Helminth-derived proteins as immune system regulators: a systematic review of their promise in alleviating colitis.

Helminth-derived proteins have immunomodulatory properties, influencing the host's immune response as an adaptive strategy for helminth survival. Helminth-derived proteins modulate the immune response by inducing anti-inflammatory cytokines, promoting regulatory T-cell development, and ultimately favouring a Th2-biased immune response. This systematic review focused on helminth-derived proteins and explored their impact on reducing inflammatory responses in mouse models of colitis. A systematic search across Medline, EMBASE, Web of Science, and Cochrane Library identified fourteen relevant studies. These studies reported immunomodulatory changes, including increased production of anti-inflammatory cells and cytokines. In mouse models of colitis treated with on helminth-derived proteins, significant improvements in pathological parameters such as body weight, colon length, and microscopic inflammatory scores were observed compared to control groups. Moreover, helminth-derived proteins can enhance the function of Tregs and alleviate the severity of inflammatory conditions. The findings underscore the pivotal role of helminth-derived proteins in immunomodulation, specifically in the axis of cytokine secretion and immune cell polarization. The findings offer new opportunities for treating chronic inflammatory conditions such Crohn's disease.

Chemistry and Bioactivity of the Deep-Water Antarctic Octocoral Alcyonium sp.

Chemical investigation of an Antarctic deep-water octocoral has led to the isolation of four new compounds, including three illudalane sesquiterpenoids (1-3) related to the alcyopterosins, a highly oxidized steroid, alcyosterone (5), and five known alcyopterosins (4, 6-9). The structures were established by extensive 1D and 2D NMR analyses, while 9 was verified by XRD. Alcyopterosins are unusual for their nitrate ester functionalization and have been characterized with cytotoxicity related to their DNA binding properties. Alcyopterosins V (3) and E (4) demonstrated single-digit micromolar activity against Clostridium difficile, an intestinal bacterium capable of causing severe diarrhea that is increasingly associated with drug resistance. Alcyosterone (5) and several alcyopterosins were similarly potent against the protist Leishmania donovani, the causative agent of leishmaniasis, a disfiguring disease that can be fatal if not treated. While the alcyopterosin family of sesquiterpenes is known for mild cytotoxicity, the observed activity against C. difficile and L. donovani is selective for the infectious agents.

Spongian Diterpenoids Derived from the Antarctic Sponge Dendrilla antarctica Are Potent Inhibitors of the Leishmania Parasite.

From the CH2Cl2 extract of the Antarctic sponge Dendrilla antarctica we found spongian diterpenes, including previously reported aplysulphurin (1), tetrahydroaplysulphurin-1 (2), membranolide (3), and darwinolide (4), utilizing a CH2Cl2/MeOH extraction scheme. However, the extracts also yielded diterpenes bearing one or more methyl acetal functionalities (5-9), two of which are previously unreported, while others are revised here. Further investigation of diterpene reactivity led to additional new metabolites (10-12), which identified them as well as the methyl acetals as artifacts from methanolysis of aplysulphurin. The bioactivity of the methanolysis products, membranoids A-H (5-12), as well as natural products 1-4, were assessed for activity against Leishmania donovani-infected J774A.1 macrophages, revealing insights into their structure/activity relationships. Four diterpenes, tetrahydroaplysulphurin-1 (2) as well as membranoids B (6), D (8), and G (11), displayed low micromolar activity against L. donovani with no discernible cytotoxicity against uninfected J774A.1 cells. Leishmaniasis is a neglected tropical disease that affects one million people every year and can be fatal if left untreated.

Bioactivity of Spongian Diterpenoid Scaffolds from the Antarctic Sponge Dendrilla antarctica.

The Antarctic sponge Dendrilla antarctica is rich in defensive terpenoids with promising antimicrobial potential. Investigation of this demosponge has resulted in the generation of a small chemical library containing diterpenoid secondary metabolites with bioactivity in an infectious disease screening campaign focused on Leishmania donovani, Plasmodium falciparum, and methicillin-resistant Staphylococcus aureus (MRSA) biofilm. In total, eleven natural products were isolated, including three new compounds designated dendrillins B-D (10-12). Chemical modification of abundant natural products led to three semisynthetic derivatives (13-15), which were also screened. Several compounds showed potency against the leishmaniasis parasite, with the natural products tetrahydroaplysulphurin-1 (4) and dendrillin B (10), as well as the semisynthetic triol 15, displaying single-digit micromolar activity and low mammalian cytotoxicity. Triol 15 displayed the best profile against the liver-stage malaria parasites, while membranolide (5) and dendrillin C (11) were strong hits against MRSA biofilm cultures.

Keikipukalides, Furanocembrane Diterpenes from the Antarctic Deep Sea Octocoral Plumarella delicatissima.

During a 2013 cruise in the Southern Ocean we collected specimens of the octocoral Plumarella delicatissima between 800 and 950 m depth. Five new furanocembranoid diterpenes, keikipukalides A-E (1-5), the known diterpene pukalide aldehyde (6), and the known norditerpenoid ineleganolide (7) were isolated from the coral. These Plumarella terpenes lack mammalian cytotoxicity, while 2-7 display activity against Leishmania donovani between 1.9 and 12 µM. Structure elucidation was facilitated by one- and two-dimensional NMR spectroscopy and mass spectrometry, and keikipukalides A and E were confirmed by X-ray crystallography.

Exploitation of Mangrove Endophytic Fungi for Infectious Disease Drug Discovery.

There is an acute need for new and effective agents to treat infectious diseases. We conducted a screening program to assess the potential of mangrove-derived endophytic fungi as a source of new antibiotics. Fungi cultured in the presence and absence of small molecule epigenetic modulators were screened against Mycobacterium tuberculosis and the ESKAPE panel of bacterial pathogens, as well as two eukaryotic infective agents, Leishmania donovani and Naegleria fowleri. By comparison of bioactivity data among treatments and targets, trends became evident, such as the result that more than 60% of active extracts were revealed to be selective to a single target. Validating the technique of using small molecules to dysregulate secondary metabolite production pathways, nearly half (44%) of those fungi producing active extracts only did so following histone deacetylase inhibitory (HDACi) or DNA methyltransferase inhibitory (DNMTi) treatment.

Synthesis, characterization, and cellular localization of a fluorescent probe of the antimalarial 8-aminoquinoline primaquine.

Primaquine (PQ) is the only commercially available drug that clears dormant liver stages of malaria and blocks transmission to mosquito vectors. Although an old drug, much remains to be known about the mechanism(s) of action. Herein we develop a fluorescent tagged PQ to discover cellular localization in the human malaria parasite, Plasmodium falciparum. Successful synthesis and characterization of a primaquine-coumarin fluorescent probe (PQCP) demonstrated potency equivalent to the parent drug and the probe was not cytotoxic to HepG2 carcinoma cells. Cellular localization was found primarily in the cytosol of the asexual erythrocytic and gametocyte stages of parasite development.

Prevalence and Predictors of Intestinal Parasitic Infections at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, from 2019 to 2023: A Retrospective Study.

Purpose: Parasitic infections are a primary cause of illness worldwide and a public health problem. This study highlighted the prevalence of intestinal parasitic (IP) infections and their updated epidemiologic status from 2019 to 2023 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Patients and Methods: A retrospective study was conducted from 2019 to 2023 at King Abdulaziz University Hospital. The laboratory results, socio-demographic information, and the year of data collection were collected from the hospital's parasitology laboratory. The data were analyzed using SPSS version 26. Ethical approval was obtained from the National Committee of Bioethics (NCBE) - King Abdul Aziz City for Science and Technology, with an approval number of 258-22. Results: During the study period, 7673 stool samples were requested for intestinal parasite examination. The prevalence of IP infection from 2019 to 2023 was 212/7673, with a percentage of 2.8%. Infected patients had a mean (SD) age of 37.68 (17.27) years. Most infected patients were females (61%) and from Saudi Arabia (37.1%). Most stool samples were brown (79.1%), and about half were soft (51.7%). 2019 had the highest number of infected cases (28.3%), while the number of cases decreased in 2023 (8.8%), the lowest during five years. The most predominant parasite among study subjects was Blastocystis hominis (48.11%). Conclusion: The prevalence of IP infection is lower than in previous comparable surveys. Maintaining personal hygiene, conducting epidemiological surveillance, and enhancing environmental sanitation can prevent and control infections.

Synthesis and Activity of a New Series of Antileishmanial Agents.

We have determined that tetrahydroindazoles such as 1 show potent activity against Leishmania donovani, the causative agent of leishmaniasis. While the Hsp90 activity and anticancer properties of 1 have previously been explored, we present here our efforts to optimize their activity against L. donovani via the synthesis of novel analogues designed to probe the hydrophobic pocket of the protozoan Hsp90 orthologue, specifically through the auspices of functionalization of an amine embedded into the scaffold.

Identification of a Hit Series of Antileishmanial Compounds through the Use of Mixture-Based Libraries.

From a screening campaign that included mixture-based libraries containing more than 6 million compounds, a lead series of bis-cyclic guanidines was identified as the most promising. Lead optimization resulted in the identification of potent (IC50 < 500 nM) and selective compounds within this series as well as potent and selective monoguanidines.