Rosmarinic acid is a phenolic compound commonly found in the Lamiaceae (Labiateae) plant species. It is considered responsible for a wide spectrum of biological and pharmacological activities of plants containing this compound. The aim of the current review is to present the fate of rosmarinic acid inside the human body, explained through pharmacokinetic steps and to briefly present the health benefits of RA. Pharmacokinetics was at first studied in animal models, but several studies were conducted in humans as well. This compound can be applied topically, pulmonary, intranasally, and via intravenous infusion. However, peroral application is the main route of entry into the human body. Presumably, it is mainly metabolized by the gut microflora, providing simple, more easily absorbed phenolic units. Inside the body, the rosmarinic acid molecule undergoes structural changes, as well as conjugation reactions. Renal excretion represents the main path of elimination. Previously conducted studies reported no serious adverse effects of herbal remedies containing RA, as well as their positive effects on human health. In addition to in vitro studies, clinical investigations suggested its benefits in dermatological, allergic, and osteoarthritic disorders, as well as for improving cognitive performance and in metabolic syndrome treatment. Future studies should investigate the kinetics during long-term application in patients who would have potential benefits from RA usage. Pharmaceutical formulations designed to prevent the fast metabolism of RA and allow its penetration into other compartments of the human body are also interesting topics for future research.

The first case of SARS-CoV-2 infection was reported in December 2019. Due to the rapid spread of the disease and the lack of adequate therapy, the use of plants that have a long history in the treatment of viral infections has often been considered. The aim of this paper is to provide a brief review of the literature on the use of phytochemicals during the new pandemic. An extensive search of published works was performed through platforms Google Scholar, PubMed, Science Direct, Web of Science and Clinicaltrials.gov. Numerous preclinical studies on the use of phytochemicals (quercetin, curcumin, baicalin, kaempferol, resveratrol, glycyrrhizin, lycorine, colchicine) against SARS-CoV-2 have shown that these components can be effective in the prevention and treatment of this infection. Clinical research has proven that the use of black cumin and green propolis as well as quercetin has positive effects. As for other phytochemicals, in addition to preclinical testing which has already been carried out, it would be necessary to conduct clinical tests in order to assert their effectiveness. For those phytochemicals whose clinical efficacy has been proven, it would be necessary to conduct research on a larger number of patients, so that the conclusions are more representative.

Since the appearance of the novel coronavirus disease of 2019—COVID-19, various therapeutic approaches were attempted, with complementary and alternative medicine (CAM) taking an important place. The aim of this study was to investigate the use of CAM with the purpose of prevention or treatment of COVID-19 during the pandemics. A prospective, cross-sectional study, in the form of an on-line survey was conducted. A total of 1704 responses were collected. Among the respondents, 2.76% declared currently and 22.12% previously having COVID-19. Approximately one quarter of interviewees (23.24%) declared themselves as phytotherapy users. The most frequently used medicinal plants were garlic, ginger and chamomile. The majority of respondents stated that they expected positive effects on immune and respiratory system. Medicinal plants were frequently used, on a daily basis. The main sources of information for applied self-medication were populistic thematic literature, followed by the Internet. Approximately one-third of phytotherapy users (35.25%) consulted with a medical professional before the application of phytotherapy. Regarding dietotherapy, 41.14% of respondents reported using non-herbal dietary supplements, while only 7.16% reported specific diet. The presented results suggest that CAM is recognized and readily used as a potential alternative and complementary regimen in the fight against COVID-19.