Digital learning Initiatives, Challenges and Achievement in Higher Education in Nepal Amidst COVID-19

The COVID-19 pandemic has affected higher education institutions (HEIs) worldwide and reshaped the existing educational system. Due to travel constraints and physical separation, there has been a global shift toward distance learning, and Nepal is no exception. This research intends to assess the practicality of online education by evaluating learners' experiences amidst COVID-19. A cross-sectional study was directed among HEIs students in Nepal using self-structured questionnaires. Our study revealed that 64.6% of the respondents were unsatisfied with online classes. More than half of the respondents (53.4%) use cell phones for online studies. Online education was reported to be unappealing to 28.8% of respondents. Variables such as age group (p = 0.05), enjoying class (p < 0.001), hours spent for an online class in a day (p = 0.05), and period for educational work using an electronic device (p = 0.1) were found significant with satisfaction level using both bivariate test and inferential test of univariate binary logistics regression. The challenges and opportunities encountered among students and faculties are highlighted along with the recommendations for fortifying communication in online-based teaching/learning

Maculosin, a non-toxic antioxidant compound isolated from Streptomyces sp. KTM18

Context Streptomyces species are prolific sources of bioactive secondary metabolites known especially for their antimicrobial and anticancer activities. Objective This study sought to isolate and characterize antioxidant molecules biosynthesized by Streptomyces sp. KTM18. The antioxidant potential of an isolated compound and its toxicity were accessed. Materials and methods The compound was purified using bioassay-guided chromatography techniques. Nuclear magnetic resonance (NMR) experiments were carried out for structure elucidation. The antioxidant potential of the isolated compound was determined using DPPH free radical scavenging assay. The toxicity of the isolated compound was measured using a brine shrimp lethality (BSL) assay. Results Ethyl acetate extract of Streptomyces sp. KTM18 showed more than 90% inhibition of DPPH free radical at 50 mu g/mL of the test concentration. These data were the strongest among 13 Streptomyces isolates (KTM12-KTM24). The active molecule was isolated and characterized as maculosin (molecular formula, C14H16N2O3 as determined by the [M + H](+) peak at 261.1259). The DPPH free radical scavenging activity of pure maculosin was higher (IC50, 2.16 +/- 0.05 mu g/mL) than that of commercial butylated hydroxyanisole (BHA) (IC50, 4.8 +/- 0.05 mu g/mL). No toxicity was observed for maculosin (LD50, <128 mu g/mL) in brine shrimp lethality assay (BSLA) up to the compound's antioxidant activity (IC50) concentration range. The commercial standard, berberine chloride, showed toxicity in BSLA with an LD50 value of 8.63 +/- 0.15 mu g/mL. Conclusions Maculosin may be a leading drug candidate in various cosmetic and therapeutic applications owing to its strong antioxidant and non-toxic properties

Comparative Study on Antioxidant Activity of Propolis of Apis mellifera from Different Regions of Nepal

Propolis is a waxy material obtained from honey bee hives. The physical and chemical property of this product is variable based on the source of hive, plant biodiversity where honeybee feed, season of collection, geographical origin etc. Propolis has several useful chemical compounds, and among them polyphenols are mainly contributing for their broad spectrum of medicinal quality such as antimicrobial, antifungal, antibacterial, and anti-inflammatory activities as well as antioxidant properties. The present study aims to analyze the ethanolic extract of propolis for their phenol and flavonoid content as well as its antioxidant characteristics. The samples (SPLs) were collected from farmers of six different locations of Nepal i.e. Jhapa, Lalitpur, Kathmandu, Banke and Chitwan districts. Total phenolic content (TPC) and total flavonoid content (TFC) were measured by Folin Ciocalteu method and the aluminum chloride method respectively expressed as the gallic acid (GAE) and quercetin (QE) and equivalent (GAE) per gram. The Diphenyl-Picrylhydrazyl (DPPH) assay method was used to evaluate the free radical scavenging activity. The antioxidant effect of propolis was reported in ascorbic acid equivalent antioxidant capacity per gram of propolis. The highest content of phenolic and flavonoid content was found in sample SPL 2. The range of these compounds' concentrations were from 127.36±5.50 mg GAE/gram to 242.7±4.50 mg GAE/gram. Similarly, total flavonoid content ranged from 1.3197±0.0261 QE mg/ grams to 5.3921±0.0261 QE mg/ grams. Whereas samples from SPL 2, and SPL 5 showed highest antioxidant properties. All samples were found to have strong antioxidant capacity which was greater than standard. It is concluded that there is no direct correlation on total antioxidant property of propolis with their total phenolic and total flavonoid content among collected samples. The phenolic characteristics of the samples were variable to the geographical location, and plant diversity of their origin

Investigation of antioxidant, antimicrobial and toxicity activities of lichens from high altitude regions of Nepal

Abstract Background Several lichen species are reported to be used tradiationally in many theraupatic practices. Many lichen species are reported as sources of several bioactive natural compounds. Several lichen species of Nepal are so far chemically unexplored. Methods The morphological, anatomical and phytochemical characteristics of lichens were compared for the taxonomic identification of the species. Methanol- water extract of lichens were sub fractionated into hexane, dichloromethane and methanol fractions for bioactivity assays. Antimicrobial activities of extracts were evaluated agaisnt pathogenic bacteria and fungal species. DPPH test was used for antioxidant potential evaluation. Brineshrimp test was perfermed to evaluate toxicity of the extracts. Results A total of 84 lichen specimens were collected and identified from Annapurna Conservation Area (ACA) Nepal. The specimens were identified as belonging to 19 genera and 47 species. Methanol fractions of 16 specimens and dichloromethane (DCM) fractions of 21 lichens specimens showed antioxidant activities comparable with commercial standards (BHA, Butylated hydroxyanisole, IC50=4.9±0.9 μg/mL) even at crude extract level. Similarly, the DCM fraction of 17 lichens showed potential antimicrobial activity against a Gram-positive bacterium (Staphylococcus aureus KCTC3881) and DCM fractions of 45 lichens showed antimicrobial activity against a Gram-negative bacterium (Klebsiella pneumoniae KCTC2242). DCM fractions of three lichens showed antifungal activity against the yeast, Candida albicans KCTC 7965. Likewise, methanol fractions of 39 lichens and DCM fractions of 74 lichens showed strong toxicity against brine shrimp nauplii with more than 80% mortality. Conclusion Such biological activity-rich lichen specimens warrant further research on exploration of natural products with antioxidant, antimicrobial and anti cancer (toxic) potential

Estimation of antioxidant, antimicrobial activity and brine shrimp toxicity of plants collected from Oymyakon region of the Republic of Sakha (Yakutia), Russia

BACKGROUND: Several plants are reported to be produced various biological active compounds. Lichens from the extreme environments such as high altitude, high UV, drought and cold are believed to be synthesized unique types of secondary metabolites than the other one. Several human pathogenic bacteria and fungi have been muted into drug resistant strains. Various synthetic antioxidant compounds have posed carcinogenic effects. This phenomenon needs further research for new effective drugs of natural origin. This manuscript aimed to screen new source of biological active compounds from plants of subarctic origin. RESULTS: A total of 114 plant species, including 80 species of higher plants, 19 species of lichens and 15 species of mosses, were collected from Oymyakon region of the Republic of Sakha (Yakutia), Russia (63˚20′N, 141˚42′E - 63˚15′N, 142˚27′E). Antimicrobial, DPPH free radical scavenging and brine shrimp (Artemia salina) toxicity of all crude extract were evaluated. The obtained result was analyzed and compared with commercial standards. A total of 28 species of higher plants showed very strong antioxidant activity (DPPH IC50, 0.45-5.0 µg/mL), 13 species showed strong activity (DPPH IC50, 5-10 µg/mL), 22 species showed moderate antioxidant activity (DPPH IC50,10-20 µg/mL) and 17 species showed weak antioxidant activity (DPPH IC50 more than 20 µg/mL). Similarly, 3 species of lichen showed strong antioxidant activity, one species showed moderate and 15 species showed weak DPPH reducing activity. In addition, 4 species of mosses showed moderate antioxidant activity and 11 species showed weak antioxidant activity. Similarly, extracts of 51 species of higher plants showed antimicrobial (AM) activity against Staphylococcus aureus and 2 species showed AM activity against Candida albicans. Similarly, 11 species of lichen showed AM activity against S. aureus and 3 species showed AM activity against Escherichia coli. One species of moss showed AM activity against S. aureus. And finally, one species of higher plant Rheum compactum and one species of lichen Flavocetraria cucullata showed the toxicity against Brine shrimp larvae in 100 µg/mL of concentration. CONCLUSION: The experimental results showed that subarctic plant species could be potential sources of various biologically active natural compounds

Antioxidant, Antibacterial activity and Brine shrimp toxicity test of some Mountainous Lichens from Nepal

A total of twenty four lichen species belonging to six families were collected from mountainous region of Nepal. The methanol extracts of each species were tested for antimicrobial and antioxidant activitiesin vitro. It was found that extracts of twenty one lichen species were active againstB. subtilis and seven species were active againstS. aureus. Similarly, in DPPH assay, three speciesPeltigera sp.,Cladonia sp., andCanoparmelia sp. showed comparable activity with commercial standard, BHA. In ABTS+ assay, extracts ofParmoterma sp.,Ramalina sp.,Peltigera sp. andCladonia sp. showed stronger activity than ascorbic acid. The observed data after comparison with previously published reports indicated that the high altitude lichens contain stronger antioxidant and antibacterial constituents. Similarly, the methanol extracts ofHeterodermia sp. andRamalina sp. showed comparable toxicity effect with commercial standard berberine chloride indicating a potent source of anticancer drugs