Effects of glycyrrhizic acid (Viusid-Vet® powder) on the reduction of influenza virus spread and on production parameters in pigs

Abstract

Influenza viruses are among the most important respiratory pathogens in pigs and humans. They cause seasonal epidemics in pigs and occasional pandemics in humans. Herbal remedies have been regarded as suitable elements to aid in controlling influenza. This study was carried out to analyse the effects of the in-feed administration of glycyrrhizic acid, the best-known component of liquorice (as Viusid-Vet® powder), in pigs suffering an outbreak of influenza. Eighty crossbred Duroc-Landrace pigs, one day post-weaning (22 days old), were included in this trial. Piglets were randomly divided into the following two groups: those treated with glycyrrhizic acid and an untreated control group. Serological measurements to assess viral load and humoral responses were carried out. Blood samples from pigs were obtained every fortnight, starting on week two and ending on week 15. With these samples, haemagglutination inhibition (HI) tests were performed, using A/swine/New Jersey/11/76 (H1N1) and A/swine/Minnesota/9088-2/98 (H3N2) as reference viruses. Quantitative RT-PCR tests against the M gene of the influenza virus were also performed to assess viral shedding from nasal swab samples on weeks 1 to 8 after the beginning of the trial. Weight variables were assessed weekly for 18 weeks. In the HI tests, treated animals showed fewer positive responses compared to the control group for H1N1 and H3N2. However, a positive response to viral protection, as assessed by HI tests, was regarded as not conclusive of humoral immune stimulation. qRT-PCR tests for viral spread exhibited a lower rate of excretion for the treated group compared to the untreated one. Hence, it appears that glycyrrhizic acid stimulates, to some extent, immune responses against pig influenza as measured by viral shedding. For mean body weight, the generalized estimating equations show a higher weight gain for pigs treated with glycyrrhizic acid than the control group (P = 0.0001). These effects may assist producers in addressing the aftermath of an influenza outbreak.

Evaluation of the VIUSID Vet (Powder and Solution) Nutritional Supplement in Growing-Finishing Pigs

“…Although VIUSID was initially designed to be used in humans to boost the immune system in all processes that caused immunodeficiency or altered immune responses, the responses observed in pigs indicate that the product has a positive impact on the productive performance of fattening pigs. The compounds comprising the product are naturally present in the animals and the molecular activation to which they are subjected gives it properties that allow its use in different species and zootechnical categories, which has been demonstrated in research on mainly pigs and birds [9,16,17].…”

A Review of the Antiviral Activities of Glycyrrhizic Acid, Glycyrrhetinic Acid and Glycyrrhetinic Acid Monoglucuronide

“…The researchers used a hem-agglutination inhibition test to conclude that glycyrrhizinate caused fewer positive reactions in animals treated with H1N1 and H3N2, showing a lower rate of viral transmission. To a certain extent, GL stimulated immune responses against pig influenza, as measured by viral shedding [ 138 ].…”

Efficacy and Safety of Viusid and Asbrip in Hospitalized Patients with Mild and Moderate COVID-19: A Randomized Controlled Trial

“…Moreover, Viusid has shown that help to increase production of interferon gamma [22]. Viusid showed its efficacy in many trials against hepatitis C virus [22], cirrhosis [23], influenza virus [24], HPV [25]. Also Viusid has proved very high anti-oxidant activity (11,587.95 μmol TE/ml) measured in Brunswick Laboratories [26].…”