Antiviral potential of plant polysaccharide nanoparticles actuating non-specific immunity

Abstract

The development of high-end targeted drugs and vaccines against modern pandemic infections, such as COVID-19, can take a too long time that lets the epidemic spin up and harms society. However, the countermeasures must be applied against the infection in this period until the targeted drugs became available. In this regard, the non-specific, broad-spectrum anti-viral means could be considered as a compromise allowing overcoming the period of trial. One way to enhance the ability to resist the infection is to activate the nonspecific immunity using a suitable driving-up agent, such as plant polysaccharides, particularly our drug Panavir isolated from the potato shoots. Earlier, we have shown the noticeable anti-viral and anti-bacterial activity of Panavir. Here we demonstrate the pro-inflammation activity of Panavir, which four-to-eight times intensified the ATP and MIF secretion by HL-60 cells. This effect was mediated by the active phagocytosis of the Panavir particles by the cells. We hypothesized the physiological basis of the Panavir proinflammatory activity is mediated by the indol-containing compounds (auxins) present in Panavir and acting as a plant analog of serotonin.

Keywords: Antiviral activity; COVID-19; Immune modulator.

Fig. 1

Infra-Red spectra of Panavir (red) and starch (blue). For clarity, the spectra were split into two regions of 3800–2600 cm^-1 (A) and 1600–700 cm^-1 (B). The arbitrary units in plots A and B are the same. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

Area-normalized absorption spectra of an aqueous solution of Panavir (green), cytosolic fraction of HL-60 cells (blue) and HMW fractions of cytosol of HNEpC cells treated with Panavir (red). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3

Release of ATP by immature (circles) and mature (squares) HL-60 cells under the influence of physiological (A) and elevated (B) Panavir concentrations of: 2.5 (blue), 10 (red), 100 (orange), and 1000 ng/ml (purple). The gray dotted lines show the background concentration of ATP in the culture medium. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)