Ethnobotany of the medicinal plants used by the ethnic communities of Kerman province, Southeast Iran

According to the reports, medicinal use of plants dates back to at least 60,000 years. During this time, traditional systems of medicines have employed medicinal plants and their derivatives as valuable sources of new biologically active compounds and have been clinically practiced all over the world [1]. Until now, approximately 80% of the world’s population still use traditional herbal medicines [2]. In fact, herbal medicines can serve as complementary or alternative therapies for different types of diseases because of their low cost, availability, and generally fewer side effects [3]. Several FDA-approved drugs including artemisinin (from Artemisia annua), quinine (from Cinchona officinalis), vinblastine, vincristine, vinorelbine (from Vinca rosea), and etoposide (from Mayapple) primarily originate from traditional herbal medicines [4]. It has been estimated that nearly 400,000 flowering plant species exist on earth, among which only 6% have been evaluated for their biological properties, and still more than 90% remains unexplored [5]. Therefore, ethnobotanical study of medicinal plants provides valuable information for the synthesis of new drugs.

Around 8000 plant species have been listed in Iran, of which 2300 species have medicinal properties among which 75% (1728) are endemic species in Iran [6, 7].

Kerman province with 23 cities and 171,993 square kilometers area has covered about 11% of the land area of Iran [8], located in the southeast of this country, and bordered by 5 provinces of Yazd, South Khorasan, Hormozgan, Fars, and Sistan and Baluchestan. It has a unique biodiversity due to its diverse natural resources and climatic conditions including desert and semi-desert in the north, and dry, mountainous and Mediterranean in the south. Kerman province is a vast plain with the lowest altitude in Lut desert (300 m) and the highest altitude in the mountaintop of Hezar (4419 m) [8]. Based on the traditional pharmacopoeia and medicinal plant reports in some parts of this province, medicinal herbs mostly belong to the families of Labiatae, Rosaceae, Papilionacae, Compositae, and Umbelliferae, and the genera of Salvia, Nepeta, Artemisia, Astragalus, Ferula, Plantago, Ephedra, and Amygdalus [9, 10].

From the cultural point of view, Kerman province has around 89 tribal communities (including Baluch, Turkish, and Fars), most of them still being partially dependent on the medicinal plants. Therefore, this province is home to different cultures and beliefs resulting in rich traditional knowledge and traditional medicine practices. For example, the old city of Jiroft in the southeastern Kerman province dates to about 5000 years ago, which, according to the reports, is the beginning of human civilization [11]. In this respect, traditional medicine has played a key role in Iranian culture and civilization [12]. Therefore, this rich traditional knowledge is useful not only in the ancient medical systems but also in the present healthcare systems [10], especially for primary health care needs [13]. In fact, the dependence of the folk communities in Kerman on the medicinal herbs is not only due to the low availability to the health care system, but it is also rooted in the Iranian-rich culture of traditional medicine [14, 15]. For example, in the face of epidemiological diseases (e.g., cholera and colds), scientists of the Iranian traditional medicine (ITM) such as Avicenna, Rhazes, and Aghili Alavi Shirazi have suggested prescription of various herbal remedies. At present, the locals of Kerman, based on their ancient knowledge, utilize herbal medicines such as Thymus fedtschenkoi, Zataria multiflora, Dracocephalum polychaetum, and Glycyrrhiza glabra in the treatment of epidemics. Generally, Kerman province with a diverse climate and biodiversity is home to various cultures (from the prehistoric times to the present) and the center of agriculture in Iran [10, 16]. Accordingly, in some areas of this region, certain non-registered herbaceous species are used that can be obtained by the local people. There are many villages and nomadic districts that are largely dependent on the ethnomedicinal knowledge for primary health care, with many specific traditional herbal medicine practices in this region that have not been recorded anywhere else. Hence, the current study aimed to carefully investigate and record the ethnobotanical knowledge of the whole districts and cultures, particularly subcultures that had the maximum dependence on the traditional health care system of the Kerman province.