Antiproliferative Activity and Impact on Human Gut Microbiota of New O-Alkyl Derivatives of Naringenin and Their Oximes

Preformulation studies and in vitro cytotoxicity of naringin

OBJECTIVE

This study evaluates the chemical and enzymatic stability of naringin (NRG), identifies its degradation metabolites, assesses its in vitro cytotoxicity, and validates a high-performance liquid chromatography (HPLC) method for precise quantification.

SIGNIFICANCE

NRG, a flavonoid with antioxidant, anti-inflammatory, and anticancer properties, faces clinical limitations due to poor solubility, rapid degradation, and low bioavailability. While research efforts on this promising compound have largely focused on overcoming these limitations through formulation strategies, it is equally necessary and complementary to focus on preformulation studies to enhance NRG's therapeutic potential. These studies represent a fundamental step in drug development, providing key insights into the physicochemical and biological properties of NRG and serving as the basis for the rational design of safe and effective formulations in future research.

METHODS

NRG stability was analyzed under various temperature and pH conditions. Cytotoxicity was evaluated in 3T3 cells, and an HPLC method was developed and validated to quantify NRG and its primary metabolite, naringenin (NRGN).

RESULTS

NRG remained stable up to 100 °C and under physiological pH (1.2, 5.8, and 7.4) but degraded at extreme pH, forming NRGN. Cytotoxicity assays showed low toxicity at ≤1 mM (viability >80%), whereas 5 mM significantly reduced viability. The validated HPLC method exhibited high precision, specificity, and accuracy in distinguishing NRG from NRGN.

DISCUSSION

This study provides critical insights into NRG's stability, safety, and quantification, supporting its potential therapeutic development. These findings establish a foundation for future research aimed at enhancing NRG bioavailability and clinical applicability.

An Updated Review Summarizing the Anticancer Potential of Naringenin

One important phytochemical is naringenin, which belongs to the flavanone class of polyphenols. It is found in citrus fruits, such as grapefruits, but it can also be found in tomatoes, cherries, and other food-grade medicinal plants. Naringenin has a significant chemotherapeutic promise, as several investigations have conclusively shown. Therefore, the goal of this review is to synthesize the literature that has been done on naringenin as a possible anti-cancer agent and clarify the mechanisms of action that have been described in treatment plans for different kinds of cancer. In a variety of cancer cells, naringenin works by affecting several pathways associated with cell cycle arrest, anti-metastasis, apoptosis, anti-angiogenesis, and DNA repair. It has been shown to alter several molecular targets linked to the development of cancer, such as drug transporters, transcription factors, reactive nitrogen species, reactive oxygen species, cellular kinases, and inflammatory cytokines and regulators of the cell cycle. In summary, this research provides significant insights into the potential of naringenin as a strong and prospective candidate for use in medicines, nutraceuticals, functional foods, and dietary supplements to improve the management of carcinoma.

Ether Derivatives of Naringenin and Their Oximes as Factors Modulating Bacterial Adhesion

Because of the close connection between adhesion and many vital cellular functions, the search for new compounds modulating the adhesion of bacteria belonging to the intestinal microbiota is a great challenge and a clinical need. Based on our previous studies, we discovered that O-lkyl naringenin derivatives and their oximes exhibit antimicrobial activity against antibiotic-resistant pathogens. The current study was aimed at determining the modulatory effect of these compounds on the adhesion of selected representatives of the intestinal microbiota: Escherichia coli, a commensal representative of the intestinal microbiota, and Enterococcus faecalis, a bacterium that naturally colonizes the intestines but has disease-promoting potential. To better reflect the variety of real-life scenarios, we performed these studies using two different intestinal cell lines: the physiologically functioning ("healthy") 3T3-L1 cell line and the disease-mimicking, cancerous HT-29 line. The study was performed in vitro under static and microfluidic conditions generated by the Bioflux system. We detected the modulatory effect of the tested O-alkyl naringenin derivatives on bacterial adhesion, which was dependent on the cell line studied and was more significant for E. coli than for E. faecalis. In addition, it was noticed that this activity was affected by the concentration of the tested compound and its structure (length of the carbon chain). In summary, O-alkyl naringenin derivatives and their oximes possess a promising modulatory effect on the adhesion of selected representatives of the intestinal microbiota.