Narirutin. A flavonoid found in citrus fruits modulates cell cycle phases and inhibits the proliferation of hormone-refractory prostate cancer cells by targeting hyaluronidase

A comprehensive and systematic review on Curcumin as a promising candidate for the inhibition of melanoma growth: From pre-clinical evidence to molecular mechanisms of action

BACKGROUND

Melanoma, a highly malignant skin tumor, can develop systemic metastases during the early stage. Several studies of melanoma animal models indicate that curcumin, a natural plant extract, inhibits melanoma growth through various mechanisms. To evaluate the relationships among different experimental conditions, curcumin itself, its derivatives, and special formulations, it is necessary to conduct a systematic review and meta-analysis.

PURPOSE

This meta-analysis aims to evaluate the potential of Curcumin as a drug for inhibiting the growth of melanoma and to determine the optimal dosage range and treatment duration for Curcumin administration.

METHODS

A systematic search of studies published from inception to December 2023 was conducted across six databases (PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Data, and VIP). Methodological quality was assessed using SYRCLE's RoB tool. Study heterogeneity was assessed using Cochran's Q test and I2 statistics. Publication bias risk was evaluated using a funnel plot. All analyses were performed using R (version 4.3.3). Additionally, three-dimensional effect analysis and machine learning techniques were utilized to determine the optimal dosage range and treatment duration for Curcumin administration.

RESULTS

Forty studies involving 989 animals were included. The results demonstrated that, relative to the control group, administration of Curcumin resulted in a significant reduction in tumor volume. [SMD=-3.44; 95 % CI (-4.25, -2.63); P<0.01; I2 = 79 %] and tumor weight [SMD=-1.93; 95 % CI (-2.41, -1.45); P<0.01; I2 = 75 %]. Additionally, Curcumin demonstrated a significant capacity to decrease the number of lung tumor nodules and microangiogenesis, as well as to extend survival time, in animal models. The results from three-dimensional effect analysis and machine learning emphasize that the optimal dosage range for Curcumin is 25-50 mg/kg, with an intervention duration of 10-20 days.

CONCLUSION

Curcumin can inhibit the growth of melanoma, and the dose-response relationship is not linear. However, further large-scale animal and clinical studies are required to confirm these conclusions.

THF induces apoptosis by downregulating initiation, promotion, and progression phase biomarkers in skin and lung carcinoma

3,5,7-Trihydroxy-2-phenylchromen-4-one (THF) possesses a diverse range of pharmacological activities. Evidence suggests that THF exerts anticancer activity by distinct mechanisms of action. This study explores the anticancer potential of THF in human lung (A549) and skin (A431) cancer cells by employing different antiproliferative assays. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, neutral red uptake, sulphorhodamine B, and cell motility assays were used to confirm the anticancer potential of THF. Cell target-based and quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were used to explore the effect of THF on the initiation, promotion and progression phase biomarkers of carcinogenesis. THF suppresses the activity of lipoxygenase-5 up to ~40% in both A549 and A431 cells and up to ~50% hyaluronidase activity in A549 cells. qRT-PCR assay reveals that THF inhibits the activity of phosphatidyl inositol-3 kinase/protein kinase B/mammalian target of rapamycin in both cell lines, which is responsible for the initiation of cancer. It also arrests the G2/M phase of the cell cycle in A431 cells and increases the sub-diploid population in both A549 and A431 cell lines which leads to cell death. Annexin V-FITC assay confirmed that THF induces apoptosis and necrosis in A431 and A549 cell lines. Further investigation revealed that THF not only enhances reactive oxygen species production but also modulates mitochondrial membrane potential in both cell lines. It significantly inhibits S-180 tumour formation at 5 and 10 mg/kg bw, i.p. dose. An acute skin toxicity study on mice showed that erythema and edema scores are within the acceptable range, besides acceptable drug-likeness properties and non-toxic effects on human erythrocytes. Conclusively, THF showed potent anticancer activity on skin and lung carcinoma cell lines, suppressed the level of the biomarkers and inhibited tumour growth in mice.

A mechanistic review of the pharmacological potential of narirutin: a dietary flavonoid

Flavanones, a type of polyphenol, are found in substantial amounts in citrus fruits. When high- or moderate-dose orange juice consumption occurs, flavanones make up a significant portion of the total polyphenols in plasma. Disaccharide derivative narirutin, mainly dihydroxy flavanone, is found in citrus fruits. The substantial chemotherapeutic potential of narirutin has been amply demonstrated by numerous experimental studies. Consequently, the purpose of this study is to compile the research that has already been done showing narirutin to be a promising anticancer drug, with its mechanism of action being documented in treatment plans for various cancer forms. Narirutin functions in a variety of cancer cells by regulating several pathways that include cell cycle arrest, apoptosis, antiangiogenic, antimetastatic, and DNA repair. Narirutin has been shown to modify many molecular targets linked to the development of cancer, including drug transporters, cell cycle mediators, transcription factors, reactive oxygen species, reactive nitrogen species, and inflammatory cytokines. Taken together, these reviews offer important new information about narirutin's potential as a potent and promising drug candidate for use in medicines, functional foods, dietary supplements, nutraceuticals, and other products targeted at improving the treatment of cancer.

α-ketoglutarate produced by lactic acid bacteria inhibits hyaluronidase activity

In Japan, the growing interest in anti-aging skin care is associated with the unprecedented aging society. Skin aging can be attributed to various factors, including the activation of hyaluronidase enzyme in subcutaneous tissues exposed to ultraviolet radiation. This enzyme breaks down hyaluronic acid, leading to skin sagging. Therefore, hyaluronidase inhibitors can effectively prevent skin aging. Previously, food components have been actively explored to search for hyaluronidase inhibitors considering the high safety of these materials. Although lactic acid bacteria (LAB)-fermented foods inhibit this enzyme, their active compounds responsible for hyaluronidase inhibition remain unknown. Thus, in this study, we aimed to explore the mechanism underlying the LAB-mediated inhibition of hyaluronidase activity. Supernatants of a LAB-fermented milk-based beverage were subjected to a hyaluronidase inhibition assay, followed by purification and separation using hydrophobic adsorbents and high-performance liquid chromatography, respectively. Subsequently, liquid chromatograph time-of-flight mass analysis was performed, revealing α-ketoglutarate (AKG) as the inhibitor of this enzyme. The half-maximal inhibitory concentration (IC50) of AKG was approximately 0.13-fold that of the known strong hyaluronidase inhibitor disodium cromoglycate (DSCG). To the best of our knowledge, this is the first report on hyaluronidase inhibition mediated by AKG, a metabolic product of LAB. Additionally, Lactobacillus acidophilus JCM1132 was identified as a highly effective AKG-producing LAB (63.9 µg/mL) through LC-MS/MS-based quantitative analyses using various LAB-fermented milk samples. We anticipate that the findings of this study will potentially support the development of functional foods and cosmetics enriched with AKG.

Comparison of vitamin C and flavanones between freshly squeezed orange juices and commercial 100% orange juices from four European countries

Knowing the true levels of nutrients and dietary bioactives in fruit juices at the point of consumption is key to properly understand their potential health benefits. The objective was to characterise the vitamin C and flavanone content in commercial orange juices consumed in Europe, compared with fresh-squeezed juices. Commercial juices were a rich source of vitamin C (>30% of the Nutrient Reference Value). Vitamin C in fresh-squeezed juices, at the end of their shelf-life, remained 33% higher than the levels found in the commercial juices. Flavanones had similar values from both commercial and fresh juices, except for fresh samples stored for 48 h, where fresh juices had higher values (22.36 mg/100 mL). Thus, orange juices preserve their bioactive compounds during storage, with very little influence of the brand, country, industrial process or storage conditions. Main bioactive compounds in commercial juices are present at nutritionally significant levels to the freshly-squeezed ones.

LC-ESI-QTOF-MS/MS characterization of phenolic compounds in Australian native passion fruits and their potential antioxidant activities

Passion fruits, renowned globally for their polyphenolic content and associated health benefits, have enjoyed growing attention from consumers and producers alike. While global cultivar development progresses, Australia has pioneered several native cultivars tailored for its distinct planting conditions. Despite their cultivation, comprehensive studies on the phenolic profiles and antioxidant capacities of these Australian-native passion fruits are notably lacking. This study aims to investigate and compare the polyphenolic content present in the by-products, which are peel (L), and consumable portions, which are the pulp and seeds (P), of four indigenous cultivars: 'Misty Gem' (MG), 'Flamengo' (FG), 'Sweetheart' (SW), and 'Panama' (SH). Employing LC-ESI-QTOF-MS/MS for profiling, a comprehensive list of polyphenols was curated. Additionally, various antioxidant assays-DPPH, FRAP, ABTS, RPA, FICA, and •OH-RSA-were performed to evaluate their antioxidant potential. A total of 61 polyphenols were identified, categorized into phenolic acid (19), flavonoids (33), and other phenolic substances (9). In the antioxidant assays, the SHP sample exhibited the highest •OH--RSA activity at 98.64 ± 1.45 mg AAE/g, while the FGL sample demonstrated prominent DPPH, FRAP, and ABTS activities with values of 32.47 ± 1.92 mg TE/g, 62.50 ± 3.70 mg TE/g, and 57.84 ± 1.22 mg AAE/g, respectively. Additionally, TPC and several antioxidant assays had a significant positive correlation, including DPPH, FRAP, and ABTS. The Australian-native passion fruits revealed distinct polyphenolic profiles and diverse antioxidant capacities, establishing a foundation for deeper health benefit analyses. This study accentuates the significance of understanding region-specific cultivars and their potential nutraceutical applications.

Citrus By-Products as a Valuable Source of Biologically Active Compounds with Promising Pharmaceutical, Biological and Biomedical Potential

Citrus fruits processing results in the generation of huge amounts of citrus by-products, mainly peels, pulp, membranes, and seeds. Although they represent a major concern from both economical and environmental aspects, it is very important to emphasize that these by-products contain a rich source of value-added bioactive compounds with a wide spectrum of applications in the food, cosmetic, and pharmaceutical industries. The primary aim of this review is to highlight the great potential of isolated phytochemicals and extracts of individual citrus by-products with bioactive properties (e.g., antitumor, antimicrobial, antiviral, antidiabetic, antioxidant, and other beneficial activities with health-promoting abilities) and their potential in pharmaceutical, biomedical, and biological applications. This review on citrus by-products contains the following parts: structural and chemical characteristics; the utilization of citrus by-products; bioactivities of the present waxes and carotenoids, essential oils, pectins, and phenolic compounds; and citrus by-product formulations with enhanced biocactivities. A summary of the recent developments in applying citrus by-products for the treatment of different diseases and the protection of human health is also provided, emphasizing innovative methods for bioaccessibility enhancements (e.g., extract/component encapsulation, synthesis of biomass-derived nanoparticles, nanocarriers, or biofilm preparation). Based on the representative phytochemical groups, an evaluation of the recent studies of the past six years (from 2018 to 2023) reporting specific biological and health-promoting activities of citrus-based by-products is also provided. Finally, this review discusses advanced and modern approaches in pharmaceutical/biological formulations and drug delivery (e.g., carbon precursors for the preparation of nanoparticles with promising antimicrobial activity, the production of fluorescent nanoparticles with potential application as antitumor agents, and in cellular imaging). The recent studies implementing nanotechnology in food science and biotechnology could bring about new insights into providing innovative solutions for new pharmaceutical and medical discoveries.