Nutraceuticals

High-throughput colourimetric assays are widely used to screen phenolic phytonutrients in foods and plants, supporting discovery, quality control, and preliminary nutraceutical assessment. This review summarises the historical development, operating principles, and limitations of phenolic-based benchtop methods, and reports practical guidance for defensible application. The following colourimetric approaches are critically evaluated: Folin–Ciocalteu for total phenolics; AlCl₃-based and alternative total flavonoid methods; the pH-differential procedure for total monomeric anthocyanins; and tannin assays including vanillin–HCl, butanol–HCl (Porter), DMACA, protein-precipitation, and hydrolysable-tannin (rhodanine/ellagic-acid) protocols. For each method, common biases are identified, matrix interferences, reagent cross-reactivity, oxidative artefacts, dependence on calibration standard, and the chemical meaning of the readout is clarified. A best-practice framework is proposed: define the analytical target; pair complementary assays; pre-clean extracts; justify standards and wavelengths; control oxidation; validate spike-recovery and conversion checks; and contextualise outcomes using functional measures. A consistent conclusion emerges: no single method quantifies “total tannins” or “total flavonoids” across diverse matrices, and transparent reporting with method triangulation is essential for comparability and credible nutraceutical interpretation. The guidance consolidated here aims to standardise practice, minimise over- and underestimation artefacts, and strengthen the evidentiary value of data in food and nutraceutical research.

Obesity and obesity-related diseases represent increasingly serious global health challenges, and effective preventive strategies are urgently needed. This study investigated the anti-obesity effects of carnosine and anserine, representative imidazole dipeptides known for their antioxidant and metabolic regulatory properties, using a mouse model of high-fat (HF) diet-induced obesity. Thirty 6-week-old male C57BL/6n mice were fed an HF diet (56% fat) for eight weeks. Carnosine or anserine was administered in drinking water ad libitum (4 mM). After one week of dietary acclimation, the mice were divided into sedentary and exercise groups (n = 5 per group). The exercise protocol consisted of treadmill running for 30 min/day at 9 m/min, five days per week, for seven consecutive weeks. The results demonstrated that only carnosine supplementation, and not anserine, significantly suppressed body weight gain, visceral white adipose tissue accumulation, and adipocyte hypertrophy induced by the HF diet. Moreover, carnosine supplementation enhanced uncoupling protein 1 (UCP1) expression in epididymal adipocytes and improved serum blood glucose levels. These findings indicate that carnosine exerts anti-obesity effects, potentially through the enhancement of thermogenic and metabolic pathways, and may have therapeutic potential as a dietary intervention for the prevention of obesity-related metabolic disorders.

Chronic pain represents a major challenge for healthcare systems worldwide. Pharmacological agents such as opioids, gabapentinoids, and non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used depending on the pain type (nociceptive, neuropathic, or nociplastic), but their use is often limited by adverse effects. Nutraceuticals and dietary supplements have emerged as potential adjuvants to conventional pain management, offering improved safety profiles. This narrative review aims to evaluate the preliminary evidence on the efficacy and safety of selected plant-derived nutraceuticals for pain management. Particular attention is given to a new fixed nutraceutical formulation containing lycopene, sulforaphane (Brassica oleracea), silymarin (extracted from Silybum marianum), reduced glutathione, escin (Aesculus hippocastanum), tryptophan, and green tea (Camellia sinensis). Although this formulation has not yet been evaluated in clinical trials, preliminary data suggest that individual components may target different pain mechanisms. None of the currently available nutraceuticals act comprehensively on all pain types. Additionally, the inclusion of hepatoprotective compounds (e.g., glutathione and silymarin) may be advantageous for patients receiving multiple medications. Current evidence on these nutraceuticals remains limited and primarily preclinical. Further randomized controlled trials are needed to confirm their efficacy and safety in human pain management.