, but also reshape the phenotype of immune cells, thereby reversing the tumor-induced immunosuppressive state (Liu et al., 2022; Deng et al., 2022; Wan et al., 2023; Zhu et al., 2024).

6.2 Apoptotic and anti-proliferative mechanisms

One of the core mechanisms by which Cordyceps polysaccharides exert their anti-tumor effects is to induce apoptosis by activating the caspase pathway. These polysaccharides can upregulate pro-apoptotic proteins (such as Bax and p53), promote the release of cytochrome c from mitochondria, and activate caspase-3, -8, and -9, thereby inducing programmed cell death in a variety of tumor cell lines (Cui et al., 2018; Liu et al., 2019; Jo et al., 2020; Qi et al., 2020; Xu et al., 2021; Tan et al., 2023). Its apoptotic pathways include both intrinsic (mitochondrial-mediated) and extrinsic (death receptor-mediated) mechanisms, and are often accompanied by cell cycle arrest in the G1 or S phase, further inhibiting tumor cell proliferation (Liao et al., 2015; Xu et al., 2019; Zhang et al., 2023; Dai et al., 2024a).

Cordyceps polysaccharides also interfere with tumor progression by inhibiting angiogenesis and metastasis. Its mechanisms include downregulating the expression of vascular endothelial growth factor (VEGF), inhibiting the activity of matrix metalloproteinases (MMPs), and regulating epithelial-mesenchymal transition (EMT)-related markers, thereby reducing tumor vascularization and metastatic potential (Qi et al., 2020; Liu et al., 2022; Gunter et al., 2025). The above effects are achieved by inhibiting key signaling pathways necessary for tumor cell migration and invasion (such as PI3K/Akt/mTOR, MAPK, and Hedgehog) (Liu et al., 2020; Lu et al., 2024; Sui et al., 2025).

6.3 Oxidative stress modulation and DNA damage response

Cordyceps polysaccharides regulate the level of oxidative stress in tumor cells by increasing the generation of reactive oxygen species (ROS), thereby inducing mitochondrial dysfunction and caspase activation, leading to cell apoptosis (Chaicharoenaudomrung et al., 2018; Li et al., 2022; Zhang et al., 2023). Increased levels of ROS lead to oxidative damage, loss of mitochondrial membrane potential, and activation of intrinsic and extrinsic apoptotic pathways (Li et al., 2022; Zhang et al., 2023). It is worth noting that some cordyceps polysaccharides also have antioxidant properties and can protect normal cells from oxidative damage, demonstrating their dual role in redox regulation (Shi et al., 2020).

In addition to inducing DNA damage, Cordyceps polysaccharides also regulate the expression of DNA repair genes and cell cycle regulatory factors. For example, they can upregulate the expression of p53 and other DNA damage response proteins, leading to cell cycle arrest in the S phase or G2/M phase, thereby inducing tumor cell apoptosis (Liao et al., 2015; Xu et al., 2019; Xu et al., 2021). This regulatory mechanism can weaken the DNA repair ability of tumor cells and enhance their sensitivity to anti-tumor treatment, thereby improving the therapeutic effect (Xu et al., 2019; Qi et al., 2020).

7 Case Studies of Chemically Modified Cordyceps Polysaccharides

7.1 Sulfated Cordyceps polysaccharides in anticancer applications

Compared with unmodified native polysaccharides, sulfonated Cordyceps polysaccharides exhibit stronger antitumor activity. An animal experiment showed that low molecular weight α-glucan (LMW-CMP) derived from Cordyceps militaris inhibited tumor growth in the H22 tumor-bearing mouse model, with a tumor inhibition rate of 45.7% at a dose of 200 mg/kg (Dai et al., 2024b). Cordyceps cicadae polysaccharides also successfully inhibited the proliferation of HeLa cells by inducing cell cycle arrest and apoptosis, upregulating p53 expression, and activating caspase cascade reactions (Xu et al., 2021).

There are few direct studies on the combined use of sulfonated Cordyceps polysaccharides and chemotherapeutic drugs, but relevant studies have shown that chemical modification of polysaccharides can enhance the efficacy of traditional chemotherapeutic drugs and reduce toxic side effects (Xie et al., 2020). For example, the anticancer activity of nanoparticles (DTX-AA-CSP nanoparticles) prepared by coupling Cordyceps polysaccharides with docetaxel on HepG2 and SW480 cells is superior to that of traditional docetaxel injection, showing potential synergistic therapeutic effects (Guan et al., 2020).

In a mouse model of liver cancer, the combination of Cordyceps sinensis polysaccharide (CP1) and cyclophosphamide (CTX) can significantly improve the tumor inhibition rate and reduce toxic reactions such as bone marrow suppression (Sui et al., 2025). In the combined drug group, CP1 significantly enhanced the tumor inhibition effect of CTX, with the highest tumor inhibition rate reaching 77.63%, and can alleviate CTX-induced spleen atrophy and peripheral blood leukopenia, indicating that it has a significant immune protective effect (Figure 2).

7.2 Study on the mechanism of Cordyceps polysaccharide against liver cancer

Hepatocellular carcinoma (HCC) is a malignant tumor with a very high mortality rate worldwide. Although traditional treatments such as 5-FU are effective, they are often accompanied by serious toxic side effects. In recent years, active ingredients of natural medicines, especially polysaccharides, have attracted attention due to their low toxicity and multi-target effects.

Tan et al. (2023) studied the therapeutic potential of macromolecular polysaccharides (WCP) extracted from wild Cordyceps sinensis on H22 tumor-bearing mice. Through a series of in vivo experiments, they found that WCP can inhibit tumor growth and improve immune organ function without affecting the normal physiological state of mice. Mechanism analysis showed that WCP inhibited the IL-10/STAT3/Bcl2 pathway by upregulating Bax, Caspase-3/8 and Cytochrome c, induced tumor cell apoptosis, and increased the levels of CD4⁺/CD8⁺ T cells and macrophages, thereby enhancing host immunity (Figure 3).

8 Concluding Remarks

The biological activity of Cordyceps polysaccharides can be enhanced through chemical modification (e.g., sulfonation, phosphorylation, and selenization), including anti-tumor, immunomodulatory, and antioxidant effects. Structure-activity relationship (SAR) studies have shown that factors such as molecular weight, monosaccharide composition, glycosidic bond type, and branching mode are key to determining its biological effects. For example, a higher degree of branching and specific glycosidic bonds can effectively enhance its immunostimulatory and anti-tumor abilities. But, the precise relationship between its structure and activity has not yet been fully revealed, and further research is still needed to clarify how various structural modifications are converted into enhanced pharmacological effects.

Mechanistic studies have confirmed that modified Cordyceps polysaccharides exert anti-tumor effects through multiple pathways, including activating the immune system (such as promoting macrophage and lymphocyte activity, stimulating cytokine secretion), inducing cell apoptosis, and regulating oxidative stress. In addition, these polysaccharides can also regulate intestinal microbiota and enhance mucosal immune function, thus further expanding their therapeutic potential.

Although the results of preliminary experimental studies are encouraging, Cordyceps polysaccharides still face many challenges in clinical transformation, such as low industrial production yield, differences in extraction and purification methods, incomplete understanding of its biosynthesis and regulatory mechanisms, and lack of a standardized quality control system. In addition, there are no large-scale, rigorously designed human clinical trials, which limits the confirmation of its safety and effectiveness.

The next research may focus on the combined application of Cordyceps polysaccharides, such as using them with commonly used chemotherapy drugs, or using nano-delivery systems to improve their utilization efficiency and targeting effect in the body. On the other hand, new technologies such as gene editing, liquid fermentation and molecular breeding are also worthy of attention. They can not only promote the large-scale production of Cordyceps polysaccharides, but also lay a good foundation for them to enter the functional food and drug market while ensuring the stability of active ingredients.

Acknowledgments

The authors sincerely thank Dr. Zhang for reviewing the manuscript and providing valuable suggestions, which contributed to its improvement. Additionally, heartfelt gratitude is extended to the two anonymous peer reviewers for their comprehensive evaluation of the manuscript.

Conflict of Interest Disclosure

The authors affirm that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.

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