Medicinal plants sold in the markets of Antananarivo, Madagascar

BACKGROUND

This study focuses on the large outdoor markets of the capital of Madagascar, Antananarivo. As the largest metropolitan area in Madagascar with a population of nearly two million, the region has great capacity for consumption of medicinal plant remedies despite numerous pharmacies. Medicinal plant use spans all socioeconomic levels, and the diverse metropolitan population allows us to study a wide variety of people who consume these plants for medical purposes. The purpose of this study is to identify and generate a list of medicinal plants sold in the traditional markets with a focus on those collected in the forests around Antananarivo, get an idea of the quantities of medicinal plants sold in the markets around Antananarivo, and assess the economy of the medicinal plant markets.

METHODS

In order to determine which medicinal plants are most consumed in Antananarivo, ethnobotanical enquiries were conducted in the five main markets of the capital city. Ethnobotanical surveys were conducted with medicinal plant traders, suppliers, harvesters and cultivators, with voucher specimens created from the plants discussed. Trade circuit information was established and the income generated by the trade of some of the species was assessed.

RESULTS

The inventory of the Antananarivo markets resulted in a list of 89 commercialized plant species. Ten of the 89 were mentioned by 60-100 % of vendors. Profitability for vendors is high and competitive with other salaried positions within Antananarivo. Transportation costs are also high and therefore lower profitability for other members in the supply chain.

CONCLUSIONS

The markets of Antananarivo have always played a vital cultural role in the lives of urban Malagasy, but our study shows they also play an economic role not only for urban residents but rural harvesters as well. Continued research and monitoring of the non-timber forest products trade in Antananarivo is needed to better understand the impact of trade on the wild plant populations.

Effects of socio-economic household characteristics on traditional knowledge and usage of wild yams and medicinal plants in the Mahafaly region of south-western Madagascar

BACKGROUND

Rural households in the Mahafaly region of semi-arid SW-Madagascar strongly depend on the exploitation of natural resources for their basic needs and income regeneration. An overuse of such resources threatens the natural environment and people's livelihood. Our study focuses on the diversity and use of wild yams and medicinal plants.

METHODS

We hypothesized that knowledge on the use of these resources highly depends on farmers' socio-economic household characteristics. To test this hypothesis, an ethnobotanical survey was conducted based on semi-structured interviews recording socio-economic base data and information on local knowledge of medicinal and wild yam species. This was followed by field inventories compiling plant material for botanical identification.

RESULTS

Six species of wild yam and a total of 214 medicinal plants from 68 families and 163 genera were identified. Cluster and discriminant analysis yielded two groups of households with different wealth status characterized by differences in livestock numbers, off-farm activities, agricultural land and harvests. A generalized linear model highlighted that economic factors significantly affect the collection of wild yams, whereas the use of medicinal plants depends to a higher degree on socio-cultural factors.

CONCLUSIONS

Wild yams play an important role in local food security in the Mahafaly region, especially for poor farmers, and medicinal plants are a primary source of health care for the majority of local people. Our results indicate the influence of socio-economic household characteristics on the use of forest products and its intensity, which should be considered in future management plans for local and regional forest conservation.

Ethnobotanical and economic value of Ravenala madagascariensis Sonn. in Eastern Madagascar

BACKGROUND

Known worldwide as the "traveler's tree", the Malagasy endemic species Ravenala madagascariensis Sonn. (Strelitziaceae) is considered as an iconic symbol of Madagascar. It is a widespread species in the eastern part of the country with four different varieties which are well represented in Ambalabe community. All of them are used for different purposes and the species represents an important cultural value in the lives of the local population. However, uses of Ravenala are only generally well known by local population. Thus, in this study, we report on the different uses of Ravenala and its importance to the Ambalabe local people.

METHODS

Semi-structured interviews among 116 people, 59 men and 57 women with ages ranging from 17 to 84 years old, free listing and market surveys were conducted in order to collect the vernacular names, the uses of Ravenala madagascariensis and the price of plant parts sold in local market. Then, the uses were categorized according to Cámara-Leret et al. classification.

RESULTS

Different parts of the plant are currently used by local population, which are grouped as heart, trunk, leaves, petioles and rachis. Seven categories of use were recorded, most cited include: human food, utensils and tools, and house building. The most commonly used parts are trunk, heart, leaves and petioles for which the price varies between $3-15. Uses mentioned for construction (floor, roofs and wall), human food and utensils and tools are the most frequent and salient for local population. But the use of the plant as first materials for house building is revealed to be the most important for them.

CONCLUSIONS

Ravenala madagascariensis is very important to the Ambalabe communities because for local population, it represents the Betsimisaraka cultural and traditional use of the plant for house building. Moreover, none of its parts are discarded. The harvest and sale of R. madagascariensis for building materials can also provide an additional source of income to the family. Besides, using Ravenala in house construction reduces the use of slow growing trees and contributes to the sustainable use of natural forest resources.

Acute toxic effects of 8-epidiosbulbin E, a 19-norclerodane diterpene from yam Dioscorea antaly, on medaka Oryzias latipes embryos

The fractionation of an aqueous extract of yam Dioscorea antaly from Madagascar led to the isolation of terpenoids and flavonoids. Compounds were identified on the basis of modern mass spectrometry and two-dimensional nuclear magnetic resonance (2D-NMR). Toxicological effects of the most abundant isolated compound, 8-epidiosbulbin E were studied on medaka Oryzias latipes embryo-larval development. The lethal concentration (killing 50%; LC(50) ) to embryos treated 24 h before hatching and for 3 days after hatching was estimated to be 0·56 mg ml(-1) (P< 0·05). No mortality was observed with O. latipes larvae exposed after hatching until day 4. Anatomo-pathological studies of embryos exposed to 0·56 mg ml(-1) showed development anomalies of the central nervous system, liver, muscle and intestine. The present data thus extend the model of O. latipes embryos as a useful animal model to analyse the effects of food toxins.

Protected area safeguard tree and shrub communities from degradation and invasion: a case study in eastern Madagascar

Despite their prevalence in both developed and developing countries, there have been surprisingly few field assessments of the ecological effectiveness of protected areas. This study aimed to assess the effectiveness of a key protected area in eastern Madagascar, Ranomafana National Park (RNP). We established paired 100 x 4-m vegetation transects (400 m(2)) within RNP and in remnant forests in the park's peripheral zone. In each 400-m(2) plot, all woody stems >1.5 cm in diameter at breast height were measured and identified to species. All species were also identified as native or non-native. We identified utilitarian species within all transects and they were sorted into use category. We calculated plot-level taxonomic biodiversity and functional diversity of utilitarian species; the latter was calculated by clustering the multivariate distances between species based on their utilitarian traits, and all metrics were tested using paired t-tests. Our results showed that there was significantly higher biodiversity inside RNP than in remnant forests and this pattern was consistent across all diversity metrics examined. Forests not located within the park's boundary had significantly higher non-native species than within RNP. There was no statistically significant difference in functional diversity of utilitarian species inside RNP vs. remnant forests; however, the overall trend was toward higher diversity inside park boundaries. These findings suggested that RNP has been effective at maintaining taxonomic diversity relative to surrounding unprotected areas and restricting the spread of non-native plants. The results also suggested that low functional redundancy of forests outside of RNP might be of concern, because residents in surrounding villages may have few other substitutes for the services provided by species that are of critical importance to their livelihoods. This study highlights the challenges of trying to reconcile biodiversity conservation with human use of natural resources in economically poor, remote areas.

Pleiotropic control mutations affecting the sporulation of Bacillus subtilis

Mutations affecting quantitatively the production of the sporulation-associated extracellular alkaline protease were isolated and characterized. They fall into at least five genes, three of which, ScoA, B and C, were mapped in the argC-metC region. The pleiotropic effects of these mutations concern several or all of the following: rate and timing of protease production, synthesis of alkaline phosphatase, time-course of spore formation. Electron microscopic evidence indicates delayed switch from one morphological stage to another. The nature of the Sco mutations and the genetic regulation of sporulation are discussed.