AN ETHNOBOTANICAL SURVEY OF ANTI-MALARIAL PLANTS IN SOME HIGHLY MALARIA AFFECTED DISTRICTS OF ASSAM

Objective: An ethnobotanical survey of potent anti-malarial plants used by different tribes and communities of highly malaria affected seven districts of Assam, India.Methods: Personal discussions and group interviews were held with the traditional practitioners. Samples were collected and authentically identified. Detailed ethno knowledge on the plant parts used and mode of administration of the plant extracts was documented. Literature survey was carried out on identified plant species and analyzed for their medicinal importance.Results: A total of 22 plant species belonging to 20 botanical families were collected and identified from different locations of seven districts of Assam. Different plant parts such as leaves, root, flower, bark etc. were found to process through different basic methods (infusion, decoction, direct mechanical crushing and maceration) for extracting the anti-malarial crude phytochemicals by the traditional healers. Extensive literature on the broad spectrum medicinal values other than anti-malarial activity of the plant species suggested a strong scientific background of selecting those particular plants species by the traditional practitioners.Conclusion: Indigenous plant species with strong claim of the natural source of anti-malarial moieties were identified in the present ethno-botanical survey. All the 22 plant species investigated could be a potential source of new antimalarial therapies.Â

Aerosol characteristics in north-east India using ARFINET spectral optical depth measurements

Four years (2010–2014) of spectral aerosol optical depth (AOD) data from 4 Indian Space Research Organisation's ARFINET (Aerosol Radiative Forcing over India) stations (Shillong, Agartala, Imphal and Dibrugarh) in the North-Eastern Region (NER) of India (lying between 22–30°N and 89–98°E) are synthesized to evolve a regional aerosol representation, for the first time. Results show that the columnar AOD (an indicator of the column abundance of aerosols) is highest at Agartala (0.80 ± 0.24) in the west and lowest at Imphal (0.59±0.23) in the east in the pre-monsoon season due to intense anthropogenic bio-mass burning in this region aided by long-range transport from the high aerosol laden regions of the Indo-Gangetic Plains (IGP), polluted Bangladesh and Bay of Bengal. In addition to local biogenic aerosols and pollutants emitted from brick kilns, oil/gas fields, household bio-fuel/fossil-fuel, vehicles, industries. Aerosol distribution and climatic impacts show a west to east gradient within the NER. For example, the climatological mean AODs are 0.67±0.26, 0.52±0.14, 0.40±0.17 and 0.41±0.23 respectively in Agartala, Shillong, Imphal and Dibrugarh which are geographically located from west to east within the NER. The average aerosol burden in NER ranks second highest with climatological mean AOD 0.49±0.2 next to the Indo-Gangetic Plains where the climatological mean AOD is 0.64±0.2 followed by the South and South-East Asia region. Elevated aerosol layers are observed over the eastern most stations Dibrugarh and Imphal, while at the western stations the concentrations are high near the surface. The climate implications of aerosols are evaluated in terms of aerosol radiative forcing (ARF) and consequent heating of the atmosphere in the region which follows AOD and exhibit high values in pre-monsoon season at all the locations except in Agartala. The highest ARF in the atmosphere occurs in the pre-monsoon season ranging from 48.6 Wm−2 in Agartala to 25.1 Wm−2 in Imphal. Winter radiative forcing follows that in pre-monsoon season at these locations. The heating rate is high at 1.2 K day−1 and 1.0 K day−1 over Shillong and Dibrugarh respectively in this season. However, Agartala experiences higher surface forcing (−56.5 Wm−2) and consequent larger heating of the atmosphere of 1.6 K day−1 in winter