Honey is abundant in bioactive compounds, which demonstrate considerable therapeutic effects, particularly on oxidative stress and inflammation. Objectives: This work sought to evaluate the antioxidant mechanisms of Manuka honey (MH) and Ohia Lehua honey (OLH), correlating them with phytochemical analyses in a rat model of experimentally induced inflammation. Methods: The identification of polyphenolic compounds in the extracts was carried out using HPLC-ESI MS. The extracts’ antioxidant activity was evaluated in vitro through DPPH, FRAP, H₂O₂, and NO scavenging assays, while in vivo assessments included measurements of total oxidative status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI), advanced oxidation protein products (AOPP), malondialdehyde (MDA), nitric oxide (NO), and total thiols (SH). Results: The phytochemical analysis found a rich content of phenolic compounds in MH and lower quantities in OLH. In terms of in vitro activity, both MH and OLH exhibited strong DPPH radical scavenging abilities, effective NO and H₂O₂ scavenging capacities, and high FRAP-reducing power. In vivo, OLH proved highly effective in enhancing antioxidant capacity and lowering oxidative stress markers, showing significant increases in TAC and substantial reductions in TOS and OSI levels. Conversely, MH displayed limited and dose-dependent antioxidant activity, a considerable increase in TAC and SH, and a moderate decrease in TOS and OSI levels. Conclusions: To our knowledge, this is the first study to assess the phenolic content of OLH and to show its capacity to scavenge free radicals and reduce oxidative stress. The effectiveness of MH primarily relies on its increased antioxidant properties and depends on concentration. These results highlight the importance of investigating natural products in developing antioxidant strategies.

Prunella vulgaris (PV) is one of the most commonly used nutraceuticals as it has been proven to have anti-inflammatory and antioxidant properties. The aim of this study was to evaluate the phytochemical composition of PV and its in vivo antioxidant properties. A phytochemical analysis measuring the total phenolic content (TPC), the identification of phenolic compounds by HPLC-DAD-ESI, and the evaluation of the in vitro antioxidant activity by the DPPH assay of the extract were performed. The antioxidant effects on inflammation induced by turpentine oil were experimentally tested in rats. Seven groups with six animals each were used: a control group, the experimental inflammation treatment group, the experimental inflammation and diclofenac sodium (DS) treatment group, and four groups with their inflammation treated using different dilutions of the extract. Serum redox balance was assessed based on total oxidative status (TOS), nitric oxide (NO), malondialdehyde (MDA), total antioxidant capacity (TAC), total thiols, and an oxidative stress index (OSI) contents. The TPC was 0.28 mg gallic acid equivalents (GAE)/mL extract, while specific representatives were represented by caffeic acid, p-coumaric acid, dihydroxybenzoic acid, gentisic acid, protocatechuic acid, rosmarinic acid, vanillic acid, apigenin–glucuronide, hesperidin, kaempferol–glucuronide. The highest amount (370.45 μg/mL) was reported for hesperidin, which is a phenolic compound belonging to the flavanone subclass. The antioxidant activity of the extracts, determined using the DPPH assay, was 27.52 mmol Trolox/mL extract. The PV treatment reduced the oxidative stress by lowering the TOS, OSI, NO, and MDA and by increasing the TAC and thiols. In acute inflammation, treatment with the PV extract reduced oxidative stress, with lower concentrations being more efficient and having a better effect than DS.

Obesity is a chronic, relapse-prone disease often associated with comorbidities such as type 2 diabetes, dyslipidemia, and non-alcoholic fatty liver disease. Intestinal dysbiosis, defined as an imbalance in the composition and function of the gut microbiota, is commonly observed in individuals with excess body weight and plays a key role in the development of related metabolic complications. Moreover, dysbiosis can disrupt nutrient metabolism, leading to imbalances in energy homeostasis. Those affected by excess weight frequently exhibit deficiencies in essential vitamins and minerals, which further exacerbate metabolic and inflammatory dysfunctions, accelerating the progression of comorbidities. Studies have shown that the gut microbiota in individuals with obesity differs significantly from that of healthy, normal-weight individuals. Obesity often shows alterations in the relative abundance of Firmicutes and Bacteroidetes (F/B), with individual variability and reduced bacterial diversity, although the F/B ratio alone may not consistently reflect dysbiosis. Prolonged or repeated antibiotic use can further disturb the microbiota, worsening dysbiosis and contributing to the development of excess body weight by impairing energy metabolism and promoting systemic inflammation. Recent evidence suggests that probiotics are a safe and promising therapeutic approach for managing metabolic disorders. Several in vivo and clinical studies have reported a potential causal relationship between probiotic supplementation and the improvement of weight-related conditions. This narrative review aims to explore the alterations of gut microbiota in obesity and their impact on nutritional deficiencies. Additionally, it highlights the potential role of probiotics in restoring microbiota balance and improving metabolic dysfunctions related to excess body weight.