Sulfated polysaccharides (SPs) isolated from the marine red macroalga Jania rubens exhibit diverse biological activities. Streptococcus agalactiae (S. agal

Colorectal cancer (CRC) treatment with standard chemotherapeutics such as capecitabine (CAP) and irinotecan (IRT) is frequently limited by toxicity and resistance. To identify novel adjuvant strategies, we investigated the dichloromethane–methanol (DM) Soxhlet extract of the red alga Jania rubens, previously shown to exert intrinsic antiproliferative effects via reactive oxygen species (ROS) induction, inhibition of epithelial–mesenchymal transition (EMT), and suppression of TET enzymes. The present study evaluated the effect of the DM extract in combination with chemotherapeutic agents in HCT-116, Caco-2, and HT-29 colorectal cancer cell lines, assessing its potential to enhance treatment response. Co-treatment with the DM extract significantly enhanced the cytotoxic and anti-migratory effects of CAP and IRT in HCT-116 and Caco-2 cells. Combination treatment also impaired long-term clonogenic survival, suggesting the inhibition of therapy-resistant subpopulations. Flow cytometric analysis (Annexin V-FITC/PI) revealed a dose-dependent increase in apoptosis in HCT-116 cells following DM treatment. Western blot analysis further supported the pro-apoptotic activity of the DM extract by demonstrating reduced BCL-2 protein expression. The extract additionally modulated the mRNA expression levels of cytokines (TNF-α, IL-6, and IL-10), suggesting potential immunomodulatory effects in colorectal cancer cells. Notably, co-administration of IRT and the DM extract enhanced apoptosis, primarily through the downregulation of the anti-apoptotic gene BCL-2. Together, these findings indicate that the Jania rubens DM extract modulates multiple cellular pathways and enhances the response to conventional CRC chemotherapeutic agents.

Jania rubens (J. rubens), a Mediterranean red seaweed, is rich in bioactive compounds with potential medicinal applications. This study investigates the therapeutic potential of Lebanese J. rubens through in vitro evaluation of its anti-diabetic, anti-coagulant, anti-inflammatory and anti-hemolytic activities. Various extracts were prepared and characterized using GC-MS and HPLC. Biological activities were assessed through α-amylase inhibition assays, effects on prothrombin time and partial thromboplastin time, anti-inflammatory activity and anti-hemolytic activity. Significant α-amylase inhibition was observed with dichloromethane/methanol and lipid extracts, comparable to acarbose. All types of extracts prolonged PT and PTT, with the lipid extract showing the strongest effect at higher concentrations. Additionally, dichloromethane/methanol extracts exhibited potent anti-hemolytic activity. Moreover, all extracts showed strong anti-inflammatory activity, achieving levels of inhibition of heat-induced BSA denaturation comparable to diclofenac. Characterization revealed 11 amino acids in the protein extracts, and significant fatty acids in the lipid profile. The crude extracts contained diverse compounds, including flavonoids, aldehydes, diterpenoids, terpenoids, fatty acids, and sterol esters, which may contribute to the observed biological activities. These results highlight J. rubens as a potential reservoir of bioactive compounds with promising in vitro activities related to diabetes, thrombotic disorders, inflammation, and oxidative stress. Further research is needed to isolate the active compounds, validate their efficacy in vivo, assess safety, and elucidate the underlying mechanisms.