Generality
Carnivorous plants are plants capable of attracting, trapping and digesting animal life forms.
There are many species of carnivorous plants that differ from one another in appearance, in the manner in which they capture their prey, in the area of origin and in numerous other characteristics. However, those most known are probably the carnivorous plants belonging to the genus Dionaea, to the genus Drosera, to the genus Sarracenia, to the genus Darlingtonia and to the genus Pinguicula .
The interest in this type of plants does not only involve fans of the genus, but also involves several researchers, who intend to study the interesting capture and digestion mechanisms and to reveal their potential therapeutic activities with the consequent medical uses.
What are
What are Carnivorous Plants?
As mentioned, carnivores are defined as all those plants capable of attracting, trapping, killing and, consequently, digesting animal species ; in particular, insects (flies, bedbugs, ants, mosquitoes, etc.), small arthropods or other small animals (for example, amphibians or small aquatic organisms - not surprisingly, there are also aquatic carnivorous plants). The correct definition requires that, for a plant to be called "carnivorous", it must necessarily be able to kill and digest the unlucky prey.
In fact, in nature there are different plants capable of attracting and trapping insects which, however, are released soon after. An example is given by some types of orchids that trap insects to favor and increase pollination and then release them. Therefore, they cannot bear the name of carnivorous plants, since they are unable to kill and digest the insects that trap them.
Did you know that ...
Given their particular ability to capture and "eat" small animal life forms, several people decide to cultivate carnivorous plants in their garden in the hope that they will "prey on" annoying "guests", first of all mosquitoes. Unfortunately, this hope is often disappointed, as carnivorous plants are in no way able to control the populations of insects or animals of any kind.
nourishment
What do Carnivorous Plants feed on?
Although it is commonly believed that carnivorous plants feed only and exclusively on insects, arthropods or other small animals, the reality of the facts is another. It is also true that from animal prey carnivorous plants obtain molecules of fundamental importance for their growth but, despite this, they are able to survive even in the absence of animal species to be digested by putting into practice nutritional mechanisms similar to those of non-carnivorous plants . In fact, what we often tend to forget about these fascinating plants is that, on balance, they always remain "only" plants, despite their peculiar and unique characteristic of feeding on some animal species.
Capture and Digestion
Carnivorous Plants and Capture of Animal Prey
In order to catch a prey, carnivorous plants must first of all be able to attract the unfortunate insect, arthropod or small animal to them. To do this, these plants can use different "stratagems", such as visual stimuli (carnivorous plant traps can present colored spots) or through olfactory stimuli (some carnivorous plants are capable of producing sweet scents able to attract insects). Once the animal prey has been attracted to the plant, the deadly entrapment mechanisms of carnivorous plants prevent it from escaping, condemning it to certain death.
Types of Traps and Trapping Mechanisms
The entrapment mechanisms possessed by carnivorous plants are different, all equally effective and lethal. For example, some of them have downward curved hairs that allow the insect to enter the trap, making it difficult, if not impossible, to exit; other plants, on the other hand, have a viscous and / or sticky surface that prevents the escape of the unfortunate prey.
However, the different types of traps these plants are equipped with can be grouped as follows:
- Adhesive traps : carnivorous plants equipped with this type of trap secrete a mucilaginous and sticky substance that prevents the escape of small animals that come into contact with it.
- Ascidian traps : carnivorous plants that exploit this type of trap have particular "closed" leaves whose shape resembles that of a carafe inside which digestive enzymes and / or bacteria are present.
- Trap or " snap " traps: these are traps made up of leaves that - as soon as they feel the presence of a potential prey - snap together thanks to complex cellular mechanisms.
- Lobster traps : carnivorous plants with these traps have hairs that push the unfortunate prey towards the digestive system.
- Suction traps: they are traps able to suck the prey inside a particular vesicle - defined " utricle " - where a pressure vacuum is created.
How does the Digestion of Preys occur in Carnivorous Plants?
Digestion occurs by means of specific digestive fluids rich in enzymes (proteases, phosphatases, ribonucleases, etc.) that can be produced independently from the plant, or from bacteria present in the digestive organ.
Some species of carnivorous plants, on the other hand - such as Sarracenia purpurea (a carnivorous plant with an ascidian trap) - exploit the action of both their own digestive enzymes and the action of digestive enzymes of a bacterial nature.
Thanks to the digestion of the preys, the carnivorous plants are able to absorb nutrients important for their growth, including amino acids and nitrogen .
Did you know that ...
Some carnivorous plants, in order to absorb the nutrients present in their prey, rely on the support of other insects or even birds (the latter case is especially true for typically tropical carnivorous plants - such as those belonging to the genus Nepenthes - capable of reaching dimensions considerable.
As for the insects that contribute to the nutritional needs of carnivorous plants, there are species that can live on them without being caught. These insects feed on corpses of prey captured by carnivorous plants and, after a meal, lay their droppings on their leaves. Only then will the carnivorous plants be able to absorb the nutrients they need from the droppings of the insects that inhabit them.
Medical Uses
Potential Medical-pharmaceutical uses of Carnivorous Plants
The fascinating methods of "hunting", nutrition and survival of carnivorous plants have led many researchers to investigate more thoroughly their properties and chemical composition, both to understand their mechanisms and characteristics, and to identify new potential molecules for pharmacological use. The data obtained certainly did not disappoint expectations: in fact, by analyzing different carnivorous plants, numerous interesting molecules have been identified that could potentially be used in the therapeutic field.
In particular, the potential medical-pharmaceutical uses of carnivorous plants belonging to the genus Drosera species rotundifolia, ramentacea, mdagascariensis and peltata, to the genus Sarracenia species purpurea and to the genus Dionaea specie muscipula are analyzed .
Sundew
Carnivorous plants of the genus Drosera are equipped with adhesive traps.
Antiseptic, anti-inflammatory, secretolytic, broncho-spasmolytic and antitussive properties are ascribed to this type of carnivorous plant - and in particular to the rotundifolia species, ramentacea, mdagascariensis and peltata . In detail, these properties are attributable to the naphthoquinone derivatives typically contained in this genus of plants.
More precisely, the main culprits of the aforementioned activities appear to be 1, 4-naphthoquinone and plumbagin .
Studies conducted in vitro on plumbagina have shown that it is able to exert an anti-inflammatory action through the inhibition of prostaglandin synthesis ; while in vivo experiments have shown that the molecule is capable of exerting antimicrobial and even cytostatic activities .
In light of what has been said so far, therefore, it is not surprising that the German Commission has approved the use of Drosera ramentacea and its derivatives against coughs and bronchitis.
Use in folk medicine
In folk medicine, carnivorous plants belonging to the genus Drosera are used as natural remedies against asthma and even against warts.
Sarracenia purpurea
Sarracenia purpurea belongs to the group of carnivorous plants with mechanisms of entrapment entrapment.
Its chemical composition is mainly characterized by the presence of piperidine alkaloids, among which sarracenina stands out. S. purpurea is attributed with stomachic and diuretic properties associated with a laxative effect .
Use in folk medicine
The S. Purpurea was used by folk medicine as a remedy against digestive disorders and constipation and against urinary tract disorders. Moreover, in the past, folk medicine even used this carnivorous plant as a cure for smallpox. Native Americans believed that S. purpurea could not only save the victims of this disease, but that it could also be useful in preventing the formation of typical scars.
Dionaea muscipula
Also known with the characteristic name of " Venus fly- catcher " (from the English Venus flytrap ), the Dionaea muscipula belongs to the group of carnivorous plants equipped with a snap trap.
The chemical composition of this carnivorous plant is characterized by the presence of naphthoquinones (including plumbagina), flavonoids and phenolic acids . Antimicrobial, immunostimulant and even anti-neoplastic properties are ascribed to D. muscipula . In detail, an interesting study conducted on this subject has shown that D. muscipula contains numerous compounds able to exercise potential preventive and therapeutic activities against some types of tumors, such as Hodgkin's and non-Hodgkin's lymphomas, colon cancer, prostate cancer and breast cancer. Of all the compounds identified, plumbagina is of great interest and - as previously mentioned - has shown to possess cytostatic properties.
However, despite the encouraging results, the road to the creation of new anticancer drugs starting from the compounds present in carnivorous plants still seems to be rather uncertain.
Please note
The use of carnivorous plants in modern medicine for the treatment of any disorder has not been officially approved . Nevertheless, it is possible to find herbal, phytotherapeutic and homeopathic products that include parts or extracts of carnivorous plants in their composition.
hazard
Are Carnivorous Plants Dangerous for Man?
The contact with carnivorous plants, generally, does not represent a danger for the man since their digestive fluids possess a rather weak acidity which, normally, does not cause any damage to the human skin. Clearly, the situation changes when there are allergies - known or unknown - to any of the molecules contained within the same fluids or of the plant.
In any case, since there are many species of carnivorous plants, before handling them and trying to cultivate them, it would be good to inquire in detail by experts in the profession, if not for the potential danger, but to make sure to handle them with knowledge of the facts and to ensure their care and attention.
For the avoidance of doubt, it should also be remembered that carnivorous plants are not edible.
