Phytochemical Screening, In Silico Molecular Docking, ADME Properties, and In Vitro Antioxidant, Anticancer, and Antidiabetic Activity of Marine Halophyte Suaeda maritima (L.) Dumort.

Medicinally valuable components derived from natural resources are highly desirable as prospective alternatives to synthetic drugs to treat fatal diseases, such as cancer and diabetes mellitus. Suaeda maritima (L.) Dumort (Amaranthaceae) (S. maritima) is a halophyte plant that can thrive in saline environments and possesses excellent medicinal properties. Hence, for the present investigation, S. maritima has been chosen, and its phytochemical constituents have been extracted utilizing various solvents, including hexane, acetone, and methanol, and identified by GC-MS, LC-MS, and HPLC analyses. The antioxidant activity of the compounds using DPPH, ABTS, and reducing power assays demonstrated that all three extracts of S. maritima possessed significant radical scavenging activity comparable to standard ascorbic acid with lower IC50 values (69.20-95.58 µg/mL). In addition, the evaluation of antidiabetic activity by α-amylase inhibition and α-glucosidase inhibition methods revealed that the acetone extract of S. maritima (SMAE) displayed equipotent activity of standard acarbose with an IC50 of 32.6 µg/mL. Advantageously, SMAE also exhibited better inhibition activity against the growth of lung cancer cells with an IC50 of 78.19. µg/mL and less toxicity on the noncancerous HUVEC cells with a high IC50 of 300 µg/mL. In addition, the cancer cell death mechanism via the apoptotic pathway induced by SMAE was confirmed by DAPI staining and ROS analysis. The analysis of ADME properties, including absorption, distribution, metabolism, and excretion, witnessed that the physicochemical and druglikeness factors were best catered by stigmasterol, γ-sitosterol, and vitamin E. Further, the key phytochemicals identified from SMAE were docked with CtBP1 and SOX2 bound to importin-α target proteins associated with carcinogenic pathways using Schrodinger software. The results showed that the phytochemicals, scilicet, stigmasterol, γ-sitosterol, octadecadienoic acid, and vitamin E, showed a good binding affinity with Glide scores in the range -2.845-4.018 kcal/mol. Overall, the findings support that the least investigated traditional edible medicinal mangrove-related S. maritima is high in pharmacologically active constituents and might be one of the finest sources of naturally derived molecules for drug development and delivery systems.

Toxicity analysis and biomarker response of Quinalphos Organophosphate Insecticide (QOI) on eco-friendly exotic Eudrilus eugeniae earthworm.

An ever-increasing use of pesticides in agricultural fields has led to a catastrophic decline in crop quality and, ultimately soil fertility. To control various pests, quinalphos is commonly used in India's tea plantations. This study aims to investigate the effects of the Quinalphos organophosphate insecticide on the non-target beneficial organism Eudrilus eugeniae earthworms and the biomarkers that respond to its effects. Earthworm species, especially E. eugeniae, remains as the most trustworthy and well-suited model organism for conducting a wide variety of environmental studies. The median lethal concentration (LC50) was identified as 3.561 µg cm-2 (contact filter paper) and 1.054 mg kg-2 (artificial soil toxicity). The 5% and 10% of LC50 value 3.561 µg cm-2 was exposed to earthworm to analyze the sublethal effects at pre-clitellum, clitellum, and post-clitellum segments. Specific enzymatic activities of neurotransmitter enzyme acetylcholinesterase; antioxidant enzymes such as lipid peroxidase, superoxide dismutase, and catalase; and detoxification enzymes including glutathione S transferase, reduced glutathione, carboxylesterase, and Cytochrome P450 were analyzed. Exposure of E. eugeniae earthworm to subacute exposures of pesticides caused significant alterations in these stress markers in a concentration-dependent manner. Morphological abnormalities like bulginess, coiling, and bleeding were observed after exposure of the insecticide treatments. Histological cellular disintegration, a reduced NRRT time, and an inhibited proteolytic zone were also identified in pesticide-exposed earthworms. Studies demonstrate that the organophosphate insecticide quinalphos causes acute toxicity in E. eugeniae; hence, it is suggested that non-target eco-friendly E. eugeniae earthworms may be at risk if exposed to the excessive concentrations of quinalphos organophosphate insecticide in soil.

Identification and structural prediction of the unrevealed amidohydrolase enzyme: Pterin deaminase from Agrobacterium tumefaciens LBA4404.

Microbes make a remarkable contribution to the health and well-being of living beings all over the world. Interestingly, pterin deaminase is an amidohydrolase enzyme that exhibits antitumor, anticancer activities and antioxidant properties. With the existing evidence of the presence of pterin deaminase from microbial sources, an attempt was made to reveal the existence of this enzyme in the unexplored bacterium Agrobacterium tumefaciens LBA4404. After, the cells were harvested and characterized as intracellular enzymes and then partially purified through acetone precipitation. Subsequently, further purification step was carried out with an ion-exchange chromatogram (HiTrap Q FF) using the Fast-Protein Liquid Chromatography technique (FPLC). Henceforward, the approximate molecular weight of the purified pterin deaminase was determined through SDS-PAGE. Furthermore, the purified protein was identified accurately by MALDI-TOF, and the sequence was explored through a Mascot search engine. Additionally, the three-dimensional structure was predicted and then validated, as well as ligand-binding sites, and the stability of this enzyme was confirmed for the first time. Thus, the present study revealed the selected parameters showing a considerable impact on the identification and purification of pterin deaminase from A. tumefaciens LBA4404 for the first time. The enzyme specificity makes it a favorable choice as a potent anticancer agent.

Microbial (Enzymatic) Degradation of Cyanide to Produce Pterins as Cofactors.

Cyanide is one of the most poisonous substances in the environment, which may have originated from natural and anthropogenic sources. There are many enzymes produced by microorganisms which can degrade and utilize cyanide. The major byproducts of cyanide degradation are alanine, glutamic acid, alpha-amino-butyric acid, beta-cyanoalanine, pterin etc. These products have many pharmaceutical and medicinal applications. For the degradation of cyanide, microbes produce necessary cofactors which catalyze the degradation pathways. Pterin is one of the cofactors for cyanide degradation. There are many pathways involved for the degradation of cyanide, cyanate, and thiocyanate. Some of the microorganisms possess resistance to cyanide, since they have developed adaptive alternative pathways for the production of ATP by utilization of cyanide as carbon and nitrogen sources. In this review, we summarized different enzymes, their mechanisms, and corresponding pathways for the degradation of cyanide and production of pterins during cyanide degradation. We aim to enlighten different types of pterin, its classification, and biological significance through this literature review.

Evaluation of Pterin, a Promising Drug Candidate from Cyanide Degrading Bacteria.

Pterin is a member of the compounds known as pteridines. They have the same nucleus of 2-amino-4-hydroxypteridine (pterin); however, the side-chain is different at the position 6, and the state of oxidation of the ring may exist in different form viz. tetrahydro, dihydro, or a fully oxidized form. In the present study, the microorganisms able to utilize cyanide, and heavy metals have been tested for the efficient production of pterin compound. The soil samples contaminated with cyanide and heavy metals were collected from Salem steel industries, Tamil Nadu, India. Out of 77 isolated strains, 40 isolates were found to utilize sodium cyanate as nitrogen source at different concentrations. However, only 13 isolates were able to tolerate maximum concentration (60 mM) of sodium cyanate and were screened for pterin production. Among the 13 isolates, only 1 organism showed maximum production of pterin, and the same was identified as Bacillus pumilus SVD06. The compound was extracted and purified by preparative high-performance liquid chromatography and analyzed by UV/visible, FTIR, and fluorescent spectrum. The antioxidant property of the purified pterin compound was determined by cyclic voltammetry. In addition, antimicrobial activity of pterin was also studied which was substantiated by antagonistic activity against Escherichia coli, and Pseudomonas aeruginosa. Besides that the pterin compound was proved to inhibit the formation of biofilm. The extracted pterin compounds could be proposed further not only for antioxidant and antimicrobial but also for its potency to aid as anticancer and psychotic drugs in future.

Identification and in silico characterization of a novel peptide inhibitor of angiotensin converting enzyme from pigeon pea (Cajanus cajan).

BACKGROUND: Plants are important sources of bioactive peptides. Among these, angiotensin converting enzyme (ACE) inhibitory peptides have a major focus on their ability to prevent hypertension. Inhibition of ACE has been established as an effective approach for the treatment of ACE associated diseases. HYPOTHESIS/PURPOSE: Some synthetic ACE inhibitory drugs cause side effects and hence there is a constant interest in natural compounds as alternatives. STUDY DESIGN: The study was designed to identify and characterize a peptide molecule from pigeon pea which has the biological property to inhibit ACE and can be developed as a therapeutic approach towards hypertension. METHODS: Seeds of pigeon pea (Cajanus cajan (L.) Millsp.) was fermented with Aspergillus niger, a proteolytic fungus isolated from spoiled milk sweet. The extract was purified by size exclusion chromatography by FPLC system. The fractions that showed ACE inhibition was subjected to LC-MS/MS for sequence identification. The stability of the peptide was analyzed by molecular dynamic simulations and the interaction sites with ACE were identified by molecular docking. RESULTS: The study report a novel ACE inhibitory octapeptide Val-Val-Ser-Leu-Ser-Ile-Pro-Arg with a molecular mass of 869.53 Da. The Lineweaver-Burk plot indicated that the inhibition of ACE by this peptide is in competitive mode. Also, molecular docking and simulation studies showed a strong and stable interaction of the peptide with ACE. CONCLUSION: The results clearly show the inhibitory property of the peptide against ACE and hence it can be explored as a therapeutic strategy towards hypertension and other ACE associated diseases.

Characterization of unexplored amidohydrolase enzyme-pterin deaminase.

Pterin deaminase is an amidohydrolase enzyme hydrolyzing pteridines to form lumazine derivatives and ammonia. The enzyme captured the attention of scientists as early as 1959 and had been patented for its application as an anticancer agent. It is ubiquitously present in prokaryotes and has been reported in some eukaryotes such as honey bee, silkworm and rats. The enzyme has been observed to have a spectrum of substrates with the formation of respective lumazines. The role of the substrates of the enzyme in various metabolic pathways warrants a significant role in the biological activity of both prokaryotes and eukaryotes. Even though the functions of the enzyme have been explored in prokaryotes, their niche in the eukaryotic system is not clear. There is very few information on the structural and functional properties of the enzyme. This review has been congregated to emphasize the significance of pterin deaminase and analyzes the lacunae in understanding the biological characters of the enzyme.