Synthesis, spectroscopic characterization, biological screening and POM analysis of potentially bioactive copper(II) carboxylate complexes

ABSTRACT. Here we are reporting the synthesis, characterization of four novel copper(II) complexes with carboxylate ligand and their evaluation for biological applications. The complexes have general formulas C22H18CuN4O12, C32H26CuN6O12, C27H23CuN5O12 and C34H26CuN6O12. The synthesized complexes were characterized by FT-IR and elemental analyses carried out through EDX. The deprotonation of the carboxylate ligand, 4-(2-methoxy-5-nitrophenylamino)-4-oxobut-2-enoic acid, was observed in FT-IR spectrum, indicating that complexation happens via the carboxylate moiety's oxygen. In complexes 1 and 3, the value of Δν value is in between 120-180 cm-1 showing the bridging mode of the carboxylate moiety while in complexes 2 and 4, its value is greater than 180 cm-1 indicating the monodentate binding mode. The findings of antimicrobial activity revealed that the complexes have adequate antibacterial and antifungal properties. The anti-promastigote analysis results showed that the complexes 1 and 4 have significant activity as compared to the standard drug. The binding mode of complexes with DNA was confirmed by UV-Visible spectroscopy and viscosity measurements and the results showed that complexes interact with DNA through intercalative mode. A new and efficient strategy was applied through POM (Petra, Osiris and Molinspiration) analyses for determining the toxicity assessment, bio-availability and drug score of the synthesized complexes. The results showed that the complexes have good bioavailability and drug scores.                 KEY WORDS: Copper(II) carboxylate complex, DNA binding, Anti-promastigote analysis, Cytotoxicity, POM analysis, Docking study Bull. Chem. Soc. Ethiop. 2022, 36(1), 57-71.                                                                     DOI: https://dx.doi.org/10.4314/bcse.v36i1.6 &nbsp

Antioxidant and Cytotoxic Activities and Phytochemical Analysis of Euphorbia wallichii Root Extract and its Fractions

Abstract Euphorbia wallichii a perennial herb growing mainly in Himalayas has been widely used in folk medicines for its medicinal properties. In the present study, the crude methanolic root extract (CME) and its fractions; n-Hexane Fraction (NHF), n-Butanol Fraction (NBF), Chloroform Fraction (CHF), Ethyl acetate Fraction (EAF) and Aqueous Fraction (AQF) of this plant specie were investigated for antioxidant and cytotoxic activities and phytochemical analysis. Antioxidant activity was determined by using 2,2-diphenyl-1-picryl-hydrazyl free radical (DPPH) and DNA protection assay performed on pBR322 plasmid DNA. In both these assays, promising results were obtained for CME as well as other fractions. The IC 50 values for DPPH assay were in a range of 7.89 to 63.35 µg/ml in which EAF showed the best antioxidant potential and almost all the tested samples showed certain level of DNA protection. The cytotoxic activity was assessed by using Sulforhodamine B (SRB) assay on human cell lines; H157 (Lung Carcinoma) and HT144 (Malignant Melanoma). The IC 50 values of the tested samples ranged from 0.18 to 1.4 mg/mL against H157 cell line whereas against HT144 cell line the IC 50 values ranged from 0.46 to 17.88 mg/mL with NBF fraction showing maximum potential for both. Furthermore, the phytochemical analysis of CME and its fractions showed the presences of flavonoids, saponins, tannins, terpenoides and cardiac glycosides with varying concentrations

Five Indigenous Plants of Pakistan with Antinociceptive, Anti-Inflammatory, Antidepressant, and Anticoagulant Properties in Sprague Dawley Rats

Five medicinal plants of Pakistan were investigated for their antinociceptive, anti-inflammatory, antidepressant, and anticoagulant potential. Antinociceptive activity was estimated by hot plate and writhing assay. In hot plate assay, Quercus dilatata (52.2%) and Hedera nepalensis (59.1%) showed moderate while Withania coagulans (65.3%) displayed a significant reduction in pain. On the other hand, in writhing assay, Quercus dilatata (49.6%), Hedera nepalensis (52.7%), and Withania coagulans (62.0%) showed comparative less activity. In anti-inflammatory assays crude extracts showed significant edema inhibition in a dose dependent manner. In carrageenan assay, the highest activity was observed for Withania coagulans (70.0%) followed by Quercus dilatata (66.7%) and Hedera nepalensis (63.3%). Similar behavior was observed in histamine assay with percentage inhibitions of 74.3%, 60.4%, and 63.5%, respectively. Antidepressant activity was estimated by forced swim test and the most potent activity was revealed by Withania coagulans with immobility time 2.2s (95.9%) followed by Hedera nepalensis with immobility time 25.3s (53.4%). Moreover, the crude extracts of Fagonia cretica (74.6%), Hedera nepalensis (73.8%), and Phytolacca latbenia (67.3%) showed good anticoagulant activity with coagulation times 86.9s, 84.3s, and 67.5s, respectively. Collectively, the results demonstrate that these five plants have rich medicinal constituents which can be further explored

Benzoic Acid Derivatives of <em>Ifloga spicata</em> (Forssk.) Sch.Bip. as Potential Anti-Leishmanial against <em>Leishmania tropica</em>

This study aimed to appraise the anti-leishmanial potentials of benzoic acid derivatives, including methyl 3,4-dihydroxybenzoate (compound 1) and octadecyl benzoate (compound 2), isolated from the ethnomedicinally important plant Ifloga spicata (I. spicata). Chemical structures were elucidated via FT-IR, mass spectrometry, and multinuclear (1H and 13C) NMR spectroscopy. Anti-leishmanial potentials of the compounds were assessed using Leishmania tropica promastigotes. Moreover, acridine orange fluorescent staining was performed to visualize the apoptosis-associated changes in promastigotes under a fluorescent microscope. A SYTOX assay was used to check rupturing of Leishmania promastigote cell membranes using 0.1% Triton X-100 as positive control. A DNA interaction assay was carried out to assess DNA attachment potential. AutoDock software was used to check the binding affinity of compounds with surface enzyme leishmanolysin gp63 (1LML). Both compounds exhibited considerable anti-leishmanial potential, with LD50 values of 10.40 ± 0.09 and 14.11 ± 0.11 μg/mL for compound 1 and compound 2, respectively. Both compounds showed higher binding affinity with the leishmanolysin (gp63) receptor/protease of Leishmania, as assessed using computational analysis. The binding scores of compounds 1 and 2 with target gp63 were −5.3 and −5.6, respectively. The attachment of compounds with this receptor resulted in their entry into the cell where they bound with Leishmania DNA, causing apoptosis. The results confirmed that the investigated compounds have anti-leishmanial potential and are potential substitutes as natural anti-leishmanial agents against L. tropica

Bioflavonoid-Induced Apoptosis and DNA Damage in Amastigotes and Promastigotes of Leishmania donovani: Deciphering the Mode of Action

Natural products from plants contain many interesting biomolecules. Among them, quercetin (Q), gallic acid (GA), and rutin (R) all have well-reported antileishmanial activity; however, their exact mechanisms of action are still not known. The current study is a step forward towards unveil the possible modes of action of these compounds against Leishmania donovani (the causative agent of visceral leishmaniasis). The selected compounds were checked for their mechanisms of action against L. donovani using different biological assays including apoptosis and necrosis evaluation, effects on genetic material (DNA), quantitative testing of nitric oxide production, ultrastructural modification via transmission electron microscopy, and real-time PCR analysis. The results confirmed that these compounds are active against L. donovani, with IC50 values of 84.65 µg/mL, 86 µg/mL, and 98 µg/mL for Q, GA, and R, respectively. These compounds increased nitric oxide production and caused apoptosis and DNA damage, which led to changes in the treated cells’ ultrastructural behavior and finally to the death of L. donovani. These compounds also suppressed essential enzymes like trypanothione reductase and trypanothione synthetase, which are critical for leishmanial survival. The selected compounds have high antileishmanial potentials, and thus in-vivo testing and further screening are highly recommended

Epidemiology of Human Adenovirus in Pakistani Children Hospitalized with Community-Acquired Gastroenteritis under the Age of Five Years

Acute gastroenteritis is the major cause of morbidity and mortality among infants and children around the globe. Along with other enteropathogens, human adenovirus (HadV) is a major etiological agent associated with diarrhea in young children. However, information about the epidemiology of Adenoviruses in Pakistan is limited or has not been reported. A total of 1082 stool samples were collected from patients with acute gastroenteritis under the age of five years with symptoms of diarrhea, vomiting, nausea, and abdominal cramps who visited Benazir Bhutto Hospital Rawalpindi and Children&rsquo;s hospital in Lahore of Punjab Province in Pakistan. Of this, 384 cases with no blood in their stool, negative for Rotavirus, and under the age of five years were recruited in this study. Human Adenoviruses were isolated in the human epithelial HEp-2 cell line. Furthermore, adenovirus antigen detection was carried out by an enzyme-linked immunosorbent assay (ELISA), and then all positive and negative samples were confirmed by nested PCR. After inoculating a clear stool supernatant on HEp-2 cell lines, we observed a positive cytopathic effect in 65 (16%) cases. Using an enzyme-linked immunosorbent assay, HAdV antigens were detected in 54 (14.06%) of the clear supernatant from gastroenteritis cases. However, HAdV hexon coding regions were amplified in 57 (14.80%) fecal samples, mainly from patients &le;24 months of age. The findings of this study suggest that adenovirus circulates significantly in the children population under the age of five years and may be the potential etiological factor of acute gastroenteritis in the mentioned cities. This study provides baseline data about the possible role of adenovirus in causing viral diarrhea in children. Further large-scale epidemiological surveys are recommended to better understand disease burden, etiological agents, and its clinical impact across the country

Biogenic Synthesis of Zinc Oxide Nanoparticles Using <i>Citrullus colocynthis</i> for Potential Biomedical Applications

Green nanoparticle synthesis is considered the most efficient and safe nanoparticle synthesis method, both economically and environmentally. The current research was focused on synthesizing zinc oxide nanoparticles (ZnONPs) from fruit and leaf extracts of Citrullus colocynthis. Four solvents (n-hexane, methanol, ethyl acetate, and aqueous) were used to prepare the extracts from both plant parts by maceration and extraction. Zinc acetate was used to synthesize the nanoparticles (NPs), and color change indicated the synthesis of ZnONPs. X-ray diffraction, UV spectroscopy, and scanning electron microscopy were used to study the ZnONPs. UV–visible spectroscopy revealed an absorbance peak in the 350–400 nm range. XRD patterns revealed the face-centered cubic structure of the ZnONPs. SEM confirmed a spherical morphology and a size range between 64 and 82 nm. Phytochemical assays confirmed that the complete flavonoid, phenolic, and alkaloid concentrations were higher in unrefined solvent extracts than in nanoparticles. Nanoparticles of C. colocynthis fruit aqueous extracts showed stronger antioxidant activity compared with the crude extracts. Strong antifungal activity was exhibited by the leaves, crude extracts, and nanoparticles of the n-hexane solvent. In a protein kinase inhibition assay, the maximum bald zone was revealed by nanoparticles of ethyl acetate extracts from leaves. The crude extracts and nanoparticles of leaves showed high cytotoxic activities of the n-hexane solvent, with LC50 values of 42.08 and 46.35, respectively. Potential antidiabetic activity was shown by the n-hexane (93.42%) and aqueous (82.54%) nanoparticles of the fruit. The bioactivity of the plant showed that it is a good candidate for therapeutic use. The biosynthesized ZnONPs showed promising antimicrobial, cytotoxic, antidiabetic, and antioxidant properties. Additionally, the in vivo assessment of a nano-directed drug delivery system for future therapeutic use can be conducted based on this study

Effect of Chilled Storage on Antioxidant Capacities and Volatile Flavors of Synbiotic Yogurt Made with Probiotic Yeast Saccharomyces boulardii CNCM I-745 in Combination with Inulin

Fermentation of available sugars in milk by yogurt starter culture initially and later by Saccharomyces boulardii (Probiotic yeast) improves the bioavailability of nutrients and produces bioactive substances and volatile compounds that enhance consumer acceptability. The combination of S. boulardii, a unique species of probiotic yeast, and inulin, an exopolysaccharide used as a prebiotic, showed remarkable probiotic and hydrocolloid properties in dairy products. The present study was designed to study the effect of fermentation and storage on antioxidant and volatile capacities of probiotic and synbiotic yogurt by incorporation of S. boulardii and inulin at 1%, 1.5%, and 2% (w/v), compared with the probiotic and control plain yogurt. All samples were stored at 4 &deg;C, and during these four weeks, they were analyzed in terms of their antioxidant and volatile compounds. The synbiotic yogurt samples having inulin and S. boulardii displayed significantly higher DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical activity values and more values of TPC (total phenol contents) than control plain yogurt. A total of 16 volatile compounds were identified in S5-syn2 and S4-syn1.5, while S3-syn1 and S2-P had 14, compared with the control S1-C plain yogurt samples, which had only 6. The number of volatile compounds increased with the increasing concentration of inulin throughout the storage period. Therefore, this novel synbiotic yogurt with higher antioxidant and volatile compounds, even with chilling storage conditions, will be a good choice for consumer acceptability

A Broad Spectrum Antiparasitic Activity of Organotin (IV) Derivatives and Its Untargeted Proteomic Profiling Using Leishmania donovani

Metals have been used in medicine since ancient times for the treatment of different ailments with various elements such as iron, gold and arsenic. Metal complexes have also been reported to show antibiotic and antiparasitic activity. In this context, we tested the antiparasitic potential of 10 organotin (IV) derivatives from 4-(4-methoxyphenylamino)-4 oxobutanoic acid (MS26) against seven eukaryotic pathogens of medical importance: Leishmania donovani, Trypanosoma cruzi, Trypanosoma brucei, Entamoeba histolytica, Giardia lamblia, Naegleria fowleri and Schistosoma mansoni. Among the compounds with and without antiparasitic activity, compound MS26Et3 stood out with a 50% effective concentration (EC50) of 0.21 and 0.19 &micro;M against promastigotes and intracellular amastigotes of L. donovani, respectively, 0.24 &micro;M against intracellular amastigotes of T. cruzi, 0.09 &micro;M against T. brucei, 1.4 &micro;M against N. fowleri and impaired adult S. mansoni viability at 1.25 &micro;M. In terms of host/pathogen selectivity, MS26Et3 demonstrated relatively mild cytotoxicity toward host cells with a 50% viability concentration of 4.87 &micro;M against B10R cells (mouse monocyte cell line), 2.79 &micro;M against C2C12 cells (mouse myoblast cell line) and 1.24 &micro;M against HEK923 cells (human embryonic kidney cell line). The selectivity index supports this molecule as a therapeutic starting point for a broad spectrum antiparasitic alternative. Proteomic analysis of host cells infected with L. donovani after exposure to MS26Et3 showed a reduced expression of Rab7, which may affect the fusion of the endosome with the lysosome, and, consequently, impairing the differentiation of L. donovani to the amastigote form. Future studies to investigate the molecular target(s) and mechanism of action of MS26Et3 will support its chemical optimization