Chemical composition and studying the possible neuroprotective effect of iridoids-rich fraction from Pentas lanceolata leaves using rotenone model of Parkinson's disease in mice.

Parkinsonism is an age-related neurodegenerative illness that affects motor coordination leading to loss of dopaminergic neurons. Many medications are used for the treatment of Parkinson's disease but are only symptomatic and have a limited effect on the progression of this ailment. Therefore, bioactive compounds which derived from plants have been examined for their ability to improve the neuronal damage and cell death happened in parkinsonian patients. In this study the iridoids-rich fraction isolated from Pentas lanceolata (PIRF) leaves was investigated for its phytoconstituents. Seven iridoids (1-7) and one flavonol diglycoside (8) were isolated, and their chemical structures were achieved by 1H and 13C nuclear magnetic resonance and ESI-MS spectral data. Compound 1 (6ß,7ß-epoxy-8-epi-splendoside) and 5 (gaertneroside) were isolated for the first time from Pentas genus as well as compound 8 (kaempferol-3-O-robinobioside). The current study aims to investigate the possible anti-parkinsonian effect of PIRF using a rotenone model of Parkinsonism in mice. Behavioural tests (wirehanging, stair and wooden-walking tests) were done to examine the motor coordination in mice after treatment. Biochemical and histopathological examinations for brain striatum in different groups were also evaluated. Results revealed that rotenone-treated mice had poor motor functions described by depletion of dopamine and Ach levels, a significant increase in proinflammatory cytokines, IL-1B, TNF-α and Mcp-1 and oxidative biomarkers with subsequent reduction in antioxidant mediators. Disorganization of striatum, degenerated neurocytes, slight vacuolation, shrunken neurons with pyknotic nuclei and apoptotic cells are displayed by histopathological examinations. Treatment with PIRF ameliorates the neurodegeneration-induced by rotenone in the brain of mice. The anti-parkinsonian effect of PIRF could be attributed to their bioactive constituents of iridoids.

Investigating the Potential Anti-SARS-CoV-2 and Anti-MERS-CoV Activities of Yellow Necklacepod among Three Selected Medicinal Plants: Extraction, Isolation, Identification, In Vitro, Modes of Action, and Molecular Docking Studies.

The anti-MERS-CoV activities of three medicinal plants (Azadirachta indica, Artemisia judaica, and Sophora tomentosa) were evaluated. The highest viral inhibition percentage (96%) was recorded for S. tomentosa. Moreover, the mode of action for both S. tomentosa and A. judaica showed 99.5% and 92% inhibition, respectively, with virucidal as the main mode of action. Furthermore, the anti-MERS-CoV and anti-SARS-CoV-2 activities of S. tomentosa were measured. Notably, the anti-SARS-CoV-2 activity of S. tomentosa was very high (100%) and anti-MERS-CoV inhibition was slightly lower (96%). Therefore, the phytochemical investigation of the very promising S. tomentosa L. led to the isolation and structural identification of nine compounds (1−9). Then, both the CC50 and IC50 values for the isolated compounds against SARS-CoV-2 were measured. Compound 4 (genistein 4'-methyl ether) achieved superior anti-SARS-CoV-2 activity with an IC50 value of 2.13 µm. Interestingly, the mode of action of S. tomentosa against SARS-CoV-2 showed that both virucidal and adsorption mechanisms were very effective. Additionally, the IC50 values of S. tomentosa against SARS-CoV-2 and MERS-CoV were found to be 1.01 and 3.11 µg/mL, respectively. In addition, all the isolated compounds were subjected to two separate molecular docking studies against the spike (S) and main protease (Mpr°) receptors of SARS-CoV-2.

LC-MS/MS and GC-MS based phytochemical perspectives and antimicrobial effects of endophytic fungus Chaetomium ovatoascomatis isolated from Euphorbia milii.

The antimicrobial activity of endophytic fungi isolated from Euphorbia milii was evaluated against Gram-positive, Gram-negative bacteria, unicellular yeast, and filamentous fungi. Chaetomium ovatoascomatis NRC was identified morphologically and genetically as the most active strain. The total ethyl acetate extract of C. ovatoascomatis NRC demonstrated significant antimicrobial activity against Gram-negative; Escherichia coli, Salmonella enteric, and fungi; Aspergillus niger with MIC of 62.5 ug/ml. Whereas n-hexane fraction demonstrated broader activity against Gram-positive; Bacillus subtilis, Lactobacillus cereus, Gram-negative; Escherichia coli and Salmonella enteric, fungi; Candida albicans and F. solani. LC-MS/MS analysis of ethyl acetate strain extract and GC-MS analysis of the n-hexane fraction were used to identify the metabolites of the strain extract. LC-MS/MS determined three major metabolites with potential antimicrobial activities including grevilline B, aflatoxin G2 and apigenin. GC-MS analysis of n-hexane fraction tentatively identified 30 compounds, where 9,12-octadecadienoic acid methyl ester was the major compound.

Genotoxicity and sperm defects induced by 5-FU in male mice and the possible protective role of Pentas lanceolata-iridoids.

5-Fluorouracil (5-FU) is a widely used antineoplastic drug. In this work, a comprehensive study was performed to detect the extent of chromosomal damage and morphological sperm defects induced by 5-FU in male mice and the possible protective role of the iridoids-rich fraction of Pentas lanceolata leaves (IFPL). Six main groups were examined in micronucleus and chromosomal assays: I- control negative, II- control positive (i.p. treated with single dose of 75 mg/kg 5-FU), III- control plant (orally administrated IFPL, 300 mg/kg, 5 consecutive days), and IV-VI- treated with IFPL (100, 200 and 300 mg/kg, 5 consecutive days) plus 5-FU (i.p. treated at the last day). Samples were taken 24 h post treatment. The study of morphological sperm anomalies, single and repeated treatments were examined and samples were taken after 35 days from the 1st treatment. In bone marrow, 5-FU induced a significant increase in the micro-nucleated polychromatic erythrocytes, chromosome anomalies (CAs) and also cytotoxic effects. A significant percentage of CAs was recorded in spermatocytes after 5-FU treatment reached 22.80 ± 1.32 vs 4.20 ± 0.37 for control (mainly X-Y univalent, 90%). IFPL was recorded to be non-mutagenic in all tests examined. In addition, it alleviated the previous defects in a dose-dependent manner. A significant and dramatic increase in the percentage of morphological sperm defects was recorded after single and repeated treatments with 5-FU reached 13.24 ± 0.24, 30.42 ± 0.32 respectively vs 2.56 ± 0.14 for control. Amorphous head-sperm and sperm with coiled tail were the most pronounced types of abnormalities. Significant protection was detected with the highest tested dose of IFPL. In conclusion: 5-FU demonstrated to be a genotoxic agent. Its genotoxicity in germ cells is serious and may lead to reproductive toxicity, infertility or heritable defects. The results also demonstrated the biosafety of IFPL and its possible protective role in combined treatment with 5-FU.

Secondary metabolites and biological activity of Pentas species: A minireview.

The genus Pentas belongs to the Rubiaceae family, which contains approximately 40 species. Several Pentas species were reported to be used as a folk treatment by African indigenous people in treating some diseases such as malaria, tapeworms, dysentery, gonorrhea, syphilis and snake poisoning. This article covers the period from 1962 to 2017 and presents an overview of the biological activity of different Pentas species and describes their phytochemical traits. As a conclusion, the main secondary metabolites from Pentas species are quinones, highly oxygenated chromene-based structures, and iridoids. Pentas species are widely used in folk medicine but they have to be more investigated for their medicinal properties.