Risk of spread of the Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) in Ghana.

The impact of invasive species on biodiversity, food security and economy is increasingly noticeable in various regions of the globe as a consequence of climate change. Yet, there is limited research on how climate change affects the distribution of the invasive Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera:Liviidae) in Ghana. Using maxnet package to fit the Maxent model in R software, we answered the following questions; (i) what are the main drivers for D. citri distribution, (ii) what are the D. citri-specific habitat requirements and (iii) how well do the risk maps fit with what we know to be correctly based on the available evidence?. We found that temperature seasonality (Bio04), mean temperature of warmest quarter (Bio10), precipitation of driest quarter (Bio17), moderate resolution imaging spectroradiometer land cover and precipitation seasonality (Bio15), were the most important drivers of D. citri distribution. The results follow the known distribution records of the pest with potential expansion of habitat suitability in the future. Because many invasive species, including D. citri, can adapt to the changing climates, our findings can serve as a guide for surveillance, tracking and prevention of D. citri spread in Ghana.

Chemical Derivatization and Characterization of Novel Antitrypanosomals for African Trypanosomiasis.

The search for novel antitrypanosomals and the investigation into their mode of action remain crucial due to the toxicity and resistance of commercially available antitrypanosomal drugs. In this study, two novel antitrypanosomals, tortodofuordioxamide (compound 2) and tortodofuorpyramide (compound 3), were chemically derived from the natural N-alkylamide tortozanthoxylamide (compound 1) through structural modification. The chemical structures of these compounds were confirmed through spectrometric and spectroscopic analysis, and their in vitro efficacy and possible mechanisms of action were, subsequently, investigated in Trypanosoma brucei (T. brucei), one of the causative species of African trypanosomiasis (AT). The novel compounds 2 and 3 displayed significant antitrypanosomal potencies in terms of half-maximal effective concentrations (EC50) and selectivity indices (SI) (compound 1, EC50 = 7.3 µM, SI = 29.5; compound 2, EC50 = 3.2 µM, SI = 91.3; compound 3, EC50 = 4.5 µM, SI = 69.9). Microscopic analysis indicated that at the EC50 values, the compounds resulted in the coiling and clumping of parasite subpopulations without significantly affecting the normal ratio of nuclei to kinetoplasts. In contrast to the animal antitrypanosomal drug diminazene, compounds 1, 2 and 3 exhibited antioxidant absorbance properties comparable to the standard antioxidant Trolox (Trolox, 0.11 A; diminazene, 0.50 A; compound 1, 0.10 A; compound 2, 0.09 A; compound 3, 0.11 A). The analysis of growth kinetics suggested that the compounds exhibited a relatively gradual but consistent growth inhibition of T. brucei at different concentrations. The results suggest that further pharmacological optimization of compounds 2 and 3 may facilitate their development into novel AT chemotherapy.

The role of tryptophan derivatives as anti-kinetoplastid agents.

Kinetoplastids are the causative agents for a spectrum of vector-borne diseases including Leishmaniasis, Chagas disease and Trypanosomiasis that affect millions of people worldwide. In the absence of safe and effective vaccines, chemotherapy, in conjunction with vector control, remain the most significant control approach for kinetoplastid diseases. However, commercially available treatment for these neglected tropical diseases frequently ends up with toxic side effects and increasing resistance. To meet the rising need for innovative medications, alternative chemotherapeutic agents are required. Moreover, insights into target-based mode of action of chemotherapeutic agents are required if novel drugs that may outwit resistance to commercially available drugs are to be developed. Tryptophan has been implicated in a variety of diseases and disorders due to its fundamental role as a precursor to several bioactive metabolites, as well as its importance in the improvement of health and nutrition, diagnostics, and therapeutics. The regulation of tryptophan metabolism plays a fundamental role in the growth of kinetoplastids. Moreover, the levels of tryptophan may serve as a biomarker to distinguish between the stages of kinetoplastids making it an important amino acid to explore for drug targets. The main aim of this review is thus to provide a comprehensive literature synthesis of tryptophan derivatives to explore as potential anti-kinetoplastids. Here we highlight the role of tryptophan derivatives as chemotherapeutic agents against kinetoplastids. The reviewed compounds provide insights into potential new drug interventions that may combat the increasing problem of anti-kinetoplastid resistance.

Insects as food and medicine: a sustainable solution for global health and environmental challenges.

Insects are a significant source of food for millions of people worldwide. Since ancient times, insects in medicine have been contributing to the treatment of diseases in humans and animals. Compared to conventional animal farming, the production of insects for food and feed generates significantly less greenhouse gas emissions and uses considerably less land. Edible insects provide many ecosystem services, including pollination, environmental health monitoring, and the decomposition of organic waste materials. Some wild edible insects are pests of cash crops. Thus, harvesting and consuming edible insect pests as food and utilizing them for therapeutic purposes could be a significant progress in the biological control of insect pests. Our review discusses the contribution of edible insects to food and nutritional security. It highlights therapeutic uses of insects and recommends ways to ensure a sustainable insect diet. We stress that the design and implementation of guidelines for producing, harvesting, processing, and consuming edible insects must be prioritized to ensure safe and sustainable use.

Remediation of pesticide residues using ozone: A comprehensive overview.

Pesticide residues historically represent a severe threat to public health and the environment. Several species worldwide are still in danger from pesticide residues, despite efforts to mitigate the adverse health effects of these pollutants. As agricultural output has increased and scientific understanding has advanced, new methods have emerged for degrading pesticide traces. The remarkable effectiveness of ozone as a broad-spectrum disinfectant and its potential to destroy pesticide residues have led to its widespread use as a residue-free method for improving soil quality, disinfecting food, and treating water, among other benefits. Ozone is cheap to manufacture, making it an affordable option for treating harmful pesticide residues. Its capacity to degrade pesticides without negatively impacting the environment has increased its adoption as a tool for cleaning up after pesticide use. This review extensively provides an overview of ozonation for pesticide residues removal in different settings and applications. Ozone treatment of pesticide residues in the soil, water and food is effective in removing pesticides residues. We highlight recent advances in methods of removing pesticide residues. We discuss several challenges related to the ozone treatment of pesticide residues. Whether used alone or in conjunction with other processes, ozone is highly effective at removing pesticide residues from the environment. Therefore, we recommend this holistic and environmentally friendly strategy to reduce pesticide residues.

Buruli ulcer in Africa: Geographical distribution, ecology, risk factors, diagnosis, and indigenous plant treatment options - A comprehensive review.

Buruli ulcer (BU), a neglected tropical disease (NTD), is an infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. The disease has been documented in many South American, Asian, and Western Pacific countries and is widespread throughout much of Africa, especially in West and Central Africa. In rural areas with scarce medical care, BU is a devastating disease that can leave patients permanently disabled and socially stigmatized. Mycobacterium ulcerans is thought to produce a mycolactone toxin, which results in necrosis of the afflicted tissue and may be involved in the etiology of BU. Initially, patients may notice a painless nodule or plaque on their skin; as the disease progresses, however, it may spread to other parts of the body, including the muscles and bones. Clinical signs, microbial culture, and histological analysis of afflicted tissue all contribute to a diagnosis of BU. Though antibiotic treatment and surgical removal of infected tissue are necessary for BU management, plant-derived medicine could be an alternative in areas with limited access to conventional medicine. Herein we reviewed the geographical distribution, socioeconomic, risk factors, diagnosis, biology and ecology of the pathogen. Complex environmental, socioeconomic, and genetic factors that influence BU are discussed. Further, our review highlights future research areas needed to develop strategies to manage the disease through the use of indigenous African plants.

Evaluation of phytochemical, proximate, antioxidant, and anti-nutrient properties of Corchorus olitorius, Solanum macrocarpon and Amaranthus cruentus in Ghana.

INTRODUCTION: In Ghana, Corchorus olitorius, Solanum macrocarpon and Amaranthus cruentus are green leafy vegetables that are customarily eaten together with a starchy staple food. The present study aimed at assessing the ethanolic leaf extract of C. olitorius, S. macrocarpon and A. cruentus for antioxidant capacity, phytochemical property, nutritional and anti-nutrient content. METHOD: Phytochemical constituent and proximate analysis were determined using standard protocols. The DPPH scavenging activity was used to determine the antioxidant activity of the ethanolic leaf extracts from the three vegetables. The antinutrients phytate and oxalate were determined by titrimetric methods of analysis. RESULTS: Pytochemical screening revealed the presence of tannins and flavonoids in C. olitorius, S. macrocarpon and A. cruentus. Alkaloids and saponins were present in C. olitorius and S. macrocarpon but not in A. cruentus. Terpenoids, steroids, carotenoids and coumarins were absent in all the three vegetables. Proximate analysis revealed varying levels of moisture, fat, protein, ash, crude fibre and carbohydrates in the three leafy vegetables. The DPPH scavenging showed 86.71%, 71.72% and 38.86% activity for S. macrocarpon, C. olitorius and A. cruentus respectively. The antinutrient results revealed an oxalate level of 2.7 ± 0.13% for C. olitorius, 6.43 ± 0.06% for A. cruentus and 12.32 ± 0.13% for S. macrocarpon. For levels of phytates, our results revealed a 3.084 ± 0.54%, 1.14 ± 0.26% and 1.71 ± 0.27% for C. olitorius, A. cruentus and S. macrocarpon, respectively. CONCLUSION: The current study has shown that C. olitorius, A. cruentus and S. macrocarpon possess important phytochemicals, nutrients and significant antioxidant activity, suggesting a potential of these vegetables against diverse disease, if eaten by humans.

The Global Impact of COVID-19: Historical Development, Molecular Characterization, Drug Discovery and Future Directions.

In December 2019, an outbreak of a respiratory disease called the coronavirus disease 2019 (COVID-19) caused by a new coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began in Wuhan, China. The SARS-CoV-2, an encapsulated positive-stranded RNA virus, spread worldwide with disastrous consequences for people's health, economies, and quality of life. The disease has had far-reaching impacts on society, including economic disruption, school closures, and increased stress and anxiety. It has also highlighted disparities in healthcare access and outcomes, with marginalized communities disproportionately affected by the SARS-CoV-2. The symptoms of COVID-19 range from mild to severe. There is presently no effective cure. Nevertheless, significant progress has been made in developing COVID-19 vaccine for different therapeutic targets. For instance, scientists developed multifold vaccine candidates shortly after the COVID-19 outbreak after Pfizer and AstraZeneca discovered the initial COVID-19 vaccines. These vaccines reduce disease spread, severity, and mortality. The addition of rapid diagnostics to microscopy for COVID-19 diagnosis has proven crucial. Our review provides a thorough overview of the historical development of COVID-19 and molecular and biochemical characterization of the SARS-CoV-2. We highlight the potential contributions from insect and plant sources as anti-SARS-CoV-2 and present directions for future research.

Mango anthracnose disease: the current situation and direction for future research.

Mango anthracnose disease (MAD) is a destructive disease of mangoes, with estimated yield losses of up to 100% in unmanaged plantations. Several strains that constitute Colletotrichum complexes are implicated in MAD worldwide. All mangoes grown for commercial purposes are susceptible, and a resistant cultivar for all strains is not presently available on the market. The infection can widely spread before being detected since the disease is invincible until after a protracted latent period. The detection of multiple strains of the pathogen in Mexico, Brazil, and China has prompted a significant increase in research on the disease. Synthetic pesticide application is the primary management technique used to manage the disease. However, newly observed declines in anthracnose susceptibility to many fungicides highlight the need for more environmentally friendly approaches. Recent progress in understanding the host range, molecular and phenotypic characterization, and susceptibility of the disease in several mango cultivars is discussed in this review. It provides updates on the mode of transmission, infection biology and contemporary management strategies. We suggest an integrated and ecologically sound approach to managing MAD.

Antiplasmodial, Antitrypanosomal, and Cytotoxic Effects of Anthonotha macrophylla, Annickia polycarpa, Tieghemella heckelii, and Antrocaryon micraster Extracts.

Malaria and trypanosomiasis are protozoan diseases which pose a devastating challenge to human health and productivity especially, in Africa where their respective vectors (female Anopheles mosquito and tsetse fly) abound. Various medicinal plants are used to treat these parasitic diseases. However, the scientific basis of their use and toxicological profiles have not been assessed. We have, therefore, evaluated the antiplasmodial, antitrypanosomal, and cytotoxic activities of four African medicinal plant extracts namely, Anthonotha macrophylla leaf (AML), Annickia polycarpa leaf (APLE), Tieghemella heckelii stem bark (THBE), and Antrocaryon micraster stem bark (AMSBE) extracts in vitro against P. falciparum (W2mef laboratory strain), T. brucei (GUTat 3.1 strain), and mammalian RAW 264.7 macrophage cell line, respectively. The most active antiplasmodial extract was AML (IC50 = 5.0 ± 0.08 µg/mL with SI of 21.9). THBE also, produced the most effective antitrypanosomal activity (IC50 = 11.0 ± 0.09 µg/mL and SI of 10.2) among the extracts. In addition, none of the extracts produced toxic effect in the RAW 264.7 macrophage cell line except APLE which was moderately cytotoxic and also produced the least SI in both antitrypanosomal and antiplasmodial assays. These results suggest that AML and THBE could offer safe and alternative therapy for malaria and trypanosomiasis. This is the first study to report the antitrypanosomal and in vitro antiplasmodial activities of these four plants/plant parts. The cytotoxicity of the plant parts used is also being reported for the first time except for the T. heckelii stem bark.

In Vitro Mechanism of Action of Acanthospermum hispidum in Trypanosoma brucei.

African trypanosomiasis is a major neglected tropical disease with significant health and economic concerns in sub-Saharan Africa. In the absence of vaccines for African trypanosomiasis, there is a consideration for alternative sources of chemotherapy. Acanthospermum hispidum DC (A. hispidum) is a herbal species of the Asteraceae family that is endowed with rich phytochemicals with unknown mechanisms of antitrypanosomal effects. This study aimed to investigate the cellular mechanisms of antitrypanosomal and antioxidant activities of A. hispidum against Trypanosoma brucei (T. brucei), a causative protozoan species of African trypanosomiasis. Fractions were prepared from the whole plant of A. hispidum through solvent partitioning by employing solvents of varying polarities (hexane, HEX; dichloromethane, DCM; ethyl acetate, EA; aqueous, AQ). The in vitro efficacies and mechanisms of antitrypanosomal activities of A. hispidum were investigated using a panel of cell biological approaches. GC-MS analysis was used to identify the major compounds with a possible contribution to the trypanocidal effects of A. hispidum. A. hispidum fractions displayed significant antitrypanosomal activities in terms of half-maximal effective concentrations (EC50) and selectivity indices (SI) (AH-HEX, EC50 = 2.4 µg/mL, SI = 35.1; AH-DCM, EC50 = 2.2 µg/mL, SI = 38.3; AH-EA, EC50 = 1.0 µg/mL, SI = 92.8; AH-AQ, EC50 = 2.0 µg/mL, SI = 43.8). Fluorescence microscopic analysis showed that at their EC50 values, the fractions of A. hispidum altered the cell morphology as well as the organization of the mitochondria, nucleus, and kinetoplast in T. brucei. At their maximum tested concentrations, the prepared fractions exhibited antioxidant absorbance intensities comparable to the reference antioxidant, Trolox, in contrast to the oxidant intensity of an animal antitrypanosomal drug, diminazene (Trolox, 0.11 A; diminazene, 0.65 A; AH-HEX, 0.20 A, AH-DCM, 0.20 A, AH-EA, 0.13 A, AH-AQ, 0.22 A). GC-MS analysis of the various fractions identified major compounds assignable to the group of alkaloids and esters or amides of aliphatic acids. The results provide useful pharmacological insights into the chemotherapeutic potential of A. hispidum toward drug discovery for African trypanosomiasis.

In vitro effects and mechanisms of action of Bidens pilosa in Trypanosoma brucei.

Background and aim: African trypanosomiasis poses serious health and economic concerns to humans and livestock in several sub-Saharan African countries. The aim of the present study was to identify the antitrypanosomal compounds from B. pilosa (whole plant) through a bioactivity-guided isolation and investigate the in vitro effects and mechanisms of action against Trypanosoma brucei (T. brucei). Experimental procedure: Crude extracts and fractions were prepared from air-dried pulverized plant material of B. pilosa using the modified Kupchan method of solvent partitioning. The antitrypanosomal activities of the fractions were determined through cell viability analysis. Effects of fractions on cell death and cell cycle of T. brucei were determined using flow cytometry, while fluorescence microscopy was used to investigate alterations in cell morphology and distribution. Results and conclusion: The solvent partitioning dichloromethane (BPFD) and methanol (BPFM) fractions of B. pilosa exhibited significant activities against T. brucei with respective half-maximal inhibitory concentrations (IC50s) of 3.29 µg/ml and 5.86 µg/ml and resulted in the formation of clumpy subpopulation of T. brucei cells. Butyl (compound 1) and propyl (compound 2) esters of tryptophan were identified as the major antitrypanosomal compounds of B. pilosa. Compounds 1 and 2 exhibited significant antitrypanosomal effects with respective IC50 values of 0.66 and 1.46 µg/ml. At the IC50 values, both compounds significantly inhibited the cell cycle of T. brucei at the G0-G1 phase while causing an increase in G2-M phase. The results suggest that tryptophan esters may possess useful chemotherapeutic properties for the control of African trypanosomiasis.

Isolation and Antitrypanosomal Characterization of Furoquinoline and Oxylipin from Zanthoxylum zanthoxyloides.

In the absence of vaccines, there is a need for alternative sources of effective chemotherapy for African trypanosomiasis (AT). The increasing rate of resistance and toxicity of commercially available antitrypanosomal drugs also necessitates an investigation into the mode of action of new antitrypanosomals for AT. In this study, furoquinoline 4, 7, 8-trimethoxyfuro (2, 3-b) quinoline (compound 1) and oxylipin 9-oxo-10, 12-octadecadienoic acid (compound 2) were isolated from the plant species Zanthoxylum zanthoxyloides (Lam) Zepern and Timler (root), and their in vitro efficacy and mechanisms of action investigated in Trypanosomabrucei (T. brucei), the species responsible for AT. Both compounds resulted in a selectively significant growth inhibition of T. brucei (compound 1, half-maximal effective concentration EC50 = 1.7 µM, selectivity indices SI = 74.9; compound 2, EC50 = 1.2 µM, SI = 107.3). With regards to effect on the cell cycle phases of T. brucei, only compound 1 significantly arrested the second growth-mitotic (G2-M) phase progression even though G2-M and DNA replication (S) phase arrest resulted in the overall reduction of T. brucei cells in G0-G1 for both compounds. Moreover, both compounds resulted in the aggregation and distortion of the elongated slender morphology of T. brucei. Analysis of antioxidant potential revealed that at their minimum and maximum concentrations, the compounds exhibited significant oxidative activities in T. brucei (compound 1, 22.7 µM Trolox equivalent (TE), 221.2 µM TE; compound 2, 15.0 µM TE, 297.7 µM TE). Analysis of growth kinetics also showed that compound 1 exhibited a relatively consistent growth inhibition of T. brucei at different concentrations as compared to compound 2. The results suggest that compounds 1 and 2 are promising antitrypanosomals with the potential for further development into novel AT chemotherapy.

Antitrypanosomal Effects of Zanthoxylum zanthoxyloides (Lam.) Zepern. & Timler Extracts on African Trypanosomes.

African trypanosomiasis is a disease caused by the parasitic protozoa of the Trypanosoma genus. Despite several efforts at chemotherapeutic interventions, the disease poses serious health and economic concerns to humans and livestock of many sub-Saharan African countries. Zanthoxylum zanthoxyloides (Lam.) Zepern. & Timler (Z. zanthoxyloides LZT) is a plant species of important phytochemical and pharmacological relevance in the subtropical zones of the African continent. However, the mechanisms of its antitrypanosomal effects in African trypanosomes remain to be elucidated. The aim of the study was to determine the in vitro effects and mechanisms of action of Z. zanthoxyloides LZT (root) fractions against Trypanosoma brucei. T. brucei (GUTat 3.1 strain), L. donovani (D10 strain), P. falciparum (3D 7 strain), Jurkat cells, and Chang liver cells were cultivated in vitro to the log phase in their respective media at 37°C. Crude extracts and fractions were prepared from air-dried pulverized plant material of Z. zanthoxyloides LZT (root) using the modified Kupchan method of solvent partitioning. Half-maximal inhibitory concentrations (IC50) were determined through the alamar blue cell viability assay. Effects of fractions on cell death and cell cycle of T. brucei were determined using flow cytometry. Fluorescence microscopy was used to investigate the effects of fractions on the morphology and distribution of T. brucei. Antitrypanosomal compounds of fractions were characterized using high-performance liquid chromatography (HPLC) and attenuated total reflectance infrared (ATR-IR) spectroscopy. Methanol, butanol, and dichloromethane fractions were selectively active against T. brucei with respective IC50 values of 3.89, 4.02, and 5.70 µg/ml. Moreover, methanol, butanol, and dichloromethane fractions significantly induced apoptosis-like cell death with remarkable alteration in the cell cycle of T. brucei. Furthermore, dichloromethane and methanol fractions altered the morphology, induced aggregation, and altered the ratio of nuclei to kinetoplasts in the parasite. The HPLC chromatograms and ATR-IR spectra of the active fractions suggested the presence of aromatic hydrocarbons with hydroxyl, carbonyl, amine, or amide functional groups. The results suggest that Z. zanthoxyloides LZT have potential chemotherapeutic effects on African trypanosomes with implications for novel therapeutic interventions in African trypanosomiasis.