Herbal Medicines that Fight Influenza (Flu virus)

A number of scientific studies have confirmed that certain medicinal herbs and combinations have the ability to reduce the duration of the flu and reduce symptoms as well. The research finds these herbs can directly inhibit influenza viruses as well as stimulate the body’s own immune system in order to counteract the flu.

Influenza-infected cells

Even in modern times, influenza epidemics have taken the lives of millions of people around the world. Yet for most influenza viruses, proven treatments are scarce. Antiviral medications have proven to be helpful in some cases, but many viruses have become resistant as new strains develop.

Often a bad case of the flu will be dangerous for those who are characterized as being immunosuppressed. In these cases, a weakened immune system can create a mortal threat after infection.

Yet there is a history of success with some herbs in traditional medicine for influenza over the centuries, especially in Asia. Some of these herbs have been confirmed in modern research as directly being antiviral to some of the most lethal influenza viral strains. At the same time, some of these herbs have been shown to help stimulate the immune system to respond to viruses. Let’s take a look at some of the research.

Three traditional herbs tested

In a 2019 study, researchers from South Korea’s Konkuk University tested three herbs that have been used in traditional Asian medicines to counteract the flu. These are:
– Brassica juncea (also called brown mustard)
– Forsythia suspensa (also called forsythia or Lian Qiao)
– Inula britannica (also called British yellowhead)

The researchers made extracts from the three herbs and tested these in the laboratory against influenza infections including H1N1 in tissue cultures. The researchers found that B. juncea (the brown mustard) extracts significantly reduced viral infection. The British yellowhead herb also showed antiviral properties in the study.

These confirmed that the traditional use of at least two of these herbs for influenza were substantiated as being truly antiviral.

Flu inhibited by two herbs

Another study from China’s Northwest A&F University confirmed the antiviral activity of two herbs used traditionally for influenza – one also studied above. In this study, researchers determined that two medicinal herbs known for clinical success in influenza treatment, and at least fifty phytochemicals contained in them, can inhibit the growth of the flu virus.

The researchers tested Forsythia or Lian Qian (Forsythia suspensa) as studied above, as well as Lonicera japonica (also called Suikazura, Jinyinhua and Japanese Honeysuckle).

The researchers exposed these herbs and their constituents to influenza viruses and human cells within a laboratory setting.

The researchers found that these two herbs, and fifty of their constituents – phytochemicals that were isolated from them – significantly inhibited the replication of the viruses. This study follows other research concluding similar findings with other herbs.

The researchers’ findings have unveiled a new dimension among the phytochemicals that nature produces within certain medicinal herbs. This has to do with a two-pronged effect:

1) The ability of these herbs and their phytochemicals to stimulate the body’s own immunity, allowing the body to be able to more effectively fight off the infection;
2) The ability of the independent constituents within the herbal medicine to shut off a virus’ ability to replicate, even in a sterile environment outside the body.

The researchers concluded:

“the overall data suggest that the medicinal herbs function by indirectly suppressing the virus proliferation via regulating the immune systems in hosts, and also, by directly inhibiting virus proliferation through targeting viral proteins essential for the viral life cycle.”

Japanese Maoto formula for the flu

Clinical research has supported that the Japanese herbal formulation called Maoto can significantly reduce the duration and fever of the flu. A 2019 review of research from Japan’s Keio University School of Medicine found 12 clinical studies that measured the effectiveness of Maoto against the flu.

The researchers concluded that Maoto significantly reduced fevers and flu duration.

In one of these studies, from Japan’s Ohmura Hospital in Chiba, 150 patients with influenza A completed a study whereby the Japanese medicinal combination called Maoto was found to significantly reduce symptoms and influenza duration as compared to those taking Oseltamivir or Zanamivir or patients not receiving any treatment.

The research found that those patients given the Maoto had an average duration of 33 hours, versus 70 hours in the patients given no treatment, versus 61 hours among those patients treated only with Oseltamivir. The marginally shortest flu duration was among those patients given both the Maoto and Oseltamivir, at 31 hours.

Researchers from Japan’s Fukuoka University also found that Maoto reduces the duration of influenza.

The researchers randomly gave 28 adults with influenza either the Maoto herbal medicine, or one of two neuraminidase inhibitor pharmaceutical drugs found to reduce influenza duration.

The Japanese herbal combination – taken in granule form – reduced the average flu duration from its typical four to five day duration down to an average of 29 hours. Because the subjects had contracted influenza symptoms within 48 hours of the study, the maximum mean duration totaled about three days, with the average at about two days.

The two neuraminidase inhibitor drugs, known also for reducing influenza duration – but can accompany side effects including vomiting and nausea – had average durations of 43 and 27 hours respectively.

The Maoto herbal treatment caused no side effects and was characterized as “well tolerated.”

The Japanese Maoto combination is composed of Ma Huang (Ephedra), Apricot Kernel, Cinnamon Bark and Licorice – also called Glycyrrhiza Root. Each of these herbs have been clinically utilized in different combinations by Traditional Japanese and Chinese Medical doctors for stimulating immunity and inhibiting viruses. Ayurveda has also utilized these herbs for boosting the immune system.

Nepal smartweed

Another recent study, from Shandong University’s School of Pharmaceutical Sciences, has determined similar results with another plant, Polygonum nepalense (also called Nepal smartweed). Polygonum nepalense is also known for effectively treating influenza.

The researchers found that six polyphenols within the herb that effectively reduced infective inflammation. These include kaempferol, glucopyranoside, quercetin, pyrogallol, gallic acid and epipinoresinol.

These herbs studied present only the tip of the iceberg among herbs that have been used among various traditional medicines around the world. There are a variety of herbs that are known to stimulate immunity, giving the immune system a stronger ability to fight off various infections.

Lomatium dissectum and influenza

We add to this the Native American legend of Lomatium dissectum. According to the legend, Ernst Krebs, M.D. of Carson City observed that the Washoe Indians of Nevada seemed to recover quickly and avoid the plague of the 1918 influenza by taking an herbal medicine called “Toh-sa.”

Dr. Krebs named it Balsamea, as it smelled like balsa. It was later named Leptotaenia dissecta and then Lomatium dissectum by botanists.

Consistent with this legend, in 1995, the root of Lomatium dissectum was tested for antiviral activity at Canada’s University of British Columbia. The Lomatium was found to inhibit the “cytopathic effects” of rotavirus.

Lomatium is only one herb from one traditional medicine among hundreds of herbs and hundreds of traditional medicines around the world. The effective inhibition of influenza by fifty constituents isolated from the two herbs in the new laboratory study from China illustrate that there are many anti-influenza herbal medicines, even besides the Maoto combination. Many of the fifty anti-influenza constituents found in Fructus forsythiae and Lonicera japonica also occur in other herbal medicines.

In 2011, a Cochrane Review of Research from the Beijing University of Chinese Medicine found among 26 studies that several Chinese herbal medicines “demonstrated a positive effect on fever resolution, relief of symptoms, and global effectiveness rate” for influenza. The research concluded, however, that more clinical research was necessary to confirm certainty.

The evidence from these and other scientific studies from Japan and China considerably advance the level of certainty that herbal medicine can be used successfully to fight the flu.

SCIENTIFIC REFERENCES:

Bae WY, Kim HY, Choi KS, Chang KH, Hong YH, Eun J, Lee NK, Paik HD. Investigation of Brassica juncea, Forsythia suspensa, and Inula britannica: phytochemical properties, antiviral effects, and safety. BMC Complement Altern Med. 2019 Sep 11;19(1):253. doi: 10.1186/s12906-019-2670-x.

Yoshino T, Arita R, Horiba Y, Watanabe K. The use of maoto (Ma-Huang-Tang), a traditional Japanese Kampo medicine, to alleviate flu symptoms: a systematic review and meta-analysis. BMC Complement Altern Med. 2019 Mar 18;19(1):68. doi: 10.1186/s12906-019-2474-z.

Wang X, Xu X, Li Y, Li X, Tao W, Li B, Wang Y, Yang L. Systems pharmacology uncovers Janus functions of botanical drugs: activation of host defense system and inhibition of influenza virus replication. Integr Biol (Camb). 2012 Nov 20.

Toriumi Y, Kamei T, Murata K, Takahashi I, Suzuki N, Mazda O. Utility of Maoto in an influenza season where reduced effectiveness of oseltamivir was observed – a clinical, non-randomized study in children. Forsch Komplementmed. 2012;19(4):179-86.

Nabeshima S, Kashiwagi K, Ajisaka K, Masui S, Takeoka H, Ikematsu H, Kashiwagi S. A randomized, controlled trial comparing traditional herbal medicine and neuraminidase inhibitors in the treatment of seasonal influenza. J Infect Chemother. 2012 Feb 16.

McCutcheon AR, Roberts TE, Gibbons E, Ellis SM, Babiuk LA, Hancock RE, Towers GH. Antiviral screening of British Columbian medicinal plants. J Ethnopharmacol. 1995 Dec 1;49(2):101-10.

Chen W, Lim CE, Kang HJ, Liu J. Chinese herbal medicines for the treatment of type A H1N1 influenza: a systematic review of randomized controlled trials. PLoS One. 2011;6(12):e28093. doi: 10.1371/journal.pone.0028093.

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