Herbal plants, plant preparations and phytoconstituents have proved useful in attenuating infectious conditions and were the only remedies available, till the advent of antibiotics (many being of plant origin themselves). Among infectious diseases, viral diseases in particular, remain the leading cause of death in humans globally. A variety of phytoconstituents derived from medicinal herbs have been extensively studied for antiviral activity. Based on this rationale, an online search was performed, which helped to identify a large number of plant species harboring antiviral molecules. These herbal sources have been reported individually or in combinations across a large number of citations studied. Activities against rabies virus, Human immunodeficiency virus, Chandipura virus, Japanese Encephalitis Virus, Enterovirus, Influenza A/H1N1 and other influenza viruses were discovered during the literature search. This review includes all such plant species exhibiting antiviral properties. The review also encompasses composition and methodologies of preparing various antiviral formulations around the globe. An elaborate section on the formulations filed for patent registration, along with non-patented formulations, has also been included in this article. To conclude, herbal sources provide researchers enormous scope to explore and bring out viable alternatives against viral diseases, considering non-availability of suitable drug candidates and increasing resistance to existing drug molecules for many emerging and re-emerging viral diseases.
Since ancient times, herbs have been used as natural treatments for various illnesses, including viral infections.
Due to their concentration of potent plant compounds, many herbs help fight viruses and are favored by practitioners of natural medicine.
At the same time, the benefits of some herbs are only supported by limited human research, so you should take them with a grain of salt.
1. Oregano
Oregano is a popular herb in the mint family that’s known for its impressive medicinal qualities. Its plant compounds, which include carvacrol, offer antiviral properties.
In a test-tube study, both oregano oil and isolated carvacrol reduced the activity of murine norovirus (MNV) within 15 minutes of exposure (1Trusted Source).
MNV is highly contagious and the primary cause of stomach flu in humans. It is very similar to human norovirus and used in scientific studies because human norovirus is notoriously difficult to grow in laboratory settings (2Trusted Source).
Oregano oil and carvacrol have also been shown to exhibit antiviral activity against herpes simplex virus type-1 (HSV-1); rota virus, a common cause of diarrhea in infants and children; and respiratory syntactical virus (RSV), which causes respiratory infections (3Trusted Source, 4Trusted Source, 5Trusted Source).
2. Sage
Also a member of the mint family, sage is an aromatic herb that has long been used in traditional medicine to treat viral infections (6Trusted Source).
The antiviral properties of sage are mostly attributed to compounds called solidification and sage one, which are found in the leaves and stem of the plant (7Trusted Source).
Test-tube research indicates that this herb may fight human immunodeficiency virus type 1 (HIV-1), which can lead to AIDS. In one study, sage extract significantly inhibited HIV activity by preventing the virus from entering target cells (8Trusted Source).
Sage has also been shown to combat HSV-1 and Indiana vesicular, which infects farm animals like horses, cows, and pigs (9, 10).
3. Basil
Many types of basil, including the sweet and holy varieties, may fight certain viral infections.
For example, one test-tube study found that sweet basil extracts, including compounds like apigenin and ursolic acid, exhibited potent effects against herpes viruses, hepatitis B, and enterovirus (11Trusted Source).
Holy basil, also known as tulsi, has been shown to increase immunity, which may help fight viral infections.
In a 4-week study in 24 healthy adults, supplementing with 300 mg of holy basil extract significantly increased levels of helper T cells and natural killer cells, both of which are immune cells that help protect and defend your body from viral infections (12Trusted Source).CORONAVIRUS Updates Stay on top of the COVID-19 outbreak
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4. Fennel
Fennel is a licorice-flavored plant that may fight certain viruses.
A test-tube study showed that fennel extract exhibited strong antiviral effects against herpes viruses and para influenza type-3 (PI-3), which causes respiratory infections in cattle (13Trusted Source).
What’s more, trans-ethanol, the main component of fennel essential oil, has demonstrated powerful antiviral effects against herpes viruses (14Trusted Source).
According to animal research, fennel may also boost your immune system and decrease inflammation, which may likewise help combat viral infections (15Trusted Source).
5. Garlic
Garlic is a popular natural remedy for a wide array of conditions, including viral infections.
In a study in 23 adults with warts caused by human papillomavirus (HPV), applying garlic extract to affected areas twice daily eliminated the warts in all of them after 1–2 weeks (16, 17Trusted Source).
Additionally, older test-tube studies note that garlic may have antiviral activity against influenza A and B, HIV, HSV-1, viral pneumonia, and rhinovirus, which causes the common cold. However, current research is lacking (18Trusted Source).
Animal and test-tube studies indicate that garlic enhances immune system response by stimulating protective immune cells, which may safeguard against viral infections (19Trusted Source).
6. Lemon balm
Lemon balm is a lemony plant that’s commonly used in teas and seasonings. It’s also celebrated for its medicinal qualities.
Lemon balm extract is a concentrated source of potent essential oils and plant compounds that have antiviral activity (20Trusted Source).
Test-tube research has shown that it has antiviral effects against avian influenza (bird flu), herpes viruses, HIV-1, and enterovirus 71, which can cause severe infections in infants and children (8Trusted Source, 20Trusted Source, 21Trusted Source, 22Trusted Source, 23Trusted Source).
7. Peppermint
Peppermint is known to have powerful antiviral qualities and commonly added to teas, extracts, and tinctures meant to naturally treat viral infections.
Its leaves and essential oils contain active components, including menthol and rosmarinic acid, which have antiviral and anti-inflammatory activity (24Trusted Source).
In a test-tube study, peppermint-leaf extract exhibited potent antiviral activity against respiratory syntactical virus (RSV) and significantly decreased levels of inflammatory compounds (25Trusted Source).
8. Rosemary
Rosemary is frequently used in cooking but likewise has therapeutic applications due to its numerous plant compounds, including oleanolic acid (26Trusted Source).
Oleanolic acid has displayed antiviral activity against herpes viruses, HIV, influenza, and hepatitis in animal and test-tube studies (27Trusted Source).
Plus, rosemary extract has demonstrated antiviral effects against herpes viruses and hepatitis A, which affects the liver (28Trusted Source, 29Trusted Source).
9. Echinacea
Echinacea is one of the most popularly used ingredients in herbal medicine due to its impressive health-promoting properties. Many parts of the plant, including its flowers, leaves, and roots, are used for natural remedies.
In fact, Echinacea purpurea, a variety that produces cone-shaped flowers, was used by Native Americans to treat a wide array of conditions, including viral infections (30Trusted Source).
Several test-tube studies suggest that certain varieties of echinacea, including E. pallid a, E. angustifolia, and E. purpurea, are particularly effective at fighting viral infections like herpes and influenza (31Trusted Source).
Notably, E. purpurea is thought to have immune-boosting effects as well, making it particularly useful for treating viral infections (30Trusted Source).
10. Sambucus
Sambucus is a family of plants also called elder. Elderberries are made into a variety of products, such as elixirs and pills, that are used to naturally treat viral infections like the flu and common cold.
A study in mice determined that concentrated elderberry juice suppressed influenza virus replication and stimulated immune system response (32Trusted Source).
What’s more, in a review of 4 studies in 180 people, elderberry supplements were found to substantially reduce upper respiratory symptoms caused by viral infections (33Trusted Source).
11. Licorice
Licorice has been used in traditional Chinese medicine and other natural practices for centuries.
Glycerine, liquiritigenin, and glabridin are just some of the active substances in licorice that have powerful antiviral properties (34Trusted Source).
Test-tube studies demonstrate that licorice root extract is effective against HIV, RSV, herpes viruses, and severe acute respiratory syndrome-related corona virus (SARS-CoV), which causes a serious type of pneumonia (35Trusted Source, 36Trusted Source, 37Trusted Source).ADVERTISEMENTGet Answers from a Doctor in Minutes, Anytime
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12. Astragalus
Astragalus is a flowering herb popular in traditional Chinese medicine. It boasts Australasia polyacrylamide (APS), which has significant immune-enhancing and antiviral qualities (38Trusted Source).
Test-tube and animal studies show that astragalus combats herpes viruses, hepatitis C, and avian influenza H9 virus (39Trusted Source, 40Trusted Source, 41Trusted Source, 42Trusted Source).
Plus, test-tube studies suggest that APS may protect human astrocyte cells, the most abundant type of cell in the central nervous system, from infection with herpes (38Trusted Source).
13. Ginger
Ginger products, such as elixirs, teas, and lozenges, are popular natural remedies — and for good reason. Ginger has been shown to have impressive antiviral activity thanks to its high concentration of potent plant compounds.
Test-tube research demonstrates that ginger extract has antiviral effects against avian influenza, RSV, and feline calicivirus (FCV), which is comparable to human norovirus (43Trusted Source, 44Trusted Source, 45Trusted Source)
Additionally, specific compounds in ginger, such as gingerols and zinger one, have been found to inhibit viral replication and prevent viruses from entering host cells (46Trusted Source).
14. Ginseng
Ginseng, which can be found in Korean and American varieties, is the root of plants in the Pan-ax family. Long used in traditional Chinese medicine, it has been shown to be particularly effective at fighting viruses.
In animal and test-tube studies, Korean red ginseng extract has exhibited significant effects against RSV, herpes viruses, and hepatitis A (47Trusted Source, 48Trusted Source, 49Trusted Source).
Plus, compounds in ginseng called ginsenosides have antiviral effects against hepatitis B, norovirus, and coxsackieviruses, which are associated with several serious diseases — including an infection of the brain called meningoencephalitis (49Trusted Source).
15. Dandelion
Dandelions are widely regarded as weeds but have been studied for multiple medicinal properties, including potential antiviral effects.
Test-tube research indicates that dandelion may combat hepatitis B, HIV, and influenza (50Trusted Source, 51Trusted Source, 52Trusted Source).
Moreover, one test-tube study noted that dandelion extract inhibited the replication of dengue, a mosquito-borne virus that causes dengue fever. This disease, which can be fatal, triggers symptoms like high fever, vomiting, and muscle pain (53Trusted Source, 54Trusted Source).
Herbs have been used as natural remedies since ancient times.
Common kitchen herbs, such as basil, sage, and oregano, as well as lesser-known herbs like astragalus and sambucus, have powerful antiviral effects against numerous viruses that cause infections in humans.
It’s easy to add these powerful herbs to your diet by using them in your favorite recipes or making them into teas.
However, keep in mind that most research has been conducted in test tubes and animals using concentrated extracts. Therefore, it’s unclear whether small doses of these herbs would have the same effects.
If you decide to supplement with extracts, tinctures, or other herbal products, consult your healthcare provider to ensure safe usage.
Winter is the time of year when we seem to be particularly vulnerable to all kinds of illnesses that are caused by viruses including colds, flu and cold sores. A virus is not to be confused with bacteria, which causes infection. Viruses are tiny bits of nucleic acids that contain information and use your body’s cells tor create more copies of themselves.
There are very few treatments, allopathic or natural that can kill a virus outright, as usually a virus must run its course. However the list of natural remedies here come as close to stopping a virus in its tracks as Mother Nature can get.
COLLOIDAL SILVER
Silver has been utilized as a medicine since ancient times to treat scores of ailments, including the bubonic plague. Colloidal silver is a suspension of pure metallic silver in water, that is used to dramatically reduce the activity of the HIV virus in AIDS patients, slow down the ravages of the hepatitis C virus and combat other viruses in general. It works by interfering with the enzymes that allow a virus to utilize oxygen thus, in essence, suffocating it so it cannot do damage in the body.
ELDERBERRY
The common black elderberry (Sambucus nigra) has long been used to reduce the length and severity of flu symptoms and studies. Taking 60 ml a day for adults and 30 ml for children helps to facilitate a complete recovery, often in three days. Elderberry extract binds to the tiny spikes on a virus protein that are used to pierce and invade healthy cells and destroys them so that the virus is ineffective. Elderberry may also be effective against the herpes simplex virus and some HIV strains.
ECHINACEA
The herb Echinacea (Echinacea purpurea) is supportive of the immune system and has a direct anti-viral action against colds and viral bronchitis. Preparations that include both the roots and the flowering tops are the most effective at helping the body resist the viruses.
GARLIC
Garlic has been prized for its medicinal properties for thousands of years. The compounds allicin and alliion are responsible for this common plant’s reputation as a triple threat. Garlic is anti-viral, anti-bacterial and anti-fungal and it is especially effective against viruses if chewed raw.
GREEN TEA
Green tea (Camellia sinensis) contains a group of flavonoids called catechist, which appear to inhibit viral infections by blocking the enzymes that allow it to reproduce. Green tea has been known to be effective in inhibiting HIV, herpes similes and the hepatitis B virus.
LICORICE
Liquor ice contains a substance called glycyrrhizin that reduces the replication of viruses and halts their ability to penetrate replicate inside healthy cells. It has been noted to be effective in the treatment of many viral illnesses including HIV strains and viral hepatitis.
OLIVE LEAF
The leaves of Olive trees (Olea euro-pea) contain a substances called elenoic acid and calcium elonate has been identified as a powerful inhibitor of a wide range of viruses in laboratory tests., including influenza, herpes, polio and coxsackie viruses. These substances block the production of enzymes that allow viruses to replicate.
PAU D’ARCO
Pau d’arco (Tabulate impetiginosa), also known as lapacho or ipe roxo, is an Amazon tree with healing inner bark that can treat colds, influenza, herpes and viral stomatis. It contains quinoids that inhibit virus replication by damaging the DNA and RNA inside the viral protein that would insert itself in a healthy human cell and replicate.