5-Fluorouracil (5-FU) is a chemotherapeutic medication commonly used to treat colorectal cancer (CRC); however, the drug-associated adverse effects and toxicity have greatly affected its clinical use. Exploring another therapeutic strategy that lowers the toxicity of 5-FU while having a synergistic effect against CRC is thus a viable option. Diosmetin, a natural flavonoid, has been shown to inhibit the proliferation of many cancer cells, including CRC cells. This study aims to investigate the synergistic effect of diosmetin and 5-FU on HCT116 and HT29 colorectal cancer cells and to explore the apoptotic activity of this combination. The MTT assay was used to assess the viability of cells treated with monotherapy and combination therapy. The combination index (CI) and dose reduction index (DRI) were calculated using the CompuSyn software (version 1.0). The SynergyFinder 2.0 software was used to calculate the synergy score, while the Combenefit software was employed to perform isobologram analysis and synergism determination. The AO/PI double staining technique was used to detect the apoptotic characteristics of cells, whereas the flow cytometry technique was used to investigate the apoptosis induction and cell cycle arrest in cells. The combination of 5-FU and diosmetin showed a synergistic effect in HCT116 cells with a mean CI value of 0.66 ± 0.4, and an additive effect in HT29 cells with a CI value of 1.0 ± 0.2. The DRI of 5-FU in HCT116 cells was three times lower in the combination therapy compared to monotherapy of 5-FU. AO/PI microscopic examination and Annexin V analysis revealed that the combination-treated cells had more apoptotic cells than the monotherapy-treated cells, which was activated mainly through intrinsic apoptosis pathway. HCT116 cell death was confirmed by mitotic arrest in the G2/M phase. Our findings suggest that 5-FU/diosmetin combination exhibits synergistic effect against HCT116 cancer cells, and potentially reduces the unfavorable adverse effect of 5-FU while enhancing the anticancer efficacy by inducing apoptosis and interrupting mitosis. Further research studies are needed to validate the combination’s anti-tumorigenic activities in a xenograft animal model.

Background: Cibotium barometz is a medical herb used traditionally in the Malaysian peninsula for several ailments, including gastric ulcer. The aim of this study was assessment the anti-ulcer effects of C. barometz hair on ethanol-induced stomach hemorrhagic abrasions in animals. Seven groups of Sprague Dawley (SD) rats were administered 10% Tween 20 in the normal control and ulcer control groups, and omeprazole 20 mg/kg and 62.5, 125, 250, and 500 mg/kg of C. barometz hair extract in the experimental groups. After 60 min, the normal control group of rats was orally administered 10% Tween 20, while absolute ethanol was orally administered to the groups of ulcer control, omeprazole and experimental groups. Stomachs of the rats were examined macroscopically and histologically. Homogenates of stomachs were used to evaluate endogenous antioxidant enzyme activities. Results: Rats pre-fed with plant extract presented a significant decrease in the sore area, increased pH of gastric contents and preserved stomach wall mucus compared to the ulcer group. Histologically, rats pre-fed with C. barometz hair extract showed mild to moderate disruptions of the surface epithelium while animals pre-fed with absolute ethanol showed severe disruptions of the stomach epithelium with edema and leucocyte penetration of the submucosal layer. A Periodic acid Schiff (PAS) staining revealed that each rat pre-treated with the plant extract displayed an intense uptake of stomach epithelial glycoprotein magenta color compared to the ulcer control group. Immunohistochemical analysis revealed that rats pre-fed with the plant extract showed an up-regulation of the heat shock protein 70 (HSP70) and down-regulation of Bax proteins compared to ulcer control rats. Homogenates of the stomach tissue demonstrated significant increases in the endogenous antioxidant enzymatic activity and decreased lipid peroxidation (MDA) in rats pre-treated with C. barometz hair extract compared with the ulcer control rats. In acute toxicity, the liver and kidney revealed no hepatotoxic or nephrotoxic effects histologically. Conclusions: The gastric cytoprotective action of C. barometz hair extract might be attributed to antioxidants, an increase in gastric pH, stomach mucus preservation, increased endogenous antioxidant enzymes, decreased lipid peroxidation, up-regulation of HSP70 and down-regulation of Bax proteins.

Thymoquinone (TQ) is a quinone derived from the black seed Nigella sativa and has been extensively studied in pharmaceutical and nutraceutical research due to its therapeutic potential and pharmacological properties. Although the chemopreventive and potential anticancer effects of TQ have been reported, its limited solubility and poor delivery remain the major limitations. In this study, we aimed to characterize the inclusion complexes of TQ with Sulfobutylether-β-cyclodextrin (SBE-β-CD) at four different temperatures (293–318 K). Additionally, we compared the antiproliferative activity of TQ alone to TQ complexed with SBE-β-CD on six different cancer cell lines, including colon, breast, and liver cancer cells (HCT-116, HT-29, MDA-MB-231, MCF-7, SK-BR-3, and HepG2), using an MTT assay. We calculated the thermodynamic parameters (ΔH, ΔS, and ΔG) using the van’t Holf equation. The inclusion complexes were characterized by X-ray diffraction (XRD), Fourier transforms infrared (FT-IR), and molecular dynamics using the PM6 model. Our findings revealed that the solubility of TQ was improved by ≥60 folds, allowing TQ to penetrate completely into the cavity of SBE-β-CD. The IC₅₀ values of TQ/SBE-β-CD ranged from 0.1 ± 0.01 µg/mL against SK-BR-3 human breast cancer cells to 1.2 ± 0.16 µg/mL against HCT-116 human colorectal cancer cells, depending on the cell line. In comparison, the IC₅₀ values of TQ alone ranged from 0.2 ± 0.01 µg/mL to 4.7 ± 0.21 µg/mL. Overall, our results suggest that SBE-β-CD can enhance the anticancer effect of TQ by increasing its solubility and bioavailability and cellular uptake. However, further studies are necessary to fully understand the underlying mechanisms and potential side effects of using SBE-β-CD as a drug delivery system for TQ.

Leukemia, a condition characterized by the abnormal proliferation of blood cells, poses significant challenges in cancer treatment. Thymoquinone (TQ), a bioactive compound derived from black seed, has demonstrated anticancer properties, including telomerase inhibition and the induction of apoptosis. However, TQ’s poor solubility and limited bioavailability hinder its clinical application. This study explored the use of Sulfobutylether-β-cyclodextrin (SBE-β-CD), a cyclodextrin derivative, to enhance the solubility and stability of TQ for leukemia treatment. SBE-β-CD offers low hemolytic activity and has been successfully employed in controlled drug release systems. The study investigated the formation of inclusion complexes between TQ and SBE-β-CD and evaluated their effects on leukemia cell growth and telomerase activity. The results indicated that the TQ/SBE-β-CD complex exhibited improved solubility and enhanced cytotoxic effects against K-562 leukemia cells compared to TQ alone, suggesting the potential of SBE-β-CD as a drug delivery system for TQ. The annexin V-FITC assay demonstrated increased apoptosis, while the qPCR quantification assay revealed reduced telomerase activity in leukemia cells treated with TQ/SBE-β-CD, supporting its anti-leukemic potential. The molecular docking analysis indicated a strong binding affinity between TQ and telomerase. However, further research is needed to optimize the apoptotic effects and minimize necrosis induction. In conclusion, TQ/SBE-β-CD shows promise as a novel strategy for leukemia treatment by inhibiting telomerase and enhancing the cytotoxic effects of TQ, offering a potential solution to overcome the limitations of TQ’s poor solubility and bioavailability.

5-Fluorouracil (5-FU) is frequently used to treat colorectal cancer (CRC), but its clinical application is limited by its toxicity. Natural compounds have been combined with chemotherapeutic drugs to reduce chemotherapy-related toxicity. Diosmetin, a natural flavonoid, has demonstrated anticancer effects against CRC. This study investigated diosmetin's potential in combination with 5-FU using a murine model of HCT-116 colon cancer xenografts in nu/nu nude mice. HCT-116 cells were injected into the right flanks of mice, and once tumors reached a size of 50 mm³, the mice were treated with diosmetin (100 mg/kg), 5-FU (30 mg/kg), or a combination of both at two dose levels (100 + 30 mg/kg and 50 + 15 mg/kg) for 4 weeks. Blood and tumors were collected on the final day for further analysis. Mice treated with the higher combination dose exhibited the smallest tumor volume (330.91 ± 88.49 mm³). Biochemistry and histology analysis showed no toxicity or abnormalities in the liver, kidney, and heart with the combination therapy. Immunohistochemistry results revealed a notable reduction in the proliferation marker (Ki67) and inflammation marker (TLR4) in tumors from high-dose combination-treated mice. Moreover, immunofluorescence data indicated increased levels of apoptotic markers (Bax, Caspase-3, p53, p21) and downregulation of anti-apoptotic protein (Bcl-2) in the high-dose combination group. The findings suggest that 100 mg/kg of diosmetin combined with 30 mg/kg 5-FU significantly reduced tumor volume and had a less toxic effect on the heart compared to 5-FU monotherapy.

Colorectal cancer (CRC) is among the most commonly occurring cancers. The management of CRC includes laparoscopic surgery, radiotherapy, chemotherapies and neoadjuvant treatment. However, conventional chemotherapies have poor impact on combating CRC and are associated with severe toxic effects and high rates of relapse. Therefore, searching for a new combination regimen is a favorable consideration. The aim of this study was to elucidate the synergistic effect of 5-fluorouracil (5-FU) and diosmetin in an in vitro model on colorectal cancer cells. An MTT assay was conducted on HCT-116 cancer cells and they were treated with a concentration gradient of 5-FU and diosmetin individually and in combination. The combination index (CI) and dose reduction index (DRI) were calculated using CompuSyn software. Isobologram analysis and synergism determination were performed using the Combenefit software tool and the synergy score was calculated using the SynergyFinder 2.0 software tool. The apoptotic features of the cells were determined via an AO/PI double staining assay and an annexin V assay using a fluorescent microscope and the flow cytometry technique, respectively. The findings showed that the DRI of 5-FU was three-fold lower in the combination with a CI value of less than one, which indicates that there was a synergistic effect. The AO/PI microscopic results revealed signs of apoptosis and dead cells after 72 h of treatment. Flow cytometry analysis confirmed that the apoptotic effect of the combination was more prominent compared to 5-FU alone. The findings of this study offer a potential strategy for reducing the cytotoxicity and enhancing the efficacy of 5-FU on colorectal cancer cells through a synergistic study model.