Combinatorial Cytotoxic Effects of Gelam Honey and 5-Fluorouracil against Human Adenocarcinoma Colon Cancer HT-29 Cells In Vitro

Apigenin and its combination with Vorinostat induces apoptotic-mediated cell death in TNBC by modulating the epigenetic and apoptotic regulators and related miRNAs

Triple-negative breast cancer (TNBC) is a metastatic disease and a formidable treatment challenge as it does not respond to existing therapies. Epigenetic regulators play a crucial role in the progression and metastasis by modulating the expression of anti-apoptotic, pro-apoptotic markers and related miRNAs in TNBC cells. We have investigated the anti-TNBC potential of dietary flavonoid 'Apigenin' and its combination with Vorinostat on MDA-MB-231 cells. At Apigenin generated ROS, inhibited cell migration, arrested the cell cycle at subG0/G1 phases, and induced apoptotic-mediated cell death. Apigenin reduced the expression of the class-I HDACs at the transcriptomic and proteomic levels. In the immunoblotting study, Apigenin has upregulated pro-apoptotic markers and downregulated anti-apoptotic proteins. Apigenin inhibited the enzymatic activity of HDAC/DNMT and increased HAT activity. Apigenin has manifested its effect on miRNA expression by upregulating the tumor-suppressor miR-200b and downregulation oncomiR-21. Combination study reduced the growth of TNBC cells synergistically by modulating the expression of epigenetic and apoptotic regulators. Molecular docking and MD simulations explored the mechanism of catalytic inhibition of HDAC1 and HDAC3 and supported the in-vitro studies. The overall studies demonstrated an anti-TNBC potential of Apigenin and may help to design an effective strategy to treat metastatic phenotype of TNBC.

α‑Phellandrene enhances the apoptosis of HT‑29 cells induced by 5‑fluorouracil by modulating the mitochondria‑dependent pathway

α‑Phellandrene (α‑PA), a natural constituent of herbs, inhibits cancer cell viability and proliferation. 5‑Fluorouracil (5‑FU) is a frequently utilized chemotherapeutic medicine for the treatment of colon cancer, which works by triggering cancer cell apoptosis. The present study examined how the combination of α‑PA and 5‑FU affects the suppression of human colon cancer cells by promoting apoptosis. The impact of this treatment on cell viability, apoptosis, and the expression levels of Bcl‑2 family members, caspase family members and mitochondria‑related molecules in HT‑29 cells was assessed by the MTT assay, immunocytochemistry, western blotting and quantitative PCR. The combination of 5‑FU and α‑PA had a synergistic inhibitory effect on cell viability, as determined by assessing the combination index value. Bax protein expression levels were higher in the 50, 100 or 250 µM α‑PA combined with 5‑FU groups compared with those in the 5‑FU alone group (P<0.05). By contrast, Bcl‑2 protein expression levels and mitochondrial membrane potential (MMP, ΔΨm) were lower in the 100 or 250 µM α‑PA combined with 5‑FU groups than those in the 5‑FU alone group (P<0.05). In addition, hexokinase‑2 (HK‑2) protein expression levels were lower in the 50, 100 or 250 µM α‑PA combined with 5‑FU groups than those in the 5‑FU alone group (P<0.05). Compared with 5‑FU alone, after HT‑29 cells were treated with 50, 100 or 250 µM α‑PA combined with 5‑FU, the mRNA expression levels of extrinsic‑induced apoptotic molecules, including caspase‑8 and Bid, were higher (P<0.05). Treatment with 50, 100 or 250 µM α‑PA combined with 5‑FU also increased the mRNA expression levels of cytochrome c, caspase‑9 and caspase‑3, regulating intrinsic apoptosis (P<0.05). These results showed that α‑PA and 5‑FU had a synergistic effect on reducing the viability of human colon cancer HT‑29 cells by inducing extrinsic and intrinsic apoptosis pathways. The mechanism by which apoptosis is induced may involve the intrinsic apoptosis pathway that activates the mitochondria‑dependent pathway, including regulating the expression levels of Bcl‑2 family members, including Bax, Bcl‑2 and Bid, regulating MMP and HK‑2 expression levels, and increasing the expression of caspase cascade molecules, including caspase‑9 and caspase‑3. In addition, it may involve the extrinsic apoptosis pathway that activates caspase‑8 and caspase‑3 leading to apoptosis.

Antimicrobial Peptides as New Combination Agents in Cancer Therapeutics: A Promising Protocol against HT-29 Tumoral Spheroids

Antimicrobial peptides are molecules synthetized by a large variety of organisms as an innate defense against pathogens. These natural compounds have been identified as promising alternatives to widely used molecules to treat infections and cancer cells. Antimicrobial peptides could be viewed as future chemotherapeutic alternatives, having the advantage of low propensity to drug resistance. In this study, we evaluated the efficiency of the antimicrobial peptide gramicidin A (GA) and the anticancer drug, doxorubicin (Doxo) against the spheroids from colorectal cancer cells (HT-29). The two drugs were applied separately against HT-29 spheroids as well as together to determine if they can act synergistically. The spheroid evolution, cell viability, and ATP levels were monitored at 24 and 48 h after the applied treatments. The results show significant drops in cell viability and cellular ATP levels for all the experimental treatments. The simultaneous use of the two compounds (GA and Doxo) seems to cause a synergistic effect against the spheroids.

Antioxidant, hypoglycemic, and hepatoprotective effect of aqueous and ethyl acetate extract of carob honey in streptozotocin-induced diabetic rats

Aim:

The aim of the study included the effect of aqueous extract (AE) and ethyl acetate extract (EAE) on blood sugar in diabetic rats and their effects on liver enzymes and lipid panel in control and diabetic rats. Furthermore, the antioxidant activity of the EAE was studied in vitro and compared with AE.

Materials and Methods:

Sugar and antioxidant content of AE and EAE were determined. In vitro antioxidant activity of AE and EAE was estimated by 2, 2-diphenyl-1-picrylhydrazyl and ABTS*+ radical scavenging assay, ferric-reducing antioxidant power assay, and total antioxidant assay. To study the effect of the extracts on blood glucose level (BGL), lipid profile, and liver function in non-diabetic and diabetic rats, five groups of six rats each were treated with distilled water, AE, EAE, glibenclamide (GLB), and sucrose for 8 days. Plasma glucose level (PGL), total cholesterol (TC), triglycerides (TG), transaminases (alanine transaminase [ALT] and aspartate transaminase [AST]), and alkaline phosphatase (ALP) were determined. The effect of the interventions on BGL after acute administration also was investigated. Diabetes was induced by streptozotocin injection.

Results:

EAE contains significantly lower content of fructose and glucose than AE (p<0.05), and it has no sucrose. AE and EAE exhibited a significant antioxidant activity and high antioxidant content; the antioxidant content was higher in AE than EAE (p<0.05). In diabetic rats, acute treatment by AE increased PGL, while EAE significantly lowered BGL as compared to the untreated diabetic rats. Both interventions significantly decreased BGL as compared to the sucrose treated group in diabetic rats (p<0.05). EAE was more potent than GLB. Sucrose caused 13% increment in BGL after 8 days of induction of diabetes, while AE caused only 1.3% increment. Daily treatment by EAE decreased significantly AST, ALT, ALP, and TC. EAE decreased significantly TC and TG level in diabetic rats in comparison to the untreated diabetic group.

Conclusion:

The study showed for the 1^st time that EAE has more hypoglycemic effect than AE, and both extracts prevent the increment in BGL on day 8 after induction of diabetes observed in the control and sucrose treated group. EAE significantly ameliorated the lipid and liver function disorders induced by diabetes.

The Influence of In Vitro Gastrointestinal Digestion on the Anticancer Activity of Manuka Honey

Manuka honey (MH) is a natural food with many beneficial properties to human health, thanks to its high variety of bioactive compounds; however, little is known about its bioaccessibility. The aim of this study was to evaluate and compare the polyphenol compounds, the antioxidant capacity and the anticancer activity of MH subjected to an in vitro gastrointestinal digestion in human HCT-116 colon cancer cells. Raw MH and digested MH (DMH) were assessed for total polyphenols and flavonoids by spectrophotometric and HPLC-ESI-MS/MS analysis, and total antioxidant capacity (TAC) using different methods. Cell viability, intracellular ROS production, apoptosis, cell cycle and colony formation capacity were tested after treatment with MH or DMH. Results showed that total polyphenols, total flavonoids and TAC were significantly (p < 0.05) reduced after in vitro digestion. In addition, MH and DMH at 8, 16 and 24 mg/mL had similar effects in inducing intracellular ROS production and in inhibiting the colon formation ability; MH induced a more marked apoptosis compared to DMH, while cell cycle was blocked in S phase by MH and in Sub G1 phase by DMH. Our results increase knowledge of the effect of gastrointestinal digestion on the biological effect of honey against colorectal cancer.