- Overall objectives:

Developing medicinal plant of Premna flavescens in some districts of Thai Nguyen province; Developed a process to extract the active ingredient group from the medicinal plant and create products to support the treatment of osteoarthritis.

- Detailed objectives:

+ Determine the scientific name of the medicinal plant called “Don vo” and build a trial planting model of this plant in Thai Nguyen province.

+ Studying the chemical composition of the leaves or stems of the plant and developing a process to extract the active ingredient group from the medicinal plant.

+ Evaluating the supportive effects of osteoarthritis treatment of the preparation extracted from the leaves or stems of the plant and creating products to support the treatment of osteoarthritis.

- Determined that the scientific name of the medicinal plant called “Don vo” is Premna lucidula Miq. and its synonym is Premna flavescens Buch.-Ham. ex C.B.Clarke, belonging to the Lamiaceae family by comparative morphological and molecular biology methods. The results of molecular biology research have decoded the sequences of 3 gene regions of Premna flavescens species including ITS, rbcL and 18S which were registered in the gene bank with codes MT935698.1, MW553265, MW485128.1, respectively.

- Studied the propagation ability of Premna flavescens by cutting method. The results showed that the cuttings were treated with N3M root stimulant at a concentration of 20g/l for 5-10 minutes and then planted on a substrate consisting of 80% crop soil, 16% manure, 3% ash, 1% super phosphate gives the best survival rate, rooting rate and root quality, growth and development.

- Conducted experimental planting of Premna flavescens from seedlings created by cutting method in Van Han commune, Dong Hy district, Thai Nguyen province. The density of about 700 trees / 900 m2. The trees at experimental area grow as well as those distributed in nature.

- Studied the chemical composition of Premna flavescens leaf essential oil by GC-MS method. The results showed the presence of 51 compounds. The main group of compounds was identified as sesquiterpenoids (83.0%). Monoterpenoids and other compounds accounted for 6.5% and 9.0%. Compound β-Caryophyllene is the main component accounted for the highest concentration (26.3%). The essential oil exhibited strong anti-inflammatory activity through the ability to inhibit NO production with IC50 value = 5.88 ± 0.19 µg/mL.

- Isolated and determined the structure of 6 pure compounds from the stems and leaves of Premna flavescens: friedelin (1), friedelinol (2), holoptelin B (3), ethyl p-methoxycinamate (4), 3β-hydroxy stigmast-5-en-7-one (5), and n-triacontanol (6). Compounds 1, 2, 6 were isolated for the first time from P. flavescens; compounds 3, 4, 5 were first isolated from the genus Premna. Friedelin was the main component isolated from the total ethanol extract of Premna flavescens with an isolation efficiency of 0.66% (165.0 mg/25.0 g).

- Evaluated the pharmacological effects of P. flavescens extract. The extract showed significant anti-inflammatory and analgesic activity in vivo, and did not cause oral toxicity. At a dose of 750 mg/kgP, the extract expressed a promising anti-inflammatory effect with a maximum percentage inhibition of 41.6% after 5 hours of carrageenan treatment, 52.0% of the number of writhes after 25-30 minutes of acetic acid injection. P. flavescens extract at a dose of 500 mg/kgP exhibited anti-inflammatory activity at a statistically significant level (P<0.05) after 4 and 5 hours of carragenan injection and inhibited 33.3% of the number of writhes after 15-20 minutes of acetic acid injection. P. flavescens extract at a dose of 250 mg/kgP did not clearly show anti-inflammatory activity and only slightly reduced the number of writhes at observation times (P > 0.05).

- Built the process of extracting the preparation containing active ingredients from the leaves and stems of Premna flavescens on a laboratory scale. The efficiency of the process was 1.7% compared to dried material weight.

- Evaluated the safety and effects of Capsules - Viên Xương khớp – Premna TN. The results showed that the product was safe and did not cause acute toxicity with the highest test dose of 10 g/kg. Viên Xương khớp – Premna TN at a dose of 750 mg/kgP reduced the level of rheumatoid arthritis in Collagen Antibody-Induced Arthritic Mice through the index of inflammation and reducing pro-inflammatory cytokine levels IL-6, TNF-alpha and PGE-2; reducing inflammation through carrageenan-induced paw edema test in mice with maximum percentage inhibition of 41.6%; significantly reduced the number of acetic acid-induced writhes in mice. Viên Xương khớp – Premna TN at a dose of 500 mg/kgP also exhibits anti-inflammatory and analgesic effects in experimental models, but the effect is lower than that of 750 mg/kgP.

- Developed the basic standard for the product of Viên Xương khớp – Premna TN and the product dossier that are eligible to apply for a circulation permit.

- Developed the formula for preparation of Viên Xương khớp – Premna TN supporting the treatment of osteoarthritis with dried extract of Premna flavescens that mixed with some kinds of medicinal extracts: Cot Toai Bo, Do Trong, Duong Quy, Tho Phuc Linh.

- Researched to create a massage cream from Premna flavescens extract on a laboratory scale of 20 cream jars/batch. The massage scream was shown to be safe, does not cause skin irritation on experimental rabbits.

- Scientific papers in referred journals (list):

02 SCIE papers: 

+ Le Minh Ha, Ngo Thi Phuong, Nguyen Thi Phuong Trang, Dinh Thi Thu Thuy, Le Ngoc Hung, Chemistry and Molecular characteristics of Premna flavescens Wall. ex C. B. Clarke in Vietnam, Natural Product Communications, Volume 16(9): 1–4, 2021.

+ Le Minh Ha, Ngo Thi Phuong, Nguyen Tuan Anh, Do Thi Thanh Huyen, Phytochemicals, analgesic, and anti-inflammatory activities of the ethanol extract from the leaves of Premna flavescens Wall. ex C. B. Clarke., Natural Product Communications, 2022, Volume 17 (7): 1–6, 2022.

02 national papers: 

 + Lê Minh Hà, Đỗ Thị Thanh Huyền, Ngọ Thị Phương, Nguyễn Thị Hương, Quy trình nhân giống cây Đòn võ (Premna flavescens) bằng phương pháp giâm cành, Kỷ yếu hội thảo khoa học “Ứng dụng Công nghệ sinh học trong chế biến, bảo quản và phát triển thực phẩm bảo vệ sức khỏe con người”, 253-259, ISBN: 978-604-82-6090-3.

+ Ngọ Thị Phương, Tô Thị Ngọc Anh, Nguyễn Tuấn Anh, Nguyễn Minh Việt, Lê Minh Hà, Phân lập và xác định cấu trúc hóa học của một vài hợp chất từ lá cây Đòn võ (Premna lucidula Miq.), Tạp chí Khoa học và Công nghệ, Đại học Công nghiệp Hà Nội, 2022, đã chấp nhận đăng.

- Patents (list):

01 useful solution was accepted with valid application: “Quy trình chiết xuất cao dược liệu Đòn võ (Premna flavescenes) phát triển tại tỉnh Thái Nguyên và tinh chế hoạt chất friedelin làm nguyên liệu sản xuất sản phẩm hỗ trợ điều trị thoái hóa xương khớp”, Decision No. 17813w/QĐ-SHTT on 2nd, November, 2021. 

- Technological products (describe in details: technical characteristics, place):

+ Viên Xương khớp – Premna TN supporting the treatment of osteoarthritis: 300 bottles, 30 hard capsules/bottle.

+ Massage cream from Premna flavescenes extract

- Other products (if applicable):

Model of experimental planting of about 700 Premna flavescenes trees in Van Han commune, Dong Hy district, Thai Nguyen province