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The alpha-amylase inhibitors are used as a drug to control hyperglycemia in type II diabetes mellitus. The plant extract is a natural source to minimize toxicity and other side effects. The alpha-amylase inhibition assay shows that the methanol extracts of fruits, seeds, leaves, and barks of Z. armatum exhibit 50% alpha-amylase inhibition activity at concentration 47.73 μg/mL, 50.25 μg/mL, 67.25 μg/mL, 152.6 μg/mL respectively, and hexane extracts of fruits, seeds, leaves and barks of Z. armatum exhibits 50% alpha-amylase inhibition activity at concentration 86.24 μg/mL, 84.02 μg/mL, 98.8 μg/mL, 138.81 μg/mL respectively, whereas the 50% alpha-amylase inhibition activity of Acarbose (standard) was found to be 33.66 μg/mL. Therefore, methanol and hexane extracts of fruits, seeds, and leaves show potential alpha-amylase inhibition activity and can be used as anti-diabetes.

Drymaria diandra is used in Nepalese traditional medicine to treat various ailments. The hexane, dichloromethane, ethyl acetate, methanol and 50% aqueous methanol extracts of D. diandra were prepared and screened for the presence of different classes of phytochemicals. Methanol and 50% aqueous methanol extracts showed the presence of phenolics, flavonoids and carbohydrates so their total contents were estimated. The highest amount of phenolics and flavonoids were found in methanol extract (190.58±2.21 mg GAE/g extract and 69.25±7.91 mg CE/g extract respectively). The highest amount of sugar was found in 50% methanol extract (185.60±2.53 mg GE/g extract). Similarly, the extracts were tested for the antibacterial activity against one gram negative bacteria, Escherichia coli and one gram positive bacteria Staphylococcus aureus. All the tested extracts showed good antibacterial activity against both bacteria with the inhibition zone ranging from 10 -22 mm. The free radical scavenging activity was determined using DPPH free radical. Both methanol and 50% aqueous methanol extracts showed strong antioxidant activity (IC50 13.61 and 16.94 μg/ml respectively). The GC-MS analysis of hexane extract revealed the presence of more than 22 compounds. However, 9 compounds were identified by comparing the mass fragmentation pattern of each compound with the standard NIST mass spectral database

The present research work has been performed to evaluate the phenolic content, flavonoids content, and cytotoxicity of a multidimensional medicinal plant; Tinospora cordifolia and as well as to determine nutritive value by proximate analysis. The total phenolic and flavonoids contents of Tinospora cordifolia were found to be significantly greater in methanol extract as compared to corresponding hexane extract. Brine shrimp bioassay indicated Tinospora cordifolia is pharmacologically active. The percentage composition of different nutrition parameters namely moisture, total ash, crude fat, protein, fibre, carbohydrate, and vitamin C were assessed. The nutritive values of fresh and dried stem samples were evaluated as 156.44 Kcal/100g and 232.61 Kcal/100g respectively. From Gas column mass spectrometry analysis, it can be reported that inositol, 1-deoxy-, trans-sinapyl alcohol, n-hexadecanoic acid were present in the major amount in methanol stem extract. The findings from this study reveal Tinospora cordifolia contains an adequate amount of phenolic and flavonoids content, vital bioactive antioxidant compounds, and a good source of carbohydrates and fibers which potentially adds to the overall value of the plant.

Castanopsis indica has been used as a medicinal plant for long period of time but rigorous phytochemical and biological studies has not been performed to assess its nutritional and medicinal importance. The objective of the present study was to explore the phytochemical constituents, antioxidant properties, total phenolic and flavonoid content of Castanopsis indica (C. indica) and proximate analysis of C. indica nuts. Free radical scavenging activities was evaluated by using2,2- diphenyl-1-picrylhydrazyl (DPPH) assay, total phenolic content was determined by using Folin-Ciocalteu method, Total flavonoid content was calculated by using Aluminum chloride (AlCl3) colorimetry assay and proximate analysis by Association of Official Analytical Chemists (AOAC) method. The IC 50 value of methanol extract of bark and leaf was found to be 74.98 μg/mL and 64.95μg/mL respectively and that of hexane extract of bark and leaf was found to be 124.41 μg/mL and 114.62 μg/mL respectively. Total phenolic content of methanol extract of bark and leaf was found to be 139.47 ± 0.17 mg GAE/g (gallic acid equivalents per gram) and 153.58 ± 0.21 mg GAE/g respectivelyand that of hexane extract of bark and leaf was found to be 30.14 ± 0.17 mg GAE/g and 35.7 ± 0.52 mg GAE/g respectively. The total flavonoids content of methanol extract of bark and leaf was evaluated to be 124.18 ± 3.18 QE/g (quercetinequivalents per gram) and 138.46 ± 1.78 mg QE/g respectively and that of hexane extract of bark and leaf was found to be 24.59 ± 1.55 QE/g and 34.66 ± 3.18 QE/g respectively. The percentage composition of different nutrition parameters (moisture, total ash, crude fat, protein, crude fiber, carbohydrate) was found to be 18.90 ± 0.02, 1.26 ± 0, 0.30 ± 0.04, 10.83 ± 0.76, 3.72 ± 0, 64.99 ± 0.71 % in nuts sample, respectively.The result suggest that C. indica contain rich sources of antioxidants and phenolic compounds which are probably considered in pharmaceutical use and nuts of this plant are good sources nutrient and considering their low cost and availability, need to be popularized.

The aim of this study was to carry out the ethno-botanical survey to determine the importance of traditional medicinal Tinospora cordifolia plant and to evaluate phytochemical screening and anti-oxidant potential of plant extract of Tinospora cordifolia. Traditionally, it is used alone or with other medicinal plants to treat common disease such as fever, diabetics, urinary tract infection and piles problem. Phytochemical screening proved that plant extracts are the rich sources of secondary metabolites such as alkaloids, glycosides, flavonoids, terpenoids etc. Antioxidant activity of these plant extracts was studied by DPPH radical scavenging assay which proved the inhibitory concentration, IC50 value of hexane and methanol extract of leaves of Tinospora cordifolia were 140 and 79.41 µg/ml and hexane and methanol extract of stem were found to be 126.52 and 76.26 µg/ml, Similarly IC50 value of methanol extract of leaves and stem from percolation method were 94.83 and 91.88 µg/ml . The IC50 value thus provided scientific information that T. cordifolia can be used as a potential candidate in different pharmaceutical purpose.

Vitex negundo (VN) is a widely used plant in folk medicine, namely for the treatment of jaundice, wounds, body ache, toothache, asthma, eye pain, and migraine. These effects have been increasingly attributed to its chemical composition. Here, we assessed the VN chemical and nutritional composition and biological activity, with particular emphasis on antioxidant and antimicrobial effects. VN methanol and hexane extracts revealed the presence of important phytochemical, such as terpenoids, polyphenol, steroids, saponins, phenolic compound and flavonoids. Total phenolic content of VN methanol extract from bark was 1082.473 mg/g GAE and that of leaves was 1382.984 mg/g GAE. The total flavonoids content in VN methanol extract from VN bark was 127.744 mg/g QE and that of leaves was 123.776 mg/g QE. VN methanol extract from bark exhibited high antioxidant effects (IC50=38.47 ppm). The content (%) of ash, moisture, crude fiber, crude protein and fat in VN leaves was, respectively, 7.86%, 18.35%, 6.52%, 9.687% and 6.19%. VN leaves methanol extract revealed antimicrobial activity against Bacillus subtilis and Staphylococcus aureus, with inhibition halos being, respectively, 13 mm and 14 mm, and the MBC values were found to be 1.562 mg/mL and 6.25 mg/mL, respectively. Similarly, VN bark methanol extract led to inhibition halos of 18 mm and 15 mm for B. subtilis and S. aureus, respectively, and the MBC values were found to be 2.372 mg/mL and 0.245 mg/mL. GC-MS analysis of the VN bark methanol extract revealed that monoolein was the major compounds, with an area of 0.57%. Thus, our results encourage the potential use of VN as a medicinal product, with high protein contents, and prominent antioxidant and anti-bacterial effects.

The progress of bacterial blight epidemics, caused by Xanthomonas oryzae pv. oryzae, varies with environment. The irrigated lowland rice production environment in central Terai (plain) is less conducive to the disease than the irrigated lowland rice production environment in eastern Terai in Nepal. The effect of partial resistance on bacterial blight was studied in central Terai during the wet seasons of 1994, 1995, and 1996. Three partially resistant rice cultivars, Sabitri, Laxmi, and IR54 (possessing the Xa4 gene), and susceptible check IR24 were included in this study. Analysis of pooled data from the 3 years of experiments indicated that rice cultivars differed in resistance based on three epidemiological parameters: disease severity (DS), area under the disease progress curve (AUDPC), and rate of disease increase (r). Estimates of DS, AUDPC, and r were reduced and yield loss was negligible in the partially resistant cultivar Laxmi compared with the susceptible check IR24. IR54, which has partial resistance to X. oryzae pv. oryzae, also showed low DS, AUDPC, and r, which prevented yield loss due to bacterial blight. The locally adapted cultivar Sabitri showed intermediate estimates of DS, AUDPC, r, and yield loss. Earlier and more severe disease developed in the susceptible check IR24, resulting in a yield loss of 22%. Yield losses were mainly due to reductions in number of tillers, number of grains per panicle, and 1,000-grain weight. These data indicate that the use of rice cultivars with high levels of partial resistance will be an effective tool for the management of bacterial blight in central Terai and similar environments in Nepal.

Fifty isolates of Xanthomonas oryzae pv. oryzae were collected from different rice-producing districts of Nepal and evaluated for their virulence on these 11 rice lines having from one to four resistance genes: IRBB4 (Xa4), IRBB5 (xa5), IRBB7 (Xa7), IRBB8 (xa8), IRBB10 (Xa10), IRBB14 (Xa14), and IRBB21 (Xa21), two-gene combination AY4+5 (Xa4 and xa5), three-gene combinations NH21-37-1-1 (Xa4, xa5, and xa13) and NH24-10-1-3 (Xa4, xa5, and Xa21), and four-gene combination NH56-1-44-4 (Xa4, xa5, xa13, and Xa21). The ability of an isolate to cause lesions with different lengths across the lines was interpreted as virulence. Isolates that were consistently associated with high or low virulence were statistically differentiated. Most isolates produced large lesions on near-isogenic lines with single genes and small lesions on lines with different gene combinations. Based on infection responses on the two-, three-, and four-gene combinations, five virulence groups were identified. Isolates in virulence group I were widely distributed. The line × isolate interactions were generally not significant with gene combinations, indicating a low possibility of specificity. A line with a four-gene combination, NH56, showed wider spectrum and higher level of resistance to X. oryzae pv. oryzae than the other lines. The results of this study will facilitate the deployment of effective resistance to X. oryzae pv. oryzae in Nepal.

The effect of crop rotation and cultivar resistance on bacterial wilt of tomato (Lycopersicon esculentum), caused by Ralstonia solanacearum (biovar 3 and race I), were studied from 1994 to 1996 in a field experiment in Chitwan, Nepal. Corn (Zea mays), lady's finger (Ahelomoschus esculentum), cowpea (Vigna unguiculata), and the partially resistant tomato line CL1131-0-0-43-4 (CL1131) were rotated with susceptible tomato in different combinations. The susceptible tomato cultivar Pusa Ruby was used as an indicator plant to assess wilt severity (percent leaves wilted) in each plot after rotation. Wilt severity was significantly (P < 0.05) reduced by rotation with corn, lady's finger, cowpea, or resistant tomato compared with continuous tomato. The onset of bacterial wilt was delayed by 1-3 weeks and wilt severity was reduced by 20-26% when susceptible tomato was grown after corn, lady's fingers, cowpea or resistant tomato. Lower area under the disease progress curve (AUDPC), based on wilt severity, and higher...