Cancer belongs to a group of diseases characterized by uncontrolled cell growth. The search for new effective treatments for cancer has led to the discovery of different molecules from plants, bacteria, and fungi with pharmacological use. Plant endophytic fungi are large producers of metabolites with antitumor properties. We aimed to evaluate the in vitro and in vivo antitumor potential of extracts from Lophocereus marginatus endophytic fungi. We obtained ethyl acetate and hexane extracts from the L. marginatus endophytes Metarhizium anisopliae and Aspergillus versicolor and evaluated their antitumor activity against murine L5178Y-R lymphoma cells and human peripheral blood mononuclear cells, using the 3-(4,5-dimethylthiazol-2-yl)-2-diphenyltetrazolium bromide reduction colorimetric technique. M. anisopliae and A. versicolor ethyl acetate extracts showed IC₅₀ values of 9.168 ± 1.21 μg/mL and 13.51 ± 1.62, respectively, and selectivity indices > 30. We also observed that the maximum tolerated dose (100 mg/kg) of ethyl acetate extracts and the vehicle in BALB/c mice did not cause hepatotoxicity. In addition, we evaluated the effects of ethyl acetate extracts on survival and tumor volume in the L5178Y-R lymphoma tumor model. An increase in survival (17 d) was observed in mice treated with A. versicolor extract. Furthermore, it did not increase tumor volume during 10 d, as compared with the control groups without treatment, vehicle, and M. anisopliae extract, which had a maximum survival of 10 d. A. versicolor ethyl acetate extract showed in vitro and in vivo antitumor activity against lymphoma L5178Y-R, increasing mice survival.

Glioblastoma is the most common and aggressive brain tumor in adults. However, due to the limitations of conventional treatments, as well as their side effects, there is a need to develop more effective and less harmful therapy strategies. There is evidence that plants endemic to northern Mexico possess biological activities that positively impact human health, particularly against cancer. Echinocereus engelmannii and Echinocereus pectinatus are cacti from the north of Mexico that produce bioactive compounds with antitumor activity. We obtained methanol extracts from previously isolated and fermented microorganisms associated with these cacti. Cell lines of extracts with cytotoxicity against glioblastoma cells U87, neuroblastoma cells SH-S5Y5, and Schwann neuronal cells (healthy control) were evaluated, using a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazole bromide (MTT) reduction technique. The selective cytotoxicity extracts were analyzed using liquid chromatography tandem mass spectrometry (LC/MS²). We isolated 19 endophytic and soil-associated microorganisms from both cacti. Two of them were selected for their high percentages of tumor growth inhibition. The microorganism ES4 possessed the best activity with an IC₅₀ of 17.31 ± 1.70 µg/mL and a selectivity index of 3.11. We identified the bacterium Stenotrophomonas maltophilia by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) from the most active microorganisms against tumor growth. LC/MS² characterized the HS4 extract, and the most abundant group (50.0%) identified included carboxylic acids and derivatives, particularly bisgerayafolin A, Cyclo (Pro-Leu), maculosin, and tryptophan. In conclusion S. maltophilia extract inhibit the growth of glioma cells, showing greater sensitivity in the U87 cell line.

Red blood cells represent a widely used cellular model in cytotoxicity studies, particularly in hemocompatibility assessments. As enucleated cells, which are abundant and easily accessible in both humans and animals, red blood cells allow for rapid, reproducible, and low-cost evaluation of the toxicity of bioactive compounds, whether natural, synthetic, or nanoparticulate. From a functional perspective, the red blood cell membrane is highly sensitive to physical and chemical environmental changes (osmolarity, temperature, pH, and the presence of oxidizing agents). This sensitivity makes red blood cells an effective biosensor for detecting membrane damage, hemolysis, oxidative stress, methemoglobin formation, and aggregation processes. Therefore, in vitro tests using red blood cells allow for the preliminary evaluation in preclinical development, particularly for the early screening of cytotoxicity, membrane-disruptive effects, and hemocompatibility of small molecules, nanomaterials, and blood-contacting biomaterials. These techniques include hemocompatibility tests, evaluation of oxidative and osmotic damage, and evaluation of erythrocyte aggregation and function. However, the use of red blood cells as a cytotoxicity model also has significant limitations. As anucleate cells, erythrocytes lack organelles such as nuclei, mitochondria, or lysosomes, which prevents the evaluation of their effects on key intracellular processes such as protein synthesis, cell signaling, apoptosis, or endoplasmic reticulum stress. This lack of cellular complexity limits their usefulness as a sole model in studies of systemic toxicity or tissue-specific cytotoxicity. These tools offer an effective preliminary approach to anticipating risks in biomedical and pharmacological research.

Microalgae are increasingly recognized as valuable dietary supplements due to their rich nutritional composition and the presence of bioactive metabolites with antioxidant, antitumor, and metabolism-modulating activities. This study evaluated the nutraceutical potential of a methanolic extract of Scenedesmus sp. using an integrated in vitro, in vivo, and metabolomic approach. The extract exhibited selective cytotoxicity against L5178Y-R murine lymphoma cells while showing low toxicity toward human peripheral blood mononuclear cells, indicating a favorable safety and selectivity profile. Additionally, it demonstrated moderate antioxidant activity, a significant antihemolytic effect, and no hemolytic activity even at high concentrations, supporting its hematological safety. In vivo assays showed that oral administration of doses up to 1000 mg/kg was well tolerated, with no adverse effects on body weight or hepatic biochemical markers. Treated animals displayed improved systemic antioxidant responses and enhanced glucose tolerance. Metabolomic analysis revealed a profile enriched in essential amino acids, osmolytes, organic acids, and bioactive metabolites such as β-hydroxybutyrate and betaine, compounds associated with metabolic regulation, redox balance, and epigenetic modulation. Overall, these findings highlight Scenedesmus sp. as a promising nutraceutical source with potential application as a complementary strategy for cancer prevention or treatment.

Background/Objectives: Cancer has been associated with significant morbidity and mortality worldwide, particularly related to chemotherapy resistance. Therefore, it is essential to investigate alternative sources of non-toxic antitumor compounds. The cactus Lophocereus marginatus is native to Mexico and is commonly used to treat gastrointestinal infections and diabetes in traditional medicine. Methods: The in vitro antitumor activity of L. marginatus extract fractions against murine L5178Y-R lymphoma cells was evaluated. The crude extract and its solvent-derived fractions were evaluated for cytotoxicity, selectivity, and hemolytic activity. Results: The crude extract exhibited an IC₅₀ of 9.09 μg/mL, demonstrating a high selectivity index (SI: 330.03), with no hemolytic activity observed at 1000 μg/mL. The LM-HP, LM-CP, and LM-MP partitions showed varying IC₅₀ values (6.74, 7.93, and 45.38 μg/mL, respectively) and selectivity indices of 445.1, 378.31, and 66.1, respectively. Only LM-HP induced hemolysis at 200 μg/mL. The most promising fraction, CP-F8, exhibited an IC₅₀ of 11.2 μg/mL, high selectivity index (354.29), and antioxidant activity, without hemolytic effects. Phytochemical analysis of CP-F8 identified phenolic compounds, triterpenes, and sterols, which are known for their anti-cancer and anti-inflammatory properties. In vivo tests showed no significant liver damage or changes in body weight, indicating the safety of CP-F8. Conclusions: These results suggest that CP-F8 is a promising antitumor candidate with selective cytotoxicity and minimal toxicity to normal cells.