Prehospital Emergency Care in Low- and Middle-Income Countries: A Systematic Review.

BACKGROUND: An under-developed and fragmented prehospital Emergency Medical Services (EMS) system is a major obstacle to the timely care of emergency patients. Insufficient emphasis on prehospital emergency systems in low- and middle-income countries (LMICs) currently causes a substantial number of avoidable deaths from time-sensitive illnesses, highlighting a critical need for improved prehospital emergency care systems. Therefore, this systematic review aimed to assess the prehospital emergency care services across LMICs. METHODS: This systematic review used four electronic databases, namely: PubMed/MEDLINE, CINAHL, EMBASE, and SCOPUS, to search for published reports on prehospital emergency medical care in LMICs. Only peer-reviewed studies published in English language from January 1, 2010 through November 1, 2022 were included in the review. The Newcastle-Ottawa Scale (NOS) and Critical Appraisal Skills Programme (CASP) checklist were used to assess the methodological quality of the included studies. Further, the protocol of this systematic review has been registered on the International Prospective Register of Systematic Reviews (PROSPERO) database (Ref: CRD42022371936) and has been conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: Of the 4,909 identified studies, a total of 87 studies met the inclusion criteria and were therefore included in the review. Prehospital emergency care structure, transport care, prehospital times, health outcomes, quality of information exchange, and patient satisfaction were the most reported outcomes in the considered studies. CONCLUSIONS: The prehospital care system in LMICs is fragmented and uncoordinated, lacking trained medical personnel and first responders, inadequate basic materials, and substandard infrastructure.

Anatomical Variations, Surgical Difficulties, and Complications Associated with Cochlear Implantation in Different Age Groups of the Pediatric Population of Nepal: A Tertiary Level Hospital-Based Study.

Pediatric cases account for the major proportion of the population for whom cochlear implantation is indicated. This study aims to review the anatomical variations, surgical difficulties, and complications associated with cochlear implantation surgery in different age groups of the pediatric population of Nepal.This study was conducted at Tribhuvan University Teaching Hospital, Nepal. A prospectively set data of cases who underwent cochlear implantation between January 2015 and March 2020 were analyzed for details of surgical procedure, surgical difficulties, and intraoperative and postoperative complications. The anatomical variations encountered during surgery were classified as: developmental anomalies, round window niche variations and acquired abnormalities resulting from inflammation. Intraoperative surgical difficulties were defined based on the operating surgeon's perspective. Complications following cochlear implantation were classified as surgical and nonsurgical or device-related. We used SPSS version 25 for the analysis of our data. Chi-square test and Fisher's exact test were used to analyze the statistical association.The most commonly encountered difficulty was the requirement of an extended posterior tympanotomy approach due to poor visualization of round window niche. There was a statistically significant association of difficult insertion of electrodes with round window niche visibility. The common complications encountered were intraoperative facial nerve exposure, bleeding, electrode-related problems, cerebrospinal fluid gusher, and device failure.Cochlear implantation with an experienced surgeon in pediatric population is a relatively safe procedure. There is no association of the difficulties and complications related to surgery with the different age groups.

Bioprospecting the Metabolome of Plant Urtica dioica L.: A Fast Dereplication and Annotation Workflow in Plant Metabolomics.

Plants have a pivotal role in ethnopharmacology, and their preparations are in use globally. However, getting down to the structure requires an effective workflow and mostly requires a time-consuming isolation process. Although bioassay-guided approaches are widely popular, they face a massive problem of rediscovery in recent times, especially in plant metabolomics. Mass spectrometry (MS)-based approach incorporated molecular networking via Global Natural Product Social Molecular Networking (GNPS) is considered here for the benefit of the fast screening of secondary metabolites. This study uses direct crude extracts obtained from various parts of the Urtica dioica plant for the characterization of secondary metabolites. The crude extract of the plant initially displayed promising antioxidant and anti-diabetic activities. Then, we employed mass spectrometry-based dereplication to identify the phytochemical components in the extracts. This led to the discovery of 7 unknown and 17 known secondary metabolites, which were further verified with the SIRIUS 4 platform, a computational tool for the annotation of compounds using tandem MS data. On the other hand, chasing the antioxidant activity of methanolic extract of U. dioica leaves, we employed a bioassay-guided isolation approach. With this method, we isolated and characterized compound 13, a known molecule, which possessed strong antioxidant activity without showing much toxicity in the brine shrimp lethality test at the test concentration of 1 mg/mL. With our results, we advocate the MS-based approach as a good starting point for the dereplication of compounds from the complex crude extracts of plants.

Bioactive secondary metabolites in Paris polyphylla Sm. and their biological activities: A review.

Paris polyphylla Sm. is an important medicinal plant used to treat a variety of diseases through traditional medicine systems such as Ayurveda, Tibetan traditional medicines, Chinese traditional medicines, and others around the world. The IUCN red list has designated it as "vulnerable" due to a decline in wild population by over-exploitation, habitat degradation, illegal collection for trade and traditional use. This review paper aims to summarize the bioactive secondary metabolites in Paris polyphylla. Paris saponins or steroidal saponins are the main bioactive chemical constituents from this plant that account for more than 80% of the total compounds. For instance, polyphyllin D, diosgenin, paris saponins I, II, VI, VII, and H are steroidal saponins having anticancer activity comparable to synthetic anticancer medicines. Antioxidant, anticancer, anti-leishmaniasis, antibacterial, antifungal, anthelmintic, antityrosinase, and antiviral effects of extracts and pure compounds were also demonstrated in vivo and in vitro. In conclusion, this review summarizes the bioactive components from the P. polyphylla which will be useful to researchers and scientists, and for the development of potential drugs.

Role of Community Health Volunteers Since the 2015 Nepal Earthquakes: A Qualitative Study.

OBJECTIVE: Nepal female community health volunteers (FCHVs) were the first available health personnel in communities during the 2015 Nepal earthquakes. This study explored the facilitating factors and barriers of the FCHVs during health emergencies. METHODS: In-depth interviews with 24 FCHVs and 4 health managers from 2 districts in Nepal (Gorkha and Sindhupalchowk) were conducted using semi-structured interview guides. The qualitative data were analyzed using thematic analysis methods. RESULTS: FCHVs were the first responders to provide services after the earthquakes and were well accepted by the local communities. Different models of supervision existed, and differences in the workload and remuneration offered to FCHVs were described. A wide range of disaster-related knowledge and skills were required by FCHVs, and lack of prior training was an issue for some respondents. Furthermore, lack of access to adequate medical supplies was a major barrier for FCHVs in the 2015 earthquakes. The 5 identified themes were discussed. CONCLUSION: Providing regular disaster response training for FCHVs and strong leadership from the public sector with sustained investments will be essential for increasing the capacities of community health workforces to prepare for and reduce the impacts of future health emergencies in resource-poor settings.

Anxiety and depressive symptoms among home isolated patients with COVID-19: A cross-sectional study from Province One, Nepal.

Home isolated patients infected with COVID-19 might be at increased risk of developing mental health problems. The study aimed to identify the prevalence and factors associated with anxiety and depression among COVID-19 home isolated patients in Province One, Nepal. This was a cross-sectional study conducted between February 17, 2021, to April 9, 2021. A total of 372 home isolated patients from Province One were phone interviewed in the study. Anxiety and depression were measured using a 14-items Hospital Anxiety and Depression Scale (HADS). Multivariable logistic regression analysis was done to determine the risk factors of anxiety and depression. Among home isolated COVID-19 infected participants, 74.2% and 79% had symptoms of anxiety (borderline: 48.7% and abnormal: 25.5%) and depression (borderline: 52.7% and abnormal: 26.3%), respectively. Watching television was significantly associated with lower odds of experiencing symptoms of anxiety and depression. Females had significantly higher odds of having depression symptoms compared to males while ever married, those with COVID-19 related complications, and those taking medicine for the treatment of COVID-19 symptoms had a higher likelihood of exhibiting symptoms of anxiety. A focus on improving the mental health well-being of COVID-19 infected patients in home settings with connection to the health services is warranted with timely psychological interventions.

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 µg/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 µg/mL) than that of commercial butylated hydroxyanisole (BHA) (IC50, 4.8 ± 0.05 µg/mL). No toxicity was observed for maculosin (LD50, <128 µg/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 µg/mL. CONCLUSIONS: Maculosin may be a leading drug candidate in various cosmetic and therapeutic applications owing to its strong antioxidant and non-toxic properties.

Health Workforce Development in Health Emergency and Disaster Risk Management: The Need for Evidence-Based Recommendations.

The Sendai Framework for Disaster Risk Reduction 2015-2030 placed human health at the centre of disaster risk reduction, calling for the global community to enhance local and national health emergency and disaster risk management (Health EDRM). The Health EDRM Framework, published in 2019, describes the functions required for comprehensive disaster risk management across prevention, preparedness, readiness, response, and recovery to improve the resilience and health security of communities, countries, and health systems. Evidence-based Health EDRM workforce development is vital. However, there are still significant gaps in the evidence identifying common competencies for training and education programmes, and the clarification of strategies for workforce retention, motivation, deployment, and coordination. Initiated in June 2020, this project includes literature reviews, case studies, and an expert consensus (modified Delphi) study. Literature reviews in English, Japanese, and Chinese aim to identify research gaps and explore core competencies for Health EDRM workforce training. Thirteen Health EDRM related case studies from six WHO regions will illustrate best practices (and pitfalls) and inform the consensus study. Consensus will be sought from global experts in emergency and disaster medicine, nursing, public health and related disciplines. Recommendations for developing effective health workforce strategies for low- and middle-income countries and high-income countries will then be disseminated.

Risk Factors of Preterm Birth in Nepal: A Hospital-Based Matched Case-Control Study.

Background: Preterm birth is a significant cause of neonatal death globally. Nepal is in the 20th position in the world, with the highest rate of preterm deliveries. The risk factors of preterm birth have not been fully identified and established in Nepal. The study aims to identify risk factors of preterm birth among women who underwent delivery in a tertiary maternal hospital in Nepal. Methods: This study employed a hospital-based matched case-control study design. The case included women who delivered before 37 weeks of gestation, and women who delivered between 37 and 42 weeks of gestation served as controls. The ratio of the case to control was 1:2, and matching was done for the type of delivery. The first author collected the data in the Paropakar Maternity and Women's Hospital between December 2015 and January 2016. Face-to-face interviews were conducted using a structured questionnaire. Backward conditional logistic regression was performed to identify the independent risk factors of preterm birth. Results: Antihelminthic treatment during pregnancy was found to be protective for preterm birth. Women performing intensive physical work during their pregnancy and women exposed to indoor air pollution were more likely to have a preterm birth than women not performing intensive physical work and women not exposed to indoor pollution, respectively. Conclusions: Women who had not consumed antihelminthic drugs per protocol, those exposed to indoor air pollution, and those who performed intensive work during pregnancy were at higher risk for preterm birth. Maternal health programs can encourage women to consume antihelminthic drugs, take proper rest during pregnancy, and prevent indoor pollution exposure.

Factors associated with child health service delivery by female community health volunteers in Nepal: findings from a national survey.

BACKGROUND: Nepal has made a significant improvement in child survival in the last few decades and the involvement of female community health volunteers (FCHVs) has been crucial in such achievement. While there have been many studies on child health in Nepal however, rarely explored the status and factors associated with the child health service provided by these volunteers. This study aimed to identify the factors associated with the child health service delivery by FCHVs. METHODS: A national survey was conducted in 2014 in Nepal that included 4302 FCHVs using the structured questionnaire across the 13 geopolitical domains of the country. Factors associated with the use of child health services was examined using Chi-square test (χ2) followed by logistic regression. RESULTS: Overall, 62.6% of FCHVs provided at least one child health service. Those FCHVs who utilized money from the FCHV fund, conducted health mothers' group meeting, involved in local committees and those who supported antenatal care and outreach clinics related activities had higher odds of providing child health services. Similarly, FCHVs equipped with the stock of Cotrimoxazole tablet, Zinc tablet, Oral Rehydration Salt packets were more likely to provide child health services. The province-wise analysis showed that FCHVs from Province 5 and Sudur Paschim Province were more likely to provide child health services compared to their counterparts from province 1. Technology-wise, FCHVs who were using mobile were more likely to provide child health services. CONCLUSIONS: FCHVs are important human resource in providing child health services in Nepal. To improve child health service delivery by FCHVs; availability of key commodities, involvement of FCHVs in regular health mothers' group meeting, use of mobile phone, involvement in other public health programs and social networks, and utilization of the FCHV fund need to be taken into consideration.

Antimicrobial and antioxidant activities of two polyketides from lichen-endophytic fungus Preussia sp.

Two compounds, compounds 1 and 2, were isolated from Preussia sp. The molecular structures of both compounds were elucidated by analyzing one-dimensional (1D) and 2D nuclear magnetic resonance data along with high-resolution mass spectrometry data. Compound 1 was obtained as novel in structure, and compound 2 was recently reported elsewhere. Compound 1 did not show antioxidant and antimicrobial activities and brine shrimp toxicity, while compound 2 showed strong antioxidant activity (DPPH reduction capacity; IC50=3 µg/mL) and brine shrimp toxicity (LD50=50 µg/mL).

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

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.

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 activities in vitro. It was found that extracts of twenty one lichen species were active against B. subtilis and seven species were active against S. aureus. Similarly, in DPPH assay, three species Peltigera sp.,Cladonia sp., and Canoparmelia sp. showed comparable activity with commercial standard, BHA. In ABTS+ assay, extracts of Parmoterma sp., Ramalina sp., Peltigera sp. and Cladonia 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 of Heterodermia sp. and Ramalina sp. showed comparable toxicity effect with commercial standard berberine chloride indicating a potent source of anticancer drugs.

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.

Ramalin, a novel nontoxic antioxidant compound from the Antarctic lichen Ramalina terebrata.

Ramalin (γ-glutamyl-N'-(2-hydroxyphenyl)hydrazide), a novel compound, was isolated from the methanol-water extract of the Antarctic lichen Ramalina terebrata by several chromatographic methods. The molecular structure of ramalin was determined by spectroscopic analysis. The experimental data showed that ramalin was five times more potent than commercial butylated hydroxyanisole (BHA) in scavenging 1-diphenyl-2-picryl-hydazil (DPPH) free radicals, 27 times more potent in scavenging 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid free radicals (ABTS(+)) than the vitamin E analogue, trolox, and 2.5 times more potent than BHT in reducing Fe(3+) to Fe(2+) ions. Similarly, ramalin was 1.2 times more potent than ascorbic acid in scavenging superoxide radicals and 1.25 times more potent than commercial kojic acid in inhibiting tyrosinase enzyme activity, which ultimately leads to whitening of skin cells. Ramalin showed no or very little cytotoxicity in human keratinocyte and fibroblast cells at its antioxidant concentration. Furthermore, ramalin was assessed to determine its antioxidant activity in vivo. One microgram per milliliter ramalin significantly reduced the released nitric oxide (NO) and 0.125 µg/ml ramalin reduced the produced hydrogen peroxide (H(2)O(2)) in LPS (lipopolysaccharide)-stimulated murine macrophage Raw264.7 cells. Considering all the data together, ramalin can be a strong therapeutic candidate for controlling oxidative stress in cells.

Antibacterial activities of Ramalin, usnic acid and its three derivatives isolated from the Antarctic lichen Ramalina terebrata.

The development of new antibacterial compounds is an urgent issue to meet the evolution of resistivity of pathogenic bacteria against the available drugs. The objective of this study was to investigate the antibacterial compounds from the Antarctic lichen species Ramalina terebrata. A total of five compounds, usnic acid, usimine A, usimine B, usimine C, and ramalin, were isolated by bioactivity guided-fractionation of the methanol extract of R. terebrata after several chromatographic procedures. The qualitative antibacterial activities of the crude extract and isolated compounds were determined by the disk diffusion method while the minimum inhibitory concentration (MIC) determination assay gave the quantitative strength of the test samples. All the test samples showed antibacterial activity against Bacillus subtilis. The crude extract and usnic acid showed antibacterial activity against Staphylococcus aureus. The MIC values of the isolated compounds against B. subtilis were in the range of 1 to 26 microg/mL. These observed experimental data showed the strong antibacterial potential of these compounds against B. subtilis.

In vitro antioxidant capacities of two benzonaphthoxanthenones: ohioensins F and G, isolated from the Antarctic moss Polytrichastrum alpinum.

Antioxidant agents against reactive oxygen species can be used for several cosmetic and medicinal applications. This study's objective was to evaluate the antioxidant activities of Polytrichastrum alpinum (Hedw.) G. L. Sm. (Polytrichaceae), an Antarctic moss species collected from King George Island (Antarctica). The identification of the moss species was performed on the basis of morphological characteristics and molecular sequencing of the 18S rRNA gene. Two benzonaphthoxanthenones: ohioensins F and G, were isolated from the extract after several chromatographic procedures. The various in vitro antioxidant capacities of a methanolic extract of P. alpinum and the isolated compounds were evaluated by analyzing the scavenging capacities of free radicals of 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), the total phenol assay with Folin-Ciocalteu reagent, the ferric ion (Fe3+) reducing power and the nitric oxide (NO) scavenging activity and compared to those of commercial standards for each assay. The experimental data showed that even the crude extract of P. alpinum exhibited potent antioxidant activity. The antioxidant activity was increased two- to seven-fold for the purified compounds. The antioxidant activities of both purified compounds were found to be more or less the same in all experiments. However, the obtained data showed that the Fe3+ reducing power of the purified compounds and crude methanolic extract was almost the same suggesting the presence of other stronger reducing agents in the methanolic extract which could not be isolated in the present experiment. Therefore, further work on the isolation of these stronger antioxidant agents from this moss specimen of the extreme environment is warranted. Developments of laboratory mass culture techniques are anticipated to achieve bulk production of the active constituents for commercial application.