Ternatins, Antioxidants, and Cognition

How butterfly pea flower's rare polyacylated anthocyanins support antioxidant defenses, cognitive function, and blood sugar regulation

Butterfly pea flower is a striking deep-blue flower from Southeast Asia and South Asia that has been brewed as a herbal tea for centuries and used in Ayurvedic medicine as a memory and mood tonic [3]. Its vivid colour comes from a rare class of antioxidants called ternatins — polyacylated anthocyanins not found in other common foods — which show significant free-radical scavenging activity in laboratory studies [1][2]. Research in animal models suggests the plant supports cognitive function and reduces anxiety through effects on the brain's cholinergic and GABAergic systems [4][5], and preliminary work points to blood sugar and liver-protective effects [6]. The tea changes from blue to purple or pink when lemon juice is added, a natural pH reaction that has made it popular in functional beverages without diminishing its health properties.

How Butterfly Pea Flower Works

The Ternatin Anthocyanins

The health properties of butterfly pea flower are driven primarily by its anthocyanin profile, which is unusual compared to other plant foods. Where blueberries and red cabbage contain simpler anthocyanin structures, butterfly pea flower is dominated by ternatins — highly acylated derivatives of delphinidin-3,3',5'-triglucoside [1]. Researchers have characterised at least 11 distinct ternatin variants (A1, A2, B1, B2, D1, D2, and related structures) in the flower's anthocyanin fraction.

The high degree of acylation makes ternatins notably stable compared to most anthocyanins. They retain antioxidant activity across a wide pH range and show better stability under mild heat and acidic conditions than simpler anthocyanin structures, which matters both for food use and for how they might survive digestion [1]. Hot water extraction of the dried or fresh petals — essentially making tea — is sufficient to draw out the anthocyanins effectively.

Beyond ternatins, the flower contains kaempferol, quercetin, and myricetin glycosides, along with flavonols, triterpenoids, and alkaloids [2][3]. The combination of these compounds likely contributes to the plant's broad range of observed effects.

Cognitive and Nervous System Effects

Butterfly pea flower has a long history in Ayurvedic medicine as a memory enhancer and anxiolytic, described in traditional texts as a medhya herb — a class of plants considered beneficial for the mind [3]. Modern animal research has investigated the mechanisms behind these traditional uses.

A 2003 pharmacological study found that methanolic extract of the plant increased time spent in open arms of an elevated plus maze by 160% (a measure of reduced anxiety) and improved novel object recognition, indicating both anxiolytic and nootropic effects [5]. The extract also reduced immobility in forced-swim tests, suggesting antidepressant-like activity, and offered protection against induced seizures, pointing to CNS-calming properties that may involve GABA receptor modulation.

More recent work has focused on the cholinergic system — the neurotransmitter pathway critical for memory and learning that degenerates in Alzheimer's disease. A 2020 study examined Clitoria ternatea root extract in rats with chronic cerebral hypoperfusion, a model of vascular cognitive impairment [4]. Doses of 200–300 mg/kg over 28 days restored spatial memory performance on a Morris water maze task, significantly reduced acetylcholinesterase (AChE) activity in the frontal cortex and hippocampus, and protected hippocampal neurons from hypoperfusion-induced cell death. Inhibiting AChE preserves acetylcholine in synapses — the same mechanism used by prescription drugs for dementia — and the extract was found safe at all tested doses.

Antioxidant and Anti-inflammatory Action

The ternatin anthocyanins and accompanying flavonols demonstrate direct free-radical scavenging in DPPH and ABTS assays, with the anthocyanin-enriched fraction showing high antioxidant capacity comparable to established plant antioxidants [2]. The flowers also exhibit antimicrobial activity against several strains of pathogenic bacteria, an antibacterial property that may explain some of their traditional wound-healing applications.

In diabetic rat models, butterfly pea flower extract at 800 mg/kg raised endogenous antioxidant enzyme activity (SOD and CAT), lowered lipid peroxidation marker MDA, and reduced inflammatory markers IL-1β and CRP [6]. Liver enzyme markers (AST and ALT) normalised over the 28-day treatment period, suggesting a hepatoprotective effect on diabetes-damaged liver tissue.

Practical Use

Butterfly pea flower is most commonly consumed as a tea, brewed from 1–2 teaspoons of dried flowers in hot water for 5–10 minutes. The tea is naturally caffeine-free. Adding lemon juice or any acidic ingredient causes the anthocyanins to shift from blue to purple or pink — this is a normal chemical reaction that does not destroy the health properties.

Dried flowers and tea bags are widely available. Powdered extracts are also sold for use in functional food products. There are no established human clinical doses; traditional Ayurvedic use typically involves 1–3 cups of tea per day. The plant is generally considered safe in culinary amounts; no significant drug interactions are established, but as with all botanicals with CNS activity, caution is appropriate during pregnancy or when taking prescription mood or memory medications.

The flower pairs well with ginger (for its complementary anti-inflammatory compounds) and honey (as a natural sweetener). It is also used in rice and dessert preparations across Thailand, Malaysia, and India.

See our Quercetin page for more on flavonol antioxidants and our BDNF page for broader coverage of brain-supporting compounds.

Evidence Review

Anthocyanin Chemistry and Antioxidant Activity

Vidana Gamage et al. (2021) published a comprehensive review of ternatin anthocyanin biosynthesis, extraction, stability, and antioxidant activity [1]. The review characterises the unique polyacylated structure of the 11 major ternatins and traces the biosynthetic pathway from phenylalanine through the chalcone-flavonoid cascade. Hot-water extraction from fresh or dried petals was found to be the most practical method, with maceration and ultrasound-assisted extraction increasing yield by 16–247% over simple infusion [2].

Stability testing showed that ternatin anthocyanins maintain activity at pH 3.2–5.2, are moderately heat-stable, but are vulnerable to prolonged light exposure — consistent with the observation that freshly brewed tea retains more colour and activity than commercially bottled beverages stored under fluorescent light.

Jeyaraj et al. (2021) characterised the full phytochemical profile of the flower and summarised biological activity data [2]. Antimicrobial activity was documented against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli at relatively low minimum inhibitory concentrations. Antioxidant capacity in the DPPH assay was strong, with IC50 values competitive with other well-characterised botanical extracts.

Traditional Use and Ethnopharmacological Review

Mukherjee et al. (2008) conducted a systematic review of Clitoria ternatea from traditional use to scientific assessment across a range of tissue and animal models [3]. The review confirmed historical use in Ayurvedic and Southeast Asian medicine for memory, anxiety, convulsions, and as an anti-inflammatory agent — applications that align with mechanisms identified in more recent mechanistic research. The authors identified triterpenoids, anthocyanins, flavonol glycosides, alkaloids, and steroids as the major active compound classes, and called for clinical translation of the strong preclinical findings.

Cognitive and CNS Studies

Jain et al. (2003) tested the CNS effects of butterfly pea methanolic extract in rats across a battery of behavioural assays [5]. Key findings:

Elevated plus maze: open-arm occupancy increased 160% vs. controls, indicating robust anxiolytic effect
Novel object recognition: discrimination index improved significantly, a measure of episodic memory
Forced-swim test: immobility duration reduced, consistent with antidepressant-like activity
Anticonvulsant activity: protection against pentylenetetrazol-induced seizures

The study provided a mechanistic basis for the traditional medhya classification, though the specific receptor targets and active compounds were not fully characterised at that time.

Damodaran et al. (2020) used a rat model of chronic cerebral hypoperfusion (CCH) — permanent bilateral carotid artery occlusion — to mimic the cognitive impairment and hippocampal neurodegeneration seen in vascular dementia and early Alzheimer's disease [4]. Over 28 days of treatment:

Memory function (Morris water maze escape latency and platform crossing): significantly restored at 200–300 mg/kg root extract vs. CCH controls
AChE activity: significantly reduced in frontal cortex (p<0.01) and hippocampus (p<0.05) at 300 mg/kg, indicating clinically relevant cholinesterase inhibition
Hippocampal histology: fewer pyknotic (dying) neurons in CA1 and CA3 regions vs. untreated CCH animals
Safety: no adverse effects on body weight, food intake, or organ weight at any tested dose over the 28-day repeated-dose period

The degree of AChE inhibition is pharmacologically meaningful; established dementia drugs such as donepezil and galantamine work by the same mechanism. However, this work was performed in rodents using the root rather than the flower, which has a somewhat different phytochemical profile than the flower preparations more commonly used as food.

Blood Sugar and Liver Protection

Widowati et al. (2024) tested butterfly pea flower extract in streptozotocin-nicotinamide-induced diabetic rats with concurrent dyslipidemia over 28 days [6]. The 800 mg/kg dose produced the strongest effects:

SOD (superoxide dismutase): significantly elevated vs. diabetic controls
CAT (catalase): significantly elevated
MDA (malondialdehyde, lipid peroxidation marker): significantly reduced
IL-1β and CRP: reduced, indicating anti-inflammatory action
AST and ALT: normalised, suggesting hepatoprotection from diabetes-induced liver stress
LDH (lactate dehydrogenase, a cell damage marker): reduced

The comparison arms included glibenclamide (standard antidiabetic) and simvastatin (cholesterol-lowering drug), allowing relative efficacy assessment. While the extract did not match pharmaceutical agents at the doses tested, the multi-target antioxidant and anti-inflammatory profile is notable.

Limitations and Evidence Quality

The evidence base for butterfly pea flower is predominantly preclinical. Human randomised controlled trials are absent for cognitive outcomes and sparse for metabolic effects. Most studies use root extract rather than the flower used in common tea preparations, and doses in animal studies (200–800 mg/kg) do not directly translate to human equivalents without dose-scaling and bioavailability data.

The antioxidant data in vitro is robust and reproducible, and the ternatin anthocyanins are genuinely unusual and well-characterised compounds. The CNS findings are mechanistically coherent and consistent across independent labs. However, the gap between animal pharmacology and clinical benefit in humans is well-established as difficult to bridge, and this plant awaits well-designed human trials to confirm the traditional indications.

For now, butterfly pea flower is a safe, pleasant, caffeine-free beverage with a legitimately distinctive antioxidant chemistry, a plausible cognitive rationale from preclinical research, and a long history of traditional use with a favourable safety record. The evidence does not yet support treating it as a clinical intervention, but it is a reasonable addition to a varied diet emphasising plant diversity.

References

Anthocyanins From Clitoria ternatea Flower: Biosynthesis, Extraction, Stability, Antioxidant Activity, and ApplicationsVidana Gamage GC, Lim YY, Choo WS. Frontiers in Plant Science, 2021. PubMed 34975979 →
Extraction methods of butterfly pea (Clitoria ternatea) flower and biological activities of its phytochemicalsJeyaraj EJ, Lim YY, Choo WS. Journal of Food Science and Technology, 2021. PubMed 33967304 →
The Ayurvedic medicine Clitoria ternatea--from traditional use to scientific assessmentMukherjee PK, Kumar V, Kumar NS, Heinrich M. Journal of Ethnopharmacology, 2008. PubMed 18926895 →
The nootropic and anticholinesterase activities of Clitoria ternatea Linn. root extract: Potential treatment for cognitive declineDamodaran T, Cheah PS, Murugaiyah V, Hassan Z. Neurochemistry International, 2020. PubMed 32650028 →
Clitoria ternatea and the CNSJain NN, Ohal CC, Shroff SK, Bhutada RH, Somani RS, Kasture VS, Kasture SB. Pharmacology, Biochemistry and Behavior, 2003. PubMed 12895670 →
Antidiabetic and hepatoprotection effect of butterfly pea flower (Clitoria ternatea L.) through antioxidant, anti-inflammatory, lower LDH, ACP, AST, and ALT on diabetes mellitus and dyslipidemia ratWidowati W, Jasaputra DK, Tjokroprawiro A, Wargasetia TL, Bachtiar I, Yellianty Y, Laksmitawati DR. Heliyon, 2024. PubMed 38681657 →