Passiflora toxicity
Poisonous?
Are Passion flowers and some Passion fruit toxic? Thanks to Dr. Les King (Forensic Scientist) for his helpful comments re this section. First of all don’t be overconcerned about the information here. Many garden plants are potentially poisonous and Passiflora or Passion flowers are far less so than most. If you only ever eat ripe fruit from shops and markets you will be fine. Passiflora incarnata in particular is even used theraputically. Passiflora nevertheless contain some very interesting and powerful potentially poisonous substances which could become dangerous when concentrated. Both foliage & unripe fruit are so bitter however that even children are unlikely to be tempted by them. I have heard anecdotal evidence though of dogs becoming ill for a day or so after eating the unripe fruit
Chemical makeup
”Many Passiflora species are cyanogenic (Olafsdottir et al. 1989; Spencer 1988), that is they liberate hydrogen cyanide (HCN) when damaged…Most plants that are cyanogenic contain both a cyanogenic glycoside and the necessary enzyme (a b-glycosidase) that when combined during structural damage to the leaf, as they would be during herbivory, liberate HCN. In most cyanogenic plants, the cyanogenic glycosides are located within the vacuoles of cells while the enzymes are attached to the outside of the cell wall (Gruhnert et al. 1994). Therefore, for Cyanogenesis to occur cells must be lysed (broken) and the intracellular contents, include the vacular contents, must spill into the intercellular spaces. Because cyanide is toxic to so many species, cyanogenesis acts as a defense against many potential predators (Jones 1988; Nahrstedt 1985; Schappert & Shore 1999). However, to some species (including the two butterflies in the population study) that have adapted to use cyanogenic species as host plants, differing levels of cyanogenesis among individual plants may have implications for the use of plants in the population.
The Passifloraceae and allied families (including Flacourtiaceae and Turneraceae) possess an unusual HCN chemistry where the cyanogenic glycosides have a cyclopentenyl structure, that is, they are aromatic compounds with an additional 5-member ring (Tober & Conn 1985). Both a cyclopentenyl cyanogenic glycoside (gynocardin) and its specific B-glycosidase have been isolated from P. incarnatatissue (Spencer & Seigler 1984)…”
Extracts above from
Cyanogenesis in Passiflora incarnata:
A PRELIMINARY REPORT
Rosbanak S. Masouri and Phil Schappert
Integrative Biology, C0930, University of Texas at Austin, 1 University Station, Austin, TX 78712-0253 Passiflora 12(2): 22-23
Herbal Secrets of the Rainforest by Leslie Taylor lists Passiflora as containing Alkaloids, Alpha-alanine, Apigenin, D-fructose, D-glucose, Flavonoids, Gum, Gynocardin, Harmaline, Harmalol, Harmine, Harmol, Homoorientin, Isoorientin, Isovitexin, Kaempferol, Lutenin-2, Luteolin, Maltol, N-nonacosane, Orientin, Passiflorine, Phenylalanine, Proline, Quercetin, Raffinose, Rutin, Saccharose, Saponaretin, Saponarine, Scopoletin, Sitosterol, Stigmasterol, Sucrose, Tyrosine, Umbelliferone, Valine, Vitexin.
Some of these compounds, like gynocardin, are cyanogenic glycosides which when broken down will quickly release poisonous cyanide. Others are psychoactive and some people even prepare Passiflora to try to get a legal Passion flower high.
Foliage
Don’t try this at home folks. To experience the consequences of herbivory I tried chewing a P. caerulea leaf. At first it is quite sweet, then as the cells are crushed the taste and smell changes, due to the bitterness caused by the very rapid cyanide release – which results in you spitting it out. It left my tongue feeling a bit odd for a while. The bitter taste is to discourage rather than kill bigger predators, so we are unlikely to come to harm, though the plants hope to do more severe damage to caterpillars. Nevertheless assume that all fresh Passiflora foliage is toxic. The foliage of many Passiflora even when undamaged also often has a pungent bitter smell to warn you.
Fruit
I would recommend only eating ripe fruit from commercial sources like shops and markets. Passion fruit juice is used worldwide in exotic drinks etc. The fruit are also widely available, usually being P.edulis, yellow or purple fruit, or occasionally P. ligularis which has a hard brittle shell. Unripe fruit can also contain poisonous cyanogenic glycosides. P. adenopoda & possibly P. gibertii unripe fruit are of particular concern. There is also a question as to whether P. ‘St. Rule’ is also P. gibertii under another name. Henk Wouters advises however that the P. gibertii grown from seed from Mauro Peixoto in Brazil, in Piet Moerman’s Collection, has bigger flowers, different buds, stronger leaves, etc compared with P. ‘St. Rule’. He also thinks the one now named as P. gibertii is possibly P. pallens.
Dr. John MacDougal comments on the Passiflora list:-
‘I must come down firmly against fooling around casually with the eating the shells or rinds of passifloras. Many are poisonous. Millions of years of God’s evolution has made the fruit to be delicious, …inside! Maybe when ripe the outside is OK, or if they are bred to be bland, like cultivated P. quadrangularis, but wild species are dangerous to play around with, especially raw. And unripe fruit walls are very very dangerous! Cut it and smell it-you can often detect the cyanide. You may have smelled it when you cut a fruit that still had seeds at the “white stage.” Most species of passiflora produce cyanide in all their parts as a protection against insects and animals eating them. The young, developing ovary and immature fruit often have the highest concentration of all!!! (to protect the baby seeds?). But not all species have been tested.
In 1972 two children in Costa Rica were poisoned by eating green, immature fruit of P. adenopoda. One kid died. Saenz, J. A. (1972) Toxic effect of fruit of Passiflora adenopoda DC. on humans: Phytochemical determination. Rev Biol Trop 20(1):137-140)
It is NOT just this species, but many, if not most species that could do this. Just as “peach leaf tea” kills kids in the USA sometimes. Even ripe fruit has a trace, but not enough to hurt you. P. quadrangularis rind is apparently OK, but is often candied, cooked, or blended with other things first.”
***So, the general rule is: Don’t Eat green , Immature, or developing fruits, especially raw! When ripe, the pulp of all species is probably OK.
Alternative medicine
Leslie Taylor lists the therapeutic properties of Passiflora as Analgesic, Antidepressant, Anti-inflammatory, Antispasmodic, Anticonvulsant, Anxiolytic, Disinfectant, Diuretic, Hypnotic, Nervine, Spasmoylic, Sedative, Vermifuge.
Passiflora incarnata is widespread in the southern United States and has been used historically by Native Americans as a herbal remedy. In Mexico the Aztecs, and in South America Incas & other Native Indians use both foliage, juice and root of a number of Passiflora. We do not have their expertise so I suggest that you always take standardised commercial products rather than make your own tea etc. The only widely available products are from P. incarnata. Usually dried foliage, tinctures etc are taken, generally to reduce anxiety, improve sleep and reduce muscle spasms. It is thought to be a very safe herb but do NOT take if on MAO inhibitors, or if pregnant or breastfeeding. There is some suggestion that in excess it may cause uterine contractions. If tempted to pick your own (6 gm dried herb a day taken as a tea typically recommended by herbalists) don’t. Your plant may not even be P. incarnata. It has very variable flowers and foliage. There is at least one herbal book (otherwise a very good one) with a photo that incorrectly shows P. caerulea as P. incarnata. (Herbs for the Soul – Emotional healing with Chinese and Western Herbs and Bach Flower Remedies (2001) Author: Tamara Kircher. Photography by: Graeme Harris. Published by Thorsons.) P. caerulea is NOT safe or beneficial to make tea from, although in practice boiling will break down any cyanide. There are a number of troubling reports (sometimes involving other factors) with a consistent theme of trembling, weakness, tachycardia and death. Here is a properly documented case of toxicity:-
Toxicity of Passiflora incarnata L.
Fisher AA, Purcell P, Le Couteur DG.
The Canberra Hospital, Garran, Australia.
J Toxicol Clin Toxicol. 2000;38(1):63-6.
BACKGROUND: Herbal medicines may have significant adverse effects which are not suspected or recognized. CASE REPORT: A 34-year-old female developed severe nausea, vomiting, drowsiness, prolonged QTc, and episodes of nonsustained ventricular tachycardia following self-administration of a herbal remedy, Passiflora incarnata L., at therapeutic doses. The possible association of symptoms with Passiflora was not recognized for several days. She required hospital admission for cardiac monitoring and intravenous fluid therapy. CONCLUSIONS: Passiflora incarnata was associated with significant adverse effects in this patient. It is important to ask specifically about the use of herbal medicines in patients with undiagnosed illnesses.”
Chrysin
P. caerulea foliage has chrysin (5,7-dihyroxyflavone ) extracted from it. It reputedly has some properties similar to benzodiazepines but is also thought to boost testosterone. Biochemically it is unlikely to do both. It is commercially available in tablet form. I would not recommend making any preparations of P. caerulea yourself.
Image manipulation by Charles Briscoe-Knight
Passiflora psychoactive substances.
Please do not ever use Passiflora to get high. They are relatively safe as they contain only very modest amounts of toxic substances, and any cyanide released when the foliage is damaged is broken down by boiling. However these toxic substances include MAO (monoamine oxidase) inhibiting beta-carboline alkaloids such as harmaline and harmine, which, if concentrated enough by extraction, can cause unpredictable, severe or fatal interactions both with prescription drugs and some foods and drinks. Gracie and Zarkov, psychedelic voyagers in the 1980’s, comment, ‘The dangerous interaction usually precipitates a hypertensive crisis and certain people are especially sensitive to the effects, particularly those with heart abnormalities or high blood pressure. We ourselves have had a few close calls while investigating the beta-carbolines.’
Beta-carboline alkaloids
and related alkaloids are serotonin antagonists, hallucinogens, CNS stimulants, and short term MAO inhibitors. It is also possible that they and other substances present in Passiflora interact with benzodiazepine (Valium) receptors. The evidence suggests that these alkaloids probably have little pharmacological significance for humans in the plants as is – the levels are too low. That said there are so many Passiflora species that no work has been done on that we simply don’t know what is in them, some could be very potent. If concentrated however, small doses of substances such as harmaline (25-50mg) act as mild and therapeutic cerebral stimulant, sometimes producing drowsy or dreamy state for 1-2 hours. Larger doses up to 750mg may have hallucinogenic effects, the intensity of which varies widely with the individual. Harmaline is also one of the active ingredients of ‘ayahuasca’, a hallucinatory Indian drink of some notoriety.
Passiflora incarnata
Dried leaves smoked have been reported as giving a mild marijuana type high. Further Gracie and Zarkov (1985) extracted a concentrate from Passiflora incarnata, which contained 0.05 – 0.1% beta carboline alkaloids, compared with two other plants which contained from 2.0 – 4.0%. They comment:-
‘The high is not particularly psychedelic or hallucinogenic. One feels calm. This calming effect is particularly noted by an observer as a significant change in facial expression and tone of voice. The limbs become heavy and lethargic and visibly tremble. Hypersalivation occurs, particularly at the back of the mouth, making for a particularly smooth smoke. A slight irritation of urethra and anus is sometimes noted. At higher dosages, dizziness and nausea sets in with very little increase in the high. Closed eye imagery is at best hypnagogic. That is to say, faint, moving outlines can be discerned with closed eyes. If one has a particularly vivid imagination, ghostly outlines of figures can be discerned. The more literal minded just see dim shifting blobs of light and dark. No one who has experienced DMT or high dose mushrooms would ever call them visions. The high comes on and stabilizes after about 5 to 10 minutes or smoking. As mentioned before, it is very difficult to get higher by smoking more. If one stops at this point, the most noticeable thing would be a calm and unapprehensive state. We take particular note of this diminishing of apprehensions since we are always apprehensive before we smoke DMT so its diminution or absence is very noticeable. The passion flower is mentally the foggiest high, but curiously has the strongest “anti-depressant” effect. This may be related to the overall mix of alkaloids in the passion flower.’
Some enthusiasts
…prepared 5lb of fresh P. incarnata foliage and reported:-
‘Within about 20 minutes, we all began to experience some profound
behavioral shifts, all of us acting in a more “primal” manner. We were also quite energized and “up”, with some slight distortion of colors. This very fun state lasted about three hours or so, followed by a very deep sleep in which all involved experienced quite profound dream states.’
Excessive doses of therapeutic commercial products may also have some effect.
Alexander & Ann Shulgin
They decribe their experiences with pure synthetic harmaline as below:-
“I took a half gram of pure synthetic harmaline after fasting for over a day. The resulting nausea was greatly attenuated after I vomited. At this dose there were intense and annoying visual disturbances, and complete collapse of motor co-ordination. I could barely stagger to the bathroom, and for safety’s sake locomoted by crawling. Tracers and weird visual ripplings disturbed my sight with open eyes. With eyes closed, there was eidetic imagery. It had no symbolic significance, just bothersome disjointed sequences that lacked a relevant theme. They proceeded to transform so slowly (in comparison to the speed of my thought) that they were predictable and boring. Throughout the experience I just lay hoping it would end soon. It did not seem as though I had encountered intrapsychic material which was being expressed through somatic symptoms. Rather, I felt that I was struggling to metabolize a chemical disruption of my physiological functions. Although the session was not enjoyable, I was satisfied at having educated myself about the effect produced by a penalty dose of this compound.”
Rather them than me. The biggest risk of such adventures, other than mental disturbance, is the potential MOA inhibition, but it would only be likely to occur with large amounts of concentrated extracted or synthesised alkaloids as above. MAO (monoamine oxidase) is an enzyme produced in the body which breaks down amines and renders them harmless and ineffective. All MAO inhibitors interfere with the protective enzyme and leave the body vulnerable to these amines. A common substance such as tyramine, which is usually metabolized with little or no pharmacological effect, may become dangerous in the presence of an MAO inhibitor and cause headache, stiff neck, cardiovascular difficulties, and even death. MAO inhibitors may intensify and prolong the effects of other drugs (CNS depressants, narcotic analgesics, anticholinergics, dibenzazepine antidepressants, etc.) by interfering with their metabolism. In the presence of an MAO inhibitor many substances which are ordinarily non-active because of their swift metabolism may become potent psychoactive drugs. The phenomenon may create a new series of mind alterants. However, because of the complex and precarious variables involved, it is risky and foolish for anyone to experiment with these possibilities on the non-professional level.
Gracie and Zarkov also comment further:-
”The interaction of certain foods and drugs with the MAO inhibition brought on by beta-carbolines can be fatal!! The following substances must not be ingested within 48 hours before and after taking the brew: All amphetamines or related compounds, such as MDA, MDMA, phenylpropanolamine, ephedrine, etc. (add “smart drugs” to this category.) Any foods containing tyramine, or where enzymatic processes have been used: e.g., yoghurt, sour cream, aged cheeses, wines, especially port or Chianti, beer, fermented sausages (pepperoni), soy sauce, etc. Certain other foods, including: shellfish, bananas, liver, avocados, broad beans, chocolate, coffee and others.”
So there you have it. In essence any Passiflora commercial therapeutic preparations are relatively safe but concentrated extracts or substances such as synthetic harmaline can be very dangerous.
Much of the above information from Gracie and Zarkov and also from unidentified authors in Usenet Groups.