Production of Fucoxanthin from Microalgae Isochrysis galbana of Djibouti: Optimization, Correlation with Antioxidant Potential, and Bioinformatics Approaches.

Fucoxanthin, a carotenoid with remarkable antioxidant properties, has considerable potential for high-value biotechnological applications in the pharmaceutical, nutraceutical, and cosmeceutical fields. However, conventional extraction methods of this molecule from microalgae are limited in terms of cost-effectiveness. This study focused on optimizing biomass and fucoxanthin production from Isochrysis galbana, isolated from the coast of Tadjoura (Djibouti), by testing various culture media. The antioxidant potential of the cultures was evaluated based on the concentrations of fucoxanthin, carotenoids, and total phenols. Different nutrient formulations were tested to determine the optimal combination for a maximum biomass yield. Using the statistical methodology of principal component analysis, Walne and Guillard F/2 media were identified as the most promising, reaching a maximum fucoxanthin yield of 7.8 mg/g. Multiple regression models showed a strong correlation between antioxidant activity and the concentration of fucoxanthin produced. A thorough study of the optimization of I. galbana growth conditions, using a design of experiments, revealed that air flow rate and CO2 flow rate were the most influential factors on fucoxanthin production, reaching a value of 13.4 mg/g. Finally, to validate the antioxidant potential of fucoxanthin, an in silico analysis based on molecular docking was performed, showing that fucoxanthin interacts with antioxidant proteins (3FS1, 3L2C, and 8BBK). This research not only confirmed the positive results of I. galbana cultivation in terms of antioxidant activity, but also provided essential information for the optimization of fucoxanthin production, opening up promising prospects for industrial applications and future research.

Unlocking the Green Gold: Exploring the Cancer Treatment and the Other Therapeutic Potential of Fucoxanthin Derivatives from Microalgae.

Fucoxanthin, a carotenoid widely studied in marine microalgae, is at the heart of scientific research because of its promising bioactive properties for human health. Its unique chemical structure and specific biosynthesis, characterized by complex enzymatic conversion in marine organisms, have been examined in depth in this review. The antioxidant, anti-inflammatory, and anti-cancer activities of fucoxanthin have been rigorously supported by data from in vitro and in vivo experiments and early clinical trials. Additionally, this review explores emerging strategies to optimize the stability and efficacy of fucoxanthin, aiming to increase its solubility and bioavailability to enhance its therapeutic applications. However, despite these potential benefits, challenges persist, such as limited bioavailability and technological obstacles hindering its large-scale production. The medical exploitation of fucoxanthin thus requires an innovative approach and continuous optimization to overcome these barriers. Although further research is needed to refine its clinical use, fucoxanthin offers promising potential in the development of natural therapies aimed at improving human health. By integrating knowledge about its biosynthesis, mechanisms of action, and potential beneficial effects, future studies could open new perspectives in the treatment of cancer and other chronic diseases.

The Effects of Khat Chewing among Djiboutians: Dental Chemical Studies, Gingival Histopathological Analyses and Bioinformatics Approaches.

This study examined the effects of khat chewing on oral gingival conditions by adopting a targeted process which combined physicochemical analyses of the teeth, histopathological examinations of the gums, and bioinformatics modeling. The physicochemical evaluation of teeth in khat consumers compared to non-consumers was carried out using specific analytical techniques; hence, the results of this initial investigation revealed significant erosion of the tooth enamel due to khat chewing, as well as an alteration of the essential chemical composition of the teeth. Additionally, the histopathological analyses complemented preliminary studies by showing severe inflammation of the gums and oral mucosa in khat users. The understanding of these studies was enriched by bioinformatics analysis, where modeling was carried out via computational methods. This analytical phase examined molecular docking mechanisms, including the interaction between cathinone, the main alkaloid of khat, and the protein receptors involved in the protection of gingival tissues against infections. In summary, this multidisciplinary research provided an in-depth view of the oral health issues related to khat chewing, combining experimental studies with bioinformatics perspectives.

Overview of Research on Leishmaniasis in Africa: Current Status, Diagnosis, Therapeutics, and Recent Advances Using By-Products of the Sargassaceae Family.

Leishmaniasis in Africa, which has been designated as a priority neglected tropical disease by various global organizations, exerts its impact on millions of individuals, primarily concentrated within this particular region of the world. As a result of the progressively grave epidemiological data, numerous governmental sectors and civil organizations have concentrated their endeavors on this widespread outbreak with the objective of devising appropriate remedies. This comprehensive examination delves into multiple facets of this parasitic ailment, scrutinizing the associated perils, diagnostic intricacies, and deficiencies within the existing therapeutic protocols. Despite the established efficacy of current treatments, they are not immune to deleterious incidents, particularly concerning toxicity and the emergence of parasitic resistance, thus accentuating the necessity of exploring alternative avenues. Consequently, this research not only encompasses conventional therapeutic approaches, but also extends its scope to encompass complementary and alternative medicinal techniques, thereby striving to identify innovative solutions. A particularly auspicious dimension of this study lies in the exploration of natural substances and by-products derived from some brown algae of the Sargassaceae family. These resources possess the potential to assume a pivotal role in the management of leishmaniasis.

The ethnopharmacological study of plant drugs used traditionally in Djibouti for malaria treatment.

ETHNOPHARMACOLOGICAL RELEVANCE: Djibouti was a country where malaria has been endemic for centuries. The local population use the plants as repellents or first aid for uncomplicated malaria. AIM OF THE STUDY: The aim was, for the first time, to collect and identify plants used by the local population to treat malaria and select the most interesting plants (those that are more commontly used, more available, and have fewer studies). These plants were evaluated for their antiplasmodial activity as well as their cytotoxicity on human cell lines for the most active ones. MATERIALS AND METHODS: A semi-structured questionnaire was developed for this study to collect information about the use and identity of botanical drugs used to treat malaria. The use-reports (percentage) of each plant were recorded to determine their use importance. Also, the availability status of the plants was assessed; and those in critical condition were discarded excluded from further study. Fifteen plants, out of the 41 listed, were extracted with hydro alcohol, ethyl acetate, and dichloromethane for biological testing. Chloroquine-resistant strain FcB-1 of P. falciparum and a human diploid embryonic lung cell line were used for the antiplasmodial test, and to assess the cytotoxicity for human cells respectively. Preliminary analysis of extract constituents was carried out using thin layer chromatography (TLC). RESULTS: This study identifies 41 plant taxa belonging to 32 families and records their use against malaria. Balanites rodunfolia, belonging to the Zygophyllaceae family, was the most commonly used plant, representing 44 % of use-reports. It was followed by Cadaba rodunfolia (15 %) from the Capparaceae family, and then the three species of Aloe: Aloe djiboutiensis (8.2 %), Aloe ericahenriettae (3.4 %), and Aloe rigens (3.4 %) from the Asphodelaceae family. The leaves are the most commonly used part of the plants to treat malaria, accounting for 76 % of usage. The preparation methods were decoction (52 %), maceration (29 %), and boiling (19 %). The administration routes were by oral (80 %), inhalation 19 %), and bathing (1 %). The best antiplasmodial activities were observed in the dichloromethane extracts of Cymbopogon commutatus and the ethyl acetate extracts of Aloe rigens and Terminalia brownii, with IC50 values of 9.8, 5, and 7.5 µg/mL, respectively. Their toxicity/activity levels were very favorable with selectivity indices of 5.6, 8.1, and 11.8 for C. commutatus, A. rigens, and T. Brownii, respectively. CONCLUSION: Forty-one species of botanical drugs were listed as being used to treat malaria in Djibouti. All fifteen selected species showed antiplasmodial activity (IC50 < 50 µg/mL). This work will help guide the valorization of botanical drugs used to treat malaria in Djibouti.

Evaluation of Antioxidant and Antibacterial Activities, Cytotoxicity of Acacia seyal Del Bark Extracts and Isolated Compounds.

Water extract of Acacia seyal bark is used traditionally by the population in Djibouti for its anti-infectious activity. The evaluation of in vitro antibacterial, antioxidant activities and cytotoxicity as well as chemical characterization of Acacia seyal bark water and methanolic extracts were presented. The water extract has a toxicity against the MRC-5 cells at 256 µg/mL while the methanolic extract has a weak toxicity at the same concentration. The methanolic extract has a strong antioxidant activity with half maximal inhibitory concentration (IC50) of 150 ± 2.2 µg/mL using 1-diphenyl-2-picrylhydrazyl (DPPH) and IC50 of 27 ± 1.3 µg/mL using 2,2'-azino-bis 3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical methods. For ferric reducing/antioxidant power (FRAP) assay, the result is 45.74 ± 5.96 µg Vitamin C Equivalent (VCE)/g of dry weight (DW). The precipitation of tannins from methanol crude extract decreases the MIC from 64 µg/mL to 32 µg/mL against Staphylococcus aureus and Corynebacterium urealyticum. However, the antioxidant activity is higher before tannins precipitation than after (IC50 = 150 µg/mL for methanolic crude extract and 250 µg/mL after tannins precipitation determined by DPPH method). By matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, the results showed that the condensed tannins consist of two types of catechin and gallocatechin-based oligomers. The fractionation led to the identification of three pure compounds: two flavanols catechin and epicatechin; one triterpene as lupeol; and a mixture of three steroids and one fatty acid: campesterol, stigmasterol, clionasterol, and oleamide.

Medicinal plants and their uses by the people in the Region of Randa, Djibouti.

ETHNOPHARMACOLOGICAL RELEVANCE: The article presents the local knowledge on medicinal plants and their relevance in managing health problems. Important ethnobotanical leads are given with priority species and disease categories, casting insight on future phytochemical and pharmacological studies. AIM OF THE STUDY: The use of traditional medicinal plants has been an integral part of the traditional healthcare systems in Djibouti. However, scientific studies on the traditional herbal healing systems of the various cultural groups have never been undertaken. This study has, therefore, aimed at assessing plant-related ethnomedicinal knowledge of the people in Randa Region; prioritising the plants with respect to common disease categories and inferring about prospects of new pharmacological products. MATERIALS AND METHODS: Interview-based ethnobotanical field study was carried out to document the plant-based ethnomedicinal knowledge handed down to the present by the oral tradition of people living in 24 villages in Tadjourah District of Randa Region (north Djibouti). Informant Consensus Factors (ICF) and Fidelity Level (FL) values of the medicinal plants were calculated to check the level of informant agreement and the healing potentials of the species. RESULTS: A total of 91 plant species that belong to 72 genera and 40 families were documented. Most of these species (92%) were collected from non-cultivated areas. Their local names and traditional uses in medicine were also studied. The plant family Fabaceae was represented by the highest number of taxa (17 species). Strong informant agreements hinted at good healing potentials of some species as shown by high values of consensus factors for eye diseases (0.98), mouth diseases (0.93), kidney problems (0.89) and microbial infections (0.84). Dodonea angustifolia, Solanum cordatum, Grewia erythraea, Acalypha indica, Acacia etbaica, Fagonia schweinfurthii, Solanum coagulans, Senna alexandrina and Grewia tembensis scored high FL values emerging as promising priority species for future pharmacological screening against microbial infections. CONCLUSION: The results of this study may inspire further ethnobotanical and ethnopharmacological research and investigations toward drug discovery in Djibouti and beyond.