Rice bran compound could prevent respiratory viral infections

By Lynda Searby

- Last updated on GMT

Getty | respiratory tract infection
Getty | respiratory tract infection

Related tags Research Respiratory tract infections

The first pilot clinical study to investigate Biobran MGN-3’s efficacy in preventing respiratory viral infections has yielded “encouraging results”.

“Biobran / MGN-3 could be a novel agent with prophylactic effects against a wide spectrum of respiratory viral infections,” ​wrote the researchers in the journal Nutrients​.

In the pilot study the incidence rate of flu-like illness was reduced by 80% in those who received Biobran MGN-3 supplementation, compared with those who were given a placebo.

What is Biobran MGN-3?

Biobran MGN-3 is a denatured hemicellulose whose main chemical structure is an arabinoxylan with a xylose in its main chain and an arabinose polymer in its side chain. It is obtained by reacting rice bran hemicellulose with several enzymes from Shiitake mushrooms, yielding a polysaccharide that contains β-1,3-glucans and activated hemicelluloses. The leading manufacturer of this type of hemicellulose food supplement is Daiwa Pharmaceutical in Japan, which has a patented process and supplied the Biobran MGN-3 and placebo that was used in this trial.

Biobran MGN-3 has previously been shown to counteract age-associated decline of NK cell activity in aged mice​ and in the older population​ and has also been found to induce potent immuno-modulatory effects in numerous studies​.

The well-documented immuno-modulatory effects of Biobran MGN-3 and its capacity to restore age-associated decline of NK cell activity prompted the researchers to investigate its ability to prevent virus induced influenza-like illnesses.

To gain insights into the mechanisms involved, the researchers assessed NK cell activity in the participants as well as the expression levels of receptors that detect viruses (RIG-1 and MDA5) and downstream protective genes (ISG15 and MX1), known for their anti-viral effects.

Study design

80 healthy older adults (over 55s) residing in Zagazig, Egypt, took part in the randomised, double-blind, placebo-controlled pilot clinical trial. Participants were randomly assigned either a placebo or Biobran MGN-3 (500mg per day) for three months during flu season. Influenza-like illness was diagnosed by documenting the incidence of acute respiratory illness, cough and temperature. The incidence rate was calculated by dividing the number of flu like cases by the number of participants in each group. Incidence density was calculated by dividing the number of incidence cases by the total person-time at risk. The effect of Biobran MGN-3 on NK cell activity was measured in six randomly selected subjects from each group.

The incidence rate in the experimental group was 5% (2/40), which was significantly lower than the rate in the placebo group which reached 22.5% (9/40). Similarly significant results were obtained when comparing the incidence density rates in the two groups. The incidence density rate in the experimental group was estimated to be 0.57 cases per 1000-person days compared to 2.95 cases per 1000-person days in the placebo group.

Biobran MGN-3 stimulates antiviral response

In addition, supplementation with Biobran MGN-3 significantly enhanced NK cell activity, and up-regulated the intracellular antiviral sensors RIG-1 and MDA5, and their downstream responsive genes ISG15 and MX1 in human lung cells.

NK cells play an essential role in the body’s immune response through their ability to eliminate virally-infected cells​. Impaired NK function has been shown to be associated with increased risk of viral infections​ including flu, hepatitis C and herpes.

“In this regard, Biobran MGN-3 could be a novel agent for modulating NK activity,”​ wrote the researchers.

In conclusion, they said that Biobran MGN-3 could be a novel antiviral agent that is well suited to long-term preventative purposes. Their future work will include studying these effects in a larger sample size and expanding the scope to include antiviral effects against Covid-19.


Source: Nutrients

Authors: Elsaid,A.F.; Agrawal,S.; Agrawal, A.; Ghoneum, M

"Dietary supplementation with Biobran/MGN-3 Increases innate resistance and reduces the incidence of influenza-like illnesses in elderly subjects: a randomized, double-blind, placebo-controlled pilot clinical trial"


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