Orientin (Luteolin-8-C-Glucoside · Flavone C-glycoside · Anxiolytic · Cardioprotective)
| Compound | Orientin (Luteolin-8-C-glucoside) |
| Chemical class | Polyphenol — Flavone C-glycoside (Luteolin with C-8 glucose attachment) |
| CAS | 28957-04-2 |
| Primary source | Passiflora incarnata (passionflower), Crataegus spp. (hawthorn), Ocimum basilicum (basil) |
| Key applications | Anxiolytic; antioxidant; anti-inflammatory; cardioprotective; anti-hyperglycaemic |
| Claim strength | Moderate |
| Typical form | Passionflower extract (orientin co-delivered with vitexin); hawthorn extract; orientin isolate |
| Buy from Herbuno |
Passion Flower Extract Powder → Vitexin 1.8% Powder (Hawthorn Extract) | Standardized Crataegus monogyna → |
Name origin: From Orientalis (Latin: eastern) — reflecting the geographic origin of plants from which it was first characterised. Orientin is a flavone C-glycoside — the luteolin aglycone linked via a direct C-C bond (not an ester or ether bond) to glucose at position 8. This C-glycosidic bond makes orientin considerably more stable to hydrolysis and gut bacterial degradation than equivalent O-glycosides, resulting in better colonic bioavailability than many flavonoid O-glycosides. It co-occurs in most plants alongside its isomer isoorientin (luteolin-6-C-glucoside), and both are structurally related to vitexin (apigenin-8-C-glucoside) and isovitexin (apigenin-6-C-glucoside). Traditional use: Passionflower (Passiflora incarnata) has been used in European and North American traditional medicine since the 19th century as a sedative and anxiolytic — approved by Germany’s Commission E for nervous restlessness. Hawthorn (Crataegus) with high orientin content has a 2,000-year history in European and Chinese traditional medicine for cardiac support. Research trajectory: Orientin has broad preclinical pharmacological evidence across anxiolytic, cardioprotective, antioxidant, and anti-hyperglycaemic domains, with mechanistic consistency across studies. Human clinical data are limited but passionflower extract RCTs (which include orientin) support the anxiolytic application. Commercial source: Passionflower extract and Vitexin-standardised Hawthorn extract from Herbuno co-deliver orientin.
Evidence for Orientin Applications
Anxiolytic — passionflower extract context: Multiple RCTs of standardised passionflower extract (typically standardised to vitexin/orientin) show significant anxiolytic benefit comparable to low-dose oxazepam in preoperative anxiety management (Movafegh et al., 2008; Akhondzadeh et al., 2011). The mechanism involves orientin and vitexin acting on GABA-A receptors (positive allosteric modulation, similar to but weaker than benzodiazepines) and MAO inhibition. Orientin specifically has been shown to modulate 5-HT1A receptors in animal anxiety models. Claim strength: Moderate (from extract RCTs; orientin-specific contribution within extract).
Cardioprotective and anti-ischaemic: Orientin is cardioprotective in myocardial ischaemia-reperfusion animal models — reducing infarct size, preserving cardiac function, and reducing apoptosis via PI3K/Akt and Nrf2 activation. Orientin’s antioxidant activity (scavenging ROS during reperfusion injury) is a primary mechanism. These findings align with hawthorn’s traditional cardiovascular use. Claim strength: Moderate (animal models).
Anti-hyperglycaemic — GLUT4 and AMPK: Orientin activates AMPK and promotes GLUT4 translocation in muscle cells, improving glucose uptake independently of insulin. In diabetic animal models, orientin reduces fasting blood glucose, improves insulin sensitivity, and reduces oxidative stress associated with hyperglycaemia. Claim strength: Moderate (animal; in vitro mechanism).
Passion Flower Extract Powder →
Vitexin 1.8% Powder (Hawthorn Extract) | Standardized Crataegus monogyna →
Browse Standardised Extract Powders →
Dosage & Formulator Specification
Passionflower extract standardised to total flavonoids (typically 3.5–4% vitexin equivalents, which includes orientin): 200–400 mg/day for anxiolytic applications. Hawthorn extract standardised to vitexin and orientin: 160–900 mg/day for cardiovascular support. Orientin as an isolated ingredient is not commercially established at supplement scale — delivery through standardised passionflower or hawthorn extract is preferred. C-glycosides like orientin are relatively resistant to heat and acidic processing, making them stable in most supplement formulation conditions. Request HPLC quantification of both orientin and its isomer isoorientin on CoA, as both contribute to pharmacological activity.
Frequently Asked Questions — Orientin
What is the difference between orientin and vitexin?
Both are flavone C-8-glucosides from the same plant sources. Orientin has luteolin as its aglycone (3’,4’-dihydroxy flavone — two hydroxyl groups on the B-ring). Vitexin has apigenin as its aglycone (4’-hydroxy flavone — one hydroxyl on the B-ring). The additional 3’-hydroxyl of orientin relative to vitexin gives orientin slightly stronger antioxidant activity (catechol B-ring is more antioxidant than 4’-OH alone) but similar anxiolytic and GABA-modulating properties. Both are present in passionflower and hawthorn and are considered synergistic co-actives.
Does orientin cross the blood-brain barrier?
C-glycosides in general have limited blood-brain barrier penetration due to their hydrophilicity from the glucose unit. However, orientin has demonstrated CNS anxiolytic and neuroprotective activity in animal studies via systemic administration — suggesting partial BBB penetration or indirect CNS effects via peripheral mechanisms (vagal afferents, gut-brain axis). The GABA-A modulatory activity of passionflower extract is well-established clinically despite this apparent BBB limitation, suggesting that either sufficient orientin reaches the CNS or that peripheral mechanisms mediate the anxiolytic effect.
Is orientin safe in pregnancy?
Passionflower (the primary orientin-delivering botanical) has historical use as a uterotonic in some traditions — both Commission E and ESCOP note that passionflower preparations are not recommended during pregnancy due to insufficient safety data. This precautionary stance applies to orientin-containing passionflower products. Hawthorn-derived orientin preparations lack specific pregnancy contraindication language but should also be used with caution given the absence of clinical safety data in pregnancy.
How stable is orientin in food and supplement processing?
Orientin’s C-glycosidic bond makes it significantly more thermostable than comparable O-glycosides (which can be hydrolysed by acids and enzymes during food processing). Orientin survives pasteurisation temperatures, mild acidic conditions, and short-term UV exposure better than most flavonoid O-glycosides. This stability advantage makes orientin a robust bioactive in fruit and vegetable food matrices and in supplement formulations. However, prolonged alkaline conditions or extreme heat (>150°C) can degrade orientin through non-hydrolytic mechanisms.
Related compounds: Isoorientin, Vitexin, Luteolin, Hispidulin
Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.
← HerbIQ Compound Index · HerbIQ P02: Extraction · HerbIQ P03: Delivery