Background: Historical evidence has verified the multifaceted antiviral efficacy of polyoxometalates (PMs). Methods: We carried out a study to investigate the antimicrobial effects of each of the 5 substances comprising virus block (VB): 3 PMs that have antibacterial and antiviral activity, an antibiotic agent, and an antibacterial agent. We also investigated the effectiveness of the addition of VB to moist hand towels in a study involving 120 volunteers. The time-dependent changes in metal ion concentrations in aqueous VB solution were analyzed using inductively coupled plasma atomic emission spectroscopy. Results: The metal elements in the aqueous VB solution remained stable for 12 weeks without undergoing time-dependent changes. Discussion: Further investigations were performed to study hand hygiene using moist hand towels in daily life settings. To this end, 120 volunteers provided 240 specimens that were used to investigate the presence of antibacterial compounds on the volunteers’ hands before and after hand towel use. An aliquot of each specimen was suspended in phosphate-buffered saline and plated on agar media, and the number of colonies formed was counted. Normal bacterial flora found on the hands of the volunteers was investigated before and after the use of 4 different moist hand towels. Conclusions: The effects of VB and PMs were superior to those of commercial moist hand towels, indicating that effective data were obtained that may be useful for the practical application of the tested items.

Safe, secure, and environmentally friendly active substances should be developed. VB (virus block) refers to an antibacterial/antiviral mixture of two kinds of polyoxometalates (PMs), i.e., K11H[(VO)3(SbW9O33)2]·27H2O (VB2) and α-Na2[SbW9O33]9− (VB3), and polyhexamethylene biguanide (PHMB). VB was demonstrated to exert antiviral effects on cultured cells. The effects were maintained even in hygiene products or solids. The antiviral effects were analyzed by reverse transcription–polymerase chain reaction (RT–PCR), and the results were correlated with TCID50, potentially eliminating the need for handling infectious viruses. VB was demonstrated to be extremely effective (up to 99.99% inhibition) in cultured cells, with antibacterial/antiviral effects maintained in VB-containing hygiene products. VB was applied to solids, demonstrating their high applicability and versatility. VB withstands high temperatures regardless of materials because its effects are enhanced by more frequent contact with viruses and bacteria due to the increased surface area of the compound.

Excessive reactive oxygen species (ROS) generation by inflammation and glycation contributes to various aging-related changes in the body. Therefore, inhibiting ROS production can prevent wrinkles, maculae, dullness, and slackness in skin. To assess the anti-aging effects of two polyoxometalates (PMs: VB2 and VB3) on skin, this study investigated whether they ameliorated the anti-aging responses of normal human dermal fibroblasts (NHDF) to oxidative stress due to ad-vanced glycation end products (AGEs) or H2O2 exposure. Compared with the mRNA expression levels of AGE receptors in cells exposed to AGEs alone, an additional treatment with VB2 or VB3 significantly increased the expression levels of FEEL-1, FEEL-2, and RAGE. Under AGE-induced stress conditions, the expression levels of five heat shock proteins were markedly increased by the VB treatments. Conversely, VBs suppressed the induction of cell death and intracellular ROS production. VBs also exerted prophylactic effects on these harmful events under stress conditions. Furthermore, VB treatments were found to prevent both the suppression of AQP-1/AQP-3 expression and the suppression of hyaluronan and elastin production induced via H2O2 exposure. These results show the potential of VB2 and VB3 as anti-aging agents.