Folk medicinal practitioners form the first tier of primary health-care providers to most of the rural population of Bangladesh. They are known locally as Kavirajes and rely almost solely on oral or topical administration of whole plants or plant parts for treatment of various ailments. Also about 2% of the total population of Bangladesh are scattered among more than twenty tribes residing within the country's borders. The various tribes have their own tribal practitioners, who use medicinal plants for treatment of diseases. The objective of the present survey was to conduct an ethnomedicinal survey among the Kavirajes and tribal practitioners to determine which species of plants belonging to the Verbenaceae family are used by the practitioners. The Verbenaceae family plants are well known for constituents having important bio-active properties. The present survey indicated that 13 species belonging to 8 genera are used by the folk and tribal medicinal practitioners of Bangladesh. A comparison of their folk medicinal uses along with published reports in the scientific literature suggests that the Verbenaceae family plants used in Bangladesh can potentially be important sources of lead compounds or novel drugs for treatment of difficult to cure debilitating diseases like malaria and rheumatoid arthritis.

It has been estimated that 300–500 million malaria infections occur on an annual basis and causes fatality to millions of human beings. Most of the drugs used for treatment of malaria have developed drug-resistant parasites or have serious side effects. Plant kingdom has throughout the centuries proved to be efficient source of efficacious malarial drugs like quinine and artemisinin. Since these drugs have already developed or in the process of developing drug resistance, it is important to continuously search the plant kingdom for more effective antimalarial drugs. In this aspect, the medicinal practices of indigenous communities can play a major role in identification of antimalarial plants. Bangladesh has a number of indigenous communities or tribes, who because of their living within or in close proximity to mosquito-infested forest regions, have high incidences of malaria. Over the centuries, the tribal medicinal practitioners have treated malaria with various plant-based formulations. The objective of the present study was to conduct an ethnomedicinal survey among various tribes of Bangladesh to identify the plants that they use for treatment of the disease. Surveys were conducted among seven tribes, namely, Bawm, Chak, Chakma, Garo, Marma, Murong, and Tripura, who inhabit the southeastern or northcentral forested regions of Bangladesh. Interviews conducted with the various tribal medicinal practitioners indicated that a total of eleven plants distributed into 10 families were used for treatment of malaria and accompanying symptoms like fever, anemia, ache, vomiting, and chills. Leaves constituted 35.7% of total uses followed by roots at 21.4%. Other plant parts used for treatment included barks, seeds, fruits, and flowers. A review of the published scientific literature showed that a number of plants used by the tribal medicinal practitioners have been scientifically validated in their uses. Taken together, the plants merit further scientific research towards possible discovery of novel compounds that can be used to successfully treat malaria with less undesirable sideeffects.

Delonix regia (Fabaceae) leaf is used in folk medicine of Bangladesh for the treatment of diabetes, but so far no scientific study has been done which may support its use in traditional medicine. The present study was carried out to evaluate the possible glucose tolerance efficacy of methanolic extract of Delonix regia leaf using glucose-induced hyperglycemic mice. The extract at different doses was administered one hr prior to glucose administration and blood glucose level was measured after two hrs of glucose administration (p.o.) using glucose oxidase method. The statistical data indicated significant oral hypoglycemic activity on glucose-loaded mice at every dose. Maximum anti-hyperglycemic activity was showed at 400 mg/kg which was comparable to that of a standard drug, glibenclamide (10 mg/kg). The methanolic extract of leaf of Delonix regia had beneficial effects in reducing the elevated blood glucose level of hyperglycemic mice.

Kavirajes or traditional medicinal practitioners form the primary healthcare providers of the predominantly rural population of Bangladesh. Kavirajes use a variety of medicinal plants for treatment of different ailments. The formulations prepared from medicinal plants vary considerably between Kavirajes of different regions of the country. The objective of this study was to conduct an ethnomedicinal survey amongst the Kavirajes of Chalna area, Khulna district, Bangladesh. That area is known to contain a diversity of medicinal plants. Information on 50 plant species was obtained. These medicinal plants belonged to 49 genera and 33 families. Twenty five plants were used to treat skin diseases and twenty three plants for treatment of intestinal tract disorders, which included constipation, indigestion, stomachache, diarrhea, and dysentery. Fourteen plants were also used by the Kavirajes to treat cancer or tumor. Nine plants were used as insecticide, eight for rheumatoid arthritis, and seven for wounds. Five plants were used to treat jaundice. Five plants were also utilized to treat animal and snake bites, which included tiger bites. Six plants were used to treat diabetes, and two each for the treatment of leprosy, and sexually transmitted diseases like gonorrhea. Five plants were used to treat impotency, while one plant was used as an abortifacient. Three plants were used to treat helminthiasis, which we found to be quite common amongst the population, while four plants were used to treat heart disorders. Taken together, these plant species offer considerable potential for discovery of novel compounds of pharmacological interest.

Cuscuta reflexa (whole plant) and Calotropis procera (leaves) are used in folk medicine of Bangladesh to control blood sugar in patients suffering from diabetes mellitus. The hypoglycemic effects of methanol and chloroform extracts of whole plants of Cuscuta reflexa, and methanol extract of leaves of Calotropis procera were investigated in oral glucose tolerance tests in Long Evans rats and Swiss albino mice, respectively. Both methanol and chloroform extracts of Cuscuta reflexa whole plant demonstrated significant oral hypoglycemic activity in glucose-loaded rats at doses of 50, 100 and 200 mg/kg body weight. The methanol extract of leaves of Calotropis procera, when tested at doses of 100 and 250 mg/kg body weight did not demonstrate any oral hypoglycemic effect when tested in glucose-loaded mice.