Background:
Probiotics, live microorganisms known for their gut health benefits, are increasingly recognized for their potential to enhance antioxidant capacity and reduce oxidative stress and inflammation. This is particularly important in inflammaging, digestive problems, cardiometabolic conditions, and neurodegenerative diseases, where oxidative stress and gut dysbiosis are common. Compared to direct antioxidant supplementation, probiotics may offer more comprehensive benefits by simultaneously modulating the gut microbiota and promoting endogenous antioxidant defenses.

Objective:
This narrative review explores how probiotics influence antioxidant capacity and the gut microbiota, emphasizing their potential advantages over traditional antioxidant supplements.

Methods:
A review of the existing literature on the effects of probiotics on the gut microbiota, antioxidant biomarkers, and related health outcomes was conducted.

Results:
Probiotic supplementation consistently increased endogenous antioxidant enzymes, including catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC). It also decreased oxidative stress markers such as malondialdehyde (MDA) and hydrogen peroxide (H₂O₂). Unlike direct antioxidants, probiotics act through multiple pathways: modulating the gut microbiota, enhancing the gut barrier, and stimulating the immune system. These effects were particularly notable in patients with disease-related oxidative stress. While all probiotics contribute to antioxidant capacity and gut health, Lactobacillus rhamnosus, Lactobacillus casei, and Bifidobacterium longum stand out for their pronounced effects on reducing oxidative stress and improving gut-related conditions. Their targeted actions make them ideal candidates for managing chronic diseases associated with inflammation and oxidative damage.

Conclusion:
Probiotics provide significant antioxidant benefits while restoring gut microbiota balance. This integrative approach makes probiotics potentially more effective than traditional antioxidants, particularly for patients with diseases characterized by oxidative stress and inflammation.

Species of the genus Achillea L. (Asteraceae) are recognized as valuable sources of natural antioxidants and are widely used for their diverse pharmacological properties. This study aimed to examine the phenolic composition of the methanolic extract of the aerial parts of yarrow, Achillea clypeolata (ACE), as well as its cytotoxicity, antioxidant effects, and the potential molecular mechanisms involved in angiogenesis, which plays a crucial role in wound healing. The extract's composition was analyzed using the HPLC method. Total polyphenol content (TPC) of 116.69±8.18 mg GAE (gallic acid equivalent)/g dry extract was determined viathe Folin–Ciocalteu assay. Antioxidant activity was assessed spectrophotometrically, showing 38.68±2.29 μmol Trolox equivalents pergram of dry extract based on the ABTS radical inhibition and an IC₅₀ (concentration required to neutralize 50% of free radicals) value of 685.6±9.8 μg/mL for DPPH• radical scavenging. Cytotoxicity was evaluated in HaCaT human keratinocyte cells over a concentration range of 1 to 200 μg/mL, identifying concentrations below 50 μg/mL as non-cytotoxic. The production of intracellular reactive oxygen species (ROS) in HaCaT cells exposed to the extract with or without hydrogen peroxide treatment was measured using the H2DCFDA assay. The results demonstrated that ACE is rich in flavonoids and phenolic acids with significant in vitro antioxidant potential. It also effectively reduced ROS levels in HaCaT cells. The impact of ACE on pro-angiogenic factors (VEGFA, HiF1α, and MIF) was evaluated at the protein level using cell-based ELISA, and it was shown that ACE at 25 μg/mL significantly enhanced the expression of all examined factors. These findings suggest that ACE is a promising bioactive compound with potential uses in the pharmaceutical and cosmetic industries, as well as in the creation of scaffolds that encourage angiogenesis and wound healing.

Punica granatum (pomegranate) possesses strong antibacterial, antiviral, antioxidant, and anti-inflammatory activity due to the presence of various organic acids, alkaloids, phenolic acids, tannins, flavonoids, anthocyanins, sugars, fatty acids, and vitamins. Thus, in the present study, spray-dried pomegranate peel extract was examined in terms of its cytotoxicity and antioxidant, anti-inflammatory, and sun protection potential. The extract showed a concentration-dependent effect on keratinocyte viability, producing a decrease in the viability of the HaCaT cells with rising concentrations. While 25 µg/mL did not significantly reduce cell viability (12% reduction), concentrations of 50 and 100 µg/mL showed a more profound effect (23% and 27% reductions, respectively). In cells exposed to the extract alone, without H₂O₂, there was no significant change in reactive oxygen species (ROS) levels compared to a non-treated control. Keratinocytes pre-incubated with three different concentrations of peel extract (25, 50, and 100 µg/mL) for 24 h before H₂O₂ exposure showed significantly decreased levels of ROS compared to ones treated with H₂O₂ alone. All three examined concentrations showed a similar decrease in ROS production. In the cell line treated with spray-dried peel extract without lipopolysaccharide (LPS), there was no significant change in the expression of interleukin 1β or macrophage inhibitory factor (MIF), indicating the absence of any pro-inflammatory effects from the extract. In the LPS-treated cells, the extract significantly reduced interleukin 1β and MIF expression when pre-incubated for 24 h compared to LPS alone, confirming the anti-inflammatory potential of the extract against an LPS challenge. Additionally, the extract provided a sun protection factor (SPF) of 11.33±0.33 (at a concentration of 100 µg/mL), and significantly lower SPF values, 3.11±0.05 and 5.97±0.21, at lower concentrations (25 and 50 µg/mL, respectively), while an SPF of 6 is generally considered the minimum degree of UVB protection required for sunscreen products.

Oxidative stress and inflammation are key contributors to various chronic diseases, necessitating the discovery of natural compounds with therapeutic potential. Urtica dioica, commonly known as stinging nettle, has been traditionally used for its medicinal properties, but its essential oil remains underexplored. This study aimed to evaluate the antioxidant properties of Urtica dioica essential oil (UDEO) through an integrative approach involving in silico, in vitro, and in vivo analyses. The phytochemical composition of UDEO was investigated to identify bioactive compounds with significant biological roles. Gas chromatography combined with triple quadrupole mass spectrometry (GC-MS/MS) revealed 97 thermolabile compounds, highlighting the complex chemical profile of the essential oil. To enhance analytical precision, various injection methods using the multimode inlet (MMI) in chromatography were optimized, achieving lower instrumental detection limits. Standard antioxidant assays, including ABTS•+ radical scavenging and total antioxidant capacity (TAC), demonstrated UDEO’s strong antioxidative potential. In silico studies further indicated that several identified compounds may target inflammatory mediators such as cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). These findings suggest that UDEO may exert anti-inflammatory effects by modulating key pathways involved in oxidative stress and inflammation.

The study assessed the antioxidant properties of UDEO through a comprehensive approach, revealing its therapeutic potential in managing oxidative stress and inflammatory conditions. This work underscores the importance of exploring essential oils as a source of natural bioactive compounds for pharmacological applications.

PHYTOCHEMICAL COMPOSITION AND IN VITRO ANTIOXIDANT ACTIVITY OF Hibiscus sabdariffa calyxes.

Nworah, F. N., *Orji, O. C., Ibegbulam, E. G.

Pharmacology and Pharma-biology Unit, Department of Biochemistry, University of Nigeria, Nsukka, Enugu State, Nigeria.

Corresponding author email: *oyidiya.orji.pg00232@unn.edu.ng

ABSTRACT

Hibiscus sabdariffa calyxes has long been used in traditional food and medicine, including cold or hot drinks, jellies, puddings, and as flavoring agents. This study evaluated the phytochemicals composition and in vitro antioxidant activities of Hibiscus sabdariffa calyxes in aqueous extract form. The analysis qualitatively and quantitatively identified several phytochemicals, revealing 4634.41 ± 10.75 mg of total phenolics, 329.99 ± 4.57 mg of alkaloids, 179.38 ± 0.83 mg of flavonoids, 14.42 ± 0.23 mg of tannins, 1.69 ± 0.00 mg of glycosides, 3.45 ± 0.00 mg of steroids, 173.48 ± 0.13 mg of reducing sugars, and 137.70 ± 2.77 mg of terpenoids per 100 grams of extract. The antioxidant activity was measured through several assays. The DPPH radical scavenging assay resulted in an EC50 of 34.89 µg//ml, compared with the standard at 29.9 µg//ml. Lipid peroxidation inhibition showed an EC50 of 8.53 µg//ml, compared to 2.73 µg//ml for the standard. Nitric oxide scavenging had an EC50 of 3.217 µg//ml, while the standard was shown to have a value of 0.895 µg//ml. The ferric reducing antioxidant power (FRAP) assay demonstrated the extract’s ability to reduce Fe³+ to Fe²+. Additionally, the extract reduced molybdenum (vi) to molybdenum (v). This study on Hibiscus sabdariffa calyxes confirms that the aqueous extract from Hibiscus sabdariffa calyxes is rich in phenolics, contributing to its antioxidant properties and supporting its traditional medicinal uses.

Keywords: Hibiscus sabdariffa, antioxidant, phytochemicals, calyxes

Introduction

Lycium fruits, commonly known as "goji berries," are recognized as superfoods with diverse bioactive properties. Lycium chinense has been introduced in the dendrological park "Olexandria" in the northeastern part of the Right Bank Forest-Steppe of Ukraine, yet data on the bioactivity of the goji berries grown there remain limited. This study aims to evaluate the antioxidant and anticancer potential of L. chinense cultivated in Ukraine.

Methods

Defatted berries were extracted with methanol/water (60:40, v/v) using a Soxhlet apparatus. The extract was used for the determination of total phenolic content (TPC) and total flavonoid content (TFC) through the Folin–Ciocalteu and AlCl3 procedures, respectively. Antioxidant activity was assessed using DPPH radical scavenging and β-carotene bleaching assays, while antiproliferative effects were evaluated by the MTT assay.

Results

The hydroalcoholic extraction of goji berries under the previously described conditions yielded 16.9% in dry weight. TPC was 11.3 mg GAE/g DW fruits, while TFC was 7,3 mg rutin/g DW. The extract demonstrated significant antioxidant capacity (DPPH IC50 = 125.9 ± 12.6 µg/ml) and lipid peroxidation inhibition (23.5 ± 2.1% in the β-carotene assay). The MTT assay showed concentration- and time-dependent inhibition of HT-29 colorectal cancer cells (GI50 at 72 h = 250 µg/ml) with a selectivity index (SI) of 13 against CCD-18 normal cells, indicating strong selectivity.

Conclusions

This is the first study to report on the antioxidant and anticancer properties of L. chinense cultivated in Ukraine. The findings suggest that Ukrainian goji berries are a promising source of natural antioxidants and demonstrate notable antiproliferative effects on HT-29 cells. Further research should explore the goji berries' polyphenolic composition, assess their local cultivars, and investigate potential uses for goji berry by-products.

The preservation of antioxidants during vegetable preparation and cooking remains a critical concern in both domestic and commercial food preparation. This study synthesizes current research on optimal cooking methods and their impact on the retention of vital phytochemicals in commonly consumed vegetables. Studies indicate that water-based cooking methods can result in a 20-60% loss of water-soluble antioxidants, particularly vitamin C and polyphenols. Steam cooking emerges as a superior method, preserving up to 80% of antioxidant content compared to boiling. The application of minimal thermal processing techniques, maintaining temperatures below 120°C, demonstrates significant benefits in retaining heat-sensitive compounds. Research reveals that lipid-soluble antioxidants, including carotenoids and vitamin E, show enhanced bioavailability when vegetables are prepared with small amounts of healthy fats, increasing absorption rates by 2.4-5 times. Mechanical processing techniques, such as chopping and slicing, should be minimized or performed immediately before cooking, as cellular disruption can lead to the enzymatic degradation of beneficial compounds. Notably, some vegetables, including tomatoes and carrots, exhibit increased antioxidant activity when subjected to moderate heat treatment, with lycopene availability increasing by up to 164% through controlled cooking. The implementation of time—temperature optimization proves crucial, with brief cooking durations (3-5 minutes) at moderate temperatures (85-95°C) showing optimal results for most vegetables. This research also addresses the significance of proper storage conditions, suggesting that storing vegetables at 4°C can preserve up to 90% of their antioxidant content for 5-7 days. These findings provide evidence-based recommendations for both home cooks and food service professionals to maximize the nutritional benefits of prepared vegetables while maintaining their sensory qualities.

Chronic inflammation, particularly in arthritis, affects millions worldwide, leading to pain, reduced mobility, and diminished quality of life. Conventional therapies such as NSAIDs, corticosteroids, and biologics provide symptomatic relief, but are associated with adverse effects like gastrointestinal issues, cardiovascular risks, and increased susceptibility to infections. This highlights the need for safer, alternative therapeutic strategies. Plant-based therapies have gained attention due to their potential antioxidant and anti-inflammatory properties. In this context, the present study investigated the antioxidant and anti-arthritic potential of Micrococca mercurialis stem (MMS) extract. Bioactive compounds, including total phenolics (TPC) and flavonoids (TFC), were quantified using standard assays. Their antioxidant capacity was evaluated through DPPH, ABTS, and total antioxidant capacity assays. Anti-arthritic efficacy was assessed in a Complete Freund’s Adjuvant (CFA)-induced arthritis model in rats. MMS extract was administered at doses of 200 and 400 mg/kg and compared with the standard drug, indomethacin. A methanolic extract of MMS showed significant bioactive content, with TPC and TFC values of 112.12 ± 4.47 mg GAE/g and 12.54 ± 0.52 mg QE/g, respectively. The ABTS radical scavenging activity (IC₅₀ = 62.85 ± 2.25 µg/mL) was stronger than DPPH activity (88.16 ± 2.01 µg/mL) and comparable to gallic acid. In the anti-arthritic model, MMS extract exhibited dose-dependent effects. The 400 mg/kg dose showed comparable efficacy to indomethacin (10 mg/kg) at all time points (days 4, 8, 14, and 21), with significant paw volume reduction (p < 0.001). Hematological parameters such as RBC, WBC, Hb, and ESR, elevated due to inflammation, were normalized in the high-dose group. The methanol extract of Micrococca mercurialis stem demonstrated potent anti-inflammatory and antioxidant activities, suggesting its potential as a source of novel therapeutic agents for inflammatory conditions.

Gut microbiota and human health are in a symbiotic relation ship and work together to mentain the healthy state. Since the gut microbiota display key immunological and anti oxidative tasks, the altered gut microbiota balance can lead to the development of sistemic inflammation and accelerate the multiple Sclerosis (MS) progression. Some gut bacteria population produce reactive oxygen species (ROS). When these type of bacteria are increased the pro and anti oxidative unbalance appear that alter gut epithelial barrier and trigger systemic inflammation, acting fair away from gut (at brain level) throught gut inflammatory and pro-oxidative signals. Growing evidence show that targeting gut microbiota can be a promising strategy for the MS diseases management. Our hypothesis is that anti oxidant compounds that add multi species beneficial bacteria and promote "good" bacteria growth by fibre substitutes (inulin) decrease ROS production. MS patients (n=25) that received multi species bacteria and inulin and 15 MS patients without supplements were included in this pilot studies. Biomarkers of oxidative stress (e.g protein carbonyl, lipids per oxidation) and anti oxidative response (e.g GSH, SOD, CAT) together with inflammatory biomarkers and intestinal barrier biomarkers (e.g zonulin) was measured in both group. All these biomarker was correlated with MS diseases status and progression using valid scales such as EDSS scale. Results: we showed a reduction of pro-inflammatory cytokines, an improvement of mitochondrial disfunction and decrease in ROS production by multi species bacteria supplements in combination with fibre substitutes such as inulin. These compounds enhance the action of standard therapy in MS people, positively impacting the diseases status and MS progression.

Onion (Allium cepa L.) is one of the most important vegetable crops worldwide. However, its processing generates significant amounts of waste, primarily consisting of peels and skins. Despite being rich in bioactive compounds, these residues are typically discarded in landfills, raising environmental challenges.
This study aims to valorize onion skin (OS) wastes by producing flavonoid-rich extracts with significant bioactive potential. The specific objectives include analyzing the chemical composition of the extracts, specifically their phenolic content, assessing their antioxidant, antidiabetic, and anti-inflammatory activities, and their antimicrobial effects, along with their cytotoxicity on human cells to ensure their safety.
The primary components in the OS extracts were phenolics and flavonoids, with quercetin and quercetin-4’-O-glucoside being the major identified phenolics, while sugars and proteins were present at less than 11%. The extracts exhibited strong ^●NO radical scavenging activity and even greater efficiency against O₂^●- anion radical (IC₅₀=26-27.7µg/mL). In terms of antidiabetic activity, the extracts completely inhibited aldose-reductase and α-glucosidase while preserving α-amylase activity, thus avoiding side effects associated with its inhibition. Anti-inflammatory effects were demonstrated by inhibiting 5-lipoxygenase (IC₅₀=30.2-47µg/mL) and reducing NO production in IFN-activated BV-2 cells to basal levels, indicating anti-neuroinflammatory potential, without showing cytotoxic effects on human cell lines. Additionally, the antimicrobial properties of the extracts were highlighted by their effective anti-dermatophytic activity. In summary, OS has been shown to be a natural source of flavonoids, mainly quercetin and its glucosides, exhibiting diverse biological activities and a favorable safety profile. These findings support their potential application in food supplements, functional foods, and nutraceuticals.