An ethnopharmacological study of aromatic Uyghur medicinal plants in Xinjiang, China

Abstract Context: An ethnobotanical survey was completed in a remote village and surrounding country of Xinjiang, where most Uyghur medicinal plants could be collected. This work clarifies and increases ethnobotanical data. Objectives: We surveyed and organized aromatic medicinal plants that are commonly used in clinical settings to provide a significant reference for studying new medical activities. Materials and methods: In the survey, informants who have traditional knowledge on aromatic Uyghur medicinal plants were interviewed between March 2014 and September 2014. Aromatic medicinal plant species and pertinent information were collected. Some therapeutic methods and modes of preparation of traditional aromatic medicinal plants were found. Results: A total of 86 aromatic medicinal plant species belonging to 36 families were included in our study. We identified 34 plant species introduced from different regions such as Europe, India and Mediterranean areas. Fruits and whole plants were the most commonly used parts of plant, and most aromatic medicinal plants could be applied as medicine and food. We assigned the medicinal plants a use value (UV). Knowing the UV of species is useful in determining the use reliability and pharmacological features of related plants. Conclusions: Xinjiang is an area in which indigenous aromatic medicinal plants are diversely used and has therefore established a sound dimensional medical healthcare treatment system. Some aromatic Uyghur medicinal plants are on the verge of extinction. Hence, further strategies for the conservation of these aromatic medicinal plants should be prioritized.


Introduction
China is a unified multi-ethnic country, where ethnic medicine is the official unified name for the traditional medicines of Chinese ethnic minorities because of the barriers produced by the different medical systems, language, culture and species characteristics. Research based on ethnic medicinal resources is rare . In some ethnic minority areas, the production technology of traditional ethnic medicine and clinically common and key ethnic medicinal prescriptions is facing the risk of severe loss, without being passed on to the next generation (Vandebroek & Balick 2012).
Uyghur medicine is the scientific summary and the synthesis of the wisdom of the Uyghur people, who have been hard-working in the long-term practice of production to fight diseases. Therefore, Uyghur medicine has a complete theoretical system, involving rich practical experience and a unique method of diagnosis and treatment, representing a treasure among Chinese traditional medicine.
Uyghur medicine originated from Hetian, located in Xinjiang, and has a long history (Jiang & Nie 2015). There are more than 1000 Uyghur medicinal plants on record, among which, approximately 450 are most commonly used. Most Uyghur medicines are made from plants. The Uyghur people are skilled at using aromatic drugs, which commonly involve roses, lavender (Gonçalves & Romano 2013;Mendoza et al. 2014), lip vanilla, safflower, coriander, chicory, clove (Dalai et al. 2014), cardamom (Bajaj et al. 1993) and long pepper Ding et al. 2014). An aromatic plant is a plant that contains a high content of aromatic substances (essential oils or resin) that can be used as a medicine or spice. These plants are both highly useful and of high value. The aromatic medicinal species included in this report were selected according to two books, on Chinese Aromatic Plants and Uyghur Medicine. There are many aromatic plants included in records on processing and utilization in the ancient literature of China. People have often used aromatic plants for flavouring, healthcare, in wine and cosmetics, as moth repellents and refreshing substances, and for cleaning air.
Uyghur medicine is the object of this article, therefore, herbal monographs from the literature, research data, standards and regulations and physical specimens were collected, mainly to obtain information about aromatic plant varieties (Shang et al. 2012). Information about the species used in Uyghur medicines and their distribution, clinical efficacy and applied resources (preparations) was collected and reorganized, supporting the analysis, application (Auerbach et al. 2012), sharing, use and protection of Uyghur herbal resources (Zheng et al. 2006;Fred-Jaiyesimi et al. 2015).
The food consumed in Xinjiang is quite rich, the cooking material mainly contains meat (mutton, beef and horsemeat), dairy products and cooked wheaten food. The method of cooking them is based on roasting, stewing, steaming and so forth. For example, the popular ethnic food in Xinjiang includes mutton kebabs, kao quanyang, zhuafan, nang, etc. The people in Xinjiang basically eat meaty food. Moreover, people eating meat and grilled food are more susceptible to chronic disease. Additionally, women in a dry climate are more likely to develop various sorts of gynaecopathy. Uyghur medicine has gradually developed in areas where the above diseases have frequently occurred for quite some time.

Field interview methods
We carried out semi-structured ethnobotanical interviews with individual natives residing in the study area in the Uyghur region between March 2014 and September 2014. A total of 200 individuals (101 men, 99 women) were interviewed in five districts, including Altay, Changji, Yili, Bazhou and Hetian. In each district, we interviewed four counties. Bazhou, Hetian are relatively large area in the south of Xinjiang. The areas are multi-ethnic areas; therefore the research on the ethnic medicine has certain representative, Altay and Yili, in the north and northwest of Xinjiang, respectively. The main nationality are Uyghur and Kazak, they have a certain understanding of the research of the ethnic medicine. Changji in the east of Xinjiang, it can be representative of the people in the east of Xinjiang on the ethnic medicine research. These five areas in Xinjiang are very representative of the region. Interviews were conducted in bazaars, houses and parks. We confirm that the field studies did not involve endangered or protected species. Additionally, no specific permissions were required for these locations because all of the locations were public, not private. After explaining the objective of our study, we asked detailed questions related to the medicinal uses of plants . People who demonstrated knowledge of plants were interviewed at least twice (Polat et al. 2013). The obtained information was compared with other areas and local counties to verify its accuracy. The interviewees ranged in age from 35 to 95 years, most of whom were elders. We transcribed all interviews and deposited the recordings with the Medicinal Resources Census Project Team of China (Chen et al. 2014).
The participants provided their verbal informed consent to participate in this study. During the survey, after explaining the objective of our study, the interviewees provided us with detailed answers to questions related to the medicinal uses of plants. We subsequently transcribed all the interviews and deposited the recordings in our storehouse. All the information on aromatic Uyghur medicinal plants was recorded in tables produced by the Resource Census Project Team of China. Written consent was collected and analyzed by the authors, and the authors used another method to express the main meaning of the participants' consent. Therefore, all of the written consents are listed in Table 1. Of course, the Medical Ethics Committees of Xinjiang Medical University approved this consent procedure.
The interview questions were aimed at understanding the traditional uses of medicinal plants, including local plant names, ailments for which the plants were used, the parts of the plants used, and methods of preparation and administration. We accompanied the interviewees into the field to collect specimens of the plants to which they were referred. We also deposited the plant materials collected in our study with the Medicinal Resources Census Project Team of China ( Figure 2).

Voucher specimen collection
To exemplify and protect the aromatic medicinal plants obtained in Xinjiang to the best extent possible, we collected voucher specimens between March and September 2014. Voucher specimens were collected and prepared under the directions of herbalists and local people, who have much experience with these aromatic Uyghur medicinal plants. The plants were identified by a research team specialized in Uyghur medicinal resources, consist of several pharmaceutical professors and several graduate students from Xinjiang Medicine University, and specimens were deposited in the Traditional Chinese Medicine Voucher Herbarium of Xinjiang Medicine University. All data were collected in a database.

Data analysis
The use value (UV), a quantitative index that indicates the relative importance of locally known species, was also calculated according to the following formula: UV ¼ U/N, where U is the number of reported uses cited by each informant for a given species, and N refers to the total number of reports in which UV refers to the UV of a species. UVs are high when there are many reported uses for a plant, thereby indicating that the plants are actively used by local people, whereas when there are few reports related to a plant's use, the UV approaches zero (0) (Boakye et al. 2015). Therefore, knowing the UV of a species may be useful in determining the reliability of the use and pharmacological features of related plants.

Families and medicinal plants
A total of 86 aromatic medicinal species belonging to 36 families were included in the present study (Table 1). About 12 medicinal species belonged to Lamiaceae, which was the family with the highest percentage (13.95%) of medicinal species used by the Uyghur people, followed by Apiaceae and Rosaceae (11.63%) with 10 species, and Compositae (9.30%) with 8 species. These four families account for 46.51% of the total number of aromatic medicinal species identified. The remaining 46 species belongs to 8 other families with less than six species each, while only one species was obtained for approximately 20 families (Table 2).
In the analysis conducted in this study, many species collected in Xinjiang were observed to be used medicinally and were easily accessed (Liu & Shawuti 1985;Liu 1999).

Plant parts and mode of preparation
Fruits (22 species) were the most commonly used parts of the plants, followed by the whole plant (17 species), seeds (15 species) and flowers (7 species), respectively ( Figure 3). Additionally, for 13 species, two or more parts are used in the treatment and curing of diseases, with different parts employed for different effects. For example, the root of Ephedra presents a hidroschesis function to treat the night sweats caused by pulmonary tuberculosis and weakness of the body, while the herbaceous stem, which is also used for sweating, is applied to cure colds, coughs, bronchial asthma and malaria. Based on the above findings, we can safely draw the conclusion that different parts of the plants exhibit different functions. We must clarify the function of every part before it can be used to cure diseases (Song et al. 2005).
The results of our survey demonstrated that decoction was the most common mode of preparing aromatic medicinal plants, accounting for 61.72% of the recorded preparations, followed by syrups (47.66%), powders (45.31%), honey pastes (35.16%), poultices (28.13%) and pills (16.41%) ( Figure 4). Therefore, there are several methods for the preparation of aromatic medicinal plants (Liu et al. 1993). However, different methods present different efficiencies, and the most appropriate preparation method should be chosen.

Disorders treated
Based on this survey, the collected aromatic plants are widely used in local traditional Chinese medicine, specifically in Uyghur medicine, to treat gastropathy, liver complaints, parasites and dysentery. Commonly, doctors combine two or more aromatic medicinal plants to treat a particular ailment. In this survey, most of the identified aromatic medicinal plants can be employed as both medicine and food. The local population uses these plants daily to maintain good health in the long-term (Halmurat et al. 2011, King et al. 2015. Some aromatic medicinal plants can be made into healthcare products, such as herbal teas, medicinal liquors and essential oils, which contribute to health in therapies or prevention. In addition, a few of the aromatic plants can be developed into insecticides against parasites. Furthermore, some farmers cultivate aromatic vegetables with certain  (Paul et al. 1996) Harmful to brain and pneamopathy characteristics that are conducive to supplying the body with necessary nutrients and particular trace elements. In our survey, plants such as lavender, saffron crocus and mint were found to be commonly used. Lavender essential oil made from lavender plants is good for nervous system disease, paralysis, amnesia, melancholia and arthralgia. Meanwhile it has anti-inflammatory and anti-bacterial functions. The lavender essential oil treatment balanced the inflammatory signaling induced by S. aureus by repressing the principal pro-inflammatory cytokines and their receptors and inducing the heme oxygenase-1 gene transcription. The essential oil can stimulate the human innate macrophage response to a bacterium, which is responsible for one of the most important nosocomial infection (Giovannini et al. 2016). Saffron crocus is a kind of common, traditional precious herb among local aromatic medicinal plants. Saffron crocus have anti-oxidant, analgesic, anti-inflammatory, anti-diabetic and several other properties. The kaempferol 3-Orutinoside and kaempferol 3-O-glucoside from saffron crocus treatment increased the level of total protein and prevented the carbon tetrachloride-induced increases in serum aspartate aminotransferase, serum alkaline phosphatase and hepatic malondialdehyde levels. And, it has protective effects against acute carbon tetrachloride-induced oxidative liver damage . Mint presents a wide range of uses; its basic pharmacology involves anti-pyretic and anti-sweating effects. Mint is both a medicinal and culinary herb, employed in mint condiments, spices, teas and so on. There were many aromatic plants identified during this survey that present unique characteristics and play specific roles in the medical community.

Intake of aromatic medicinal plants
According to the results of our study, the most common methods of application are oral and external, accounting for 72.2% of applications, while 23 of the aromatic plants can be used as oral medicines (26.8%), whereas only one plant, Nerium indicum Mill., was reported to be employed only as an externally applied drug (Qian et al. 2005). Under some circumstances, oral and external treatments can better cure disease.

Families and plant parts
In the present study, some of the medicinal plants we investigated were not native materials. We identified 34 introduced plants, belonging to 24 families, coming from different regions, such as surrounding areas of Europe and the Mediterranean (Souza et al. 2014). Zingiberaceae was the family accounting for the greatest percentage of introduced medicinal materials (25.00%), followed by Rutaceae (20.83%), Lamiaceae (16.67%), Rosaceae (12.50%). Fruits (22.73%) are the most widely used part of the plant, followed by the whole plant (15.91%), roots (13.64%) and seeds (6.82%).

Remedy of aromatic plants, administration form and route
Aromatic plants are vital as remedies and in the economic development of Xinjiang. Introduced plants can be used to treat diseases such as colds, gastric diseases and asthma. The most important form of administration of these plants is decoction, similar to findings for native medicinal plants, while the oral administration route is used for every plant. Compared with the native plant species employed in Xinjiang, some introduced plants present specific functions in local use (Di Novella et al. 2013).

Conclusions
This study first recorded use information on aromatic plants employed in traditional Uyghur medicine in Xinjiang, demonstrating that Xinjiang possesses various raw medicinal herbs. A total of 86 kinds of aromatic plants used by local people belonging to 36 genera were identified, and these plants are still commonly used in daily life. To evaluate the value of the medicinal plants in the target region, the UV was employed in a quantitative analysis. Many plants are used to relieve coughs, eliminate phlegm in treating cardiovascular diseases, colds, haemorrhoids, constipation, stomach diseases, diabetes, urinary diseases, respiratory conditions and throat disease. Therefore, Xinjiang is an area where indigenous medicinal plants present diverse uses, and a sound dimensional medical healthcare treatment system has been developed in this region. However, some of the traditional Uyghur medicines used in this region still lack physiotherapeutic evidence. Hence, analysis of the chemical constituents and pharmacological activities of certain Uyghur medicines are necessary to explore the potential of Uyghur medicinal plants. This study also provides protection for the local medicinal plant group. Some Uyghur medicinal plants are on the verge of extinction because of frequent natural disasters and the development of urbanization, and the UV of these plants therefore cannot be presented. Thus, the development of further strategies for the conservation of these medicinal plants should be of priority.

Disclosure statement
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.