Exploring Cassia mimosoïdes as a promising natural source of steroids with potent anti-cancer, urease inhibition, and antimicrobial properties.

The genus Cassia is a rich source of physiologically active secondary metabolites, including a novel compound named 21-methylene-24-ethylidene lophenol, alongside 15 known compounds. These compounds were characterized using different spectroscopic techniques. They exhibited promising antimicrobial activity, particularly against bacteria causing gastrointestinal infections. Compound 1 showed strong anti-bacterial activity against H. pylori and S. aur with MIC values of 0.28 and 0.12 µg mL-1 respectively. The study investigated their impact on H. pylori, a contributor to ulcer development, by inhibiting the urease enzyme. Inhibiting urease can reduce H. pylori's pathogenic potential, evident from the fact that the compounds evaluated toward urease enzyme showed higher inhibitory activity (1.024 ± 0.43 6.678±0.11 µM) compared to standard thiourea (IC50 = 18.61 ± 0.11 µM). Molecular docking studies confirmed their inhibitory action, with compound 7 notably outperforming thiourea in inhibiting urease (-6.95 kcal mol-1vs. -3.13 kcal mol-1). Additionally, these compounds showed positive effects on liver functioning, which H. pylori can impair. Compound 9 shows the best response against human HepG2 liver cancer cell lines i.e., % viability is 14.47% ± 0.69 and IC50 is 7.8 µM ± 0.21. These compounds hold potential as lead compounds for addressing gastrointestinal and liver disorders caused by H. pylori.

Novel Coumarin Derivatives as Potential Urease Inhibitors for Kidney Stone Prevention and Antiulcer Therapy: From Synthesis to In Vivo Evaluation.

The presence of ammonium ions in urine, along with basic pH in the presence of urease-producing bacteria, promotes the production of struvite stones. This causes renal malfunction, which is manifested by symptoms such as fever, nausea, vomiting, and blood in the urine. The involvement of urease in stone formation makes it a good target for finding urease enzyme inhibitors, which have the potential to be developed as lead drugs against kidney stones in the future. The documented ethnopharmacology of coumarin 2-one against bacterial, fungal and viral strains encouraged us to synthesize new derivatives of coumarins by reacting aromatic aldehydes with 4-aminocoumarin. The synthesized compounds (2a to 11a) were evaluated for their antimicrobial, in vitro, and in silico properties against the urease enzyme. The study also covers in vivo determination of the synthesized compounds with respect to different types of induced ulcers. The molecular docking study along with extended MD simulations (100 ns each) and MMPBSA study confirmed the potential inhibitory candidates as evident from computed ∆Gbind (3a = -11.62 and 5a = -12.08 Kcal/mol) against the urease enzyme. The in silico analyses were augmented by an enzymatic assay, which revealed that compounds 3a and 5a had strong inhibitory action, with IC50 of 0.412 µM (64.0% inhibition) and 0.322 µM (77.7% inhibition), respectively, compared to standard (Thiourea) with 82% inhibition at 0.14 µM. Moreover, the most active compound, 5a, was further tested in vivo for antiulcer activity by different types of induced ulcers, including pyloric ligation-, ethanol-, aspirin-, and histamine-induced ulcers. Compound 5a effectively reduced gastric acidity, lipid peroxidation, and ulceration in a rat model while also inhibiting gastric ATPase activity, which makes it a promising candidate for ulcer treatment. As a result of the current research, 3a and 5a may be used as new molecules for developing potent urease inhibitors. Additionally, the compound 3a showed antibacterial activity against Staphylococcus aureus and Salmonella typhimurium, with zones of inhibition of 41 ± 0.9 mm and 35 ± 0.9 mm, respectively. Compound 7a showed antibacterial activity against Staphylococcus aureus and Salmonella typhimurium, with zones of inhibition of 30 ± 0.8 mm and 42 ± 0.8 mm, respectively. These results prove that the synthesized compounds also possess good antibacterial potential against Gram-positive and Gram-negative bacterial strains.

Bioactivity-Guided Synthesis: In Silico and In Vitro Studies of ß-Glucosidase Inhibitors to Cope with Hepatic Cytotoxicity.

The major cause of hyperglycemia can generally be attributed to ß-glucosidase as per its involvement in non-alcoholic fatty liver disease. This clinical condition leads to liver carcinoma (HepG2 cancer). The phthalimides and phthalamic acid classes possess inhibitory potential against glucosidase, forming the basis for designing new phthalimide and phthalamic acid analogs to test their ability as potent inhibitors of ß-glucosidase. The study also covers in silico (molecular docking and MD simulations) and in vitro (ß-glucosidase and HepG2 cancer cell line assays) analyses. The phthalimide and phthalamic acid derivatives were synthesized, followed by spectroscopic characterization. The mechanistic complexities associated with ß-glucosidase inhibition were identified via the docking of the synthesized compounds inside the active site of the protein, and the results were analyzed in terms of the best binding energy and appropriate docking pose. The top-ranked compounds were subjected to extensive MD simulation studies to understand the mode of interaction of the synthesized compounds and binding energies, as well as the contribution of individual residues towards binding affinities. Lower RMSD/RMSF values were observed for 2c and 3c, respectively, in the active site, confirming more stabilized, ligand-bound complexes when compared to the free state. An anisotropic network model was used to unravel the role of loop fluctuation in the context of ligand binding and the dynamics that are distinct to the bound and free states, supported by a 3D surface plot. An in vitro study revealed that 1c (IC50 = 1.26 µM) is far better than standard acarbose (2.15 µM), confirming the potential of this compound against the target protein. Given the appreciable potential of the candidate compounds against ß-glucosidase, the synthesized compounds were further tested for their cytotoxic activity against hepatic carcinoma on HepG2 cancer cell lines. The cytotoxicity profile of the synthesized compounds was performed against HepG2 cancer cell lines. The resultant IC50 value (0.048 µM) for 3c is better than the standard (thalidomide: IC50 0.053 µM). The results promise the hypothesis that the synthesized compounds might become potential drug candidates, given the fact that the ß-glucosidase inhibition of 1c is 40% better than the standard, whereas compound 3c holds more anti-tumor activity (greater than 9%) against the HepG2 cell line than the known drug.

In-vitro high-throughput library screening-Kinetics and molecular docking studies of potent inhibitors of α-glucosidase.

High throughput screening of synthetic compounds against vital enzymes is the way forward for the determination of potent enzyme inhibitors. In-vitro high throughput library screening of 258 synthetic compounds (comp. 1-258), was performed against α-glucosidase. The active compounds out of this library were investigated for their mode of inhibition and binding affinities towards α-glucosidase through kinetics as well as molecular docking studies. Out of all the compounds selected for this study, 63 compounds were found active within the IC50 range of 3.2 µM to 50.0 µM. The most potent inhibitor of α-glucosidase out of this library was the derivative of an oxadiazole (comp. 25). It showed the IC50 value of 3.23 ± 0.8 µM. Other highly active compounds were the derivatives of ethyl-thio benzimidazolyl acetohydrazide with IC50 values of 6.1 ± 0.5 µM (comp. 228), 6.84 ± 1.3 µM (comp. 212), 7.34 ± 0.3 µM (comp. 230) and 8.93 ± 1.0 µM (comp. 210). For comparison, the standard (acarbose) showed IC50 = 378.2 ± 0.12 µM. Kinetic studies of oxadiazole (comp. 25) and ethylthio benzimidazolyl acetohydrazide (comp. 228) derivatives indicated that Vmax and Km, both change with changing concentrations of inhibitors which suggests an un-competitive mode of inhibition. Molecular docking studies of these derivatives with the active site of α-glucosidase (PDB ID:1XSK), revealed that these compounds mostly interact with acidic or basic amino acid residues through conventional hydrogen bonds along with other hydrophobic interactions. The binding energy values of compounds 25, 228, and 212 were -5.6, -8.7 and -5.4 kcal.mol-1 whereas RMSD values were 0.6, 2.0, and 1.7 Å, respectively. For comparison, the co-crystallized ligand showed a binding energy value of -6.6 kcal.mol-1 along with an RMSD value of 1.1 Å. Our study predicted several series of compounds as active inhibitors of α-glucosidase including some highly potent inhibitors.

Isoxazole Derivatives against Carbonic Anhydrase: Synthesis, Molecular Docking, MD Simulations, and Free Energy Calculations Coupled with In Vitro Studies.

Heterocyclic compounds with a five-membered ring as a core, particularly those containing more than one heteroatom, have a wide spectrum of biological functions, especially in enzyme inhibition. In this study, we present the synthesis of five-membered heterocyclic isoxazole derivatives via sonication of ethyl butyrylacetate with aromatic aldehyde in the presence of a SnII-Mont K10 catalyst. The synthesized compounds were characterized using sophisticated spectroscopic methods. In vitro testing of the compounds reveals three derivatives with significant inhibitory action against carbonic anhydrase (CA) enzyme. The compound AC2 revealed the most promising inhibitory activity against CA among the entire series, with an IC50 = 112.3 ± 1.6 µM (%inh = 79.5) followed by AC3 with an IC50 = 228.4 ± 2.3 µM (%inh = 68.7) compared to the standard with 18.6 ± 0.5 µM (%inh = 87.0). Molecular docking (MD) study coupled with extensive MD simulations (400 ns) and MMPBSA study fully supported the in vitro enzyme inhibition results, evident from the computed ΔG bind (AC2 = -13.53 and AC3 = -12.49 kcal/mol). The in vitro and in silico studies are also augmented by a fluorescence-based enzymatic assay in which compounds AC2 and AC3 showed significant fluorescence enhancement. Therefore, on the basis of the present study, it is inferred that AC2 and AC3 may serve as a new framework for designing effective CA inhibitors.

Three New Acrylic Acid Derivatives from Achillea mellifolium as Potential Inhibitors of Urease from Jack Bean and α-Glucosidase from Saccharomyces cerevisiae.

(1) Background: Achillea mellifolium belongs to a highly reputed family of medicinal plants, with plant extract being used as medicine in indigenous system. However, limited data is available regarding the exploitation of the medicinal potential of isolated pure compounds from this family; (2) Methods: A whole plant extract was partitioned into fractions and on the basis of biological activity, an ethyl acetate fraction was selected for isolation of pure compounds. Isolated compounds were characterized using different spectroscopic techniques. The compounds isolated from this study were tested for their medicinal potential using in-vitro enzyme assay, coupled with in-silico studies; (3) Results: Three new acrylic acid derivatives (1-3) have been isolated from the ethyl acetate fraction of Achillea mellifolium. The characterization of these compounds (1-3) was carried out using UV/Vis, FT-IR, 1D and 2D-NMR spectroscopy (1H-NMR, 13C-NMR, HMBC, NOESY) and mass spectrometry. These acrylic acid derivatives were further evaluated for their enzyme inhibition potential against urease from jack bean and α glucosidase from Saccharomyces cerevisiae, using both in-silico and in-vitro approaches. In-vitro studies showed that compound 3 has the highest inhibition against urease enzyme (IC50 =10.46 ± 0.03 µΜ), followed by compound 1 and compound 2 with percent inhibition and IC50 value of 16.87 ± 0.02 c and 13.71 ± 0.07 µΜ, respectively, compared to the standard (thiourea-IC50 = 21.5 ± 0.01 µΜ). The investigated IC50 value of compound 3 against the urease enzyme is two times lower compared to thiourea, suggesting that this compound is twice as active compared to the standard drug. On the other hand, all three compounds (1-3) revealed mild inhibition potential against α-glucosidase. In-silico molecular docking studies, in combination with MD simulations and free energy, calculations were also performed to rationalize their time evolved mode of interaction inside the active pocket. Binding energies were computed using a MMPBSA approach, and the role of individual residues to overall binding of the inhibitors inside the active pockets were also computed; (4) Conclusions: Together, these studies confirm the inhibitory potential of isolated acrylic acid derivatives against both urease and α-glucosidase enzymes; however, their inhibition potential is better for urease enzyme even when compared to the standard.

Green synthesis, in vivo and in vitro pharmacological studies of Tamarindus indica based gold nanoparticles.

The current investigation aims to synthesize gold nanoparticles (AuNPs) from aqueous extract of Tamarindus indica and to evaluate the in vitro anti-bacterial and in vivo sedative and anelgescic activities of crude extract as well as synthesized AuNPs. Several methods have been reported to synthesize AuNPs; however, most of them were not ecofriendly. In the present study, the green synthesis of AuNPs has been carried out. Using the green synthesis method, AuNPs of T. indica were synthesized at room temperature (25 °C) by mixing 5 mL of HAuCl4 (1 mM) with 1 mL of T. indica seed extract solution. This extract solution was prepared by taking 5 gm dry seeds in 100 mL of double deionized water with continuous stirring for up to 24 h at 80 °C. The stability of AuNPs was confirmed with the help of relevant experimental techniques including ultraviolet-visible (UV/Vis) showing maximum absorbance at 535-540 nm, Fourier transform infrared showing a broad signal at 3464 cm-1 which can be attributed to either amide or hydroxyl functionalities and atomic force microscopy analysis showed that the biomaterial surrounding AuNPs was agglomerated which proves the formation of discrete nanostructutres. These AuNPs have been evaluated for their antibacterial potential. The results revealed good antibacterial activity of the samples against. Klebsiella pneumonia, Bacillus subtilis and Staphylococcus epidermidis with 10-12 mm zone of inhibition range. The AuNPs were also found stable at high temperature, over a range of pH and in 1 mM salt solution. Moreover, the crude extract and respective AuNPs also exhibited interesting sedative and analgesic activities. Hence, we focused on phytochemicals-mediated synthesis of AuNPs considered as greatest attention in the treatment of anti-bacterial, analgesic, and sedative.

Enzyme inhibition and antibacterial potential of 4-Hydroxycoumarin derivatives

The 4-Hydroxycoumarin derivatives are known to show a broad spectrum of pharmacological applications. In this paper we are reporting the synthesis of a new series of 4-Hydroxycoumarin derivatives synthesized through Knovenegal condensation; they were characterized by using UV-Vis, FT-IR, NMR spectroscopies. The synthesized compounds were evaluated for antibacterial activity against Staphylococcus aureus and Salmonella typhimurium strains. The compounds (2), (3) and (8) showed favorable antibacterial activity with zone of inhibitions 26.5± 0.84, 26.0 ± 0.56 and 26.0 ± 0.26 against Staphylococcus aureus (Gram-positive) respectively. However, the compounds (5) and (9) were found more active with 19.5 ± 0.59 and 19.5 ± 0.32 zone of inhibitions against Salmonella typhimurium (Gram-negative). Whereas, in urease inhibition assay, none of the synthesized derivatives showed significant anti-urease activity; although, in carbonic anhydrase-II inhibition assay, the compound (2) and (6) showed enzyme inhibition activity with IC50 values 263±0.3 and 456±0.1, respectively.

Sedative and antinociceptive activities of two new sesquiterpenes isolated from Ricinus communis.

Two new sesquiterpenes, trivially named ricinusoids A (1) and ricinusoids B (2), were isolated from ethyl acetate fraction of Ricinus communis. The structures of new compounds were elucidated by detailed spectroscopic techniques, including 1D- and 2D-NMR, UV, IR spectroscopy, and mass spectrometry. The compounds (1-2) were also assessed for in-vivo sedative and analgesic like effects in open field and acetic acid induced writhing tests respectively at 5, 10, and 20 mg·kg-1 i.p. Pretreatment of both test compounds caused significant (P ≤ 0.05) reduction in locomotive activity like sedative agents and abdominal constrictions like analgesics. Both compounds (1-2) possessed marked sedative and antinociceptive effects in animal models.

Changes in thyroid function status of suicidal patients

Abstract Background This study was carried out at Punjab Institute of Mental Health and Centre for Nuclear Medicine Mayo Hospital, Lahore. It is aimed at the possible association of thyroid malfunctioning with suicide attempts of patients. Objective Determination of thyroid function status of suicidal psychiatric patients and their comparison with psychiatric patients without suicide attempt or ideation. Methods Total 54 patients with either past history of suicide attempt or current suicidal ideation were selected for analysis of their thyroid function status (age 15-55 years). Age matched 50 non-suicide psychiatric patients were included for comparison. Results Two patients with suicide attempt had overt thyroid dysfunction. Remaining patients had serum FT4, FT3 and TSH level within normal range. Suicide attempter patients had lower FT4 but increased FT3 and TSH levels compared to suicidal ideation patients. Serum FT4 and TSH levels in suicidal patients were not different from psychiatric patients. Serum FT3 in suicidal patients was lower than psychiatric patients (3.7 ± 0.8 vs. 4.3 ± 0.5; p < 0.05). Female suicidal patients had lower FT3 levels compared to male patients (3.4 ± 0.6 vs. 3.9 ± 0.8 pmol/L; p < 0.05). Discussion Local suicidal patients have higher incidence of overt thyroid disorder and lower FT3 levels compared to non-suicidal psychiatric patients.

Isolation and characterization of three new anti-proliferative Sesquiterpenes from Polygonum barbatum and their mechanism via apoptotic pathway.

BACKGROUND: The emergence of chemoresistant cancers and toxicity related to existing chemotherapeutic agents, demand the search for new pharmacophore with enhanced anti-cancer activity and least toxicity. For this purpose, three new sesquiterpenes were isolated from ethyl acetate fraction of the aerial parts of the plant Polygonum barbatum and evaluated for their anti-cancer potential. METHODS: The structural elucidation and characterization of the isolated compounds 1-3 were performed using various spectroscopic techniques such as mass, UV, IR, and extensive 1D/2D-NMR spectroscopy. Furthermore, the compounds 1-3 were subjected to screening of anti-cancer activity against different cell lines followed by brief analysis of apoptotic and anti-angiogenic potentials of the potent hit against non-small cell lung carcinoma cell line. RESULTS: All the compounds 1-3 were subjected to anti-proliferative potential against non-small cell lung carcinoma (NCI-H460), breast cancer (MCF-7), cervical cancer (HeLa) and normal mouse fibroblast (NIH-3 T3) cell lines. Among these, compound 3 was found to be more cytotoxic against NCI-H460 and MCF-7 cells (IC50 = 17.86 ± 0.72 and 11.86 ± 0.46 µM respectively). When compared with the standard drug cisplatin compound 3 was found to have more potent activity against NCI-H460 (IC50 = 19 ± 1.24 µM) as compared to MCF-7 cell lines (IC50 = 9.62 ± 0.5 µM). Compound 3 induced apoptosis in NCI-H460 cells in a dose dependent manner. It significantly downregulated, the expression of anti-apoptotic (BCL-2 L1 and p53) and increased the expression of pro-apoptotic (BAK and BAX) genes. Besides apoptosis, it also significantly reduced the cell migration and downregulated the angiogenic genes (i.e. VEGF and COX-2), thereby, inhibiting angiogenesis in NCI-H460 cells. CONCLUSION: Compound 3 possesses potent anti-proliferative potential as well as induced apoptosis and inhibited the cell migration of the cancerous cells by altering the gene expression, responsible for it.

Bioassay-guided isolation of novel and selective urease inhibitors from Diospyros lotus.

Two new dimeric naphthoquinones, 5',8'-dihydroxy-6,6'-dimethyl-7,3'-binaphthyl-1,4,1',4'-tetraone (1; Di-naphthodiospyrol D) and 5',8'-dihydroxy-5,8-dimethoxy-6,6'-dimethyl-7,3'-binaphthyl-1,4,1',4'-tetraone (2; Di-naphthodiospyrol E), along with known naphthoquinones diospyrin (3) and 8-hydroxy diospyrin (4) were isolated from the chloroform fraction of extract of Diospyros lotus roots. Their structures were elucidated by advanced spectroscopic analyses, including HSQC, HMBC, NOESY, and J-resolved NMR experiments. The fractions and compounds 1-4 were evaluated for urease activity and phosphodiesterase-I, carbonic anhydrase-II and α-chymotrypsin enzyme inhibitory activities. Compounds 1 and 2 and their corresponding fractions showed significant and selective inhibitory effects on urease activities. The IC50 values of 1 and 2 were 260.4 ± 6.37 and 381.4 ± 4.80 µmol·L-1, respectively, using thiourea (IC50 = 21 ± 0.11 µmol·L-1) as the standard inhibitor. This was the first report demonstrating that the naphthoquinones class showed urease inhibition.

Three new anthraquinone derivatives isolated from Symplocos racemosa and their antibiofilm activity.

Three new alkyl substituted anthraquinone derivatives, trivially named as symploquinones A-C (Compounds 1-3) were isolated from Symplocos racemosa. The structures of these compounds were determined on the basis of extensive spectroscopic analyses (UV, IR, Mass, 1H- and 13C-NMR, and two-dimensional (2D) NMR techniques). The resulting data were also compared with the reported literature. These compounds were then subjected to antibacterial or antibiofilm testing. Compounds 1 and 3 exhibited good antibacterial activity in the concentration range of 160-83 µg·mL-1 against Streptococcus mutans, methicillin resistant Staphylococcus aureus and Proteus mirabilis. Both compounds were further screened for anti-biofilm activity, which revealed promising activities at sub-MIC concentrations. None of the compounds were found to be active against Klebsiella pneumoniae.

CHLOROGENIC ACID: A PHARMACOLOGICALLY POTENT MOLECULE.

Chlorogenic acid (CGA; (IS,3R,4R.5R)-3-{[(2Z)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}-1,4,5-trihydroxycyclohexanecarboxylic acid) is a naturally occurring polyphenol mostly present in vegetables and fruits. CGA is a prominent component of Traditional Chinese Medicines and is known for various pharmacological activities such as antioxidant, antimicrobial, anti-inflammatory and hepatoprotective etc. This mini-review is an attempt to summarize the available literature in the last decade and to point out future perspectives in this area of research.