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Journal of Ethnopharmacology 265 (2021) 113319 Contents lists available at ScienceDirect Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jethpharm Potential anti-influenza effective plants used in Turkish folk medicine: A review Seyid Ahmet Sargin Alanya Alaaddin Keykubat University, Faculty of Education, 07400, Alanya, Antalya, Turkey ARTICLE INFO ABSTRACT Keywords: Ethnopharmacological relevance: Due to the outbreaks such as SARS, bird flu and swine flu, which we frequently Anti-influenza encounter in our century, we need fast solutions with no side effects today more than ever. Due to having vast Antiviral ethnomedical experience and the richest flora(34% endemic) of Europe and the Middle East, Turkey has a high Antimalarial potential for research on this topic. Plants that locals have been using for centuries for the prevention and COVID-19 treatment of influenza can offer effective alternatives to combat this problem. In this context, 224 herbal taxa Traditional treatment Turkey belonging to 45 families were identifiedamong the selected 81 studies conducted in the seven regions of Turkey. However, only 35 (15.6%) of them were found to be subjected to worldwide in vitro and in vivo research con­ ducted on anti-influenza activity. Quercetin and chlorogenic acid, the effectiveness of which has been proven many times in this context, have been recorded as the most common (7.1%) active ingredients among the other 56 active substances identified. Aim of the study: This study has been carried out to reveal the inventory of plant species that have been used in flu treatment for centuries in Turkish folk medicine, which could be used in the treatment of flu or flu-like pan­ demics, such as COVID 19, that humanity has been suffering with, and also compare them with experimental studies in the literature. Materials and methods: The investigation was conducted in two stages on the subject above by using electronic databases, such as Web of Science, Scopus, ScienceDirect, ProQuest, Medline, Cochrane Library, EBSCO, High­ Wire Press, PubMed and Google Scholar. The results of both scans are presented in separate tables, together with their regional comparative analysis. Results: Data obtained on taxa are presented in a table, including anti-influenza mechanism of actions and the active substances. Rosa canina (58.7%) and Mentha x piperita (22.2%) were identifiedas the most common plants used in Turkey. Also, Sambucus nigra (11.6%), Olea europaea (9.3%), Eucalyptus spp., Melissa officinalis, and Origanum vulgare (7.0%) emerged as the most investigated taxa. Conclusion: This is the first nationwide ethnomedical screening work conducted on flu treatment with plants in Turkey. Thirty-nine plants have been confirmed in the recent experimental anti-influenza research, which strongly shows that these plants are a rich pharmacological source. Also, with 189 (84.4%) taxa, detections that have not been investigated yet, they are an essential resource for both national and international pharmaco­ logical researchers in terms of new natural medicine searches. Considering that the production of antimalarial drugs and their successful use against COVID-19 has begun, this correlation was actually a positive and remarkable piece of data, since there are 15 plants, including Centaurea drabifolia subsp. Phlocosa (an endemic taxon), that were found to be used in the treatment of both flu and malaria. 1. Introduction plants in the prevention and treatment of various diseases for centuries. People living in rural areas still have an especially rich medicinal plant Plants have always been the primary choice for preventing and repertoire (Ertug,˘ 2004). Although herbal cures such as rosehip tea, treating various diseases faced by human beings, and contain specificor peppermint-lemon tea and garlic-lemon tea, which are used to prevent broad-spectrum active compounds for almost any type of disease and treat flu outbreaks, are well known by the local people, the vast (Alaoui-Jamali, 2010). People living in Turkey have also benefitedfrom majority of them and their anti-influenza effects have not yet been E-mail address: [email protected]. https://doi.org/10.1016/j.jep.2020.113319 Received 20 May 2020; Received in revised form 18 August 2020; Accepted 22 August 2020 Available online 31 August 2020 0378-8741/© 2020 Elsevier B.V. All rights reserved. S.A. Sargin Journal of Ethnopharmacology 265 (2021) 113319 adequately investigated in vitro by the related industries (Bekut et al., In this study, the total list of plant taxa used in Turkish folk medicine 2018). against diseases caused by influenza viruses is presented for the first In virus classification, influenza viruses are RNA viruses that time. It also reveals which of these plants are researched worldwide for comprise 4 of the 7 genera of the family Orthomyxoviridae (Kawaoka, anti-influenzaactivity, along with their active compounds. Taxa that do 2006), while Human Rhinoviruses (HRVs) are within the genus not have a research record are an important resource for new drug Enterovirus and the family Picornaviridae (Jacobs et al., 2013). Never­ researchers. theless, the flucaused by influenzaviruses and the common cold caused by Human Rhinovirus are very similar, although both are types of res­ 2. Materials and methods piratory virus in terms of disease symptoms (CDC, 2019). In general, it is the most common cause of respiratory viral disease in spring, summer 2.1. Data collection and autumn, while the flu virus is dominant in winter. On the other hand, flu or flu-like viruses are highly contagious and cause serious This research was conducted in two stages. While, in the firststage, a complications and outbreaks that erupt with a different genetic code list of herbs that are used for the treatment of flu in Turkish folk med­ each year and even life-threatening pandemics (Jacobs et al., 2013). icine is presented, in the second stage, it was investigated whether there Nowadays, COVID-19 is one of the most striking examples of a flu-like are experimental studies of “anti-influenza” effects of the plants from virus. Due to its fast transmission through direct contact with infected this list in the world literature. Among these studies those with active people and contaminated substances or droplets, thousands of patients compound determination were especially preferred. Various electronic are dying every day with a fever, cough, and shortness of breath, and, databases, such as Web of Science, Scopus, ScienceDirect, ProQuest, currently, there is no definitive treatment or vaccine, except for some Medline, Cochrane Library, EBSCO, HighWire Press, PubMed and Goo­ available malaria medicines (Basiri, 2020). There is an urgent need to gle Scholar, have been scanned for both studies. In the interest of the identify new naturally occurring antiviral molecules, as resistance to plant inventory survey, the national studies conducted in all regions anti-influenza drugs appears to be prevalent to an alarming extent (Fig. 1) of Turkey were taken into account. Moreover, to achieve (Haidari et al., 2009). Herbal remedies have been used for centuries to detailed coverage, the database of the Higher Education Council of treat flu symptoms, and essential oils derived from them have been Turkey National Thesis Center was also included in the research litera­ prescribed as complementary and alternative treatments against influ­ ture. The results of both scans are presented in Tables 3 and 4. enza (Setzer, 2016). Therefore, to contribute to the treatment of influ­ Only English and Turkish words were used in the search engines. If enza disease and bearing in mind their greater importance, we focused they exist, their English translations were reviewed for the studies on plants whose successful anti-influenza effects have been tried and conducted in different languages, such as Chinese, Korean and French. trusted by Turkish people for centuries. In this context, approximately 700 articles conducted between January Essentially, some antiviral medicines, such as Oseltamivir and 1977 and February 2020 throughout Turkey were excluded since they Zanamivir, are available for treatment; however, the emergence of drug- did not meet the inclusion criteria and a consensus has been provided resistant strains as a new type of virus is a serious concern (Watanabe among the 81 works on the determination of medicinal plants used by and Kawaoka, 2015). In addition, vaccines are only around 50% effec­ local people for centuries. The list of selected plants from these studies is tive in the elderly, where the highest mortality rates occur (Wang et al., presented in Table 1. 2006; Rajasekaran et al., 2013), and side effects, such as nausea, vom­ iting, neuropsychiatric events, abdominal pain, diarrhoea, sinusitis, 2.2. Data selection headache and dizziness, are very common (Grienke et al., 2009). For this reason, natural active ingredients or traditional applications with The studies determined to be within the scope of plant screening proven effectiveness are accepted more in the world (Rajasekaran et al., were reviewed, compared and carefully selected according to the 2013). following criteria. Accordingly, a study should: Empirical information and bio experiments based on the ethno­ medical benefits of plants show that they have the potential to identify • be carried out in an area within the borders of Turkey.