Iso-orientin (Flavone C-Glycoside · Antioxidant · Hepatoprotective)

Compound	Iso-orientin (Isoorientin; 6-C-Glucosylluteolin)
Chemical class	Polyphenol — Flavone C-Glycoside (luteolin with C-6 glucose)
CAS	4261-42-1
Primary source	Hordeum vulgare (barley grass), Passiflora incarnata, Crataegus spp.
Key applications	Antioxidant; hepatoprotective; AMPK-mediated glucose regulation; anti-inflammatory
Claim strength	Moderate
Typical form	Barley grass liquid extract or passionflower extract powder; orientin co-delivered as positional isomer
Buy from Herbuno	Passion Flower Extract Powder → Barley Grass Liquid Extract (Water Soluble) - Hordeum vulgare | Jau →

Name origin: Iso-orientin is the 6-C positional isomer of orientin, which carries the glucosyl unit at C-8 of the luteolin backbone; the prefix iso- denotes this regiochemical distinction. Traditional use: Barley grass (Hordeum vulgare) has been used in Ayurvedic and Chinese medicine as a cooling, liver-clearing food-medicine — the young leaf juice prescribed for jaundice, heat disorders, and digestive inflammation. Modern isolation work identified iso-orientin as a significant contributor to barley grass's antioxidant capacity, now mainstream in the green superfood market. Research trajectory: The compound's C-C glycosidic bond resists acid hydrolysis unlike O-glycosides, giving it notable metabolic stability. Research has focused on hepatoprotection via Nrf2/HO-1 induction, AMPK-mediated glucose uptake improvement, and anxiolytic activity overlapping with passionflower's GABAergic mechanism. Commercial source: Iso-orientin is available from Herbuno via Passion Flower Extract Powder and Barley Grass Liquid Extract, both delivering a spectrum of C-glycosyl flavones with iso-orientin as a key bioactive.

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Evidence for Iso-orientin Applications

Hepatoprotection: In hepatocyte models and rodent CCl₄-induced liver injury, iso-orientin activates Nrf2 and upregulates HO-1 and NQO1, reducing lipid peroxidation and ALT elevation. The Nrf2/Keap1 interaction provides mechanistic rationale for NAFLD and drug-induced liver stress formulations. Claim strength: Moderate.

Glucose regulation: Iso-orientin activates AMPK in muscle and adipose models, promoting GLUT4 translocation and improving insulin-independent glucose uptake. Rodent STZ and high-fat diet studies show reduced fasting glucose and improved insulin sensitivity. Human clinical data for isolated iso-orientin are not yet available. Claim strength: Moderate.

Antioxidant and anti-inflammatory: Iso-orientin's catechol B-ring and extended chromone conjugation confer high ORAC and DPPH scavenging capacity comparable to its aglycone luteolin. NF-κB nuclear translocation inhibition reduces TNF-α and IL-6 in macrophage models. Claim strength: Moderate.

Anxiolytic support: Passionflower's clinical anxiolytic profile — including a preoperative RCT versus midazolam — involves multiple GABAergic constituents; iso-orientin contributes alongside chrysin, vitexin, and isovitexin via 5-HT1A partial agonism. Isolated iso-orientin anxiolytic data remain preclinical. Claim strength: Emerging.

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Dosage & Formulator Specification

Iso-orientin is not the subject of standardised human dose-ranging studies. As a constituent of barley grass extract, formulators work with 2–5 g/day whole barley grass powder or 200–500 mg of a 10:1 concentrated extract. For passionflower extract standardised to flavonoids (0.8–2.5%), typical product doses of 250–500 mg provide iso-orientin alongside the full C-glycosyl flavone spectrum.

C-glycoside stability is a formulation advantage: unlike O-glycosides, iso-orientin's C-C bond is not cleaved by gastric acid or most gut brush-border glycosidases, ensuring the intact molecule reaches the colon for bacterial transformation. Highly compatible with tablet, sachet, and RTD applications without special pH protection.

Thermal stability is good up to 100 °C for short durations; extended high-heat processing causes partial degradation. In aqueous formulations, pH 4–7 is optimal. Blending with other C-glycosyl flavones (vitexin, isovitexin, orientin) from the same plant sources creates synergistic antioxidant matrices.

No significant herb-drug interactions are documented for iso-orientin in isolation; formulators should note parent plant interactions (passionflower — mild CNS depressant caution; barley grass — gluten trace risk for coeliac-sensitive markets).

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Frequently Asked Questions — Iso-orientin

How does iso-orientin differ from orientin?
Both are luteolin C-glucosides: iso-orientin is glucosylated at C-6 of the A-ring, orientin at C-8. Iso-orientin predominates in barley grass and passionflower; orientin is more abundant in rooibos. The positional difference affects receptor binding geometry and microbiome metabolism.

Is iso-orientin bioavailable after oral ingestion?
C-glycosides resist upper GI hydrolysis, reaching the colon largely intact. Colonic microbiota cleave the C-C bond, releasing luteolin and glucose for absorption. Plasma appearance of luteolin metabolites occurs 2–6 hours post-ingestion — later than O-glycoside equivalents but with sustained kinetics.

Which Herbuno products are relevant for iso-orientin formulations?
Passion Flower Extract Powder and Barley Grass Liquid Extract both deliver iso-orientin as part of their C-glycosyl flavone complement. Hawthorn Extract Powder is a third source contributing iso-orientin alongside vitexin and hyperoside.

What labels or claims are supported for iso-orientin-containing products?
Structure-function language referencing antioxidant support and liver wellness is appropriate for barley grass and passionflower extracts. Specific iso-orientin percentage claims require HPLC quantification; standardised barley grass extracts at 0.1–0.5% iso-orientin are commercially achievable.

Related compounds: Orientin, Vitexin, Luteolin, Patuletin

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Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.

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