Browsing by Author "Maharjan, Naresh"

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    Evaluation of Antibacterial Activities of medicinal Plants
    (Department of Microbiology, 2008) Maharjan, Naresh
    In this study, antibacterial activities of 9 different medicinal plants were tested against 10common pathogenic bacterial species. Medicinal plants were selected on the basis of their common use among the differentethnic groups for common disorder. The selected medicinal plants wereAcorus calamus,Aegle marmelos, Asparagus racemosus, Holarrhena antidysenterica, Mimosa pudica,Terminalia bellirica, Terminalia chebula, Tinospora cordifolia and Woodfordiafruticosa. These medicinal plants were subjected to solvent extraction using hot solventof increasing polarity into 3 fractions viz: hexane, ethylacetate and methanol usingsoxhlet apparatus. After removing the solvent under reduced pressure, residues weresuspended separately in DMSO. The highest yield was obtained in methanol fraction ofTerminalia chebula(46.1%) while lowest in hexane fraction of Asparagus racemosus(0.7%). The bacteria selected for the study were Staphylococcus aureus, Escherichia coli,Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris,Pseudomonas aeruginosa, Salmonella Typhi, Salmonella Paratyphi A and Shigelladysenteriae. Out of nine tested plants, four plant extracts (44%) showed activity against at least five ormore test bacteria and 5 plant extracts (56%) were active against three or less than threebacteria. None of the tested plants extracts were active against all the tested bacteria.Asparagus racemosuswas the least effectiveagainst the tested bacterial species. Plants extracts showed significant antibacterial activity towards Gram positive bacteriathan Gram negative bacteria.Staphylococcus aureuswas the most susceptible bacteriabeing sensitive to 18 fractions from 8 medicinal plants.Proteus vulgariswas the mostresistance bacteria being resistance to all selected plants. Largest ZOI (31 mm) wasproduced by ethylacetate fraction of Terminalia belliricawhile lowest MBC of 3.12mg/ml was shown by ethylacetate fraction ofT. belliricaagainstE. coli. Key words: Medicinal plants, Antibacterial activity, Plant extracts
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    Geology and Mineral Resources of the Bandipur Area, Lesser Himalaya, Central Nepal
    (Department of Geology, 2011) Maharjan, Naresh
    The present study was carried out around the Bandipur-Hilekharka-Keshavtar areas, west of Muglin, Central Nepal, Lesser Himalaya in an attempt to draw the stratigraphic set up, tectonic structures and mineral resources of the area. It consists of the rocks of the Nawakot Complex. The Fagfog Quratzite is the oldest unit of Lower Nawakot Group which is followed by the Dandagaon Phyllite, Nourpul Formation and Dhading Dolomite in successively higher positions and the Benignat Slate of Upper Nawakot Group but the Malekhu Limestone is missing in the study area. Based on lithology and environment of deposition, Nourpul Formation has been mapped into four members as Purebensi Quartzite, Amdanda Phyllite (laminated phyllile) and Labdi Khola Carbonate (observed in LabdiKhola areas) and Bandipur Slate (observed in Bandipur areas). The monotonous sequence of Carbonaceous Phyllite, well exposed on LabdiKhola-Mastipur section, poorly resembles with Benighat Slate of the type locality. Different types of erosional and tectonic structures are mapped in the study area. The Dadagaon Phyllite shows a broad inlier around Chipleti area and a small elliptical outlier of Purebensi Quartzite is mapped in Hilekharka area. A prominent thrust contact is mapped in between Dhading Dolomite and Nourpul Formation continuously around Chandrakot, Ripthok, Tilahar, Takmare and Kamalbari areas which is named as Jal Bhanjyang Thrust in present study. Two major folds viz. Bandipur Syncline and Hilekharka Anticline are also observed in the territory. Different types of sedimentary structures like ripple marks; mudcracks and graded beddings show the right side up sequence of the different units. A large number of tight isoclinal folds with folded quartz veins are observed in the Carbonaceous Phyllite of Benighat Slate. The rock units of the area consist of pelitic, psammatic and calcareous metasediments up to chlorite/sericite grade of metamorphism. Basic plutonic rocks are intruded in the upper part of Nourpul Formation which is sill like in nature and mappable in the field. Different types of both metallic and non-metallic minerals are found in the study area. Among them, copper deposit of Bhut Khola, hematite of Labdi Khola, roofing quality slate of the Bandipur and graphite deposit of Ghumaune-Labdi section are the potential resources of the area.