Antioxidant Status

Multiple small RCTs demonstrate MitoQ reduces oxidative stress biomarkers. Rossman et al. (2018) found lower plasma oxidized LDL in 20 older adults. Broome et al. (2021) reported reduced F2-isoprostanes post-exercise in 19 cyclists. Moradbaki et al. (2025) showed improved GPx, CAT, SOD, and reduced MDA in 42 septic shock patients. Effects consistent across populations.

A controlled clinical trial (PMID:34401649) demonstrated upregulation of NRF2, SOD2, CAT, and GPX4 antioxidant gene expression in human sperm cells. Animal studies (PMID:38145102) confirm reduced oxidative stress markers against hepatotoxic and testicular insults. Antioxidant activity is considered a primary mechanism underlying reproductive benefits.

A randomized crossover trial demonstrated upregulated NRF2, GPX7, GSR, GSTM3, and PRDX6 gene expression in human skeletal muscle biopsies — the first in vivo confirmation in humans. In vitro studies in human myoblasts showed SOD activity increased 34-37%, GPx 72-83%, and CAT 37-42%. Supported by animal data showing enhanced liver GPx and GSH.

In vitro assays (ORAC, DPPH) demonstrate high antioxidant capacity from chaga's melanin and polyphenol content. Animal models show reduced oxidative stress markers. Polysaccharide fractions from wild chaga conks show greater activity than cultivated mycelium.

An open-label trial in 8 aging HIV patients (12 weeks) and a pilot study in 10 T2D patients (14 days) both found GlyNAC supplementation corrected glutathione deficiency, with benefits reversing upon cessation in the HIV trial washout period.

Two small human trials (HIV patients and T2D patients) found GlyNAC reduced oxidative stress markers. The T2D pilot showed a 47% reduction in methylglyoxal (p<0.01). A review of glutathione supplementation in HIV/TB populations supports these findings.

Multiple human studies found that L-cysteine supplementation protected against exercise-induced oxidative stress, preventing DNA oxidation, preserving erythrocyte G6PD activity, and maintaining erythrocyte membrane ATPase activities during forced training.

An RCT in metabolic syndrome patients (n~100) found curcuminoids plus 10 mg piperine significantly increased SOD activity and decreased MDA vs. placebo over 8 weeks. A separate RCT in hemodialysis patients (n=49) showed turmeric + piperine was superior to turmeric alone in reducing oxidative stress markers. An RCT in stroke patients (n=56) showed significant increases in total antioxidant capacity.

Extensive in vitro and animal studies demonstrate strong DPPH radical scavenging, ferric-reducing antioxidant activity, superoxide dismutase stimulation, and improved glutathione levels. Key polyphenols include gallic acid, ellagic acid, chebulagic acid, and chebulinic acid. Human RCTs report improvements in oxidative stress biomarkers.

Multiple in vitro studies confirm strong free radical scavenging and antioxidant activity of mulberry fruit extracts, attributed to anthocyanins and phenolic compounds (PMID:22408465, PMID:19241543). In vivo studies in rats showed enhanced antioxidant enzyme systems (PMID:29767238). Flavonoid fractions demonstrated both in vitro and in vivo antioxidant activity (PMID:27076749).

Multiple preclinical studies demonstrate salidroside reduces oxidative stress across diverse models including neuronal cells, cardiomyocytes, and C. elegans. Mechanisms involve direct antioxidant activity and upregulation of endogenous antioxidant defenses.

In cell culture and animal models, 7,8-DHF demonstrated antioxidant effects through HO-1 expression activation, Nrf2 signaling, and caspase inhibition. Protected endothelial cells and neurons against H2O2 and high-glucose-induced oxidative damage. Also reduced lipid peroxidation in a phenylketonuria model.

In cell-free and chemical oxidation assays, capsanthin and capsorubin demonstrate strong antioxidant activity, scavenging superoxide anion, hydroxyl radical, and singlet oxygen. Capsorubin shows greater oxidative stability than capsanthin, and both are markedly more resistant to free radical degradation than beta-carotene or yellow xanthophylls. A 2021 review confirms these carotenoids are detectable in human red blood cells after dietary paprika intake, though oral bioavailability from paprika oleoresin is low.

In vitro studies consistently show clove has exceptionally high antioxidant capacity among spices. Eugenol, gallic acid, and flavonoids contribute to radical scavenging activity confirmed across cold-pressed oil, essential oil, and aqueous extract preparations. Systemic bioavailability and clinical relevance in humans remain unestablished.

Multiple preclinical studies document increased antioxidant enzyme activity (SOD, catalase, glutathione) and decreased lipid peroxidation in brain tissue following Convolvulus pluricaulis administration. Antioxidant effects are consistently observed across neuroprotection, memory, and ischemia models in rodents.

In vitro studies show strong antioxidant activity in DPPH and ORAC assays, with some bibenzyl compounds exceeding vitamin C potency. No human trials have assessed antioxidant outcomes.

In vitro and animal studies show haskap berry extracts reduce intracellular ROS, upregulate SOD, CAT, GPX1, and HMOX1 expression, and increase NOS activity in aortic tissue. Haskap contains up to 1.6x more antioxidants than blueberries by ORAC, with cyanidin-3-O-glucoside comprising 79-92% of total anthocyanins.

In animal and in vitro studies, longan extracts (particularly pericarp and flower) demonstrate potent antioxidant activity exceeding glutathione and Trolox. In rodent models, longan pericarp extract increased catalase (121-144%), SOD (128-153%), and GPx (111-126%) while reducing lipid peroxidation markers. Key bioactive polyphenols include ellagic acid, corilagin, and epicatechin.

In vitro studies confirm that hesperidin and other flavonoids from orange peel exhibit strong antioxidant capacity via free radical scavenging (electron spin resonance assays) and protection against oxidative stress in cell models. Human bioavailability data remain limited.

In vitro and animal studies show C3G prevents H2O2-induced oxidative damage in HepG2 cells, protects against ochratoxin A-mediated oxidative damage in rats, activates Nrf2/HO-1 antioxidant pathways, and ameliorates diabetic nephropathy through regulation of the glutathione pool. Antioxidant liposome formulations have been developed. Bioavailability concerns limit translational relevance.

Multiple in vitro studies demonstrate antioxidant activity of D-limonene and limonene-rich citrus peel essential oils, including DPPH radical scavenging. No human clinical trials have specifically evaluated D-limonene's antioxidant effects in vivo.

In vitro studies demonstrate that loquat leaf flavonoids (quercetin, kaempferol glycosides, chlorogenic acid) inhibit free radical generation and lipid peroxidation. In animal NASH models, seed extract enhanced antioxidant enzyme activity and reduced oxidative DNA and lipid damage markers (8-OHdG, 4-HNE).

In vitro studies demonstrate myricetin has antioxidant properties, though it can switch to prooxidant behavior in the presence of copper(II) ions. Its antioxidant capacity is well-characterized biochemically but unvalidated in human studies.

Multiple in vitro studies and chemical characterization analyses confirm sericin possesses antioxidant activity, including free radical scavenging capacity. A 2025 study of Portuguese silkworm cocoon sericin confirmed bioactive antioxidant properties, though no human trials have been conducted.

Brassinosteroids show moderate antioxidant capacity in cell-free and cell culture systems. Plant studies confirm brassinosteroids reinforce antioxidant defenses under stress conditions, but no human or mammalian in vivo antioxidant data exists.

In vitro studies show flavonoids and procyanidins from C. pinnatifida fruit provide antioxidant activity, including reduction of LDL oxidation. NIRS-based analysis confirmed significant antioxidant capacity of fruit extracts. A formula combining hawthorn with Salvia miltiorrhiza showed enhanced antioxidant effects.

In vitro studies demonstrate chlorophyllin scavenges free radicals and reduces lipid peroxidation via its porphyrin ring structure. A series of studies showed protective effects against peroxidative damage in rat liver lysosomes. However, no controlled human trials have confirmed systemic antioxidant effects.

Aqueous extracts of S. tenuifolia demonstrated radical scavenging, reducing activity, and liposome protection in vitro, attributed to polyphenolic components including hesperidin, luteolin, and diosmetin. In UVB-irradiated hairless mice, ethanolic extract reduced wrinkle formation, collagen degradation, and AGE accumulation while upregulating hyaluronan synthases and hyaluronic acid levels, suggesting protection against oxidative skin damage. All evidence is preclinical.

In rodent and animal models, D-glucuronolactone supplementation increased antioxidant enzyme activities including superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and glutathione (GSH) levels. In thioacetamide-treated rats, 75 mg/kg DGL elevated trolox equivalent antioxidative capacity (TEAC). Similar antioxidant effects were observed in Chinese soft-shelled turtles (reduced MDA) and laying hens. All evidence is preclinical; no human data.

In aged mice, P. olacoides extract (100 mg/kg) reduced free radical production in hypothalamus, decreased lipid peroxidation across multiple brain regions, and increased catalase and glutathione peroxidase activity in hippocampus and cortex.

Multiple in vitro studies demonstrate strong antioxidant capacity of Persicaria minor extracts, including DPPH radical scavenging (up to 89.5%), high ORAC values (16,964 μmol TE/g), and LDL oxidation inhibition. One animal study showed cellular antioxidant protection of red blood cells. No human studies have specifically measured antioxidant outcomes.

Multiple in vitro studies demonstrate piceatannol has superior radical scavenging activity compared to resveratrol due to its additional hydroxyl group. Effectively scavenges hydroxyl and peroxyl radicals (PMID:18959413) and shows greater antioxidant potency than resveratrol in structure-activity comparisons (PMID:15748702).

In an in vitro study, γ-PGA demonstrated 85.2% hydroxyl radical scavenging at 1 mg/mL, 94.1% superoxide anion radical scavenging, and 96.0% lipid peroxidation inhibition. It showed complete protective effects in Caco-2 intestinal cells against oxidative damage, with antioxidant capacity remaining stable through simulated digestion.

In vitro studies demonstrate that capsanthin and other paprika-derived carotenoids exhibit antioxidant activity. A 2023 review summarized the pharmacological activities of capsanthin including free radical scavenging, but human clinical trials specifically on paprika extract are lacking.

Multiple reviews document squalene as a highly effective oxygen-scavenging agent that quenches singlet oxygen and prevents lipid peroxidation. In vitro studies confirm antioxidant activity, and squalene is a major lipid-soluble antioxidant in human skin (comprising ~13% of sebum). Mouse studies showed squalene increased paraoxonase 1 activity and decreased oxidative stress markers. Direct human supplementation trials for antioxidant endpoints are lacking.

In vitro studies demonstrated that Acorus calamus leaf extract exhibited significant free radical scavenging activity comparable to ascorbic acid in DPPH and hydrogen peroxide assays, with dose-dependent ferric ion reduction in the FRAP assay (Haran et al. 2024). A 2020 review also noted antioxidative properties among the documented pharmacological effects.

In vitro, Trichopus zeylanicus significantly scavenged free radicals, reduced lipid peroxidation, inhibited lipoxygenase activity, exhibited iron-chelating activity, and protected against ROS-induced DNA damage. The herb contains NADH, polyphenols, and sulfhydryl compounds. In aged mice, the extract increased antioxidant status in liver mitochondria and showed greater lipid peroxidation inhibition than Ganoderma lucidum.

In vitro studies demonstrate strong radical scavenging capacity of bearberry leaf extract (90.4 mmol Trolox equivalents/g dry weight by ABTS assay), with ability to retard lipid oxidation in model food systems. Phytochemical profiling confirms high phenolic acid and tannin content contributing to antioxidant properties.

In preclinical studies, the flavonoid-rich extracts of Butea monosperma showed antioxidant activity, which is proposed to underlie its hepatoprotective and cytoprotective effects. Evidence is limited to in vitro and animal models.

In vitro studies demonstrate cocoa flavanols and procyanidins protect human erythrocytes against free radical-induced hemolysis and protect liposomes from lipid peroxidation. Phenolic-rich cocoa powder with high flavanol content shows improved antioxidant capacity in food matrices. No controlled human antioxidant status trials are in the provided evidence set.

In vitro studies demonstrated that quercetin, myricetin, and fisetin serve as intracellular electron donors for erythrocyte trans-plasma membrane oxidoreductase, representing an additional antioxidant mechanism beyond direct radical scavenging. Quercetin metabolites isorhamnetin and tamarixetin showed comparable electron-donating activity to the parent compound.

A pharmacological review noted antioxidant properties among the broad biological effects of R. carthamoides preparations. A 2025 C. elegans study demonstrated enhanced resistance to paraquat-induced oxidative stress following treatment with maral root extract and 20-hydroxyecdysone.

In vitro and animal studies demonstrate pelargonidin's strong electron-donating capabilities underlying its antioxidant mechanism. In animal models, pelargonidin increased protective serum levels of glutathione and catalase while reducing nitrite (an oxidative stress marker). Computational studies confirm favorable radical-scavenging structural properties.

Preclinical research demonstrates significant antioxidant potential across lipophilic and hydrophilic fractions of Salvia officinalis. Contains rosmarinic acid, carnosic acid, and carnosol, but human clinical data on antioxidant outcomes is lacking.

In vitro and animal studies across all three Shivlingi-related species show antioxidant activity. Diplocyclos palmatus fruits demonstrated scavenging activity against hydroxyl, nitric oxide, and DPPH radicals. Bryonia laciniosa reduced MDA levels and enhanced catalase and glutathione peroxidase activity in cadmium-exposed rats.

In vitro characterization of Flor-Essence, a compound herbal product containing slippery elm bark among other herbs, identified phenolic compounds with antioxidant properties. However, the contribution of slippery elm specifically versus other ingredients was not isolated, and no in vivo or clinical evidence exists.

In diabetic rats, Tulbaghia violacea extract increased antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase), elevated plasma nitric oxide, and reduced lipid peroxidation markers (TBARS) in liver tissue.

In male albino rats, oral jojoba oil co-administration with the pesticide fipronil significantly enhanced antioxidant enzyme activities (SOD, CAT) and glutathione levels while reducing oxidative stress markers, compared to fipronil alone. This is a single animal toxicology study and the antioxidant effects were demonstrated in the context of toxicant-induced oxidative stress, not baseline supplementation.

An in vitro study (1991) demonstrated that calcium L-threonate stimulated ascorbic acid uptake by human T-lymphoma cells in a dose-dependent manner. This provides mechanistic support for L-threonate enhancing cellular vitamin C bioavailability, but has not been confirmed in vivo.

Preclinical studies report antioxidant activity of Chlorophytum borivilianum extracts, attributed to its saponin and polysaccharide content. Evidence is limited to in vitro and early animal models.