Anti-Infective Agents - Volume 20, Issue 3, 2022

Pests, such as cockroaches, thrive in polluted conditions that are detrimental to Homo sapiens, suggesting that such species possess mechanisms to protect themselves against pathogens. Besides their immunity to fight pathogens, we hypothesize that the microbial gut flora of pests produces antimicrobials to thwart communicable diseases. It is proposed that the search for new antimicrobials originating from unusual sources will generate useful leads in the identification of new anti-infective agents.

Background: Herbal medicines are one of the giant creations of nature. Several medicinal agents developed from natural sources, which open a new era of health sciences. Cassia sophera is a prevalent medicinal plant that is locally known as “Kasondi”, belonging to the family Caesalpinaceae. Many secondary metabolites like alkaloids, tannins, anthraquinones, flavonoids are isolated from roots, stems, leaves, flowers, and seeds of C. sophera, which are very effective against several diseases. Objective: Cassia sophera has an enormous potential in public health to protect from diabetes, microbes, and cancer. Hence, the aim of the present review is to collect the reported antidiabetic, antimicrobial, and anticancer activity of Cassia sophera along with a detailed discussion about mechanism of action of various phytoconstituents. Discussion: Antidiabetic activity of Cassia sophera is due to the activation of β cell and stimulation of surviving pancreatic β-cells to release more insulin. Plasma membrane disruption, inhibition of cell wall formation, inhibition of cell division by the Cassia sophera is the prime causes of antimicrobial activity. The anticancer activity of the plant is mainly due to the prevention of reactive oxygen species formation, induction of cell cycle arrest, apoptosis, and angiogenesis. Conclusions: The findings from this review article confirm the potential activities and mechanisms of various phytoconstituents responsible for preventing diabetes, cancer, and microbial infections. Further investigation regarding possible pharmaceutical side effects, contraindications, drug interactions involving drugs synthesized from C. sophera should be carried out by the researchers.

Pathogenic Acanthamoeba is responsible for causing serious eye and fatal brain infections. A successful prognosis remains elusive despite advances in chemotherapeutics and supportive care. Natural products of medicinal value remain a promising source for drug development due to their broad-spectrum antimicrobial activities. Herein, we discuss anti-Acanthamoebic properties of natural products originating from plants, marine, and microbial sources that could be exploited as a potential avenue for drug discovery against infections caused by Acanthamoeba.

This article reviews preclinical and clinical studies on the repurposed use of disulfiram (Antabuse) as an antimicrobial agent. Preclinical research covered on the alcohol sobriety aid includes uses as an anti-MRSA agent, a carbapenamase inhibitor, antifungal drug for candidiasis, and treatment for parasitic diseases due to protozoa (e.g., giardiasis, leishmaniasis, malaria) and helminthes (e.g., schistosomiasis, trichuriasis). Past, current, and pending clinical studies on disulfiram as a post-Lyme disease syndrome (PTLDS) therapy, an HIV latency reversal agent, and intervention for COVID-19 infections are also reviewed..

The colchicine binding site in microtubules is the most flourishing target for anticancer treatment. Microtubule inhibitor drugs, including paclitaxel and vinca alkaloids, have been considered to exert their activity primarily by increasing or decreasing the cellular microtubule mass. This review describes the microtubular assembly along with the combretastatin derivatives as microtubules inhibitors, the structures of compounds known to interact with colchicines binding sites, and their possible mechanism of action. Additionally, the utility of other heterocyclic rings and their combretastatin derivatives in treating cancer is also discussed. Colchicines binding site represents a stimulating new molecular target in the design of combretastatin drugs.

Satureja genus belongs to the Lamiaceae family, and they are used in food products and by pharmaceutical and cosmetic industries. The chemical composition of Satureja is responsible for its pharmacological and phytochemical properties. Among the various biological activities, notably antioxidant, antibacterial and antifungal, Satureja also has a potential antiviral activity. The existence of a microbiota modulation potential by Satureja in farming animals has also been reported. Viral pathologies are one of the main causes of disease in the world. It is commonly known that gut microbiota plays a crucial role in the fight and progression of viral infection. Previous studies conducted on coronavirus disease 2019 (COVID-19) pandemic have proved an imbalance in the intestinal and pulmonary microbiota via gut-lung axis. Knowing the properties of Satureja and its traditional use, one can suggest the possibility of using it as dietary supplement to modulate immune system in order to prevent and fight viral infections. The objective of this review is to reveal the potential impact of medicinal plants such as Satureja genus as a food supplement, on immune enhancing during SARS-CoV-2 infection and their relationships with the intestinal microbiota.

Background: Reduced efficacy of the available antifungal drugs is the major public health concern of the population all over the world. Despite significant advances in the treatment of these life-threatening infections, severe toxicity and increasing median effective dose have limited the efficacy of frontline therapy applicable against them. Objective: The quintessential occurrence of systemic toxicity handicaps the clinical utility of currently available antifungal drugs. 1,2,3-Triazoles in the same context are relatively less toxic. Consequently, conjugation of quinine with the triazole moiety for enhanced efficacy and reduced toxicity have been excessively envisaged and reported in the context of a range of activities ranging from inflammation to cancer, however lack of toxicity profile sabotages the translation of the laboratory prototype into successful clinical practice. Methods: We herein report the synthesis and characterization of a series of quinine triazole hybrids via o-mesylation followed by azide displacement, then reacting it with aliphatic and aromatic alkynes in water: t-butanol mixture. The reaction was carried in the presence of copper sulphate and sodium ascorbate. Product 6a-s was screened for in-vitro antifungal activity. The in-vitro antifungal potential of synthesized compounds was estimated against prominent fungal strains (Candida albicans, Aspergillus niger and, Aspergillus clavatus). Results: The results showed that some of the synthesized compounds exhibited marked activity. Compounds 6a, 6b, 6c, 6d, 6g, and 6q showed significant antifungal activity at micromolar concentration. The studies revealed that some of the compounds exhibited activities more than that of reference drugs. The compound containing thiazole ring 6c is the most potent compound of the series. Conclusion: Compound 6c was found to be the most vigorous against C. albicans, A. niger, A. clavatus with MIC values of 119.4, 112.7, and 121.3 μM/mL, respectively. Our SAR study revealed that the introduction of the 1,2,3-triazole ring in the structure of quinine modulated its potency for treating fungal infection.

Background: A new series of copper (II), cobalt (II), zinc (II), manganese (II), and iron (II) metal complexes were synthesized by the condensation of a novel Schiff base with various metal chlorides in ethanol. Schiff base was synthesized by reacting salicylaldehyde with Lglutamic acid and L-tyrosine dissolved in ethanol, respectively. Methods: The structures of all the synthesized metal complexes (4a-e, 7a-e) were investigated using elemental analysis, FT-IR,¹H NMR,¹³C NMR and MS spectral data. The metal complexes were also screened for their anti-bacterial, anti-fungal, and anti-tubercular activities against various tested strains. Results: Assessment of in silico ADMET properties of all metal complexes showed to be in accordance with Lipinski’s rule of five. Further enzymatic assay was aided by a molecular docking study of Enoyl CoA reductase (INHA) using Autodock Vina and evaluated by Autodock 4.0. Conclusion: The metal complexes, 4b,4c, 4d,7b and 7d, containing metals, like Zn, Co, and Fe, exhibited good anti-bacterial, anti-fungal and anti-tubercular activities against the tested strains.