• Investigating and setting up the data base of medicinal plants used in Tay Nguyen including: scientific names, local name, distribution and its value in traditional remedies in TayNguyen.
• Analysing research of pharmaceutical values, chemical compoude and bio-activities of some medicinal plant used in traditional remedies and their prospect in Tay Nguyen.
• The methods of conservation, exploitation, development and durable uses of the medicinal plants used in the traditional remedies in Tay Nguyen.

Theoretical results:

Results of study on medicinal plants and traditional remedies:

The checkist of 1,633 medicinal plant species, belonging to 197 families of high plant was finished in Tay Nguyen. Among them, 51 species is new for the checklist of medicinal plants. Magnoliaphyta is highest with 1,559 species about 95,47%. The family Asteraceae is highest species number with 88 species, about 5.39% of species amount.

Among 1,633 recorded medicinal plant species in Tay Nguyen, there is 88 species recorded in the Red book of Vietnam. Among them 4 species is at CR level such as Thông nước – Glyptostrobus pensilis (Staunt.) K. Koch, Ba gạc ấn độ - Rauvolfia serpentina (L.) Benth. ex Kurz, Vù hương – Cinnamomum parthenoxylon (Jack) Meisn, Kim cang petelot – Smilax petelotii T. Koyam; 37 species are at EN level and 47 species are at VU level.

The map of rare and precious medicinal plants in Tay Nguyen at rate of 1/500.000 was established.

During carried out the project, 362 traditional remedies were collected and listed, of which, 2 groups of patients with the highest number of prescription medications is all about intestinal helminth treatment and woman health remedies.

The survey of medicinal plants used in medicine showed that most of the drug remedies is used only one medicinal plant species: 315 remedies, two species: 32 items, 3 species: 9 remedies, and 4 species: 6 items. This also shows the knowledge of using medicinal plants of the Central Highlands ethnic minority people is limited in comparison with the peoples in the north.

The database of 796 medicinal plants used in traditional remedies was set up.

The study of chemistry:

The extract process from 104 samples of 104 different species of medicinal plants used in traditional medicinal remedies was designed.

Experimented 104 bioactive samples of rough extracts from 104 medicinal plants. Results indicate:

• 61 samples have inhibit active for the growth of at least 1 line of auditted virus, equivalent 58.65% of samples experimented;

• Determined 8 samples havin active cytotoxic form for at least one cell line (7.7%);

• Determined 41 samples bearing antioxidant bio-activity (39.4%).

Medicinal experiments on pharmacological effects showed that:

• The stem bark extract of Antidesma acidum Retz. at different concentrations of 25 µg/ml, 50 µg/ml, 150 µg/ml and 200 µg/ml were shown inhibitory effect xanthin oxidase enzyme activity respectively 31.75%, 52.34%, 55.66% and 61.14%. Inhibiting effect increases as the concentration increases.

• The extract of Antidesma acidum Retz. can reduce uric acid in blood of experimented mices.

• For the sample of extractfrom Barringtonia acutangula(L.) Gaertn on mice increased hyperglycaemia by STZ, results showed that:
  • By the doses 3g/kg of body weight, the mice drink after 2 hours, 3 hours and 4 hours, hypoglycemic reduced with the rate of11.17%, 18.46% and 17.71% respectively.
  • By the doses 3,8g/kg of body weight, after drinking 1, 2, 3 and 4 hours, the hypoglycemic in experimented mices reduced 22.75% , 25.63%, 31.59% and 26.36% respectively.
• The leaf extracts of Barringtonia acutangula (L.) Gaertn) can limit the increasing blood sugar.

• The extract of Harrisonia perforata Merr. at a dose of 680 mg/kg of body weight can have a diuretic effect through an increase in urine volume after 10-24h and increased excretion of Na⁺ and have lower blood pressure effect clearly pronounced in a mouse model caused by cortisone acetate hypertension.

• The extracts from Premna latifolia Roxb. have a liver protective effects in a experimented mice toxic caused by Paracetamol. This result allows developing medicinal applications from Premna latifolia supporting to the treatment of liver disease.

• High extract from Tylophora sp. at a dose of 0.5 g/kg/day and 1 g/kg/day, taken consecutively in 28 days, have a therapeutic effect on dyslipidemia cause hyperlipidemia model caused by increased blood mixture.

Isolating and determining the structure of bio-active compound

47 clean compounds were isolated from 10 extract samples of 10 medicinal plant species, 2 of them were new compounds.

The chemical structure of 5 compounds from Dalbergia vietnamensis were isolated and determined for the first time. Among them, 2 compounds ED1 and EC6 were isolated in the first time.

For the first time, 4 compounds AC18, AC19, AC10 và AC4 were isolated from Antidesma acidum extract.

For the first time, 2 lignan and sterol compounds from the extracts of Zanthoxylum rhetsa were isolated. Based on spectral data obtained with reference combination compared to published literatures, their chemical structure is identified as Icariside E5 (ZW7.3), (+)-Lyoniresinol 3a-OBD-glucopyranoside (ZW8.1), β-sitosterol (ZE2.1) and daucosterol (ZE4.3).

For the first time, 8 compounds as CX1, CX3, CX5, CX6, CX7, CX8, CX13 và CX17 were isolated and puried from Xylia xylocarpa (Roxb.) Taub.

For the first time, 4 compounds TT1, TT2, TT5 và TT7 of Tylophora sp. were isolated and determined their chemical structure.

04 compounds from Barringtonia acutangula extract were and determined their chemical structures. In which there are 3 compounds BA4.6, BA7.1 and BA6.7 for the first time were isolated from họ Lecythidaceae. The layer of flavan-3-ol also for the first time found from the genus Barringtonia.

4 compounds: 3-methyl-5-hexanolide 3-O-b-D-glycopyranoside (ZA21A), (+)-lyoniresinol 3a-O-b-D-glucopyranoside (ZA22), a-tocopherol (ACH31), trans-phytol (ACH26) were isolated from Antidesma walker. Among which compound ZA21A is a new compound, the other 3 for the first time found in Antidesma walkeri.

04 compound: SA01, SA02, SA03 and SA04 were isolatmed for the first time from the extract of Sida acuta.

06 compounds: HP1, HP2, HP5, HP6, HP7 và HP9 were isolated by the method of associate sorptography from the extract of Harrisonia perforata. Among which HP9 for the first time was isolated from the nature and HP7 for the first time was isolated from Harrisonia perforata.

For the first time isolated and determine the chemical structure of 4 compounds from extract of Dillenia hookeri Pierre. They are DHE-B6.1 β-Sitosterone, DHE-B6.1β-Sitosterone, DHE-B7.50 Betulinic acid và DHE-B9.6 Oleanolic acid.

Proposition of preserving methods:

Method 1: Establisting traditional medicinnal groups or clubs for people interested in herbal pharmacy and valuable pharmaceutical remedies.

This is a method aiming to help people with the occupation of traditional doctors, people interested in herbal pharmacy can learn from each other. Through that many people will know about each other’s remedies or other local areas’ recipes. Through exploring, the research group has observed that there are local areas with traditional medicinal groups but these groups have not paid attention to meeting and exchanging experiences. This requires regulations for group activities, as well as policy to attracts a lot of traditional doctors, especially traditional doctors in distant villages to participate.

Method 2: Requiring complete research and documenting valuable recipes

Currently, in Tay Nguyen there are many lost or incomplete recipes for different reasons. But the most common reason is lack of thorough research and documentation of some medicine. Moreover, in order to document for wide use, there need to be complete research of these recipes. After documenting, there need to be publication and distribution to library of districts, traditional medicinal groups. However, research and exploitation of the recipes is difficult due to a problem: monopolization.

Method 3: Requiring preservation of valuable herb species or research to find replacement species for the rare ones

Construction of preservation sites and development of herb species is very practical. It does not only contribute to preserving rare and valuable species, but also helps keeping and enhancing valuable recipes that are being lost. For this reason, the first and foremost step is to research and determining valuable species that are in the danger of extinction in Tay Nguyen. From there, there need to be method for cultivation and construction cultivation sites to keep and enhance these species. Moreover, there need to be research on the active elements in these species in order to produce pharmaceutical products or to find replacement species.

The action that need to be taken immediately is adding many species into the Red Book or Red Index of Vietnam like Tylophora sp., or Dalbergia vietnamensis, v.v. It is necessary to propose collaborative project with the provinces to preserve, cultivate and developing the source of some species like Anoectochilus spp., Smilax glabra, Curculigo sp., Uncarria spp., v.v, species that are over exploited or in the danger of extinction due to receding area of natural forest.

On application:

The list of medicinal plant species, that need to be preserved, was proposed, preserving methods of the herb species or pharmaceutical recipes were also proposed.

From the rough extracts of 104 known species, the percentages of species having bio-active elements are quite high with 61 samples (58,65%) that can inhibit the development of at least 1 audittin virus, 41 samples (39,4%) having anti-oxidation effect, 8 samples (7,7%) having anti-poison effect at least 1 cell line.

Medical experiment result on pharmaceutical effect of the herb species shows the following results: extrat from the bark of Antidesma acidum Retz. has the effect of lowering blood uric acid on the mice increated uric adic; The extracts of Barringtonia acutangula (L.) Gaertn) has the effect of lowering blood sugar; the extract of Harrisonia perforata Merr. has the effect of significantly lowering blood pressure on the mice increased high blood pressure by cortison acetat.

• Discovered a new species Rhaphidophora lacduongensis V.D, Nguyen from Lam Dong province.
• Discovered 2 new compounds.
• The first time full checklist of medicinal plant in Tay Nguyen region was set up.
• 51 medicinal plant were recorded in Tay Nguyen region for the first time.
• For the first time, the list of traditional remedies of Tay Nguyen minorities was established.