Winged-Stem Passionflower

In Brazil, several Passiflora species share the name maracujá, and they are widely used as sedatives and tranquillisers ^{2Reference 2Petry et al. · 2001AnimalComparative pharmacological study of hydroethanol extracts of Passiflora alata and Passiflora edulis leaves — animal modelView study →}. P. alata is maracujá-doce, the sweet one, for its edible fruit.

The leaf infusion is the traditional preparation, taken in the evening for nervousness, agitation and difficulty sleeping ^{2,10Reference 2Petry et al. · 2001AnimalComparative pharmacological study of hydroethanol extracts of Passiflora alata and Passiflora edulis leaves — animal modelView study →Reference 10Doyama et al. · 2005AnimalChemical investigation and effects of the tea of Passiflora alata on biochemical parameters in rats — animal modelView study →}. It is used interchangeably with the leaf of passion fruit.

The plant entered the Brazilian Pharmacopoeia in 1929 ^{13Reference 13Amaral et al. · 2020In vitroCytotoxic, antitumor and toxicological profile of Passiflora alata leaf extract — in vitro / animal modelView study →}. Its leaves are used for anxiety and as a sedative and antispasmodic ^{17Reference 17Müller et al. · 2005LC and UV determination of flavonoids from Passiflora alata medicinal extracts and leaves — analyticalView study →}, and the modern standardised extracts are sold for the same uses ^{1Reference 1Barros et al. · 2026RCTClinical, humanistic, and economic outcomes of Passiflora alata Curtis use in participants with mild to moderate anxiety — open-label, non-randomised human studyView study →}.

The human study was a 90-day, open-label, non-randomised before-and-after study in 30 adults with mild to moderate anxiety ^{1Reference 1Barros et al. · 2026RCTClinical, humanistic, and economic outcomes of Passiflora alata Curtis use in participants with mild to moderate anxiety — open-label, non-randomised human studyView study →}. It used a commercial dry leaf extract standardised to 0.07% total flavonoids as apigenin, dosed by severity from 500 mg/day up to 1,500–2,000 mg/day.

GAD-7 scores fell substantially. At baseline 53% scored in the severe band, and at the final visit 3% did, with 30% scoring in the no-anxiety band. The authors reported clinical effectiveness in 29 of the 30 participants ^{1Reference 1Barros et al. · 2026RCTClinical, humanistic, and economic outcomes of Passiflora alata Curtis use in participants with mild to moderate anxiety — open-label, non-randomised human studyView study →}. With no control group, regression to the mean and expectation cannot be separated from a drug effect.

The animal evidence is better replicated. Hydroethanolic leaf extracts were anxiolytic on the elevated plus-maze at about 50, 100 and 150 mg/kg ^{2Reference 2Petry et al. · 2001AnimalComparative pharmacological study of hydroethanol extracts of Passiflora alata and Passiflora edulis leaves — animal modelView study →}. Aqueous extracts injected into rats reproduced the effect at 100 and 150 mg/kg. Diazepam disrupted performance on a memory test, and neither passionflower extract did ^{3Reference 3Barbosa et al. · 2008AnimalThe aqueous extracts of Passiflora alata and Passiflora edulis reduce anxiety-related behaviors without affecting memory process in rats — animal modelView study →}. The earliest crude-extract work had reported the same depressant profile ^{5Reference 5Oga et al. · 1984AnimalPharmacological trials of crude extract of Passiflora alata — animal modelView study →}.

Passion fruit was active at a lower dose in the same rat experiment, which the authors attributed to its roughly doubled flavonoid content ^{3Reference 3Barbosa et al. · 2008AnimalThe aqueous extracts of Passiflora alata and Passiflora edulis reduce anxiety-related behaviors without affecting memory process in rats — animal modelView study →}.

Gap: no controlled human trial exists. The entire human case rests on one uncontrolled study.

Antioxidant activity is the most consistently reproduced biochemical effect in the species.

Oral pretreatment for 30 days protected rat liver against carbon-tetrachloride injury, lowering lipid peroxidation and raising catalase and superoxide dismutase ^{9Reference 9Rudnicki et al. · 2007AnimalProtective effects of Passiflora alata extract pretreatment on carbon tetrachloride induced oxidative damage in rats — animal modelView study →}. In non-obese diabetic mice, long-term aqueous leaf extract raised glutathione in liver and kidney ^{7,8Reference 7Colomeu et al. · 2014AnimalAntioxidant and anti-diabetic potential of Passiflora alata Curtis aqueous leaves extract in type 1 diabetes mellitus (NOD-mice) — animal modelView study →Reference 8Figueiredo et al. · 2016AnimalAqueous leaf extract of Passiflora alata Curtis promotes antioxidant and anti-inflammatory effects and consequently preservation of NOD mice beta cells — animal modelView study →}. A rat leaf-tea study reported altered antioxidant parameters and a rise in HDL-cholesterol at 1,000 mg/kg ^{10Reference 10Doyama et al. · 2005AnimalChemical investigation and effects of the tea of Passiflora alata on biochemical parameters in rats — animal modelView study →}, and extracts of cultivated plants scavenge DPPH in vitro in proportion to their phenolic content ^{20Reference 20Vasic et al. · 2012In vitroBiological activities of extracts from cultivated granadilla Passiflora alata — in vitroView study →}.

The phenolics credited are catechin, epicatechin, rutin and related flavonoids. No human antioxidant endpoint has been measured.

Spray-dried aqueous leaf extract at 100–300 mg/kg suppressed leukocyte migration and exudate in carrageenan-induced mouse pleurisy, with falls in myeloperoxidase, adenosine deaminase and serum C-reactive protein ^{6Reference 6Vargas et al. · 2007AnimalPassiflora alata and Passiflora edulis spray-dried aqueous extracts inhibit inflammation in mouse model of pleurisy — animal modelView study →}.

In the NOD-mouse diabetes model the extract reduced inflammatory-cell infiltration of the pancreatic islets ^{7,8Reference 7Colomeu et al. · 2014AnimalAntioxidant and anti-diabetic potential of Passiflora alata Curtis aqueous leaves extract in type 1 diabetes mellitus (NOD-mice) — animal modelView study →Reference 8Figueiredo et al. · 2016AnimalAqueous leaf extract of Passiflora alata Curtis promotes antioxidant and anti-inflammatory effects and consequently preservation of NOD mice beta cells — animal modelView study →}. In vitro, the aqueous extract raised indoleamine-2,3-dioxygenase and lowered CD86 in antigen-presenting cells, shifting T cells toward a regulatory profile and reducing IL-6 and IFN-γ release ^{11Reference 11Schumacher et al. · 2022In vitroAqueous extract of Passiflora alata leaves modulates in vitro the indoleamine 2,3-dioxygenase (IDO) and CD86 expression in antigen-presenting cells polarizing NOD mice T cells to a Treg profile — in vitroView study →}.

All of this work is in animals and cells.

Radiotelemetry in mice compared P. alata and passion-fruit extracts against midazolam and caffeine. All extracts cut spontaneous locomotor activity dose-dependently across 300–1,200 mg/kg. P. alata extracts were more active than passion-fruit extracts, and extracts of the fruit rind (pericarp) were more active than leaf extracts ^{4Reference 4Klein et al. · 2014AnimalAssessment of sedative effects of Passiflora edulis f. flavicarpa and Passiflora alata extracts in mice, measured by telemetry — animal modelView study →}. Older crude-extract trials reported the same depressant profile ^{5Reference 5Oga et al. · 1984AnimalPharmacological trials of crude extract of Passiflora alata — animal modelView study →}.

Repeated 14-day dosing up to 250 mg/kg produced no central cumulative effect, which suggests the sedation does not build up with continued use ^{15Reference 15Braga et al. · 2013AnimalRepeated administration of an aqueous spray-dried extract of the leaves of Passiflora alata Curtis inhibits body weight gain without altering mice behavior — animal modelView study →}. No human study has measured a sedation endpoint directly.

Two long feeding studies gave aqueous leaf extract to non-obese diabetic mice for 28 and 30 weeks. Both found a lower incidence of diabetes, 28.6% lower in the second, with fewer inflammatory cells infiltrating the pancreatic islets, more insulin-positive cells, and raised antioxidant defences in liver and kidney ^{7,8Reference 7Colomeu et al. · 2014AnimalAntioxidant and anti-diabetic potential of Passiflora alata Curtis aqueous leaves extract in type 1 diabetes mellitus (NOD-mice) — animal modelView study →Reference 8Figueiredo et al. · 2016AnimalAqueous leaf extract of Passiflora alata Curtis promotes antioxidant and anti-inflammatory effects and consequently preservation of NOD mice beta cells — animal modelView study →}.

The mechanism appears immunomodulatory: the extract polarises antigen-presenting cells toward tolerance and expands regulatory T cells in vitro ^{11Reference 11Schumacher et al. · 2022In vitroAqueous extract of Passiflora alata leaves modulates in vitro the indoleamine 2,3-dioxygenase (IDO) and CD86 expression in antigen-presenting cells polarizing NOD mice T cells to a Treg profile — in vitroView study →}.

Gap: this is prevention of onset in a genetically predisposed mouse, not reversal of established disease, and it has never been tested in a person.

Thirty days of oral pretreatment with the leaf extract at 1 and 5 mg/kg protected rat liver against carbon-tetrachloride damage, with less necrosis, lower lipid peroxidation and higher catalase and superoxide dismutase. The higher dose also protected the heart ^{9Reference 9Rudnicki et al. · 2007AnimalProtective effects of Passiflora alata extract pretreatment on carbon tetrachloride induced oxidative damage in rats — animal modelView study →}.

A repeated-dosing study found that 14 days at 25 and 250 mg/kg reduced relative liver weight, caused mild hepatic hydropic degeneration and lowered serum ALT in mice. Its authors called for a study of liver toxicity ^{15Reference 15Braga et al. · 2013AnimalRepeated administration of an aqueous spray-dried extract of the leaves of Passiflora alata Curtis inhibits body weight gain without altering mice behavior — animal modelView study →}.

Gap: the protective and the harmful findings come from different doses and different models. The effect of sustained use on the liver is not known.

The leaf extract inhibited proliferation of prostate and sarcoma cell lines below 30 µg/mL ^{13Reference 13Amaral et al. · 2020In vitroCytotoxic, antitumor and toxicological profile of Passiflora alata leaf extract — in vitro / animal modelView study →}. Given by injection to mice with sarcoma, it cut tumour growth by 37–45% at 100–150 mg/kg a day. The mice also ate less and lost weight, and showed an enlarged spleen and a shifted white-cell count ^{13Reference 13Amaral et al. · 2020In vitroCytotoxic, antitumor and toxicological profile of Passiflora alata leaf extract — in vitro / animal modelView study →}.

In vitro, the extract’s polyphenols — isoorientin, vitexin, catechin and rutin — were antiproliferative against activated T lymphocytes through a pro-oxidant, apoptosis-inducing mechanism ^{12Reference 12Colomeu et al. · 2022In vitroAntiproliferative and pro-oxidant effect of polyphenols in aqueous leaf extract of Passiflora alata Curtis on activated T lymphocytes from non-obese diabetic mice — in vitroView study →}.

This is early cell-line and single-model work.

Ethanol, acetone and ethyl-acetate extracts of cultivated P. alata inhibited mainly Gram-positive bacteria and some fungi in vitro, the ethyl-acetate fraction most strongly ^{20Reference 20Vasic et al. · 2012In vitroBiological activities of extracts from cultivated granadilla Passiflora alata — in vitroView study →}. Isolated leaf saponins showed strong activity against Trichomonas vaginalis at a minimum inhibitory concentration of 0.025%, and also lysed red blood cells ^{21Reference 21Rocha et al. · 2012In vitroAnti-Trichomonas vaginalis activity of saponins from Quillaja, Passiflora, and Ilex species — in vitroView study →}.

Gap: all of it is in vitro and comes from solvent extracts or isolated saponins, not from the leaf preparations used as a sedative.

The leaves are used as an antispasmodic as well as a sedative ^{17Reference 17Müller et al. · 2005LC and UV determination of flavonoids from Passiflora alata medicinal extracts and leaves — analyticalView study →}.

No modern experimental study has tested a smooth-muscle or spasmolytic endpoint in this species.

Tolerability. Over 90 days in the human study, three of thirty participants reported mild effects: one had drowsiness and two had passing stomach or bowel discomfort. Nothing serious was recorded ^{1Reference 1Barros et al. · 2026RCTClinical, humanistic, and economic outcomes of Passiflora alata Curtis use in participants with mild to moderate anxiety — open-label, non-randomised human studyView study →}.

Genotoxicity. A Brazilian toxicology study found no deaths in mice at a single oral dose of 4,800 mg/kg. Rats given 300 mg/kg daily for 14 days showed no biochemical, blood or tissue changes, though they were irritable and did not gain weight ^{14Reference 14Boeira et al. · 2010AnimalToxicity and genotoxicity evaluation of Passiflora alata Curtis (Passifloraceae) — animal modelView study →}.

On DNA-damage tests the same extract behaved differently. The comet test found damage in blood cells after single doses of 50 mg/kg and above. Mice dosed at 12.5, 25 or 50 mg/kg daily for three days showed dose-dependent comet and micronucleus damage ^{14Reference 14Boeira et al. · 2010AnimalToxicity and genotoxicity evaluation of Passiflora alata Curtis (Passifloraceae) — animal modelView study →}. The authors concluded that the species needs further toxicity testing before its safety in people can be assumed. There are no human genotoxicity data.

Liver. Low-dose pretreatment protected rat liver against carbon tetrachloride ^{9Reference 9Rudnicki et al. · 2007AnimalProtective effects of Passiflora alata extract pretreatment on carbon tetrachloride induced oxidative damage in rats — animal modelView study →}. Repeated dosing at 25–250 mg/kg caused mild hydropic degeneration and a fall in ALT in mice, and its authors asked for a liver-toxicity study ^{15Reference 15Braga et al. · 2013AnimalRepeated administration of an aqueous spray-dried extract of the leaves of Passiflora alata Curtis inhibits body weight gain without altering mice behavior — animal modelView study →}.

Allergy. Occupational IgE-mediated asthma and rhinitis to P. alata were confirmed in a pharmacy worker who handled the extract, by skin-prick test, Western blot and bronchial challenge ^{16Reference 16Giavina-Bianchi et al. · 1997Case reportOccupational respiratory allergic disease induced by Passiflora alata and Rhamnus purshiana — case reportView study →}. People with a known passionflower allergy, and anyone handling bulk extract, should take this into account.

Interactions. No pharmacokinetic, CYP450 or P-glycoprotein study exists for this species. Its sedative action may add to that of sedative drugs, alcohol and benzodiazepines.