Medicinal and Aromatic Plants of Bangladesh

ANM Aalamgir, Ataur Rahman, Minhazur Rahman and Fahmida Hoque

Bulk of our nutrients comes from plants as food, minerals and food additives. Many of the plants could be used as stimulants, allergens, toxins, poisons, teratogens, hallucinogens or as medicine. A plant which, in one or more of its organ, contains substance that can be used for therapeutic purpose or which is a precursor for synthesis of useful drugs is known as medicinal plant. This definition of medicinal plant has been coined by the World Health Organization (WHO). When a plant is designated as medicinal, it is implied that the said plant is useful as a drug or an active ingredient of a medicinal preparation. The global demand for medicinal plants is increasing rapidly due to their increased use in pharmaceutical, cosmetic, detergents, dyes, insecticides, foods and paints industries, traditional healthcare systems, individual health practitioners, and in other sectors. According to World Health Organization (WHO), medicinal plants are an accessible, affordable and culturally appropriate source of primary health care for more than 80% of Asia’s population. Despite all the progress in synthetic chemistry and biotechnology, medicinal plants are still an indispensable source of medicinal preparations. Thounds of species are recognized as having medicinal values, and many of those are commonly used to treat and prevent specific ailments and diseases.

Medicinal plants can not be differentiated from other plants by any morphological character but they possess some special qualities or virtues that make them medicinally important. Therapeutic properties of medicinal plants largely depend on the presence of different types of secondary metabolites like alkaloids, terpenoids, phenolics, glycosides and others. These chemicals make a plant valuable as medicinal plant because: i. alkaloids have addictive or pain killing or poisonous effect and sometimes help in important cures, ii. glycosides are used as heart stimulant or drastic purgative or better sexual health, iii. tannins are used for gastro- intestinal problems like diarrhoea, dysentery, ulcer and for wounds and skin diseases, iv. volatile/essential oils enhance appetite and facilitate digestion or are used as antiseptic/insecticide and insect repellant properties, v. fixed oils present in seeds and fruits could diminish gastric/acidity, vi. gum- resins and mucilage possess analgesic property that suppress inflammation and protect affected tissues against further injury and cause mild purgative, and vii. vitamins and minerals from fruits and vegetables as food additives; function as structurial material, osmoprotectants, coenzyme and cofactors in the cellular metabolism.
Herbal products are staging a comeback and herbal ‘renaissance’ is happening all over the globe. The herbal drugs, sweeteners, flavorings, colorings, cosmetics etc. today symbolize safety in contrast to the synthetics that are regarded as unsafe to human and environment. Population rise, inadequate supply of drugs, prohibitive cost of treatments, side effects of several allopathic drugs and development of resistance to currently used drugs for infectious diseases have led to increased emphasis on the use of plant materials as a source of medicines for a wide variety of human ailments. The dependence on synthetics of the modern age is over and people are returning to the naturals with hope of safety and security. Over three-quarters of the world population and about 80% of the world’s rural people rely on herbal medicine for primary health care. In Europe and America, plant drugs constitute 25% of the total drugs, while in developing countries the contribution is as much as 80%.

The secondary metabolites of plants are important because of their function as therapeutically active principles and lead structures of herbal and modern medicines, respectively. More than 120 therapeutic principles of plant origin are used in modern medicine and they include ajmalacin, allicin, aspirin, artemesinin, atropine, berberine, camptothecine, capscicine,  catechin, cocaine, codeine,  curcumin, diospyrin, digitoxigenin, digoxigenin, elipticine, emetin, ephedrine, forskolin, glycyrrhizin, gossypol, homoharringtonine, indicine N-oxide, magnolol, morphine, nerrifolin, nimbidin, pilocarpine, plumbagin, podophyllin, podophyllotoxin, pristimerin, quassinoids, quinine, rescinnamine, reserpine, ricin, sophoradin, taxol, thevenerin,  tubocurarine, vinblastine and vincristine among others. Where the active molecule cannot be synthesized economically, the product must be obtained from the cultivation of medicinal plant. Allicin, aspirin, artemesinin, atropine, camptothecin, capscicine, codeine, curcumin, digitoxigenin, digoxigenin, ephedrine, gitoxigenin, morphine, podophyllotoxin, taxol, and tubocurarine are among those major plant drugs for which no synthetic one is currently available.  Some important chemical intermediates needed for manufacturing the modern drugs are also obtained from plants (e.g. diosgenin, solasodine, β -ionone). Modern medicine has adopted a number of plant-derived drugs viz. (a) anticancer drugs (ajmalacine, vinblastine, vincristine from Catharanthus roseus), (b) hypotensive-tranquilizer drugs (rescinnamine, reserpine from Rauvolfia serpentina), (c) antimalarial drug (quinine from Cinchona sp.) and (d) antiglucoma drugs (pilocarpine from Pilocarpus jaborandi).

The world is rich in diverse types of vegetation. There are about 250 000- 500 000 plant species on earth and more than 80 000 are known as medicinal plants. About 35000 to 70000 species of plants are used medicinally across the world and only 1-10 % of them have been studied chemically and pharmacologically for their potential medicinal value. An enumeration of the WHO from the late1970s listed 21 000 medicinal species and now it is assumed that the number of plant species used for medicinal purposes across the world is more than 50 000. In China, 4 941 of 26 092 native species (18.9%) are used as drugs in Chinese traditional medicine, in India, more than 45000 different plant species grow and out of them, about 15000-20000 plants have good medicinal value, but only 7000-7500 species are used by traditional communities for medicinal purposes. In Bangladesh, more than 5000 higher plant species grow and about 1000 plant species are considered to have medicinal properties. About 455-747 plant species of Bangladesh have been described recently with their specific medicinal properties. In Bangladesh, medicinal plants are mainly used in the preparations of traditional Unani, Ayurvedic and Homeopath medicines and also prescribed by practitioners of traditional medicine in different parts of the country and others are used as household remedies by the common people.

Medicinal plants constitute an important natural wealth of a country and can play a significant role in the economic growth. Medicinal herb is an important international trade item and a substantial amount of foreign currency can be earned by exporting medicinal plants.  Plant-derived drugs offer a stable market world wide and plants continue to be an important source for new drugs. The international trade on herbal products is a large and expanding trade of medicinal plants. It is estimated that about 2500 species of medicinal plants are traded in the international market. An average of 400000 tones of medicinal plants, valued at $1.2 billion, was traded annually during 1990s. World market for plant derived drugs and aromatics may account for > $ 70 billion and is likely to touch $ 5 trillion by 2050. Medicinal and aromatic plants grow in wild enrich biodiversity, but rising global demand has created medicinal and aromatic plants an important international trade item in different world markets of Asia, Europe and America leading to an unregulated indiscriminate harvest of wild varieties causing an unprecedented serious damage to biodiversity. So plant users, collectors, growers and traders need to be careful about the sustainable use of this invaluable wealth of the nature.

With the rapid depletion of forests, impairing the availability of raw drugs, the major system of indigenous herbal medicine (e.g. Ayurveda, Siddha, Unani etc.) in Bangladesh, as else where in the world, has reached a very critical phase. Natural forests, the treasure house of plant and animal diversity, have already been destroyed, left at present is only about 8% as against a mandatory 25% of the geographical area. Many valuable medicinal plants are under the verge of extinction. The Red Data Book of Vascular Plants of Bangladesh has 427 entries of endangered species; of which 28 are considered extinct, 124 endangered, 81 vulnerable, 100 rare and 34 insufficiently known species. Natural forest should be regenerated and forest flora should be conserved for the sake of the indigenous systems of herbal medicine.

Medicinal plants documented in the literature from thick vegetations of the world are routinely used for high throughput screening in small molecular drug discovery. A large number of such plants are known to be recognized in a discrete manner. Therefore, it is important to document the availability and location and store other information (botanical name, common name, local name, botany, chemistry, folklore medicinal use and medicinal uses) about the medicinal and aromatic plants of Bangladesh in the form of a web database. This will help in the use and exploitation of the plant materials for drug discovery. Here, we describe the development and use of a database containing information on medicinal and aromatic plants from Bangladesh. Medicinal and Aromatic Plant Database of Bangladesh (MAPDB) aims to create opportunities for researcher and students from different disciplines such as Botany, Zoology, Pharmacology, Pharmarmacognosy, Microbiology, Biochemistry and different herbal medicine and cosmetic industries to easily access, retrieve data and as a suitable tool for identification of plants. A plan for regular update and enrich this database has been made.

Distribution of secondary metabolites in 75 medicinal and aromatic plants of Bangladesh

Sl.no. of plant sp.  Scientific name  Family  Plant parts used  Active priciples      
Alk Flv Str Res Tan Gly Sap
1 Achyranthes aspera L. Amarathaceae Leaf 4+ + + - + + +
2 Adhatoda zeylanica Medic. Acanthaceae Leaf 4+ + - + + + +
3   Aegle marmelos   Rutaceae   Leaf 2+ + + + + + -
Fruit 3+ + + + + + -
Stem bark 2+ + + + + + -
Albizia odoratissima (L. f.) Benth.  Mimosaceae  Leaf +            
Seed 2+            
Albizzia lebbeck (L.) Benth  Mimosaceae  Leaf +            
Pods 2+            
6 Allium cepa L. Liliaceae Bulb + + - - + - +
7 Allium sativum L. Liliaceae Bulb 3+ + + + + - -
8 Aloe barbadensis Mill. Liliaceae Leaf 2+ + + + + + +
9 Amaranthus viridis L. Amaranthaceae Leaf 3+ + + - + + +
10 Amomum aromaticum Benth. Zingiberaceae Rhizome 3+ + - + + + +
11   Anacardium occidentale L.   Anacardiaceae   Stem bark + + + + +    
Fruit 2+ + - + + + +
Leaf 3+ + + - + + +
12 Andrographis peniculata (Burm.f.) Wall ex. Ness Acanthaceae Leaf 3+ + + + + - +
13 Annona squamosa L. Annonaceae Leaf 4+ + - - + - +
14 Anthocephalus chinensis (Lamk.) Rich. Ex.Walp Rubiaceae Stem bark 4+ + + - + - +
15 Areca catechu L. Aracaceae Nut 3+ + + + + + -
16   Asparagus racemosus L.   Liliaceae   Root 2+ + - + + - +
Aerial part 2+ + + + + + +
17 Bacopa monniera (L.) Pennel. Scrophulariaceae Leaf 3+ + - + + + +
18 Bambusa bambosa Poaceae Leaf 3+ - - + - + +
19  Barringtonia acutangula(L.) Gaertn.  Barringtoniaceae  Leaf 3+ + + + + - +
Stem bark 4+ + - - + - +
19   Bauhinia purpurea L.   Caesalpiniaceae   Leaf 3+ + + - + - +
Flower +            
Stem bark 3+ + - - - + +
20 Benincasa hispida (Thunb.) Cagn. Cucurbitaceae Leaf + + + + + + -
21  Cajanus cajan (L.) Huth.  Fabaceae  Leaf 3+ + + - - + -
Pod 3+ + - + + + -
22  Carica papaya L.  Caricaceae  Leaf 4+            
Fruit 2+ + - - + - +
23  Cassia alata L.  Caesalpiniaceae  Leaf + + + - + + -
Pod 2+ - - - - + -
24   Cassia fistula L.   Caesalpiniaceae   Leaf 2+ + + - + + -
Stem bark + + - - + + -
Pod + + - - - + -
25 Cassia obtusifolia L. Caesalpiniaceae Leaf + + + + + + +
26 Cassia occidentalis L. Caesalpiniaceae Leaf 3+ + - - + + +
27   Cassia sophera L.   Caesalpiniaceae   Leaf 2+ + - - - + -
Fruit 3+ - - - + - -
Stem bark +            
28  Catharanthus roseus (L.)G. Don.  Apocynaceae  Leaf 3+ + + - - + -
Flower 2+ + - - - + -
29 Cicer arietinum L. Fabaceae Seed 3+ + + - + - -
30 Cinnamomum tamala Lauraceae Leaf + + + - + + +
31 Coccinia grandis (L.)Voigt. Cucurbitaceae Leaf 3+ + + - + + +
32  Cocos nucifera L.  Arecaceae  Flower +            
Leaf 3+            
33   Coriandrum sativum L.   Apiaceae   Leaf 3+ + + + + + -
Root 3+            
Seed +            
34 Croton bonplandanium.Bail. Euphorbiaceae Leaf +            
35 Cuminum cyminum L. Apiaceae Seed 3+ + + - + + +
36 Curcuma longa L. Zingiberaceae Rhizome 2+ + + - + - +
37 Dioscorea sp. Dioscoraceae Rhizome 4+            
38 Diospyros malabarica (Desr.) Kostel Ebenaceae Stem bark 3+            
39 Eclipta alba (L.) Hassk Asteraceae Leaf 2+ - + - + - +
40   Emblica officinales Gaertn.   Phyllanthaceae   Leaf 4+ + - - + + +
Fruit 2+ -     + - -
Stem bark 3+            
41  Eupatorium odoratum L.  Asteraceae  Leaf 2+ + + - - + +
Flower 2+            
42   Euphorbia hirta L.   Euphorbiaceae   Leaf 3+            
Flower 4+            
43  Ficus benghalensis L.  Moraceae  Leaf 3+ + - + + - +
Fruit 2+ + + + +    
44 Ficus racemosa L. Moraceae Stem bark + + + + + + -
45 Ficus religiosa L. Moraceae Stem bark 3+ - - + + -  
46 Gmelina arborea Roxb. Verbenaceae Stem bark 2+            
47 Heliotropium indicum L. Boraginaceae Leaf 3+ - - - - - +
48 Hibiscus rosa-sinensis L. Malavaceae Flower 2+            
49  Holarrhena pubescence (Buch. Ham.) Wall.  Apocynaceae  Stem bark 4+ - - - + + -
Leaf 3+            
50 Ipomoea aquatica Forsk. Convolvulaceae Leaf 3+ + - - + - +
51 Ipomoea batatus (L.) Lamk. Convolvulaceae Leaf 4+ - + - + + +
52  Jatropa gossypifolia L.  Euphorbiaceae  Leaf +            
Bark 2+            
53 Kalanchoe pinnata (L.)Pers. Crassulaceae Leaf 2+ + - = + + +
54  Lagerstroemia reginae Roxb.  Lythraceae  Leaf +            
Bark 2+            
55 Litchi chinensis Sonn. Sapindaceae Leaf +            
56  Mangnifera indica L.  Anacardiaceae  Leaf 4+            
Stem bark 4+ + - + + + +
57 Melia azadirachta L. Meliaceae Leaf 2+ + - - + - -
58 Momordica charantea L. Cucurbitaceae Fruit 3+ - - - - + -
59 Momordica cochinchinensis Spreng. Cucurbitaceae Leaf 2+            
60 Moringa oleifera Lamk. Moringaceae Leaf 3+ + + + - - +
61  Murraya koenigii (L.) Spreng.  Rutaceae  Leaf 4+ + + - + + +
Stem bark 3+            
62 Musa paradisiacal L. Musaceae Flower 2+            
63 Ocimum gratissimum L. Lamiaceae Leaf + + + - + + +
64 Ocimum sanctum L. Lamiaceae Leaf + - + - + + +
65 Phylanthus amarus Schum. Euphorbiacae Leaf + + + - + - +
66 Premna esculenta Roxb. Verbeneceae Aerial plant 3+            
67 Scoparia dulcis L. Scrophulariaceae leaf 3+            
68 Syzygium cumini (L.)Skeel. Myrtaceae Seed + + - + + + +
69  Tamarindus indica L.  Fabaceae  Leaf 3+ + + - + + -
Fruit 3+            
70 Vernonia patula (Dryand.) Merr. Asteraceae Leaf 2+            
71 Vitex negundo L. Verbenaceae Leaf 2+ - + - + - -
72 Wedelia chinensis (Osbeck.) Merr. Asteraceae Leaf 3+ + + + + - +
73 Withania somnifera (L.) Dunal. Solanaceae Leaf 3+ + + - - - +
74 Zingiber officinale Rose. Zingiberaceae Rhizome 2+ + - + + + +
75   Zizyphus mauritiana Lamk.   Rhamnaceae   Leaf 3+ + - + + + +
Fruit + + + - + + +
Stem bark + + - + + + +