In Silico-Based Discovery of Natural Anthraquinones with Potential against Multidrug-Resistant E. coli.

E. coli is a Gram-negative bacterium that causes different human infections. Additionally, it resists common antibiotics due to its outer protective membrane. Natural products have been proven to be efficient antibiotics. However, plant natural products are far less explored in this regard. Accordingly, over 16,000 structures covering almost all African medicinal plants in AfroDb in a structural-based virtual screening were used to find efficient anti-E. coli candidates. These drug-like structures were docked into the active sites of two important molecular targets (i.e., E. coli's Ddl-B and Gyr-B). The top-scoring hits (i.e., got docking scores < -10 kcal/mol) produced in the initial virtual screening (0.15% of the database structures for Ddl-B and 0.17% of the database structures for Gyr-B in the database) were further refined using molecular dynamic simulation-based binding free energy (ΔG) calculation. Anthraquinones were found to prevail among the retrieved hits. Accordingly, readily available anthraquinone derivatives (10 hits) were selected, prepared, and tested in vitro against Ddl-B, Gyr-B, multidrug-resistant (MDR) E. coli, MRSA, and VRSA. A number of the tested derivatives demonstrated strong micromolar enzyme inhibition and antibacterial activity against E. coli, MRSA, and VRSA, with MIC values ranging from 2 to 64 µg/mL. Moreover, both E. coli's Ddl-B and Gyr-B were inhibited by emodin and chrysophanol with IC50 values comparable to the reference inhibitors (IC50 = 216 ± 5.6, 236 ± 8.9 and 0.81 ± 0.3, 1.5 ± 0.5 µM for Ddl-B and Gyr-B, respectively). All of the active antibacterial anthraquinone hits showed low to moderate cellular cytotoxicity (CC50 > 50 µM) against human normal fibroblasts (WI-38). Furthermore, molecular dynamic simulation (MDS) experiments were carried out to reveal the binding modes of these inhibitors inside the active site of each enzyme. The findings presented in this study are regarded as a significant step toward developing novel antibacterial agents against MDR strains.

Targeting allosteric sites of human aromatase: a comprehensive in-silico and in-vitro workflow to find potential plant-based anti-breast cancer therapeutics.

Recent findings suggested several allosteric pockets on human aromatase that could be utilised for the development of new modulators able to inhibit this enzyme in a new mechanism. Herein, we applied an integrated in-silico-based approach supported by in-vitro enzyme-based and cell-based validation assays to select the best leads able to target these allosteric binding sites from a small library of plant-derived natural products. Chrysin, apigenin, and resveratrol were found to be the best inhibitors targeting the enzyme's substrate access channel and were able to produce a competitive inhibition with IC50 values ranged from 1.7 to 15.8 µM. Moreover, they showed a more potent antiproliferative effect against ER+ (MCF-7) than ER- one (MDA-MB-231) cell lines. On the other hand, both pomiferin and berberine were the best hits for the enzyme's haem-proximal cavity producing a non-competitive inhibition (IC50 15.1 and 21.4 µM, respectively) and showed selective antiproliferative activity towards MCF-7 cell lines.

A metabolomic approach to target antimalarial metabolites in the Artemisia annua fungal endophytes.

Fungal endophytes are a major source of anti-infective agents and other medically relevant compounds. However, their classical blinded-chemical investigation is a challenging process due to their highly complex chemical makeup. Thus, utilizing cheminformatics tools such as metabolomics and computer-aided modelling is of great help deal with such complexity and select the most probable bioactive candidates. In the present study, we have explored the fungal endophytes associated with the well-known antimalarial medicinal plant Artemisia annua for their production of further antimalarial agents. Based on the preliminary antimalarial screening of these endophytes and using LC-HRMS-based metabolomics and multivariate analyses, we suggested different potentially active metabolites (compounds 1-8). Further in silico investigation using the neural-network-based prediction software PASS led to the selection of a group of quinone derivatives (compounds 1-5) as the most possible active hits. Subsequent in vitro validation revealed emodin (1) and physcion (2) to be potent antimalarial candidates with IC50 values of 0.9 and 1.9 µM, respectively. Our approach in the present investigation therefore can be applied as a preliminary evaluation step in the natural products drug discovery, which in turn can facilitate the isolation of selected metabolites notably the biologically active ones.

Testicular Caspase-3 and ß-Catenin Regulators Predicted via Comparative Metabolomics and Docking Studies.

Many routes have been explored to search for effective, safe, and affordable alternatives to hazardous female contraceptives. Herbal extracts and their secondary metabolites are some of the interesting research areas to address this growing issue. This study aims to investigate the effects of ten different plant extracts on testicular spermatogenesis. The correlation between the chemical profile of these extracts and their in vivo effect on male reproductive system was evaluated using various techniques. Approximately 10% of LD50 of hydro-methanolic extracts were orally administrated to rats for 60 days. Semen parameters, sexual organ weights, and serum levels of male sex hormones in addition to testes histopathology, were evaluated. Moreover, metabolomic analysis using (LC-HRESIMS), multivariate analysis (PCA), immunohistochemistry (caspase-3 and ß-catenin), and a docking study were performed. Results indicated that three plant extracts significantly decreased epididymal sperm density and motility. Moreover, their effects on testicular cells were also assured by histopathological evaluations. Metabolomic profiling of the bioactive plant extracts showed the presence of diverse phytochemicals, mostly oleanane saponins, phenolic diterpenes, and lupane triterpenes. A docking study on caspase-3 enzyme showed that oleanane saponins possessed the highest binding affinity. An immunohistochemistry assay on ß-catenin and caspase-3 indicated that Albizzia lebbeck was the most active extract for decreasing immunoexpression of ß-catenin, while Rosmarinus officinalis showed the highest activity for increasing immunoexpression of caspase-3. The spermatogenesis decreasing the activity of A. lebbeck, Anagallis arvensis, and R. officinalis can be mediated via up-regulation of caspase-3 and down-regulation of ß-catenin existing in testis cells.

Ameliorative Effect of Camel's Milk and Nigella Sativa Oil against Thioacetamide-induced Hepatorenal Damage in Rats.

BACKGROUND: Camel milk (CM) and Nigella sativa (NS) have been traditionally claimed to cure wide range of diseases and used as medicine in different part of world, particularly in Saudi Arabia. Several research studies have been published that proved beneficial effects of CM and NS. OBJECTIVE: This study was undertaken to investigate the antihepatotxic potential of CM and NS oil (NSO) against thioacetamide (TAA)-induced hepato and nephrotoxicity in rats. MATERIALS AND METHODS: Thirty female Albino Wistar rats were randomly divided in to six groups having five rats in each group. A single subcutaneous injection of TAA (100 mg/kg b. w.) was administered to all the rats in Group-II to VI on 1st day to induce hepatorenal damage. Group I served as a normal control while Group II served as toxic control for comparison purpose. Experimental animals in Group III, IV, and V were supplemented with fresh CM, (250 mL/24 h/cage), NSO (2 mL/kg/day p. o.), and NSO + fresh CM, respectively. Group VI was treated with a polyherbal hepatoprotective Unani medicine Jigreen (2 mL/kg/day p. o.) for 21 days. TAA-induced hepatorenal damage and protective effects of CM and NSO were assessed by analyzing liver and kidney function tests in the serum. Histopathology of liver and kidney tissues was also carried out to corroborate the findings of biochemical investigation. RESULTS: The results indicated that the TAA intoxicated rats showed significant increase in the alanine transaminase, aspartate transaminase, gamma-glutamyl transpeptidase, alkaline phosphatase, lipid profile, urea, creatinine, uric acid, sodium, and potassium levels in serum. Treatment of rats with CM, NSO, and CM plus NSO combination and Jigreen significantly reversed the damage and brought down the serum biochemical parameters and lipid profile toward the normal levels. The histopathological studies also support the hepato and nephroprotective effects of CM and NSO. CONCLUSION: This study demonstrated the ameliorative effects of CM, NSO, and CM plus NSO combination against TAA-induced hepatorenal toxicity in rats. SUMMARY: The antihepatotxic potential of Camel's Milk (CM) and Nigella sativa oil (NSO) against thioacetamide (TAA) induced hepatorenal toxicity was evaluated in ratsThe oral administration of fresh CM (250 mL/24h/cage), NSO (2 mL/kg/day) and NSO+fresh CM and Jigreen (2 mL/kg/day) for 21 days significantly decreased the hepatorenal toxicity as evidenced from analyzed biochemical parameters in serum and histopathological studies of liver and kidney tissuesThis study demonstrated the ameliorative effects of CM and NSO against TAA induced hepatorenal toxicity. Abbreviations used: CM: Camel milk; NS: Nigella sativa; NSO: Nigella sativa Oil; TAA: Thioacetamide; S.C.: Subcutaneous; Jig: Jigreen; b.w.: Body Weight; mL: Milli liter; mg: Milli gram; g: Gram; Kg: Kilo gram; ALT: Alanine transaminase; AST: Aspartate transaminase; GGT: Gamma-Glutamyl Transpeptidase; ALP: Alkaline Phosphatase; TC: Total Cholesterol; HDL-C: High Density Lipoprotein Cholesterol; LDL-C: Low Density Lipoprotein Cholesterol; TG: Triglyceride; TB: Total bilirubin; K+: Potassium; Na+: Sodium; CCl4: Carbon Tetrachloride; °C: Degree Celsius; p.o.: Per Oral; RPM: Revolutions per minute; H&E: Hematoxylin and Eosin; SEM: Standard Error of Mean; ANOVA: The one-way analysis of variance.

High affinity truncated DNA aptamers for the development of fluorescence based progesterone biosensors.

Aptamers have shown a number of potential applications in sensing and therapeutic due to the high affinity and specificity towards their target molecules. Not all the nucleotides in the full length aptamers are involved in the binding with their targets. The non-binding domain of the aptamer may affect the binding affinity of the aptamer-target complex. Mapping the aptamer binding region could increase the affinity and the specificity. In this paper, we designed aptamer-based fluorescence sensors from a truncated progesterone (P4) aptamer. Then, fluorescein and quencher labelled aptamer complementary oligonucleotide sequences were hybridized to the truncated aptamer at different sites to form duplex structures. We used fluorescence-quencher pair displacement assay upon progesterone binding for the determination of P4. One of the truncated sequences has shown high binding affinity with 16 fold increase in the dissociation constant, Kd (2.1 nM) compared to the original aptamer. The aptasensor was highly selective for P4 against similar compounds such as 17-ß estradiol, bisphenol-A and vitamin D. The sensor has been applied for the detection of P4 in spiked tap water and in urine samples showing good recovery. This new developed aptamer-based fluorescence biosensor can be applied in food, pharmaceutical, and clinical industries.