Preliminary results on investigation of genetic resources of anticancer medicinal plants in Vietnam

Introduction

Using Plant as drugs has been a goal of mankind since prehistoric times. Most of drugs in use today have their origin from plants used by healers since time immemorial. It is estimated that there are about 250,000 – 300,000 species of flowering plant o­n this planet of which 150,000 are found in the tropical forests. (Prance, 1977). Less than 5% of these plants have been so far investigated for pharmacologically active compounds. Higher plants are untapped reservoirs, o­nly waiting to be investigated. For many classes of drugs widely employed in humans, synthesis of novel structures has not yielded entities with new mechanism of action.

Plants have been used in the treatment of cancer for over 3,500 years (Hartwell, 1967), but it is o­nly since 1959 that a concerted systematic effort has been made to screen crude plant extracts for their inhibitory activity against animal tumor systems. About 11,373 plant species are present throughout the forests, hills, plains, crop fields, marshy lands... of Vietnam, of which 3870 species reported to be used in traditional medicines for the health care of the millions of people of this country (Do Huy Bich et al. 2004).

For long time minority people in Vietnam have been effectively using traditional medicinal plants. They are sometimes used as sources of direct therapeutic agents. With the large number of ethnic minority, Vietnam is endowed with vast resources of medicinal plants and the plant may provide lead compounds for the future anticancer therapy. Some of them have been studied and details recorded and some are industrial produced and sold. When Western medicines became more popular, the traditional medicinal plants were less used. Beside, modern medicine is limited and the high cost of many modern drugs means that traditional medicine is the first choice in the case of having cancer as well as other illness.

Object and Methods

This paper sheds light o­n the anticancer plants used in the popular herbal remedies. With this objective, 50 different anti-cancer plant species were collected. They are suggested for using as sources of starting point for the elaboration of more complex semi-synthetic compounds. The research was carried out in the hope of finding out some new potential plants for modern medicine used in the treatment of cancer.

The local people were interviewed to obtain certain details and the specimens were identified and arranged according to the system of Brummitt, 1992.

- Systematic evaluation of traditional medicinal plants collected and investigated

- From the list of plants some species are suggested for analysis and treatment.

Results and discussion

Table 1: The list of the families of anti-cancer plant.

There are 50 anti-cancer plants of 36 genera of 24 families collected. Taxa of medicinal plants are completely diverse and they are distributed differently in different families. The most diverse is Zingiberaceae (16%) and the next are Myrsinaceae and Annonaceae (10%). The greatest numbers of species are in the genera of Ardisia (5 species) and the next is Annona and Curcuma (4 species).

Diversity of life-forms of anti-cancer plants

The life-form of all the plant reported are shown in the table 2 below:

Table 2: Life–form of medicinal species

The anti-cancer plants used as herbs and trees are the most common (34%), shrubs (26%), and lianas (6%)

Distribution

The distribution of anti-cancer plants in different habitats is shown in table 3. The distribution of wild anti-cancer plants are mainly in forest (38%) and then are cultivated plants by local people (36%).

Table 3: Distribution of anti-cancer plants in different habitats

1.     Do Huy Bich et al. 2004. Plants and animals used as medicine in Vietnam. Sci-Techn. Publ. House, Hanoi. Vol 1&2.
2.     Vo Van Chi 1997. Dictionary of medicinal plants of Vietnam. Med. Publ. House, Hanoi. 3.     Vo Van Chi, Tran Hop 2002. Useful plants in Vietnam, Ha Noi
4.     Pham Hoang Ho 1999-2000. Plants of Vietnam. Vol 1,2&3, Young Publisher, Hanoi.
5.     Phung Ngoc Lan, Nguyen Nghia Thin, Nguyen Ba Thu 1996. Plant diversity in Cuc Phuong. Agr. Publ. House, Hanoi
6.     Đo Tat Loi 2001. Medicinal plants and drugs of Vietnam. Sci-Techn. Publ. House, Hanoi
7.     Nguyen Nghia Thin 2001. Medicinal plants of Thai minority of Con Cuong, Nghe An
8.     Olayiwola Akerele, Vernon Heywood & Hugh Synge, 1991. Conservation of medicinal plant. Cambridge university press.
9.     Jounal of tropical medicinal plants, 2001. Vol.1 (1&2), 148pp.
10.     Jounal of tropical medicinal plants, 2000. Vol.2 (1), 154pp.

Nguyen Nghia Thin, Nguyen Thi Kim Thanh
Faculty of Biology, Vietnam National University, Hanoi
Van Ngoc Huong
Faculty of Chemisstry and