Plants produce a wide variety of natural volatile organic compounds (NVOCs), many of which are unique to each species. These compounds serve many purposes, such as fending off herbivores and adapting to changes in temperature and water supply. Interestingly, although NVOCs are synthesized to deter herbivores, many of these compounds have been found to possess several therapeutic qualities, such as promoting nerve stability, enhancing sleep, and suppressing hyperresponsiveness, in addition to acting as antioxidants and anti-inflammatory agents. Therefore, many NVOCs are promising drug candidates for disease treatment and prevention. Given their volatile nature, these compounds can be administered to patients through inhalation, which is often more comfortable and convenient than other administration routes. However, the development of NVOC-based drug candidates requires a careful evaluation of the molecular mechanisms that drive their therapeutic properties to avoid potential adverse effects. Furthermore, even compounds that appear generally safe might have toxic effects depending on their dose, and therefore their toxicological assessment is also critical. In order to enhance the usage of NVOCs this short review focuses not only on the biological activities and therapeutic mode of action of representative NVOCs but also their toxic effects.

In 2016, infectious microbes were one of the leading causes of death, especially in developing countries. Puriton^® is a mineral mixture consisting of biotite, kaolinite, montmorillonite, serpentine, clinochlore, and vermiculite, and evaluated antimicrobial activity in vitro and safety in vivo. Nine pathogens and opportunistic bacteria, namely Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, Alcaligenes faecalis, Staphylococcus aureus, Enterococcus faecalis, Micrococcus luteus, Mycobacterium smegmatis, and Bacillus subtilis, and the two viruses Zika and Influenza A/Duck/MN/1525/81 were used. A 26-week oral repeated safety study of Puriton^® was conducted. Puriton^® suppressed the bacterial proliferation, with a minimum proliferative rate of 91.1% in B. subtilis ATCC6633. The virucidal efficacy of Puriton^® against Zika virus after 4 h and 18 h of contact time was significant in all groups treated with Puriton^®. Twenty-six-week repeated oral administration of Puriton^® was considered safe based on physiological results, such as behavior and blood cells/chemistry, and histopathological changes in the brain, heart, kidney, liver, and lung. We concluded that Puriton^® exerted bactericidal and virucidal efficacies and was safe for 26-week repeated oral administration.

Codonopsis lanceolate exerts various medicinal effects and has been used as a traditional medicine for inflammation, asthma, gastritis, and liver disease. Recently, we reported the xanthine oxidase inhibitory activity of C. lanceolata extract and that lobetyolin, one of the key components, was a xanthine oxidase inhibitor. Lobetyolin showed anti-hyperuricemic activity in vitro and in vivo. In this study, we prepared various types of C. lanceolata extracts for the development of functional materials and natural drugs. We present the optimal analytical approach for the quality control and extraction optimization of C. lanceolata preparations. We established and validated a HPLC analysis for easy separation and quantification of the lobetyolin biomarker. Solvent extracts of C. lanceolata root were prepared and the profiles of the active marker and the optimal extraction methods were evaluated. The 100% ethanolic extract demonstrated the highest lobetyolin content. The validated HPLC method confirmed that lobetyolin was present in C. lanceolata root extracts. We suggest that the anti-hyperuricemic activities of C. lanceolata extract could be attributed to this marker compound. The results proposed that the 100% ethanolic extract could be used for the prevention of hyperurecemia, and that this analytical method and biomarker could be useful for the quality control of C. lanceolata preparations.

In 2016, obese patients represented 13% of the worldwide adult population, and by 2030, they are projected to make up 34%. Obesity is an incommunicable disease, but it can induce many health problems. The groups consisted of a control, a 65% high-fat group, and a 250 mg/kg P. erosus group. Several biomarkers, such as body weight gain, the presence of TC/LDL/HDL in the serum, the weight of fat tissue, and liver weight/morphology, were investigated to define the anti-obesity mechanisms of P. erosus, and the adipogenesis pathway was studied. P. erosus suppressed body weight gain, decreased TC and LDL, prevented fat tissue weight gain, and prevented liver weight gain by blocking lipid droplet accumulation. P. erosus effectively decreased the up-regulated levels of leptin, significantly controlled both C/EBPα and PPARγ levels, and prevented increased FAS expression levels. We concluded that P. erosus effectively controlled obesity by regulating leptin-C/EBPα-PPARγ and FAS and might be a promising AOM.