Recent Developments in 1,2,3-Triazole Based α-Glucosidase Inhibitors: Design Strategies, Structure-Activity Relationship and Mechanistic Insights.

Diabetes mellitus is a chronic and most prevalent metabolic disorder affecting 422 million the people worldwide and causing life-threatening associated conditions including disorders of kidney, heart, and nervous system as well as leg amputation and retinopathy. Steadily rising cases from the last few decades suggest the failure of currently available drugs in containment of this disease. α-Glucosidase is a potential target for effectively tackling this disease and attracting significant interest from medicinal chemists around the globe. Besides having a set of side effects, currently available α-glucosidase inhibitors (carbohydrate mimics) offer better tolerability, safety, and synergistic pharmacological outcomes with other antidiabetic drugs therefore medicinal chemists have working extensively over last three decades for developing alternative α-glucosidase inhibitors. The 1,2,3-Triazole nucleus is energetically used by various research groups around the globe for the development of α-glucosidase inhibitors posing it as an optimum scaffold in the field of antidiabetic drug development. This review is a systematic analysis of α-glucosidase inhibitors developed by employing 1,2,3-triazole scaffold with special focus on design strategies, structure-activity relationships, and mechanism of inhibitory effect. This article will act as lantern for medicinal chemists in developing of potent, safer, and effective α-glucosidase inhibitors with desired properties and improved therapeutic efficacy.

In silico molecular modelling studies and antibiofilm efficacy of shikonin against Candida albicans: mechanistic insight.

In the recent past, the occurrence of fungal infections has increased drastically and candidiasis, caused prominently by Candida albicans, is foremost among them which has caused significant mortality and morbidity majorly in immune-compromised patients. Shikonin is a well-known natural naphthazarin derivative with promising antifungal efficacy, but it's mechanism of action is still unclear. Keeping this in view, present work was designed to get a mechanistic insight of anti-candida efficacy of shikonin via in vitro experiments and in situ molecular modelling studies. The current exploratory study is based on research that uses both qualitative and quantitative techniques, including minimum inhibitory concentration, minimum biofilm inhibitory concentration, time kill assay, cell cycle analysis and apoptotic assays, static biofilm formation assays, microscopic biofilm assessment assays, ergosterol content estimation and molecular docking/simulation studies. The study revealed a notable effect of shikonin against Candida albicans, including retardation of biofilms. Shikonin, with its increasing concentration leads to candidal cell apoptosis and necrosis establishing its dose-dependent effect. Additionally, it exhibited fungicidal activity via a mechanism of action likely related to ergosterol complexation which was further corroborated by molecular docking and simulation studies.

Mechanistic insight and structure activity relationship of isatin-based derivatives in development of anti-breast cancer agents.

Breast cancer is most common in women and most difficult to manage that causes highest mortality and morbidity among all diseases and posing significant threat to mankind as well as burden on healthcare system. In 2020, 2.3 million women were diagnosed with breast cancer and it was responsible for 685,000 deaths globally, suggesting the severity of this disease. Apart from that, relapsing of cases and resistance among available anticancer drugs along with associated side effects making the situation even worse. Therefore, it is a global emergency to develop potent and safer antibreast cancer agents. Isatin is most versatile and flying one nucleus which is an integral competent and various anticancer agent in clinical practice and widely used by various research groups around the globe for development of novel, potent, and safer antibreast cancer agents. This review will shed light on the structural insights and antiproliferative potential of various isatin-based derivatives developed for targeting breast cancer in last three decades that will help researchers in design and development of novel, potent, and safer isatin-based antibreast cancer agents.

Antimicrobial and antibiofilm effects of shikonin with tea tree oil nanoemulsion against Candida albicans and Staphylococcus aureus.

The current work aims to develop a shikonin and tea tree oil loaded nanoemulsion system stabilized by a mixture of GRAS grade surfactants (Tween 20 and monoolein) and a cosurfactant (Transcutol P). This system was designed to address the poor aqueous solubility and photostability issues of shikonin. The authenticity of shikonin employed in this study was confirmed using nuclear magnetic resonance (NMR) spectroscopy. The optimized nanoemulsion exhibited highly favorable characteristics in terms of zeta potential (-23.8 mV), polydispersity index (0.216) and particle size (22.97 nm). These findings were corroborated by transmission electron microscopy (TEM) micrographs which confirmed the spherical and uniform nature of the nanoemulsion globules. Moreover, attenuated total reflectance (ATR) and X-ray diffraction analysis (XRD) analysis affirmed improved chemical stability and amorphization, respectively. Photodegradation studies were performed by exposing pure shikonin and the developed nanoemulsion to ultraviolet light for 1 h using a UV lamp, followed by high performance liquid chromatography (HPLC) analysis. The results confirmed that the developed nanoemulsion system imparts photoprotection to pure shikonin in the encapsulated system. Furthermore, the research investigated the effect of the nanoemulsion on biofilms formed by Candida albicans and methicillin resistant Staphylococcus aureus (MRSA). Scanning electron microscopy, florescence microscopy and phase contrast microscopy unveiled a remarkable reduction in biofilm area, accompanied by disruptions in the cell wall and abnormalities on the cell surface of the tested microorganisms. In conclusion, the nanoencapsulation of shikonin with tea tree oil as the lipid phase showcased significantly enhanced antimicrobial and antibiofilm potential compared to pure shikonin against resistant strains of Candida albicans and Staphylococcus aureus.

Physiological and behavioral assessment of Metaphire posthuma in response to clothianidin insecticide: Insights from molecular and biochemical analysis.

In the present study, Clothianidin [(E) - 1-(2 - chloro-1,3 - thiazol - 5-ylmethyl) - 3-methyl - 2- nitroguanidine] (CLO) was selected as a soil pollutant and earthworm was employed as a test organism. The various responses like biochemical and detoxification process of earthworm Metaphire posthuma towards Clothianidin at lethal and sublethal doses were studied using OECD-standardized toxicological guidelines. The present study examined the toxicity of CLO to earthworms after 28 days of exposure at conc. 0, 1.5, 3, 6, 12 and 24 mg kg-1 in a soil mixture. Biochemical markers including Guaiacol peroxidase (POD), Superoxide dismutase (SOD), Catalase (CAT), Glutathione S-transferase (GST) and content of Malondialdehyde (MDA) in earthworms were measured. Acute toxicity tests revealed that CLO caused a concentration-dependent increase in mortality with LC50 (Lethal concentration) values of 10.960 and 8.201 mg kg-1 for 7th and 14th day respectively. The earthworms were exposed to CLO contaminated soil for 56 days and reflecting the significant decrease in earthworm growth, cocoon and hatchling production. Moreover, enzyme activities such as CAT, SOD, POD and MDA content were significantly enhanced with the increased concentration and exposure period of CLO. Molecular docking studies indicated that CLO primarily interacts to the junction site of SOD and in active centres of CAT, POD and GST. As a result, the current findings imply that the sub chronic CLO exposure can induce variations in physiology and avoidance behaviour of earthworms, oxidative stress as well as alterations in enzyme activities.

1,2,3-Triazole Derivatives as an Emerging Scaffold for Antifungal Drug Development against Candida albicans: A Comprehensive Review.

Candida infections are most prominent among fungal infections majorly target immunocompromised and hospitalized patients and cause significant morbidity and mortality. Candida albicans is the notorious and most prevalent among all pathogenic Candida strains. Its emerging resistance toward available antifungal agents making it hard to tackle and emerging as global healthcare emergency. Simultaneously, 1,2,3-triazole nucleus is a privileged scaffold that is gaining importance in antifungal drug development due to being a prominent bioactive linker and isostere of triazole based antifungal class core 1,2,4-triazole. Numerous reports have been updated in scientific literature in last few decades related to utilization of 1,2,3-triazole nucleus in antifungal drug development against Candida albicans. Present review will shed light on various preclinical studies focused on development of 1,2,3-triazole derivatives targeting Candida albicans along with brief highlight on clinical trials and newly approved drugs. Structure-activity relationship has been precisely discussed for each architect along with future perspective that will help medicinal chemists in design and development of potent antifungal agents for tackling infections derived from Candida albicans.

Design, Synthesis, biological investigations and molecular interactions of triazole linked tacrine glycoconjugates as Acetylcholinesterase inhibitors with reduced hepatotoxicity.

Tacrine is a known Acetylcholinesterase (AChE) inhibitors having hepatotoxicity as main liability associated with it. The present study aims to reduce its hepatotoxicity by synthesizing tacrine linked triazole glycoconjugates via Huisgen's [3 + 2] cycloaddition of anomeric azides and terminal acetylenes derived from tacrine. A series of triazole based glycoconjugates containing both acetylated (A-1 to A-7) and free sugar hydroxyl groups (A-8 to A-14) at the amino position of tacrine were synthesized in good yield taking aid from molecular docking studies and evaluated for their in vitro AChE inhibition activity as well as hepatotoxicity. All the hybrids were found to be non-toxic on HePG2 cell line at 200 µM (100 % cell viability) as compared to tacrine (35 % cell viability) after 24 h of incubation period. Enzyme kinetic studies carried out for one of the potent hybrids in the series A-1 (IC50 0.4 µM) revealed its mixed inhibition approach. Thus, compound A-1 can be used as principle template to further explore the mechanism of action of different targets involved in Alzheimer's disease (AD) which stands as an adequate chemical probe to be launched in an AD drug discovery program.

Metsulfuron-methyl induced physiological, behavioural and biochemical changes in exotic (Eisenia fetida) and indigenous (Metaphire posthuma) earthworm species: Toxicity and molecular docking studies.

In modern agricultural practices, Metsulfuron-methyl (sulfonylurea herbicide) is widely employed to inhibit the weeds and grasses. The current study revealed that Metaphire posthuma was more sensitive than Eisenia fetida against Metsulfuron-methyl (MSM). The LC50 values for Eisenia fetida were 2884.08 mgkg-1 and 1871.18 mgkg-1after 7 and 14 days, respectively. Similarly, the LC50 values for Metaphire posthuma were 2449.34 mgkg-1 and 1673.10 mgkg-1for 7 and 14 days, respectively. Reproduction parameters were significantly decreased at 400 (T3), 800 (T4) and 1600 (T5) mgkg-1 MSM in E. fetida whereas at 200 (T2), 400 (T3), 800 (T4), 1600 (T5) mgkg-1 MSM in M. posthuma. EC50 of avoidance response for 20% MSM by E. fetida and M. posthuma was recorded 901.76 mgkg-1and 544.21 mgkg-1 respectively. Malondialdehyde (MDA) content along with guaiacol peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) activities were initially increased up to 21st day by MSM, inducing a slight oxidative stress in earthworms and recovered to control level on 28th day. The GST activities were continuously stimulated throughout the exposure period and enhance the detoxification effect thereby preventing the earthworms from toxins. Molecular docking studies indicated that hydrogen bonding and hydrophobic interactions are key forces in binding between MSM and SOD/CAT/POD/GST. As a result, this is the first study to be reported on physiological, behavioural and biochemical changes in two different earthworm species under the exposure of sulfonyl urea herbicide.

Design, synthesis, and biological evaluation of novel morpholinated isatin-quinoline hybrids as potent anti-breast cancer agents.

Keeping in view the emerging need for potent and safer anti-breast cancer agents as well as the pharmacological attributes of isatin, quinolone, and morpholine derivatives, novel hydrazine-linked morpholinated isatin-quinoline hybrids were designed, synthesized, and evaluated as anti-breast cancer agents. The synthesized hybrid compounds were preliminarily screened against two breast cancer cell lines (MCF-7 and MDA-MB-231). Almost all synthetics showed potent inhibitory potential against hormone-positive MCF-7 cells while being inactive against hormone-negative MDA-MB-231 cells. Potent compounds were further evaluated against the L929 (noncancerous skin fibroblast) cell line and found to be highly selective for MCF-7 cells over L929 cells. Cell cycle analysis confirmed that the most potent compound AS-4 (MCF-7: GI50 = 4.36 µM) causes mitotic arrest at the G2 /M phase. Due to higher selectivity toward estrogen receptor alpha (ERα)-dependent MCF-7 cells, various binding interactions of AS-4 with ERα are also streamlined, suggesting the capability of AS-4 to completely block ERα. Overall, the study suggests that AS-4 can act as a potential lead for further development of potent and safer anti-breast cancer agents.

Design, synthesis, and biological evaluation of isatin-indole-3-carboxaldehyde hybrids as a new class of xanthine oxidase inhibitors.

A novel series of triazole-linked isatin-indole-3-carboxaldehyde hybrids based on the febuxostat skeleton and its binding site interactions were rationally designed and synthesized as potential xanthine oxidase inhibitors. Among the synthesized hybrids, A19 showed the most potent xanthine oxidase inhibition (IC50 = 0.37 µM) with the mixed-type inhibitory scenario. Structure-activity relationship studies revealed that methoxy (OCH3 ) substitution on position 5 of the isatin nucleus and a two-carbon distance between isatin and the triazole moiety is most tolerable for the inhibitory potential. Various binding interactions of A19 with the binding site of xanthine oxidase are also streamlined by molecular docking studies, which showcase the favorable binding pattern for xanthine oxidase inhibition by the hybrid. Furthermore, molecular dynamic studies were performed that suggest the stability of the enzyme-hybrid complex. Overall, the study suggests that hybrid A19 can act as an effective hit lead for further development of potent xanthine oxidase inhibitors.

Most recent strategies targeting estrogen receptor alpha for the treatment of breast cancer.

Breast cancer is the most prominent, frequently diagnosed and leading cause of death among women. Estrogen is an agonist of estrogen receptor alpha (ER-α), expressed in mammary glands and is responsible for initiating many signalling pathways that lead to differentiation and development of breast tissue. Any mutations in these signalling pathways result in irregular growth of mammary tissue, leading to the development of tumour or cancer. All these observations attract the attention of researchers to antagonize ER-α receptor either by developing selective estrogen receptor modulators or by selective estrogen receptor degraders. Therefore, this article provides a brief overview of various factors that are responsible for provoking breast cancer in women and design strategies recently used by the various research groups across the world for antagonizing or demodulating ER-α.

New coumarin-benzotriazole based hybrid molecules as inhibitors of acetylcholinesterase and amyloid aggregation.

A novel series of triazole tethered coumarin-benzotriazole hybrids based on donepezil skeleton has been designed and synthesized as multifunctional agents for the treatment of Alzheimer's disease (AD). Among the synthesized compounds 13b showed most potent acetylcholinesterase (AChE) inhibition (IC50 = 0.059 µΜ) with mixed type inhibition scenario. Structure-activity relationship revealed that three-carbon alkyl chain connecting coumarin and triazole is well tolerable for inhibitory potential. Hybrids obtained from 4-hydroxycoumarin and 1-benzotriazole were most potent AChE inhibitors. The inhibitory potential of all compounds against butyrylcholinesterase was also evaluated but all showed negligible activity suggesting that the hybrid molecules are selective AChE inhibitors. 13b (most potent AChE inhibitor) also showed copper-induced Aß1-42 aggregation inhibition (34.26% at 50 µΜ) and chelating properties for metal ions (Cu2+, Fe2+, and Zn2+) involved in AD pathogenesis along with DNA protective potential against degenerative actions of OH radicals. Molecular modelling studies confirm the potential of 13b in blocking both PAS and CAS of AChE. In addition, interactions of 13b with Aß1-42 monomer are also streamlined. Therefore, hybrid 13b can act as an effective hit lead molecule for further development of selective AChE inhibitors as multifunctional anti-Alzheimer's agents.

Discovery of triazole tethered thymol/carvacrol-coumarin hybrids as new class of α-glucosidase inhibitors with potent in vivo antihyperglycemic activities.

Keeping in view the inhibitory potential of monoterpenes thymol and carvacrol as well as coumarin nucleus against α-glucosidase, novel series of thymol/carvacrol-coumarin hybrids was designed, synthesized and evaluated for α-glucosidase inhibitory potential. Among the series of hybrid molecules, AS14 with IC50 value of 4.32 ± 0.11 µM was selective α-glucosidase inhibitor over α-amylase (IC50 = 37.36 ± 0.84 µM). AS14 was non-toxic toward mouse normal fibroblast cells (L929: IC50 > 100 µM). Molecular docking and dynamic simulation studies confirmed desired interactions of AS14 with α-glucosidase responsible for the inhibition of its catalysis capabilities. Acute oral toxicity study confirmed AS14 as safer molecule for in vivo pharmacological investigations with LD50 value of 300 mg/kg. AS14 also showed acute hypoglycaemic effects [reduction in blood glucose levels at 1 h of administration in maltose loading test (at 10 and 20 mg/kg by 62.65 % and 70.12 %) and sucrose loading test (at 10 and 20 mg/kg by 59.65 % and 60.23 %), respectively] as well as long term (28 days) fasting blood glucose reduction (At day 28: 10 mg/kg = 54.69 % and 20 mg/kg = 62.23 % reduction in fasting blood glucose levels) capabilities in streptozotocin induced diabetic rats. Overall study represents, AS14 as potential α-glucosidase inhibitor with adequate efficacy and safety profile and act as an effective hit lead for the further development of potent and safer α-glucosidase inhibitors for the management of postprandial hyperglycemia in diabetic patients.

Bakuchiol nanoemulsion loaded electrospun nanofibers for the treatment of burn wounds.

The present work aims to develop and evaluate the wound healing potential of bakuchiol nanoemulsion loaded electrospun scaffolds. Since oxidative stress and microbial burden leads the burn wounds to become chronic and fatal to patients, a phytoconstituent, bakuchiol (BAK), was screened on the basis of antioxidant and antimicrobial potential which also defined its dose. Furthermore, BAK was incorporated into a nanoemulsion to enhance its therapeutic efficacy, reduce its dosage frequency, and maximize its stability. The present study is inclined towards the collaborative interaction of natural products and novel drug delivery systems to develop safe and therapeutically efficient systems for burn wound healing. The optimized nanoemulsion showed excellent antioxidant and antimicrobial potential against wound susceptible pathogens, i.e., Candida albicans and Methicillin-resistant Staphylococcus aureus which was further loaded into gelatin based hydrogel and nanofibrous scaffold system. The mesh structure of scaffolds was chosen as a suitable carrier system for wound healing process not only because it offers resemblance to skin's anatomy but is also capable of providing uniform distribution of wound biomarkers across the skin. The prepared nanofibers were assessed for their analgesic, anti-inflammatory, and wound healing potential which was observed to be significantly better than its gel formulation.

Coumarin as an Elite Scaffold in Anti-Breast Cancer Drug Development: Design Strategies, Mechanistic Insights, and Structure-Activity Relationships.

Breast cancer is the most common cancer among women. Currently, it poses a significant threat to the healthcare system due to the emerging resistance and toxicity of available drug candidates in clinical practice, thus generating an urgent need for the development of new potent and safer anti-breast cancer drug candidates. Coumarin (chromone-2-one) is an elite ring system widely distributed among natural products and possesses a broad range of pharmacological properties. The unique distribution and pharmacological efficacy of coumarins attract natural product hunters, resulting in the identification of numerous natural coumarins from different natural sources in the last three decades, especially those with anti-breast cancer properties. Inspired by this, numerous synthetic derivatives based on coumarins have been developed by medicinal chemists all around the globe, showing promising anti-breast cancer efficacy. This review is primarily focused on the development of coumarin-inspired anti-breast cancer agents in the last three decades, especially highlighting design strategies, mechanistic insights, and their structure-activity relationship. Natural coumarins having anti-breast cancer efficacy are also briefly highlighted. This review will act as a guideline for researchers and medicinal chemists in designing optimum coumarin-based potent and safer anti-breast cancer agents.

The development of thymol-isatin hybrids as broad-spectrum antibacterial agents with potent anti-MRSA activity.

Bacterial resistance toward available therapeutic agents has become a nightmare for the healthcare system, causing significant mortality as well as prolonged hospitalization, thereby needing the urgent attention of research groups working on antimicrobial drug development worldwide. Molecular hybridization is a well-established tool for developing multifunctional compounds to tackle drug resistance. Inspired by the antibacterial profiles of isatin and thymol, along with the efficiency of a triazole linker in molecular hybridization, herein, we report the design, synthesis and antibacterial activity of a novel series of triazole tethered thymol-isatin hybrids. Most of the hybrids exhibited a broad-spectrum antibacterial efficacy against standard human pathogenic as well as clinically isolated multidrug-resistant bacterial strains listed in the WHO's 'priority pathogen' list and also in the ESKAPE group. Among them, hybrid compound AS8 was the most effective against methicillin-resistant Staphylococcus aureus (MIC = 1.9 µM and MBC = 3.9 µM), exhibiting biofilm inhibitory potential. AS8 exhibited dehydrosqualene synthase (CrtM) inhibitory potential in MRSA and decreased the production of virulence factor staphyloxanthin, which is one of the key mechanisms of its anti-MRSA efficacy, which was further supported by molecular docking and simulation studies. Moreover, AS8 was found to be non-toxic and showed a potent in vivo antibacterial efficacy (90% survival at 10 mg kg-1) as well as a modulated immune response in the larva-based (Galleria mellonella) model of systemic infections. Overall findings confirmed that AS8 can be a promising candidate or take the lead in the treatment and further drug development against drug-resistant infectious diseases, especially against MRSA infections.

Past, present and future of xanthine oxidase inhibitors: design strategies, structural and pharmacological insights, patents and clinical trials.

Xanthine oxidase, a molybdo-flavoenzyme, and an isoform of xanthine dehydrogenase both exist as xanthine oxidoreductase and are responsible for purine catabolism. Xanthine oxidase is more involved in pathological conditions when extensively modulated. Elevation of xanthine oxidase is not only the prime cause of gout but is also responsible for various hyperuricemia associated pathological conditions like diabetes, chronic wounds, cardiovascular disorders, Alzheimer's disease, etc. Currently available xanthine oxidase inhibitors in clinical practice (allopurinol, febuxostat and topiroxostat) suffer from fatal side effects that pose a serious problem to the healthcare system, raising global emergency to develop novel, potent and safer xanthine oxidase inhibitors. This review will provide key and systematic information about: a. design strategies (inspired from both marketed drugs in clinical practice and natural products), structural insights and pharmacological output (xanthine oxidase inhibition and associated activities) of various pre-clinical candidates reported by various research groups across the globe in the past two decades; b. patented xanthine oxidase inhibitors published in the last three decades and c. clinical trials and their outcomes on approved drug candidates. Information generated in this review has suggested fragment-based drug design (FBDD) and molecular hybridization techniques to be most suitable for development of desired xanthine oxidase inhibitors as one provides high selectivity toward the enzyme and the other imparts multifunctional properties to the structure and both may possess capabilities to surpass the limitations of currently available clinical drugs. All in combination will exclusively update researchers working on xanthine oxidase inhibitors and allied areas and potentially help in designing rational, novel, potent and safer xanthine oxidase inhibitors that can effectively tackle xanthine oxidase related disease conditions and disorders.

Recent advances in antifungal drug development targeting lanosterol 14α-demethylase (CYP51): A comprehensive review with structural and molecular insights.

Fungal infections are posing serious threat to healthcare system due to emerging resistance among available antifungal agents. Among available antifungal agents in clinical practice, azoles (diazole, 1,2,4-triazole and tetrazole) remained most effective and widely prescribed antifungal agents. Now their associated side effects and emerging resistance pattern raised a need of new and potent antifungal agents. Lanosterol 14α-demethylase (CYP51) is responsible for the oxidative removal of 14α-methyl group of sterol precursors lanosterol and 24(28)-methylene-24,25-dihydrolanosterol in ergosterol biosynthesis hence an essential component of fungal life cycle and prominent target for antifungal drug development. This review will shed light on various azole- as well as non-azoles-based derivatives as potential antifungal agents that target fungal CYP51. Review will provide deep insight about structure activity relationship, pharmacological outcomes, and interactions of derivatives with CYP51 at molecular level. It will help medicinal chemists working on antifungal development in designing more rational, potent, and safer antifungal agents by targeting fungal CYP51 for tackling emerging antifungal drug resistance.

Pathogenesis of Alzheimer's Disease and Diversity of 1,2,3-Triazole Scaffold in Drug Development: Design Strategies, Structural Insights, and Therapeutic Potential.

Alzheimer's disease is a most prevalent form of dementia all around the globe and currently poses a significant challenge to the healthcare system. Currently available drugs only slow the progression of this disease rather than provide proper containment. Identification of multiple targets responsible for this disease in the last three decades established it as a multifactorial neurodegenerative disorder that needs novel multifunctional agents for its management and the possible reason for the failure of currently available single target clinical drugs. 1,2,3-Triazole is a miraculous nucleus in medicinal chemistry and the first choice for development of multifunctional hybrid molecules. Apart from that, it is an integral component of various drugs in clinical trials as well as in clinical practice. This review is focused on the pathogenesis of Alzheimer's disease and 1,2,3-triazole containing derivatives developed in recent decades as potential anti-Alzheimer's agents. The review will provide (A) precise insight of various established targets of Alzheimer's disease including cholinergic, amyloid, tau, monoamine oxidases, glutamate, calcium, and reactive oxygen species hypothesis and (B) design hypothesis, structure-activity relationships, and pharmacological outcomes of 1,2,3-triazole containing multifunctional anti-Alzheimer's agents. This review will provide a baseline for various research groups working on Alzheimer's drug development in designing potent, safer, and effective multifunctional anti-Alzheimer's candidates of the future.

4-methylthiobutyl isothiocyanate synergize the antiproliferative and pro-apoptotic effects of paclitaxel in human breast cancer cells.

Multidrug resistance (MDR) is considered as a major obstacle in achieving an effective treatment of breast cancer. Paclitaxel has been used to treat cancers of the cervical, breast, ovarian and brain but MDR limits its therapeutic potential. Phytochemicals have received much interest in recent decades especially in combination approaches to tackle MDR due to their negligible harm to healthy cells and synergistic potential. Considering this notion, the present study aimed at investigating the synergistic activity of 4-MTBITC and PTX against a panel of breast cancer cells. Our results revealed that the combination had a significant antiproliferative activity against T-47D cells. Mechanistic studies revealed that 4-MTBITC and PTX also promoted the production of reactive oxygen species (ROS) and reduced mitochondrial membrane potential. In the presence of 4-MTBITC- PTX, T-47D cells were found to be arrested in the G2/M phase which also confirmed the enhancement of late apoptotic cell population in the flow cytometer analysis. In western blot experiment, the combination had a significant decrease in Bcl-xl protein level, whereas a higher level of p53, cleaved caspase-3, and cleaved caspase-9 proteins compared to individual treatment in T-47D cells. The RT-qPCR analysis also showed that the combination had significant upregulation in the gene expression of p53, cytochrome-c, Apaf-1 and downregulation in the expression of Bcl-2 gene in T-47D cells. Hence, all the results showed that a combination of 4-MTBITC-PTX significantly enhanced the apoptosis pathway in the T-47D cell line which indicates its clinical application for the treatment of breast cancer.Abbreviations: Apaf-1: Apoptotic protease activating factor 1; AO/EB: Acridine orange/ethidium bromide; Bcl-2: B-cell lymphoma 2; CI: Combination Index; Cyt-c: Cytochrome c; CO2: Carbon dioxide; DCFH-DA 2,7-Dichloroflourescein diacetate; DMEM: Dulbecco's modified Eagle's medium; ELISA: Enzyme-linked immunosorbent assay; EA: Early apoptosis; EDTA: Ethylenediaminetetraacetic acid; L929: Normal mouse fibroblast cells; LA: Late apoptosis; L: Live; 4-MTBITC: 4-methylthiobutyl isothiocyanate; MCF-7: Human breast cancer cells; MDA-MB-231: Human triple negative breast cancer cells; MMP: Mitochondria membrane potential; MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide; NCCS: National Centre for Cell Science; N: Necrotic; PTX Paclitaxel; PVDF: Polyvinylidene fluoride; PAGE: Polyacrylamide gel electrophoresis; PBS: Phosphate-buffered saline; RPMI-1640: Roswell Park Memorial Institute Medium- 1640; RT-qPCR: Quantitative real-time polymerase chain reaction; ROS: Reactive oxygen species; Rh-123: Rhodamine123; g Relative centrifugal force; SDS: Sodium dodecyl sulphate; SEM: Scanning electron microscopy; T-47D: Human estrogen positive breast cancer cells; WB: Western blotting.