Bioactivities of extracts, debromolaurinterol and fucosterol from macroalgae species

Parasitic diseases including malaria, and other numerous microbial infections and physiological diseases are threatening the global population. Tanzanian coast shores are endowed with a variety of macroalgae (seaweeds), hitherto unsystematically explored to establish their biomedical potentials. Thus, antiplasmodial activity using malarial imaging assay, antimicrobial activity using microplate dilution technique, antioxidant activity using DPPH radical scavenging method and cytotoxicity using brine shrimp test were carried out on crude extracts from the selected species of algae (Acanthophora spicifera, Cystoseira myrica, Cystoseira trinodis, Laurencia filiformis, Padina boryana, Sargassum oligocystum, Turbinaria crateriformis, Ulva fasciata and Ulva reticulata) occurring along the coast of Tanzania. The extracts showed antimicrobial activities with MIC ranging from 0.3- 5.0 µg/mL against Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Cryptococcus neoformans; DPPH radical scavenging activity at EC50 1.0- 100 µg/mL and cytotoxicity on brine shrimp larvae with LC50 value ranging from20 - 1000 µg/mL. The extracts from C. myrica and P. boryana inhibited growth of Plasmodium falciparum (3D7 strain) by 80 and 71%, respectively at 40 µg/mL while a sesquiterpene debromolaurinterol (1) which was chromatographically isolated from C. myrica exhibited antiplasmodial activity with IC50 20 µM whereas a sterol fucosterol (2) from P. boryana showed weak activity at 40 µM. Bioactivities portrayed by the investigated extracts indicate their ingredients as potential sources of bioactive agents that warrant further explorations.Keywords:     Macrolgae, antiplasmodial, antimicrobial, antioxidant, cytotoxicity, DPPH radical scavenging, debromolaurinterol and fucosterol

Post-harvest Practices Associated with Aflatoxins Contamination of Complementary Flours in Bahi District, Dodoma,Tanzania

Aflatoxins are secondary metabolites produced by several species of Aspergillus fungi, which occur in food crops due to exposure of pre-harvest and post-harvest conditions. Complementary foods are considered an important source of energy, protein and fat for children aged between 6-24 months. The study was carried out to explore the association between post-harvest handling practices and aflatoxins contamination in maize-based complementary foods. Complementary flour samples were collected from randomly selected household and analyzed by using HPLC. The presence and concentration of aflatoxins B1, B2, G1, G2 and total AFs was detected. About 48.95% of all samples were found to be contaminated with aflatoxins.A stepwise linear regression in generalized linear model was used to identify factors that significantly affected contamination of complementary food with aflatoxins. The analyzed sample was found to be less contaminated with aflatoxins B1 across all six villages with range of 0.24-1.39 µg/kg, with mean value of 0.67µg/kg     and total mean aflatoxins were found to be 4.79µg/kg. Results indicated that some of the post-harvest handling practices used by parents/caregivers to agricultural produce used to prepare complimentary food are highly associated with aflatoxins contamination (p<0.05). The occurrence of total aflatoxin levels in complimentary flour composite across the six villages was significantly associated with insect infestation, maize/cereals stored for more than 12 months, drying on bare ground, uses of pesticides to protect stored maize/cereals (p<0.05). Estimate from the linear regression model indicated that, insect infestation (0.3870), and drying on bare ground (0.0856) were positively associated with aflatoxins contamination. This study recommends education and awareness campaign are needed to inform farmers, traders, processors about the risk of fungal growth and toxins contamination

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa.

The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Chemical profiling of Cannabis sativa from eleven Tanzanian regions

The aim of this research was to investigate the chemical profiles of Cannabis sativa from 11 Tanzanian regions using preliminary tests as well as instrumental analyses with GC-MS and LC-MS. Generally, all the seized samples tested positive for the presence of (Δ9-THC. The preliminary test with Duquenois method followed by chloroform addition revealed the presence of Δ9-tetrahydrocannabinol (Δ9-THC) in all the samples. GC-MS analyses of the samples revealed the presence of nine cannabinoids including Δ9-THC, Δ8-THC, cannabidivarol, cannabidiol, Δ9-tetrahydrocannabivarin (Δ9-THCV), cannabichromene, cannabinol, caryophyllene, and cannabicouramaronone, whereas LC-MS chemical profiling revealed the presence 24 chemical substances, including 4 cannabinoids, 15 different types of drugs and 5 amino acids. The Pwani region had the highest percentage composition of Δ9-THC (13.45%), the main psychoactive ingredient of Cannabis sativa, followed by Arusha (10.92%) and Singida (10.08%). The sample from Kilimanjaro had the lowest percentage of Δ9-THC (6.72%). Apart from cannabinoids, the majority of other chemical substances were found in the Dar es Salaam region sample, which could be attributed to the fact that the city is the epicenter of business rather than the cultivation area, implying that the samples were obtained from different sources and blended as a single package

Therapeutic potential of Equisetum arvense L. for management of medical conditions

Background: Equisetum arvense L. has a long history of use in traditional medicines for treating ailments like digestive, inflammatory, respiratory and urinary disorders. Researchers have been focused on developing drugs from natural sources particularly the medicinal plants for global mitigation of medical conditions while protecting the environment. The use of natural products is one of the strategies that the WHO recommended to manage global medical conditions. The interest to use natural remedies as alternative medicines for management of medical conditions is increasing considerably. Purpose: This review intended to discuss the therapeutic potential of E. arvense for the mitigation of various diseases by providing up-to-date information on its benefits, challenges and potential future opportunities. Methods: The information is collected and systematically analysed from various online databases including Google scholar, ScienceDirect, Springer, Web of Science, PubMed and Plant of the World Online. Results: This study demonstrated the enormous therapeutic potential of E. arvense for the management of various ailments. The significant changes in the phytoconstituents amongst the plant parts have been observed, which correspond to the variation in its pharmacological properties. Several pharmacological activities of E. arvense such as anticancer, anti-inflammatory, antibacterial, antifungal and antidiabetics support its traditional uses. Conclusion: E. arvense has a lot of therapeutic promises for treating a number of health disorders. The extension of its clinical study requires further identification of the bioactive compounds, their modes of action as well as toxicological study. The existing therapeutic potential of E. arvense, suggesting that it is a suitable medicinal plant for management of medical conditions

Ethnomedicinal uses, phytochemistry and pharmacological study of Ocimum americanum L.: A review

Background: Ocimum americanum L., commonly known as Hoary basil, is a wild aromatic shrub traditionally used to treat different ailments. Its leaves, flowers and aerial parts have been widely studied to evaluate its medicinal potential such as lowering blood pressure, treatment of microbial infections, malaria, cold, liver and eye problems. Purpose: This study aims to provide an in-depth review of ethnomedicinal uses, phytochemistry, and pharmacological activities of O. americanum, to evaluate its benefits, challenges and potential future prospects. Methods: All the information about O. americanum was collected from various platforms, including google scholar, PubMed, ScienceDirect, plants of the world online and Research4Life. The acceptance criteria of the collected information based on the PICOS model. The GRADE approach was used to analyze and evaluate the quality of the collected information. Results: This study showed that O. americanum has tremendous therapeutic potential to be integrated into mainstream medical practice to manage various medical conditions. The inconsistence of the phytoconstituents among the plant parts resulted in a significant variation of pharmacological activities. Plant originality, genetic variability and extraction techniques are among the factors contributing to the variation of phytoconstituents that are responsible for pharmacological activities. Conclusion: This study revealed that O. americanum is a potential medicinal plant for mitigating various medical conditions. However, future study should continue to focus on the bioactive compounds and their mechanisms of action. Additionally, the utilization of the O. americanum for the development of drugs as well as quality evaluation in clinical settings are highly recommended