Chemopreventive Potential of Apple Pulp Callus Against Colorectal Cancer Cell Proliferation and Tumorigenesis

Anti-Inflammatory, Antioxidant, and Genoprotective Effects of Callus Cultures Obtained from the Pulp of Malus pumila cv Miller (Annurca Campana Apple)

Apples are rich in phytochemicals useful for human health. However, environmental factors can greatly affect the accumulation of these compounds. To face this problem, the callus culture technique was used to obtain large quantities of phytochemicals. Specifically, two callus cultures were obtained from ripe Annurca apple pulp (Malus pumila cv Miller) and cultivated under different light conditions: darkness and an 18-h photoperiod. The hydro-alcoholic extracts from the calli underwent analysis using GC-MS, GC-FID, and HPLC-DAD-ESI-MSn to determine the qualitative and quantitative content of phenolic and triterpenic acids. The study revealed the predominant presence of triterpenic compounds in both calli. Furthermore, we investigated their radical scavenging and antioxidant activities through DPPH, ABTS, ORAC assays, and lipoxygenase inhibition activity. Genoprotection was evaluated via nicking assay, and the anti-inflammatory effect was investigated via Griess assay on LPS-injured murine macrophages. All the analyses performed were compared with peel and pulp hydroalcoholic extracts. The results showed that both calli primarily show anti-inflammatory activity and moderate antioxidant effect and can protect DNA against oxidative stimuli. This data encouraged further research aimed at utilizing callus as a bioreactor to produce secondary metabolites for use in preventive and therapeutic applications to combat acute or chronic age-associated diseases.

The potential role of Listeria monocytogenes in promoting colorectal adenocarcinoma tumorigenic process

BACKGROUND

Listeria monocytogenes is a foodborne pathogen, which can cause a severe illness, especially in people with a weakened immune system or comorbidities. The interactions between host and pathogens and between pathogens and tumor cells have been debated in recent years. However, it is still unclear how bacteria can interact with tumor cells, and if this interaction can affect tumor progression and therapy.

METHODS

In this study, we evaluated the involvement of L. monocytogenes in pre-neoplastic and colorectal cancer cell proliferation and tumorigenic potential.

RESULTS

Our findings showed that the interaction between heat-killed L. monocytogenes and pre-neoplastic or colorectal cancer cells led to a proliferative induction; furthermore, by using a three-dimensional cell culture model, the obtained data indicated that L. monocytogenes was able to increase the tumorigenic potential of both pre-neoplastic and colorectal cancer cells. The observed effects were then confirmed as L. monocytogenes-specific, using Listeria innocua as negative control. Lastly, data suggested the Insulin Growth Factor 1 Receptor (IGF1R) cascade as one of the possible mechanisms involved in the effects induced by L. monocytogenes in the human colorectal adenocarcinoma cell line.

CONCLUSIONS

These findings, although preliminary, suggest that the presence of pathogenic bacterial cells in the tumor niches may directly induce, increase, and stimulate tumor progression.

The potential chemo-preventive roles of Malus domestica against the risk of colorectal cancer: A suggestive insight into clinical application

Biologically active compounds in fruit-derived ingredients, particularly phytochemicals, have significant potential to modulate and mitigate many pathological processes in the development of disease conditions, including cancer. Colorectal cancer (CRC) remains a major public health issue. Nonetheless, prevention is an important step in lowering the rate of mortality from this cancer. Currently, the link between apple consumption and improved health is becoming remarkably evident and is reported to be beneficial for human health. Phytochemicals, such as flavonoids and other polyphenol compounds extensively available in apple fruits, have well-known positive effects on health outcomes and the potential to combat and prevent the development of CRC, including antioxidant, anti-proliferative, and anti-carcinogenic effects. This review describes the bioactive compounds derived from apple fruits, particularly the polyphenols and flavonoids, their proposed mechanisms responsible for their bioactive properties and health-promoting attributes that could provide potential chemo-preventive effects against the risk of CRC development. The conclusion of the review provides insights into the potential effects of apple-derived bioactive compounds and proposes the need for more clinical studies in large trials for future strategies regarding the valuable effects of apple phytochemicals, which might be therapeutic candidates in the campaign against CRC.

Antioxidant, Anti-Inflammatory, and Cytotoxic Activity of Extracts from Some Commercial Apple Cultivars in Two Colorectal and Glioblastoma Human Cell Lines

Cancer initiation and development are closely related to oxidative stress and chronic inflammation. The aim of this study was to evaluate apple extracts and individual tritepenes antioxidant, anti-inflammatory, and cytotoxic activities. Dry extracts of apple were analyzed by HPLC-PDA. A hyaluronidase inhibition assay was selected to determine the anti-inflammatory effect. Cytotoxic activities against human colon adenocarcinoma cell line (HT-29) and human glioblastoma cell line (U-87) were determined using MTT, cell colony formation, and spheroid growth assays. Radical scavenging and reducing activities were evaluated using DPPH, ABTS, FRAP, and CUPRAC assays, respectively. The apple extracts inhibited hyaluronidase from 26.38 ± 4.4% to 35.05 ± 3.8%. The AAW extract possessed the strongest cytotoxic activity (EC₅₀ varied from 113.3 ± 11.11 µg/mL to 119.7 ± 4.0 µg/mL). The AEW extract had four and five times stronger antiradical activity when determined by ABTS and DPPH, and two and eight times stronger reducing activity when evaluated by CUPRAC and FRAP, respectively. Understanding the mechanisms of apple extracts and individual triterpenes as hyaluronidase inhibitors and antioxidants related in cancer development may be a benefit to future study in vivo, as well as cancer prognosis or the development of new, innovative food supplements, which could be used for chronic disease prevention.