When it comes to treatments for virus infections, doctors’ first to be used are drugs. However, it is known that these types of medicines have high profiles of side effects and can cause rapid resistance between viral strains.
Plants and herbs have been used since ancient times for human health care in the form of traditional medicines, extracts, spices, and other food components.
Recently, science has confirmed the antiviral properties of certain plants, which has generated particular interest in their use in Western medicine. In particular, the possible use of its extracts as an alternative or complement to drug treatments.
This article details examples of plants with antiviral effects with supporting reliable evidence.
Antiviral Plants – Examples
Here are examples of antiviral plants and their health effects:
The echinacea is a plant native to Central America. There are several species and varieties of echinacea, but only three are used for medicinal purposes: E. Angustifolia, E. Pallida, and E. purpurea.
This plant is known for its immunostimulating effects; that is, many of its active compounds are potent immune system stimulators.
Some of its compounds have been shown to stimulate natural killer (NK) cells, which are the first line of defense for our immune system. (2)
In different clinical trials, it was concluded that certain phytochemicals derived from echinacea act as stimulants of the cells responsible for nonspecific immunity (3)
Echinacea is one of the most potent antiviral plants against certain human viruses. The ability to decrease the duration and severity of common cold symptoms is highlighted. (2)
Likewise, echinacea favors granulation tissue formation; it has a healing activity.
On the other hand, it is necessary to clarify that medicine needs more research to confirm these antiviral properties in a generalized way. In some studies, echinacea does not show significant benefits. (4) Using different types of echinacea may have contributed to different results.
Important: Echinacea can have side effects and interact with antiviral medications you may take, so it is necessary to consult your doctor before taking echinacea or any other herbal supplement.
The elderberry is a genus of plants belonging to the Adoxáceas family, with a long history of medicinal use. It is native to the temperate and subtropical regions of both hemispheres.
The best-known species is the Sambucus nigra or black elderberry, and it is also the one that has been most investigated.
The medicinal properties of the elderberry plant are multiple: anti-inflammatory, antiviral, immunostimulating, antioxidant, among others.
The antiviral properties of elderberry are due to its content of polysaccharides and polyphenol acids (anthocyanins) (13).
One of the most studied properties is the immunostimulant used to reduce the common cold symptoms. Today’s most common product made from the elderberry plant is cold syrups made from fresh or dried berries.
In addition, elderberry has antioxidant properties, so it is also used for natural cosmetics. (14)
It is essential to mention that the flowers and ripe fruits are the only parts suitable for medicinal use, while the rest of its components, such as the stem, leaves, bark, and immature fruits, can be toxic.
Garlic (Allium sativum) is a species in the Amaryllidaceae family. Its main active component is allicin, an organosulfur compound that gives it its characteristic taste and smell.
The extracts and isolated compounds of garlic have antiviral, antibacterial, antifungal, antiprotozoal, antioxidant, anti-inflammatory, anticancer, and hypoglycemic. (5.6)
Likewise, various studies have shown that the garlic plant’s antioxidant, antibacterial, and vascular protective activity is reduced when it is heated. Allicin, it’s main phytochemical, breaks down in the heat.
To boost the antiviral properties of garlic, the best way is to eat fresh garlic without it having been shredded, sliced , or heated.
Most of the possible side effects of garlic are nonspecific. Nausea and gastrointestinal upset are the most common side effects. (5)
It is necessary to emphasize that studies on garlic’s required dose, duration, and pharmacological interaction with other plants and medications should be deepened.
More research needs to be done to identify specific garlic compounds or garlic products responsible for most of its biological effects. The effects seem to be highly dependent on the quality of the plant. (6)
- Cat’s claw
Cat’s claw (Uncaria tomentosa) is a medicinal plant that grows in the Amazon region of Peru and neighboring countries.
This plant has broad therapeutic potential as an antiviral, antioxidant, anti-inflammatory, and antimutagenic.
In vitro studies have shown the ability of a cat’s claw to treat viral diseases such as herpes. In particular, the bark extracts can inhibit viral binding with host cells.
The immunomodulatory properties of a cat’s claw seem to be related to the stimulation of B and T lymphocyte’s production of interleukins by macrophages, among others.
In turn, a cat’s claw is a plant with antioxidant properties and reduces the production of free radicals. (8)
More in vivo studies must be conducted to confirm the results, and this plant can be used as a clinical treatment for viral infections. (7)
Oregano (Oreganum Vulgare) is a genus that includes several species of plants, the most common being Origanum vulgare (native to Europe) and Lippia graveolens (native to Mexico).
The organ has medicinal, culinary, and cosmetic properties.
Carvacrol, the primary active component of oregano oil, has shown excellent antiviral efficacy. (1)
Likewise, the alcoholic extracts of oregano have antibacterial, antifungal, and insecticidal activities.
Oregano also has an excellent antioxidant capacity. Antioxidant compounds are essential because they can protect cells against oxidative damage, which causes aging and chronic degenerative diseases, such as cancer, cardiovascular disease, and diabetes.
Today, the study of oregano’s antiviral and antimutagenic properties continues to be deepened. (1)
While there is insufficient evidence to use garlic as a clinical treatment for viral and bacterial infections, some studies support the use of garlic to ease the duration of common cold symptoms. (6)
In addition to its antiviral properties, garlic stands out for its cardioprotective effect. A study has confirmed an inverse relationship between garlic consumption and the risk of cardiovascular disease progression. (5)
Turmeric is a herbaceous plant, a member of the ginger family. Turmeric is native to southwestern India and is the main spice in curry.
The main active ingredient in turmeric is curcumin, a compound with anti-inflammatory, antioxidant, antiviral, anticancer, and antidepressant.
Current data suggest that one of the properties of curcumin is the inhibition of HIV-1 integrase, which is why it could have antiviral properties. (11) Integrase is an intracellular protein HIV uses to insert its viral DNA into the host’s CD4 lymphocyte DNA.
In addition, turmeric has potential properties in cancer immunotherapy. Turmeric components could have the ability to modulate the immune response to the tumor, exerting various effects on the malignant activities of tumor cells. (9)
Regarding its antidepressant therapeutic effects, a clinical trial with patients with major depressive disorder showed improvement in symptoms 4 to 8 weeks after curcumin treatment. However, the number of the study sample was small, so investigations with more extensive tests should be continued. (eleven)
It is necessary to clarify that in clinical practice, curcumin presents several limitations, such as the disproportionate dose effect of the drug, low bioavailability, and low solubility in water (10). Therefore, it is necessary to continue research to improve bioavailability and have better therapeutic effects in its use as an antiviral plant.
Fennel ( Foeniculum vulgare ) is a plant that can fight certain viruses. A test-tube study showed that fennel extract has antiviral effects against the herpes virus and parainfluenza type 3, which causes respiratory infections in grazing animals. (fifteen)
In addition, a study has shown that trans-anethole, the main component of fennel essential oil, has antiviral effects against the herpes virus. (16)
According to animal research, fennel may also strengthen the immune system and reduce inflammation. Which can also help fight viral infections. (17)
As with other plants, fennel should not be used as a substitute for antiviral treatments prescribed by your doctor.
Ginger ( Zingiber officinale ) is a plant of the Zingiberáceae family. Ginger is a relative of galangal, cardamom, and turmeric.
The antiviral properties of ginger are mainly attributed to the bioactive component gingerol.
A study has proven that gingerol and other components of ginger are capable of isolating and preventing the spread of certain types of viruses in the respiratory tract. (18)
In addition to acting as an antiviral, other properties of gingerol are reducing nausea; it can reduce inflammation in the body and reduce menstrual pain and muscle pain.
Fresh ginger inhibits the binding of viruses and cells; it could stimulate the mucosa cells to secrete interferon-β, possibly contributing to counteracting the viral infection. (twenty)
One of the effects of the active component in the plant is to inhibit the activity of COX-1, the same enzyme that aspirin acts. Studies claim that gingerol is more potent and has antiulcer activity as well. (19)
For this reason, doctors and scientists continue to investigate how to isolate this compound so that it can be used as a treatment for viruses. In any case, it is essential to know that the properties of ginger for virus infections apply only when eaten fresh and that it is not a substitute for medications.
Can antiviral plants replace drugs?
There is still not enough evidence to replace drugs with antiviral plants.
The differences between species and cultivation methods mean that the use of plants and their extracts is not precise.
However, antiviral plants and their extracts have future potential in medicine.
More studies are needed to use these plants as a clinical treatment.
- Plant extracts with antiviral properties have potential uses as treatments, or as supplements to drugs, against virus infections.
- Examples of plants with antiviral properties are echinacea, elderberry, garlic, oregano, and catclaw.
- Research on antiviral plants should be deepened, including their therapeutic spectrum and toxicological risks.
- Teamwork should be encouraged among health professionals and professionals specializing in medicinal herbs to educate on the use of medicinal plants and obtain better health for all.