Carboxylate derivatives of tributyltin (IV) complexes as anticancer and antileishmanial agents

Updates on drug designing approach through computational strategies: a review

The drug discovery and development (DDD) process in pursuit of novel drug candidates is a challenging procedure requiring lots of time and resources. Therefore, computer-aided drug design (CADD) methodologies are used extensively to promote proficiency in drug development in a systematic and time-effective manner. The point in reference is SARS-CoV-2 which has emerged as a global pandemic. In the absence of any confirmed drug moiety to treat the infection, the science fraternity adopted hit and trial methods to come up with a lead drug compound. This article is an overview of the virtual methodologies, which assist in finding novel hits and help in the progression of drug development in a short period with a specific medicinal solution.

Biological Evaluation of Triorganotin Derivatives as Potential Anticancer Agents

Metal-derived platinum complexes are widely used to treat solid tumors. However, systemic toxicity and tumor resistance to these drugs encourage further research into similarly effective compounds. Among others, organotin compounds have been shown to inhibit cell growth and induce cell death and autophagy. Nevertheless, the impact of the ligand structure and mechanisms involved in the toxicity of organotin compounds have not been clarified. In the present study, the biological activities of commercially available bis(tributyltin) oxide and tributyltin chloride, in comparison to those of specially synthesized tributyltin trifluoroacetate (TBT-OCOCF₃) and of cisplatin, were assessed using cells with different levels of tumorigenicity. The results show that tributyltins were more cytotoxic than cisplatin in all the tested cell lines. NMR revealed that this was not related to the interaction with DNA but to the inhibition of glucose uptake into the cells. Moreover, highly tumorigenic cells were less susceptible than nontumorigenic cells to the nonunique pattern of death induced by TBT-OCOCF₃. Nevertheless, tumorigenic cells became sensitive when cotreated with wortmannin and TBT-OCOCF₃, although no concomitant induction of autophagy by the compound was detected. Thus, TBT-OCOCF₃ might be the prototype of a family of potential anticancer agents.

Design, synthesis and screening of indole acetic acid-based tri-azo moieties as antioxidants, anti-microbial and cytotoxic agents

Multidrug resistance and infectious disease have enormous spread despite drug discovery and development advancements. 1, 2, 4 -triazoles have been extensively studied, playing an imperative role in many pathologic conditions. A series of Schiff base triazoles; derived from Indole -3- acetic acid with substituted Benzaldehydes (5a-5g) were designed, synthesized, and evaluated through various Spectroanalytical techniques. SwissADME was used to assess physicochemical properties and pharmacokinetic drug-likeliness behavior. (5a-5g) were evaluated for their varied biological potential through antioxidant, antimicrobial, enzyme inhibition, and cytotoxic evaluation. Schiff bases express drug-like nature as they follow Lipinski's rule of five. 5b showed good antioxidant potential in total antioxidant capacity (TAC) and total reducing power (TRP) assays and was most active in the library in % free radical scavenging assay (%FRSA), showing 32% inhibition at 50 μg/mL concentration. Compounds showed antibacterial activity against various tested strains. 5e and 5f showed a minimum inhibitory concentration (MIC) value of 3.12 μg/mL for P.aeruginosa and K.pneumoniae, respectively. In the antifungal assay, only 5e inhibited one strain with a zone of inhibition >6 mm. These synthetic molecules possess good cytotoxic potential in the Brine Shrimp Lethality screening; 5c, 5d, and 5f exhibited LC_{50 =}5.7 μg/mL. In the protein kinase inhibition assay, 5a, 5b, and 5g demonstrated inhibitory potential, showcasing the zone of inhibition as 7.5-10.5 mm for the bald one and 6-7.5 for the clear zone. These findings suggest that the compounds have antibacterial and cytotoxic potential, and there is a chance for further research and development in this area.

Models for cytotoxicity screening of antileishmanial drugs: what has been done so far?

A growing number of studies have demonstrated the in vitro potential of an impressive number of antileishmanial candidates in the past years. However, the lack of uniformity regarding the choice of cell types for cytotoxicity assays may lead to uncomparable and inconclusive data. In vitro assays relying solely on non-phagocytic cell models may not represent a realistic result as the effect of an antileishmanial agent should ideally be presented based on its cytotoxicity profile against reticuloendothelial system cells. In the present review, we have assembled studies published in the scientific literature from 2015 to 2021 that explored leishmanicidal candidates, emphasising the main host cell models used for cytotoxicity assays. The pros and cons of different host cell types as well as primary cells and cell lines are discussed in order to draw attention to the need to establish standardised protocols for preclinical testing when assessing new antileishmanial candidates.

Molecular docking and in vitro anticancer studies of silver(I)-N-heterocyclic carbene complexes

A series of symmetric and unsymmetrical benzimidazolium-based N-heterocyclic carbene (NHC) precursors (1a-i) and their silver complexes (2a-i) have been synthesized. The Ag(I)–NHC complexes were characterized by ¹H, ¹³C{¹H} NMR, FTIR, LC/MS-QTOF, and elemental analysis. Anticancer and cytotoxic activity of all Ag(I)–NHC complexes were tested against healthy fibroblast cell line (L929), breast cancer cell line (MCF-7), and neuroblastoma cell line (SH-SY5Y) by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4sulfophenyl)-2H-tetrazolium] assay. The 2b, 2c, 2e, 2g, 2h, and 2i complexes showed higher cytotoxicity than cisplatin against SH-SY5Y and MCF-7 and lower cytotoxic activity against L929 cell lines. Because of their high cytotoxic activity against cancer cells and low cytotoxicity against healthy fibroblast cell lines, the 2b, 2c, 2e, 2g, 2h, and 2i are expected to be new lead compounds. In addition, molecular docking studies were performed to explore the binding interactions of silver complexes with the enzyme to explore new anticancer compounds. Furthermore, ADME properties of all complexes were predicted to explore lead-like characteristics and may be a potential drug candidate for cancer treatment.

Phytochemical analysis and comprehensive evaluation of pharmacological potential of Artemisia brevifolia Wall. ex DC

Multitude of diseases and side effects from conventional drugs have surged the use of herbal remedies. Thus, the current study aimed to appraise various pharmacological attributes of Artemisia brevifolia Wall. ex DC. Extracts prepared by successive solvent extraction were subjected to phytochemical and multimode antioxidant assays. Various polyphenolics and artemisinin derivatives were detected and quantified using RP-HPLC analysis. Compounds present in methanol (M) and distilled water (DW) extracts were identified using high resolution mass spectrometry (HRMS). Extracts were pharmacologically evaluated for their antibacterial, antifungal, antimalarial, antileishmanial and antidiabetic potentials. Moreover, cytotoxicity against Artemiasalina, human cancer cell lines and isolated lymphocytes was assessed. Genotoxicity was evaluated using comet, micronucleus and chromosomal aberration assays. Lastly, anti-inflammatory potential was determined through a series of in vitro and in vivo assays using BALB/c mice.

Maximum extract recovery (5.95% w/w) was obtained by DW extract. Highest phenolics and flavonoids content, total antioxidant capacity, total reduction potential, percentfree radical scavenging, β-carotene scavenging and iron chelating activities were exhibited by M extract. RP-HPLC analysis revealed significant amounts of various polyphenolic compounds (vanillic acid, syringic acid, emodin and luteolin), artemisinin, dihydro artemisinin, artesunate and artemether in ethyl acetate (EA) extract. Total 40 compounds were detected through HRMS. A noteworthy antimicrobial activity (MIC 22.22 µg/ml) was exhibited by EA extract against A. fumigatus and several bacterial strains. Maximum antimalarial, antileishmanial, brine shrimp lethality and cytotoxic potential against cancer cells was manifested by EA extract. None of the extracts exhibited genotoxicity and toxicity against isolated lymphocytes. Highest α-amylase and α-glucosidase inhibition capacities were demonstrated by DW extract. Various in-vivo anti-inflammatory models revealed significant (p < 0.05) anti-inflammatory potential of M and DW extracts. In conclusion, present findings divulged theremarkable pharmacological potential of A. brevifolia and endorse its richness in artemisinin.

Anti-Inflammatory Potential of Daturaolone from Datura innoxia Mill.: In Silico, In Vitro and In Vivo Studies

Exploration of leads with therapeutic potential in inflammatory disorders is worth pursuing. In line with this, the isolated natural compound daturaolone from Datura innoxia Mill. was evaluated for its anti-inflammatory potential using in silico, in vitro and in vivo models. Daturaolone follows Lipinski's drug-likeliness rule with a score of 0.33. Absorption, distribution, metabolism, excretion and toxicity prediction show strong plasma protein binding; gastrointestinal absorption (Caco-2 cells permeability = 34.6 nm/s); no blood-brain barrier penetration; CYP1A2, CYP2C19 and CYP3A4 metabolism; a major metabolic reaction, being aliphatic hydroxylation; no hERG inhibition; and non-carcinogenicity. Predicted molecular targets were mainly inflammatory mediators. Molecular docking depicted H-bonding interaction with nuclear factor kappa beta subunit (NF-κB), cyclooxygenase-2, 5-lipoxygenase, phospholipase A2, serotonin transporter, dopamine receptor D1 and 5-hydroxy tryptamine. Its cytotoxicity (IC₅₀) value in normal lymphocytes was >20 µg/mL as compared to cancer cells (Huh7.5; 17.32 ± 1.43 µg/mL). Daturaolone significantly inhibited NF-κB and nitric oxide production with IC₅₀ values of 1.2 ± 0.8 and 4.51 ± 0.92 µg/mL, respectively. It significantly reduced inflammatory paw edema (81.73 ± 3.16%), heat-induced pain (89.47 ± 9.01% antinociception) and stress-induced depression (68 ± 9.22 s immobility time in tail suspension test). This work suggests a possible anti-inflammatory role of daturaolone; however, detailed mechanistic studies are still necessary to corroborate and extrapolate the findings.

Investigating the anticancer properties of the two new platinum complexes with iso- and tert-pentylglycine by the DFT, molecular docking, and ADMET assessment and experimental confirmations

In this study, two new anticancer platinum complexes formulated as [Pt(bpy)(L)]NO₃ were synthesized using the iso and tert-pentylglycine ligands, two structural isomer ligands, to investigate side branches effect on the complex-DNA interaction. According to the comparative results of the ADMET assessment, these compounds can be considered as the drug-like molecules and oral medication. Mechanism of tumor inhibition and DNA binding parameters indicated the higher ability of the tert-isomer and also, both complexes acted through the disruption of the base pairs and stacks of helicity by the endothermic process. Fluorescence spectroscopy showed that the quenching mechanism is static for both drugs with large binding constant and high binding affinity towards the DNA. Also, the amount of binding constant of the tert -isomer was about 14 times of another structural isomerous complex. CD spectra indicated the conversion of the B-DNA into A-DNA form via electrostatic interaction for positively charged complexes. The cytotoxic data showed that both compounds have antiproliferative effects against the MCF-7 cell line and the inhibitory effect of the iso-derivative was better than the tert-one. Docking studies showed that the desolvation energy and hydrogen bond are more effective between the other interactions. The torsional free energy for both complexes mainly provided the groove binding along with partially electrostatic and intercalate binding. According to the density-functional theory data and because of positive electron density on the surface of complexes and facilitating of the metal drug to DNA phosphate groups approaching, both complexes may be good candidates for the anticancer drugs. Two new anticancer Pt(II) complexes were synthesized with glycine derivatives. In vitro cytotoxicity effects were tested against the human breast cancer cell line of MCF-7. Moreover, the modes of DNA binding with synthesized compounds were investigated using ADME prediction, DFT, molecular docking and spectroscopic methods.

Unveiling the Targets Involved in the Quest of Antileishmanial Leads Using In silico Methods

BACKGROUND

Leishmaniasis is a neglected tropical disease associated with several clinical manifestations, including cutaneous, mucocutaneous, and visceral forms. As currently available drugs have some limitations (toxicity, resistance, among others), the target-based identification has been an important approach to develop new leads against leishmaniasis. The present study aims to identify targets involved in the pharmacological action of potent antileishmanial compounds.

METHODS

The literature information regarding molecular interactions of antileishmanial compounds studied over the past half-decade is discussed. The information was obtained from databases such as Wiley, SciFinder, Science Direct, National Library of Medicine, American Chemical Society, Scientific Electronic Library Online, Scopus, Springer, Google Scholar, Web of Science, etc. Results: Numerous in vitro antileishmanial compounds showed affinity and selective interactions with enzymes such as arginase, pteridine reductase 1, trypanothione reductase, pyruvate kinase, among others, which are crucial for the survival and virulence of the Leishmania parasite.

CONCLUSION

The in-silico activity of small molecules (enzymes, proteins, among others) might be used as pharmacological tools to develop candidate compounds for the treatment of leishmaniasis. As some pharmacologically active compounds may act on more than one target, additional studies of the mechanism (s) of action of potent antileishmanial compounds might help to better understand their pharmacological action. Also, the optimization of promising antileishmanial compounds might improve their biological activity.

Withametelin: a biologically active withanolide in cancer, inflammation, pain and depression

Withanolides are natural medicinal agents whose safety and therapeutic profiles make them valuable to mankind. Among multiple withanolides, withametelin is underexplored. The present study was aimed to create a general biological profile of isolated withametelin from Datura innoxia Mill. targeting different biological models. In-silico studies include drug-likeliness, pharmacokinetics, toxicity, molecular targets and cytotoxicity to cancer cell lines predictions. In silico directed preliminary in-vitro evaluation comprised of cancer/normal cell cytotoxicity, DPPH and protein kinase inhibition assays while in-vivo bioactivities include antiinflammatory, analgesic, antidepressant and anticoagulant assays. Pharmacological findings were strengthened by molecular docking studies to check interactions with various proteins and to propose the future path of studies. Results indicated compliance with Lipinski drug-likeliness rule (score −0.55). ADMET prediction showed strong plasma protein binding, GI absorption (Caco-2 cells permeability = 46.74 nm/s), blood brain barrier penetration (Cbrain/Cblood = 0.31), efflux by P-glycoprotein, metabolism by CYP1A2, CYP2C19 and CYP3A4, medium hERG inhibition and non-carcinogenicity in rodents. Predicted molecular targets included mainly receptors (glucocorticoid, kappa opioid, delta opioid, adrenergic and dopamine), oxidoreductase (arachidonate 5-lipoxygenase and cyclooxygenase-2), enzymes (HMG-CoA reductase) and kinase (NFκb). Withametelin was more cytotoxic to cancer cells (DU145 IC₅₀ 7.67 ± 0.54 µM) than normal lymphocytes (IC₅₀ 33.55 ± 1.31 µM). It also showed good antioxidant and protein kinase inhibition potentials. Furthermore, withametelin (20 mg/kg) significantly reduced inflammatory paw edema (68.94 ± 5.55%), heat-induced pain (78.94 ± 6.87%) and immobility time (50%) in animals. Molecular docking showed hydrogen bonding interactions (binding energies: −11.3 to −7.8 kcal/mol) with arachidonate 5 lipoxygenase, NFκb and glucocorticoid receptor. Withametelin has potential for advance investigations for its cytotoxic, anti-inflammatory, analgesic and antidepressant activities.

Computational Approaches in Preclinical Studies on Drug Discovery and Development

Because undesirable pharmacokinetics and toxicity are significant reasons for the failure of drug development in the costly late stage, it has been widely recognized that drug ADMET properties should be considered as early as possible to reduce failure rates in the clinical phase of drug discovery. Concurrently, drug recalls have become increasingly common in recent years, prompting pharmaceutical companies to increase attention toward the safety evaluation of preclinical drugs. In vitro and in vivo drug evaluation techniques are currently more mature in preclinical applications, but these technologies are costly. In recent years, with the rapid development of computer science, in silico technology has been widely used to evaluate the relevant properties of drugs in the preclinical stage and has produced many software programs and in silico models, further promoting the study of ADMET in vitro. In this review, we first introduce the two ADMET prediction categories (molecular modeling and data modeling). Then, we perform a systematic classification and description of the databases and software commonly used for ADMET prediction. We focus on some widely studied ADMT properties as well as PBPK simulation, and we list some applications that are related to the prediction categories and web tools. Finally, we discuss challenges and limitations in the preclinical area and propose some suggestions and prospects for the future.

Preclinical anticancer studies on the ethyl acetate leaf extracts of Datura stramonium and Datura inoxia

Background

Cancer is a horrific disease relentlessly affecting human population round the globe. Genus Datura encompasses numerous species with reported medicinal uses. However, its potential as a source of natural anticancer agents is yet to be determined. Datura stramonium (DS) and Datura inoxia (DI) are the two species chosen for this study.

Methods

Total phenolic and flavonoid content (TPC and TFC) as well as antioxidant activity were assessed through colorimetric method. Polyphenolic quantification was done by RP-HPLC. Following extract standardization ethyl acetate leaf extracts of both species (DSL-EA and DIL-EA) were chosen for anticancer studies. In vitro cytotoxicity using various models including cancer cell lines was monitored. Following toxicity studies, benzene (0.2 ml) was used to induce leukemia in Sprague-Dawley rats. Extracts were orally administered to preventive (100 and 200 mg/kg) and treatment (200 mg/kg only) groups. The antileukemic potential of extracts was assessed through haematological, biochemical, endogenous antioxidants and histological parameters.

Results

Significant TPC and TFC were estimated in DSL-EA and DIL-EA. RP-HPLC quantified (μg/mg extract) rutin (0.89 ± 0.03), gallic acid (0.35 ± 0.07), catechin (0.24 ± 0.02) and apigenin (0.29 ± 0.09) in DSL-EA while rutin (0.036 ± 0.004) and caffeic acid (0.27 ± 0.03) in DIL-EA. Both extracts exhibited significant brine shrimp cytotoxicity (LC₅₀ < 12.5 μg/ml). DIL-EA exhibited greater cytotoxicity against PC-3, MDA-MB 231 and MCF-7 cell lines (IC₅₀ < 3 μg/ml in each case) as well as higher protein kinase inhibitory action (MIC: 25 μg/disc) compared to DSL-EA. Leukemia induced in rats was affirmed by elevated serum levels of WBCs (7.78 ± 0.012 (× 10³) /μl), bilirubin (7.56 ± 0.97 mg/dl), Thiobarbituric acid reactive substances (TBARs) (133.75 ± 2.61 nM/min/mg protein), decreased RBCs (4.33 ± 0.065 (× 10⁶)/μl), platelets (344 ± 3.19 (× 10³)/μl), total proteins (2.14 ± 0.11 g/dl), Glutathione S-transferases (GST) (81.01 ± 0.44 nM/min/ml), endogenous antioxidant enzymes levels and abnormal liver and kidney functionality in disease control rats. Both species revealed almost identical and significant (p < 0.05) alleviative effects in benzene induced leukemia.

Conclusion

Comprehensive screening divulged the tremendous potential of selected species as potent source of natural anticancer agents in a variety of cancers particularly leukemia. Present study might provide useful finger prints in cancer research and mechanistic studies are prerequisite in logical hunt of this goal.

Ipomoea batatas L. Lam. ameliorates acute and chronic inflammations by suppressing inflammatory mediators, a comprehensive exploration using in vitro and in vivo models

BACKGROUND

Ipomoea batatas L. Lam. is a functional food and belongs to family Convolvulaceae. It is used as an antiinflammatory, aphrodisiac, antiasthmatic, anticonvalescent, antitumor, antanemic and antidiabetic agent by local communities. This study has been planned to evaluate its antiinflammatory and antiarthritic potentials.

METHODS

Dry powder of I. batatas tuber and roots were extracted with ethyl acetate (IPT-EA, IPR-EA) and methanol (IPT-M, IPR-M), respectively. These extracts were tested for total phenolic and flavonoid contents (TPC and TFC), HPLC finger printing, multidimensional in vitro and in vivo antioxidant potential and albumin denaturation inhibition. Carrageenan-induced paw edema, croton oil-induced ear and anal edema inhibition and Complete Freund's Adjuvant (CFA)-induced antiarthritic assays were executed at a dose of 300 mg/kg body weight on Sprague-Dawley rats. Serum levels of interleukins IL-1β and IL-6 and nitric oxide (NO) were assessed to measure the inhibition of inflammation.

RESULTS

Maximal TPC (319.81 ± 14.20 μg GAE/mg dry extract) and TFC (208.77 ± 9.09 μg QE/mg DE) were estimated in IPR-EA extract. IPT-EA and IPR-EA yielded the maximum amounts of rutin (7.3 ± 1.12 and 4.5 ± 0.55), caffeic acid (1.60 ± 0.25 and 2.17 ± 0.26) and myricetin (2.7 ± 0.14 and 1.01 ± 0.08 μg/mg DE), respectively in HPLC-DAD analysis. All extracts showed dose dependent response in in vitro antioxidant assays. Best inhibition (76.92 ± 3.07%) of albumin denaturation was shown by IPT-EA in comparison to ibuprofen (79.48 ± 4.71%). IPR-EA exhibited highest edema inhibition in models of carrageenan-induced paw edema (79.11 ± 5.47%) and croton oil-induced ear and anal edema (72.01 ± 7.80% and 70.80 ± 4.94%, respectively). Significant inhibition of CFA-induced arthritic edema and arthritic score were observed by IPR-EA as compared to ibuprofen. Suppression of pro-inflammatory cytokines (IL-1β, IL-6) and NO levels was shown by IPR-EA and IPT-EA, respectively.

CONCLUSION

These results depict that richness of polyphenols and phytoconstituents in I. batatas ameliorates oxidative stress and inflammation of acute and chronic nature. Dose dependent antioxidant potential and inhibition of inflammatory edema, pro-inflammatory cytokines and hematological, biochemical and histological changes prove I. batatas therapeutic potential as an antiinflammatory and antiarthritic agent.

Reverse Screening Methods to Search for the Protein Targets of Chemopreventive Compounds

This article is a systematic review of reverse screening methods used to search for the protein targets of chemopreventive compounds or drugs. Typical chemopreventive compounds include components of traditional Chinese medicine, natural compounds and Food and Drug Administration (FDA)-approved drugs. Such compounds are somewhat selective but are predisposed to bind multiple protein targets distributed throughout diverse signaling pathways in human cells. In contrast to conventional virtual screening, which identifies the ligands of a targeted protein from a compound database, reverse screening is used to identify the potential targets or unintended targets of a given compound from a large number of receptors by examining their known ligands or crystal structures. This method, also known as in silico or computational target fishing, is highly valuable for discovering the target receptors of query molecules from terrestrial or marine natural products, exploring the molecular mechanisms of chemopreventive compounds, finding alternative indications of existing drugs by drug repositioning, and detecting adverse drug reactions and drug toxicity. Reverse screening can be divided into three major groups: shape screening, pharmacophore screening and reverse docking. Several large software packages, such as Schrödinger and Discovery Studio; typical software/network services such as ChemMapper, PharmMapper, idTarget, and INVDOCK; and practical databases of known target ligands and receptor crystal structures, such as ChEMBL, BindingDB, and the Protein Data Bank (PDB), are available for use in these computational methods. Different programs, online services and databases have different applications and constraints. Here, we conducted a systematic analysis and multilevel classification of the computational programs, online services and compound libraries available for shape screening, pharmacophore screening and reverse docking to enable non-specialist users to quickly learn and grasp the types of calculations used in protein target fishing. In addition, we review the main features of these methods, programs and databases and provide a variety of examples illustrating the application of one or a combination of reverse screening methods for accurate target prediction.

Triorganotin Derivatives Induce Cell Death Effects on L1210 Leukemia Cells at Submicromolar Concentrations Independently of P-glycoprotein Expression

The acceleration of drug efflux activity realized by plasma membrane transporters in neoplastic cells, particularly by P-glycoprotein (P-gp, ABCB1 member of the ABC transporter family), represents a frequently observed molecular cause of multidrug resistance (MDR). This multiple resistance represents a real obstacle in the effective chemotherapy of neoplastic diseases. Therefore, identifying cytotoxic substances that are also effective in P-gp overexpressing cells may be useful for the rational design of substances for the treatment of malignancies with developed MDR. Here, we showed that triorganotin derivatives—tributyltin-chloride (TBT-Cl), tributyltin-bromide (TBT-Br), tributyltin-iodide (TBT-I) and tributyltin-isothiocyanate (TBT-NCS) or triphenyltin-chloride (TPT-Cl) and triphenyltin-isothiocyanate (TPT-NCS)—could induce the death of L1210 mice leukemia cells at a submicromolar concentration independently of P-gp overexpression. The median lethal concentration obtained for triorganotin derivatives did not exceed 0.5 µM in the induction of cell death of either P-gp negative or P-gp positive L1210 cells. Apoptosis related to regulatory pathway of Bcl-2 family proteins seems to be the predominant mode of cell death in either P-gp negative or P-gp positive L1210 cells. TBT-Cl and TBT-Br were more efficient with L1210 cells overexpressing P-gp than with their counterpart P-gp negative cells. In contrast, TBT-I and TPT-NCS induced a more pronounced cell death effect on P-gp negative cells than on P-gp positive cells. Triorganotin derivatives did not affect P-gp efflux in native cells measured by calcein retention within the cells. Taken together, we assumed that triorganotin derivatives represent substances suitable for suppressing the viability of P-gp positive malignant cells.

Polarity directed optimization of phytochemical and in vitro biological potential of an indigenous folklore: Quercus dilatata Lindl. ex Royle

BACKGROUND

Plants have served either as a natural templates for the development of new chemicals or a phytomedicine since antiquity. Therefore, the present study was aimed to appraise the polarity directed antioxidant, cytotoxic, protein kinase inhibitory, antileishmanial and glucose modulatory attributes of a Himalayan medicinal plant- Quercus dilatata.

METHODS

Total phenolic and flavonoid contents were determined colorimetrically and various polyphenols were identified by RP-HPLC analysis. Brine shrimp lethality, SRB and MTT assays were employed to test cytotoxicity against Artemia salina and human cancer cell lines respectively. Antileishmanial activity was determined using standard MTT protocol. Glucose modulation was assessed by α-amylase inhibition assay while disc diffusion assay was used to establish protein kinase inhibitory and antifungal spectrum.

RESULTS

Among 14 extracts of aerial parts, distilled water-acetone extract demonstrated maximum extract recovery (10.52% w/w), phenolic content (21.37 ± 0.21 μg GAE/mg dry weight (DW)), total antioxidant capacity (4.81 ± 0.98 μg AAE/mg DW) and reducing power potential (20.03 ± 2.4 μg/mg DW). On the other hand, Distilled water extract proficiently extracted flavonoid content (4.78 ± 0.51 μg QE/mg DW). RP-HPLC analysis revealed the presence of significant amounts of phenolic metabolites (0.049 to 15.336 μg/mg extract) including, pyrocatechol, gallic acid, catechin, chlorogenic acid, p-coumaric acid, ferulic acid and quercetin. Highest free radical scavenging capacity was found in Methanol-Ethyl acetate extract (IC₅₀ 8.1 ± 0.5 μg/ml). In the brine shrimp toxicity assay, most of the tested extracts (57%) showed high cytotoxicity. Among these, Chloroform-Methanol extract had highest cytotoxicity against THP-1 cell line (IC₅₀ 3.88 ± 0.53 μg/ml). About 50% of the extracts were found to be moderately antiproliferative against Hep G2 cell line. Methanol extract exhibited considerable protein kinase inhibitory activity against Streptomyces 85E strain (28 ± 0.35 mm bald phenotype at 100 μg/disc; MIC = 12.5 μg/ disc) while, Chloroform extract displayed maximum antidiabetic activity (α-amylase inhibition of 21.61 ± 1.53% at 200 μg/ml concentration). The highest antileishmanial potential was found in Ethyl acetate-Acetone extract (12.91 ± 0.02% at 100 μg/ml concentration), while, Q. dilatata extracts also showed a moderate antifungal activity.

CONCLUSION

This study proposes that multiple-solvent system is a crucial variable to elucidate pharmacological potential of Q. dilatata and the results of the present findings prospects its potential as a resource for the discovery of novel anticancer, antidiabetic, antileishmanial and antioxidant agents.