2.1. Study technique and sampling of the informants Primary and secondary data were used and analyzed qualitatively and quantitatively to conduct the study. A survey was conducted throughout the country to collect the primary data from the participants being infected with COVID-19 and recovered eventually. A semi-structured and open-ended questionnaire was adopted for this survey, partially followed by Martin (1995) and Alexiades and Sheldon (1996). To facilitate a better understanding, the questionnaire was prepared in the Bengali language. The participants were asked about what traditional home remedies based on plant and plant-derived products they used to recover from COVID-19. Questionnaires were converted to Google Docs form via Google service to make the online survey easier and faster. The Google Docs questionnaire form was shared among selective people using the snowball-sampling technique through online-based various social media platforms such as FacebookÓ, Messen-gerÓ, WhatsAppÓ, email, and other online platforms. In addition to the online survey, the printed questionnaire form was supplied to apart a number of participants who are less knowledgeable and uninterested in the online platform. After all, the necessary questionnaire data was collected by contacting them over the mobile phone. Initially, the questionnaire was sent to FacebookÓfriendsand other personal acquaintances who were known and confirmed to be infected with COVID-19, and special requests were made for answering the questionnaire. They were later requested to send the questionnaire form to their acquaintances who had been infected and recovered from COVID-19.
2.2. Data collection2.2.1. Ethical statementThe study was conducted following the ethical guidelines formulated by the American Anthropological Association (2012) and the Code of Ethics of the International Society of Ethnobiology(with 2008 additions). 2006; (http://www.ethnobiology.net/what-we-do/core-programs/ise-ethics-program/code-of-ethics/-code-in-English/). Ethical approval was taken from the Research and Ethics Committee, Department of Botany, University of Barishal, Bangladesh (approval number-BU/BOT/01/20). Before all interviews, we explained the aims and objectives of the study and obtained verbal informed consent from each respondent participating in the study. They have also been assured that their personal information would be kept confidential and obtained data will be used for research purposes only.
2.2.2. Primary data: To gather primary data, 436 respondents were interviewed from June to December 2020. It should be noted that in the case of respondent selection, only those were considered who were confirmed their infection and recovery with COVID-19 through RT-PCR nucleic acid test results. The data is collected and aggregated and sorted into different categories based on different titles in the Excel sheet. In the case of data on plants and plant-derived products used in the treatment of COVID-19 in the home-traditional method, the scientific names, family, and other botanical information of these plants were recorded with the help of standard literature books and the internet. All scientific names of plants were further reviewed and checked through the standardized database (http://www.theplantlist.org, Version 1.1). The herbarium voucher specimens were prepared and stored in the herbarium of the Department of Botany, University of Barishal, Bangladesh based on the availability of plant species found in the nearby area of our locations. Since most of the plants and plant-derived products used in COVID-19 treatment were collected from local marketplaces and some of the plants are not endemic in Bangladesh, therefore, herbarium sheets and/or voucher specimens of all their plants could not be prepared and stored except for a few.
.2.3. Secondary data: The primary data obtained by the survey are further explained by the secondary data. Secondary data were generated from literature references of published articles on ethnomedicinal uses and pharmacological evidence related to antiviral, anti-inflammatory, and immunomodulatory activities of the studied plant species. To scientifically interpret the possible potentiality of the obtained primary data to fight against COVID-19, many published articles connected to the ethnobotanical study, antiviral activity, and bioactive compounds responsible for their antiviral properties were down-loaded from various bibliographical databases such as Science Direct Ò, PubMedÒ, ScopusÒ, Google ScholarÒ, etc., and reviewed. The keywords used for searching the ethnobotanical use / antiviral activity and phytochemical compounds responsible for inhibitingthe virus of the respective plant/anti-inflammatory and immunomodulatory activity were ‘‘ethnomedicinal use + scientific names of related plants, antiviral activity + scientific names of related plants, anti-inflammatory activity + scientific names of related plants and immunomodulatory activity + scientific namesof related plants”; as - antiviral activity+ Allium cepaL., ‘‘ anti-inflammatory activity + scientific names of related plants”, and/or ‘‘immunomodulatory activity + scientific names of related plants”.
2.2.4. Data analysis: Obtained primary and secondary data were systematically arranged in tabulated form using Microsoft Excel spreadsheets. The data were then analyzed and computed to determine the values of different variables such as socio-demographics of the informants, quantitative ethnomedicinal data such as Frequency Citation (FC), Relative Frequency Citation (RCF), Use Reports (UR) and use value (UV) for all plant species. Besides, all types of graphs, charts, and figures were prepared using statistical equations in Microsoft Excel 2013.