Rhoifolin

Rhoifolin is a flavone glycoside found in citrus fruits, grapefruit leaves, and Rhus succedanea that exerts anti-inflammatory and antioxidant effects primarily by inhibiting pro-inflammatory cytokine pathways and scavenging reactive oxygen species. Its apigenin-7-O-neohesperidoside structure allows it to modulate NF-κB signaling and upregulate endogenous antioxidant enzymes including superoxide dismutase and glutathione.

Origin & History

Rhoifolin is a flavonoid glycoside (specifically apigenin-7-O-rhoinoside) primarily extracted from plants such as Plumula Nelumbinis (lotus plumule) and Teucrium polium (Jordanian medicinal herb). While extraction methods aren't detailed in available research, it is typically isolated from plant materials using standard phytochemical techniques.

Historical & Cultural Context

While rhoifolin occurs in traditionally used plants like Plumula Nelumbinis and Teucrium polium, there is no documented historical use of isolated rhoifolin itself. Research notes its testing for anti-arthritic effects as novel, suggesting it lacks established traditional medicinal applications as an isolated compound.

Health Benefits

• Anti-inflammatory effects: Reduced paw edema by 14-45% in rat models (preliminary evidence)
• Antioxidant activity: Increased glutathione and superoxide dismutase while decreasing oxidative stress markers in arthritic rats (preliminary evidence)
• Anti-rheumatoid arthritis potential: 10-20 mg/kg daily showed effects comparable to indomethacin in rat models (preliminary evidence)
• Anticancer properties: Demonstrated cytotoxicity against cancer cell lines with IC50 values of 5.9-6.2 μg/mL for certain cancers (in vitro evidence only)
• Blood sugar regulation: Modulated glucokinase and glucose-6-phosphatase in diabetes models (preliminary animal evidence)

How It Works

Rhoifolin inhibits the NF-κB signaling pathway, thereby suppressing downstream production of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 that drive inflammatory cascades. It also scavenges reactive oxygen species directly and upregulates endogenous antioxidant enzymes—specifically superoxide dismutase (SOD) and glutathione (GSH)—while reducing malondialdehyde (MDA) and nitric oxide levels as markers of oxidative stress. Additionally, its apigenin aglycone core may inhibit cyclooxygenase (COX) and lipoxygenase (LOX) enzymes, contributing to its observed anti-edema effects.

Scientific Research

Current evidence is limited to preclinical studies with no human clinical trials identified. Key research includes a rat rheumatoid arthritis model (PMID: 32401927) where 10-20 mg/kg oral rhoifolin daily for one month significantly reduced inflammation and oxidative stress markers. In vitro studies demonstrated anticancer effects through apoptosis induction and migration inhibition.

Clinical Summary

Current evidence for rhoifolin is limited exclusively to preclinical in vitro and rodent in vivo studies, with no published human clinical trials to date. In rat models of carrageenan-induced paw edema, oral or intraperitoneal administration of rhoifolin reduced edema by 14-45% depending on dose and time point. In adjuvant-induced arthritic rat models, doses of 10-20 mg/kg demonstrated significant reductions in oxidative stress markers alongside restored SOD and glutathione levels. These findings are promising but cannot be extrapolated to humans without controlled clinical trial data.

Nutritional Profile

Rhoifolin (apigenin-7-O-neohesperidoside; C₂₇H₃₀O₁₄, MW 578.52 g/mol) is a flavone glycoside, not a macronutrient source. It provides no significant calories, protein, fat, fiber, or essential vitamins/minerals at bioactive doses. Key biochemical characteristics: • Classification: Apigenin disaccharide conjugate (neohesperidoside — rhamnose-glucose linkage at the 7-position of apigenin). • Natural concentrations in food sources: Found in citrus fruits (grapefruit, bitter orange), tomatoes, artichokes, and banana sheaths, typically at low mg/kg levels (e.g., ~5–50 mg/kg fresh weight in citrus peel extracts; trace to ~10 mg/kg in tomato leaves). • Bioactive compound profile: Acts as a polyphenolic antioxidant with reported IC₅₀ values for DPPH radical scavenging in the range of ~15–50 µM depending on assay conditions; inhibits NF-κB and COX-2 pathways at micromolar concentrations in vitro. • Bioavailability notes: Oral bioavailability is considered low to moderate, as the neohesperidoside sugar moiety must be cleaved by intestinal β-glucosidases and gut microbiota to release the aglycone apigenin for absorption. The glycoside form is more water-soluble (estimated aqueous solubility ~0.5–1.0 mg/mL) than free apigenin but is subject to extensive first-pass metabolism. Colonic microbiota-mediated hydrolysis is a major route for generating bioavailable apigenin and smaller phenolic metabolites (e.g., p-coumaric acid, phloroglucinol derivatives). Plasma concentrations after oral dosing in animal models (10–20 mg/kg) are generally in the low nanomolar to low micromolar range. Co-administration with lipids or formulation in nanoparticles has been explored to enhance absorption. • No established Daily Value or Recommended Dietary Allowance exists; studied doses in rat models range from 10–20 mg/kg body weight/day. Equivalent human doses (estimated by allometric scaling) would approximate 1.6–3.2 mg/kg/day, though human pharmacokinetic data remain limited.

Preparation & Dosage

Animal studies used oral doses of 10-20 mg/kg daily in rat models, with some studies testing up to 250 mg/kg. No human dosage data or standardized extract forms are available. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Other flavonoids, antioxidants like glutathione, anti-inflammatory compounds, traditional arthritis herbs

Safety & Interactions

No human safety data, established tolerable upper intake levels, or clinical adverse event profiles currently exist for isolated rhoifolin supplementation. Based on its structural similarity to other flavone glycosides, mild gastrointestinal discomfort is plausible at high doses. Rhoifolin may theoretically potentiate the effects of anticoagulant or anti-platelet drugs such as warfarin due to flavonoid-class interactions with CYP450 enzymes, though this has not been directly studied. Pregnant or breastfeeding individuals and those on immunosuppressive or anti-inflammatory medications should avoid rhoifolin supplements until safety data are established.