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Bioactive compounds and biological activities of some medicinal plants from central Nepal
(2016) Ghimire, Gyandra Prasad; Krishna Das Manandhar
Considerable attempts have been made globally to validate the traditional use of plants in
phytomedicine. Phytomedicine can counter the challenge posed by drug resistance and
toxicity by continuous search for novel drugs. This study focuses on the estimation of total
phenolic content, total flavonoid content, examination of antioxidant activities, GC‐MS
identification of bioactive compounds, observation of antimicrobial, cytotoxic, and anticancer
effects. Twelve medicinal plants with some history of use as traditional medicine have been
selected for the purpose. They include Loxogramme involuta, Hydrocotyle javanica,
Phyllanthus emblica, Chrysopogan aciculatus, Rhododendron lepidotum, Geranium
wallichianum, Tsuga dumosa, Anemone rivularis, Scurrula elata, Terminalia bellerica,
Ranunculus scleratus, and Symplocos lucida.
Total phenolic content was determined by the Folin‐Ciocalteu method, total flavonoid
content by aluminium chloride colorimetric method. Antioxidant activity was tested by their
capacity to scavenge DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) free radicals. GC‐MS analysis was
performed to identify the bioactive compounds. The antimicrobial efficacy was tested against
Staphylococcus aureus, methicillin‐resistant Staphylococcus aureus, Klebsiella pneumoniae,
Salmonella Typhi, Saccharomyces cerevisiae and Pichia sp. by agar well diffusion method.
Cytotoxicity was determined by brine shrimp bioassay. Anticancer activity was determined
by MTT assay on HeLa and MDCK cell lines.
P. emblica (55.66 ± 0.84 mgGAE/g) possessed the highest amount of total phenolic content.
Higher amount of TPC was also observed in G. wallichianum (54.99 ± 0.74 mgGAE/g), S. elata
(54.71 ± 0.68 mgGAE/g), T. bellerica (54.69 ± 0.77 mgGAE/g), and T. dumosa (54.19 ± 0.93
mgGAE/g). The lowest amount of TPC was observed in R. scleratus (6.74 ± 0.62 mgGAE/g).
The highest amount of total flavonoid content was observed in P. emblica (25.65 ± 0.77
mgQE/g). The lowest amount of TFC was observed in T. bellerica (7.51 ± 0.54 mgQE/g). TFC
for other plant extracts locate within the short range between these two values. T. dumosa
(4.54 ± 0.18 µg/ml) showed the highest antioxidant activity with the lowest IC
50
value – lower
than that observed in ascorbic acid (4.57 ± 00 µg/ml). Higher antioxidant activity was also
observed in P. emblica (6.64 ± 0.71 µg/ml), G. wallichianum (7.24 ± 0.48 µg/ml), T. bellerica
(12.08 ± 0.76 µg/ml), and S. elata (14.20 ± 0.94 µg/ml). R. scleratus (195.55 ± 2.45 µg/ml)
showed the lowest antioxidant activity. A significant Pearson’s correlation between TPC and
IC
50
of DPPH RSA (r = ‐0.9684) attributed phenolic compounds to be the main contributor of
antioxidant activity in plants. GC‐MS analysis showed the presence of a wide range of
bioactive compounds such as fatty acids, esters, sugars, steroidal, phenolic, and heterocyclic
xiv
compounds. Maximum inhibition of S. aureus and MRSA both were shown by T. bellerica.
Highest inhibition of S. Typhi was caused by T. dumosa. Minimum number of plants inhibited
K. pneumoniae on which L. involuta exerted the highest effect. Ten of the twelve plants
inhibited at least three of the six organisms. Eight of them inhibited at least four organisms.
G. wallichianum inhibited five of the six organisms. S. elata and T. bellerica both inhibited all
of them. Plants showed higher effects on gram positive bacteria. Nine of the twelve plants
showed significant toxicity to brine shrimps (LC
50
<500µg/ml) of which three were found to
be highly toxic (LC
50
<100 µg/ml) which includes A. rivularis, L. involuta and T. bellerica.
Maximum number of plants showed higher inhibition of HeLa cell line than of MDCK. The
highest inhibition of HeLa cell was shown by S. lucida (52.22 μg/ml) which precedes other ten
with EC
50
value less than 1000 μg/ml. T. bellerica (1048 μg/ml) showed the lowest inhibition.
Highest inhibition of MDCK cell was shown by L. involuta (240 μg/ml) followed by T. dumosa
(305 μg/ml), A. rivularis (407.7 μg/ml), S. elata (751.1 μg/ml), and P. emblica (925.3 μg/ml).
Other showed less inhibition with EC50 value more than 1000 μg/ml.
The results provide justification for traditional use of medicinal plants in treatment of various
diseases. The biological activities of medicinal plants may have been attributed due to the
presence of bioactive compounds identified. These plants can be the candidates as the
potential source of high valued phytopharmaceuticals. Further meticulous analysis of plants
might lead to isolation, identification and characterization of biologically active substances.
Keywords: medicinal plants, phenolic, flavonoid, antioxidant, bioactive compounds,
antimicrobial, cytotoxicity, anticancer
Genetic Affinity of Newa Population of Kathmandu Valley and Changpa Population of Ladhak
(2016) Basnet, Rajdip; Tilak R. Shrestha
Nepal harbors a variety of ancient and indigenous haplogroups that have been largely ignored in
several recent studies. To evaluate the matrilineal gene pool of the Himalayan populations and
their genetic adaptation to the high-altitude hypoxia environment, 695 (508 newly generated)
samples belonging to three different populations of Nepal (Newar, Magar and Brahmin) and 3
different populations from India (North India, Changpa and general individuals of Ladhak) were
analyzed. Investigation was performed based on the high resolution mtDNA sequencing followed
by the most precise identification of East Asian, Southeast Asian, South Asian and West Eurasian
Haplogroups. Further, Phylogeographic analysis of the genealogical lineages where obtained by
comparing the whole mtDNA sequences of the studied populations with the other Asian
populations. Desired variants of Epas1 and EDAR gene were obtained through direct sequencing.
Newar are considered to be the original and ancient inhabitants of the Kathmandu valley but
when and where the Newar people originated from remains contentious. Hypothesis are
proposed to have shared ancestry with the East Eurasian, South Asian and West Eurasian. Present
study revealed the presence of albeit limited, ancient and deep time depth South Asian lineages
in Newar, Magar and Brahmin. Further, Newar experiences several waves of migration adding
several East Asian, South Asian as well as West Eurasian lineages into Newar via multiple
dispersal, from several distinct sources in different time, rather than just one or two major
admixture events in the Neolithic/Bronze age. Most of the East Eurasian haplotype, observed in
Newar, Magar and Brahmin branched off directly from the nodes occupied by the Tibetan lineage,
albeit a few haplotypes were shared in between Nepali and Northeast Indian. Taking into account
the previous studies on East Eurasian maternal components, now it is convincing that the major
Genetic Influx from East Asia across the Himalayas into Nepal occurred in between 3-6 Kya and
these lineages has made a hefty contribution to the modern gene pools of the Newar and Magar.
Hence, our analysis supports a close genetic relationship between Newar and East Asian
population with substantial genetic contribution from South Asia and West Eurasia. This was
further supported by the analysis of the EPAS1 gene and 1540C variants of the EDAR gene. In a
good agreement with the previous studies on Tibetans and Sherpa, high-altitude adaptation in
Ladhak also identified positive signal of selection in genetic variants of EPAS1 gene. Further, a
strong linear correlation between genotyped alleles of EPAS1 gene and different level of altitude
were detected in the Himalayan populations, suggesting that extremely high-altitude hypoxia
environment exert a selective effect on Epas1 variants. Changpa shares most of their matrilineal
lineages with the indigenous Tibetans suggesting that the Tibetans are the ancestral populations
of Changpa and the adaptive traits for the high-altitude adaptation has been recently inherited
form their ancestors in Tibet. Whereas the general individuals from Ladhak shows higher
proportion of West Eurasian maternal components with substantial genetic contribution from
Tibet and India.
Nutritional status of cultivated mushrooms (a dissertation submitted as the partical fulfilment of the requirement)
(2016) Devkota, Dilli Raman; Rajani Malla
This investigation provides the proximate screening of nutrients and minerals
present in the four cultivated mushroom species sold in the markets of Kathmandu
valley. The cultivation practices include all the exotic mushroom species introduced
from India, Japan and China. They are Lentinula edodes, Pleurotus ostreatus,
Agaricus bisporus and Pleurotus djamor. All these mushrooms are cultivated in the
corners of Kathmandu valley and brought to the vegetable markets such as Asan,
Kalimati, Balkhu and Lagankhel for sale.
The result of the analysis indicated that the mushrooms are good sources of Crude
Protein (23%to 46.3%), Carbohydrate (28% to 50%), Fat (2.4% to 4.2%), Fiber (11.9%
to 17.9%), Ash (6.3% to 18.3%) and moisture (79% to 93.3%). The nutrient
contentvaries widely among the mushroom species. The result showed that the
mushrooms are good source of nutritionally important minerals including
Phosphorus (100.7mg to 837mg), Calcium (11.82mg to 165mg) and Iron (6.07mg to
52mg) per 100g on dry weight basis.
GC- MS result analysis suggested that mushroom samples are free of pesticides.
Based on the result of this study, it is suggested that these mushroom species are
nutritionally good without any human hazard.
Key words: Edible mushrooms, proximate composition, Mineral composition,
nutrient supply, GC-MS analysis.