Viral infections play an important role in human diseases, and recent outbreaks in the advent of globalization and ease of travel have underscored their prevention as a critical issue in safeguarding public health. Despite the progress made in immunization and drug development, many viruses lack preventive vaccines and efficient antiviral therapies, which are often beset by the generation of viral escape mutants. Thus, identifying novel antiviral drugs is of critical importance and natural products are an excellent source for such discoveries. In this mini-review, we summarize the antiviral effects reported for several natural products and herbal medicines.Key words: Antiviral, Drug development, Herbal medicines, Natural products Go to:
Viruses are responsible for a number of human parthenogenesis including cancer. Several hard-to-cure diseases and complex syndromes including Alzheimer’s disease, type 1 diabetes, and hepatocellular carcinoma have been associated with viral infections Moreover, due to increased global travel and rapid urbanization, epidemic outbreaks caused by emerging and re-emerging viruses represent a critical threat to public health, particularly when preventive vaccines and antiviral therapies are unavailable. Examples include the recent emergence of dengue virus, influenza virus, measles virus, severe acute respiratory syndrome (SARS) virus, and West Nile virus outbreaks.To date, however, many viruses remain without effective immunization and only few antiviral drugs are licensed for clinical practice. The situation is further exacerbated by the potential development of drug-resistant mutants, especially when using viral enzyme-specific inhibitors, which significantly hampers drug efficacy Hence, there is an urgent need to discover novel antivirals that are highly efficacious and cost-effective for the management and control of viral infections when vaccines and standard therapies are lacking.
Herbal medicines and purified natural products provide a rich resource for novel antiviral drug development. Identification of the antiviral mechanisms from these natural agents has shed light on where they interact with the viral life cycle, such as viral entry, replication, assembly, and release, as well as on the targeting of virus–host-specific interactions. In this brief report, we summarize the antiviral activities from several natural products and herbal medicines against some notable viral pathogens including corona virus (CoV), coxsackievirus (CV), dengue virus (DENT), enterovirus 71 (EV71), hepatitis B virus (HBV), hepatitis C virus (HCV), herpes simplex virus, human immunodeficiency virus (HIV), influenza virus, measles virus (MV), and respiratory syntactical virus (RSV)
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
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 Let Health line provide clarity on what’s going on
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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. Australasia
Australasia is a flowering herb popular in traditional Chinese medicine. It boasts Australasia polyacrylamide (APS), which has significant immune-enhancing and antiviral qualities
Test-tube and animal studies show that astragalus combats herpes viruses, hepatitis C, and avian influenza H9 virus
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
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
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
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
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
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
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
Herbal therapy has been an important part of health and wellness for hundreds of years. The renewed interest in medicinal plants has focused on herbal cures among indigenous populations around the world. Recent surveys have indicated that worldwide people now make more visits to healthcare professionals who specialize in alternative medicine than to doctors who practice conventional medicine. It is hoped that extracts from herbs will add new medicinal plants to the world’s pharmacopoeia before they are lost forever that too particularly against viral infection. Based on the ethnobotanical data and the information collected from Siddha/Ayurvedic practitioners of India, extracts obtained from Boerhavia diffusa, Eclipta alba and Phyllanthus amarus will be having great potential in curing various viral infections.