Investigations of anticholinestrase and antioxidant potentials of methanolic extract, subsequent fractions, crude saponins and flavonoids isolated from Isodon rugosus

A study on green synthesis, characterization of chromium oxide nanoparticles and their enzyme inhibitory potential

The conventional chemical methods of nanoparticles synthesis have been effectively replaced by nanoparticle synthesis mediated by plants. The current study describes the environmental friendly synthesis of chromium oxide nanoparticles (Cr₂O₃ NPs) using Erythrophleum guineense plant extract. The synthesis of Cr₂O₃ NPs was validated by UV/VIS spectroscopy, Energy Dispersive X-Ray (EDX), Scanning Electron Microscopy (SEM), and X-ray diffraction (XRD) studies. The appearance of the Sharpe peak at 460 nm in the UV/Vis spectrum and the colour change caused by surface plasma resonance confirmed the formation of Cr₂O₃ NPs. The EDX spectrum of Cr₂O₃ nanoparticles revealed the presence of carbon, oxygen, and chromium, while SEM analysis revealed an irregular round morphology (with a size below 400 nm). In addition, XRD studies suggested their crystalline nature by the characteristic peaks at 34° and 36° and 42° (2Ɵ), respectively. The green synthesized Cr₂O₃ NPs showed promise as in-vitro cholinesterase inhibitor at tested concentrations (62.5–1,000 μg/ml), with IC₅₀ values of 120 and 100 μg/ml against Acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE), respectively. The results suggested that the green synthesized Cr₂O₃ NPs could be used in the future to stop enzyme from working and for other biological activities.

Succinimide Derivatives as Antioxidant Anticholinesterases, Anti-α-Amylase, and Anti-α-Glucosidase: In Vitro and In Silico Approaches

Based on the diverse pharmacological potency and the structural features of succinimide, this research considered to synthesize succinimide derivatives. Moreover, these compounds were estimated for their biological potential in terms of anti-diabetic, anti-cholinesterase, and anti-oxidant capacities. The compounds were synthesized through Michael addition of various ketones to N-aryl maleimides. Similarly, the MOE software was used for the molecular docking study to explore the binding mode of the potent compounds against different enzymes. In the anti-cholinesterase activity, the compounds MSJ2 and MSJ10 exhibited outstanding activity against acetylcholinesterase (AChE), i.e., 91.90, 93.20%, and against butyrylcholinesterase (BChE), i.e., 97.30, 91.36% inhibitory potentials, respectively. The compounds MSJ9 and MSJ10 exhibited prominent α-glucosidase inhibitory potentials, i.e., 87.63 and 89.37 with IC₅₀ value of 32 and 28.04 μM, respectively. Moreover, the compounds MSJ2 and MSJ10 revealed significant scavenging activity against DPPH free radicals with IC₅₀ values of 2.59 and 2.52, while against ABTS displayed excellent scavenging potential with IC₅₀ values 7.32 and 3.29 μM, respectively. The tentative results are added with molecular docking studies in the active sites of enzymes to predict the theoretical protein-ligand binding modes. Further detailed mechanism-based studies in animal models are essential for the in vivo evaluation of the potent compound.

Underlying Anticancer Mechanisms and Synergistic Combinations of Phytochemicals with Cancer Chemotherapeutics: Potential Benefits and Risks

Cancer therapies are associated with various challenges including the emergence of multidrug resistant tumors, toxicological issues, severe side effects, and economic burden. To counteract these effects, natural products as substitutes and adjuvant therapies have received considerable attention owing to their safety, efficacy, and economic aspects. Various preclinical and clinical studies revealed that natural products and their combinations with chemotherapeutics mediate their anticancer effects via modulation of various signaling pathways implicated in promoting apoptosis, inhibiting excessive cellular proliferation, and mobilizing the immune system. Several lead phytochemicals including curcumin, resveratrol, quercetin, and cannabinoids synergistically act with cancer chemotherapeutics reducing cell proliferation and inducing apoptosis and cell cycle arrest. However, clinical studies on the subject matter are limited and need further extensive studies. It has been observed that patients undergoing chemotherapy use alternative therapies to ameliorate the symptoms associated with the use of chemotherapeutic agents. Nevertheless, some of the patients inform their physicians regarding herbal medicine during chemotherapy while others do not, and even most of the patients do not know the composition of herbal medicine they consume during chemotherapy. Herbal interactions with chemotherapeutics are associated with both beneficial and harmful aspects, but the beneficial aspect overweighs the harmful ones in terms of controlling the symptoms associated with the chemotherapy. Nonetheless, a large number of herbal medicines have been demonstrated to have synergistic effect with chemotherapy and alleviate the side effects of chemotherapeutic agents. The concomitant use of the majority of herbal medicines with chemotherapy has been demonstrated to be beneficial in multiple malignant tumors like cancer of blood, lungs, kidneys, liver, skin, and gastrointestinal tract. However, herbal medicines which possess positive interaction and improve the quality of life of patients should be sorted out and integrated with the chemotherapy. There should be a quality control system for the appraisal of herbal medicine, and there should also be an appropriate system of patient-doctor communication to counsel the patients regarding the beneficial and deleterious effects of the herbal medicine in combination with chemotherapy.

α-Glucosidase, α-Amylase and Antioxidant Evaluations of Isolated Bioactives from Wild Strawberry

Diabetes mellitus is a metabolic disorder and is a global challenge to the current medicinal chemists and pharmacologists. This research has been designed to isolate and evaluate antidiabetic bioactives from Fragaria indica. The crude extracts, semi-purified and pure bioactives have been used in all in vitro assays. The in vitro α-glucosidase, α-amylase and DPPH free radical activities have been performed on all plant samples. The initial activities showed that ethyl acetate (Fi.EtAc) was the potent fraction in all the assays. This fraction was initially semi-purified to obtain Fi.EtAc 1–3. Among the semi-purified fractions, Fi.EtAc 2 was dominant, exhibiting potent IC₅₀ values in all the in vitro assays. Based on the potency and availability of materials, Fi.EtAc 2 was subjected to further purification to obtain compounds 1 (2,4-dichloro-6-hydroxy-3,5-dimethoxytoluene) and 2 (2-methyl-6-(4-methylphenyl)-2-hepten-4-one). The two isolated compounds were characterized by mass and NMR analyses. The compounds 1 and 2 showed excellent inhibitions against α-glucosidase (21.45 for 1 and 15.03 for 2 μg/mL), α-amylase (17.65 and 16.56 μg/mL) and DPPH free radicals (7.62 and 14.30 μg/mL). Our study provides baseline research for the antidiabetic bioactives exploration from Fragaria indica. The bioactive compounds can be evaluated in animals-based antidiabetic activity in future.

HPLC-DAD phenolics analysis, α-glucosidase, α-amylase inhibitory, molecular docking and nutritional profiles of Persicaria hydropiper L

BACKGROUND

Natural phenolic compounds and Phenolics-rich medicinal plants are also of great interest in the management of diabetes. The current study was aimed to analyze phenolics in P. hydropiepr L extracts via HPLC-DAD analysis and assess their anti-diabetic potentials using in-vitro and in-silico approaches.

METHODS

Plant crude methanolic extract (Ph.Cme) was evaluated for the presence of phenolic compounds using HPLC-DAD analysis. Subsequently, samples including crude (Ph.Cr), hexane (Ph.Hex), chloroform (Ph.Chf), ethyl acetate (Ph.EtAc), butanol (Ph.Bt), aqueous (Ph.Aq) and saponins (Ph.Sp) were tested for α-glucsidase and α-amylase inhibitory potentials and identified compounds were docked against these target enzymes using Molecular Operating Environment (MOE) software. Fractions were also analyzed for the nutritional contents and acute toxicity was performed in animals.

RESULTS

In HPLC-DAD analysis of Ph.Cme, 24 compounds were indentfied and quantified. Among these, Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside (275.4 mg g- 1), p-Coumaroylhexose-4-hexoside (96.5 mg g- 1), Quercetin-3-glucoronide (76.0 mg g- 1), 4-Caffeoylquinic acid (58.1 mg g- 1), Quercetin (57.9 mg g- 1), 5,7,3'-Trihydroxy-3,6,4',5'-tetramethoxyflavone (55.5 mg g- 1), 5-Feruloylquinic acid (45.8 mg g- 1), Cyanidin-3-glucoside (26.8 mg g- 1), Delphinidin-3-glucoside (24 mg g- 1), Quercetin-3-hexoside (20.7 mg g- 1) were highly abundant compounds. In α-glucosidase inhibition assay, Ph.Sp were most effective with IC50 value of 100 μg mL-1. Likewise in α-amylase inhibition assay, Ph.Chf, Ph.Sp and Ph.Cme were most potent fractions displayed IC50 values of 90, 100 and 200 μg mL-1 respectively. Docking with the α-glucosidase enzyme revealed top ranked conformations for majority of the compounds with Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside as the most active compound with docking score of - 19.80899, forming 14 hydrogen bonds, two pi-H and two pi-pi linkages with the Tyr 71, Phe 158, Phe 177, Gln 181, Arg 212, Asp 214, Glu 276, Phe 300, Val 303, Tyr 344, Asp 349, Gln 350, Arg 439, and Asp 408 residues of the enzyme. Likewise, docking with α-amylase revealed that most of the compounds are well accommodated in the active site residues (Trp 59, Tyr 62, Thr 163, Leu 165, Arg 195, Asp 197, Glu 240, Asp 300, His 305, Asp 356) of the enzyme and Cyanidin-3-rutinoside displayed most active compound with docking score of - 15.03757.

CONCLUSIONS

Phytochemical studies revealed the presence of highly valuable phenolic compounds, which might be responsible for the anti-diabetic potentials of the plant samples.

Crude extract and isolated bioactive compounds from Notholirion thomsonianum (Royale) Stapf as multitargets antidiabetic agents: in-vitro and molecular docking approaches

Background

Diabetes mellitus is a common disease effecting the lifestyles of majority world population. In this research work, we have embarked the potential role of crude extracts and isolated compounds of Notholirion thomsonianum for the management diabetes mellitus.

Methods

The crude extracts of N. thomsonianum were initially evaluated for α-glucosidase, α-amylase and antioxidant activities. The compounds were isolated from the activity based potent solvent fraction. The structures of isolated compounds were confirmed with NMR and MS analyses. The isolated compounds were tested for α-glucosidase, α-amylase, protein tyrosine phosphatase 1B (PTP1B) and DPPH activities. The molecular docking studies were carried out to find the binding interactions of isolated compounds for α-glucosidase, α-amylase and PTP1B.

Results

Initially, we screened out crude extracts and subfractions of N. thomsonianum against different in-vitro targets. Among all, Nt.EtAc was observed a potent fraction among all giving IC₅₀ values of 67, 70, < 0.1, 89 and 16 μg/mL against α-glucosidase, α-amylase, DPPH, ABTS and H₂O₂ respectively. Three compounds (Nt01, Nt02 and Nt03) were isolated from Nt.EtAc of N. thomsonianum. The isolated compounds Nt01, Nt02 and Nt03 exhibited IC₅₀ values of 58.93, 114.93 and 19.54 μM against α-glucosidase, while 56.25, 96.54 and 24.39 μM against α-amylase respectively. Comparatively, the standard acarbose observed IC₅₀ values were 10.60 and 12.71 μM against α-glucosidase, α-amylase respectively. In PTP1B assay, the compounds Nt01, Nt02 and Nt03 demonstrated IC₅₀ values of 12.96, 36.22 and 3.57 μM in comparison to the standard ursolic acid (IC₅₀ of 3.63 μM). The isolated compounds also gave overwhelming results in DPPH assay. Molecular docking based binding interactions for α-glucosidase, α-amylase and PTP1B were also encouraging.

Conclusions

In the light of current results, it is obvious that N. thomsonianum is potential medicinal plant for the treatment of hyperglycemia. Overall, Nt.EtAc was dominant fraction in all in-vitro activities. Three compounds Nt01, Nt02 and Nt03 were isolated from ethyl acetate fraction. The Nt03 specifically was most potent in all in-vitro assays. The molecular docking studies supported our in-vitro results. It is concluded that N. thomsonianum is a rich source of bioactive antidiabetic compounds which can be further extended to in-vivo based experiments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03443-7.

Neuroprotective potentials of selected natural edible oils using enzyme inhibitory, kinetic and simulation approaches

BACKGROUND

Edible oils have proven health benefits in the prevention and treatment of various disorders since the establishment of human era. This study was aimed to appraise neuropharmacological studies on the commonly used edible oils including Cinnamomum verum (CV), Zingiber officinale (ZO) and Cuminum cyminum (CC).

METHODS

The oils were analyzed via GC-MS for identifications of bioactive compounds. Anti-radicals capacity of the oils were evaluated via 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals scavenging assays. The samples were also tested against two important acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) which are among the important drug targets in Alzheimer's disease. Lineweaver-Burk plots were constructed for enzyme inhibition studies which correspond to velocity of enzymes (Vmax) against the reciprocal of substrate concentration (Km) in the presence of test samples and control drugs following Michaelis-Menten kinetics. Docking studies on AChE target were also carried out using Molecular Operating Environment (MOE 2016.0802) software.

RESULTS

(Gas chromatography-mass spectrometry GC-MS) analysis revealed the presence of thirty-four compounds in Cinnamon oil (Cv.Eo), fourteen in ginger oil (Zo.Eo) and fifty-six in cumin oil (Cc.Eo). In the antioxidant assays, Cv.Eo, Zo.Eo and Cc.Eo exhibited IC50 values of 85, 121, 280 μg/ml sequentially against DPPH radicals. Whereas, in ABTS assay, Cv.Eo, Zo.Eo and Cc.Eo showed considerable anti-radicals potentials with IC50 values of 93, 77 and 271 μg/ml respectively. Furthermore, Cv.Eo was highly active against AChE enzyme with IC50 of 21 μg/ml. Zo.Eo and Cc.Eo exhibited considerable inhibitory activities against AChE with IC50 values of 88 and 198 μg/ml respectively. In BChE assay, Cv.Eo, Zo.Eo and Cc.Eo exhibited IC50 values of 106, 101 and 37 μg/ml respectively. Our results revealed that these oils possess considerable antioxidant and cholinesterase inhibitory potentials. As functional foods these oils can be effective remedy for the prevention and management of neurological disorders including AD. Synergistic effect of all the identified compounds was determined via binding energy values computed through docking simulations. Binding orientations showed that all the compounds interact with amino acid residues present in the peripheral anionic site (PAS) and catalytic anionic site (CAS) amino acid residues, oxyanion hole and acyl pocket via π-π stacking interactions and hydrogen bond interactions.

Prospective Application of Two New Pyridine-Based Zinc (II) Amide Carboxylate in Management of Alzheimer's Disease: Synthesis, Characterization, Computational and in vitro Approaches

Background

Alzheimer’s disease (AD) is a neurodegenerative illness described predominantly by dementia. Even though Alzheimer’s disease has been known for over a century, its origin remains a mystery, and researchers are exploring many therapy options, including the cholinesterase technique. A decreased acetylcholine ACh neurotransmitter level is believed to be among the important factors in the progression of Alzheimer’s disease.

Methods

In continuation of synthesizing potential anti-Alzheimer agents and known appreciative pharmacological potential of amide-containing compounds, this study presents the synthesis of two novel amide-based transition metal zinc (II) complexes, AAZ7 and AAZ8, attached with a heterocyclic pyridine ring, which was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis, ¹H_NMR, and ¹³C_NMR. FT-IR spectroscopic records showed the development of bidentate ligand as Δν value was decreased in both complexes when compared with the free ligand. Both of the synthesized complexes were analyzed for acetylcholinesterase and butyrylcholinesterase inhibitory potential along with the antioxidizing activity.

Results

Importantly, the complex of AAZ8 exhibited more potent activity giving IC₅₀ values of 14 µg/mL and 18µg/mL as AChE and BChE cholinesterase inhibitors, respectively, when compared with standard positive control galantamine. Interestingly, AAZ8 also displayed promising antioxidant potential by showing IC₅₀ values of 35 µg/mL for DPPH and 29 µg/mL for ABTS in comparison with positive control ascorbic acid.

Conclusion

Herein, we report two new amide carboxylate zinc (II) complexes which were potentially analyzed for various biological applications like acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory potentials, and antioxidant assays. Computational docking studies also simulated results to understand the interactions. Additionally, thermodynamic parameters utilizing molecular dynamic simulation were performed to determine the ligand protein stability and flexibility that supported the results. Studies have shown that these compounds have the potential to be good anti-Alzheimer candidates for future studies due to inhibition of cholinesterase enzymes and display of free radical scavenging potential against DPPH as well as ABTS free radicals.

Heavy metals analysis, GCMS-QP quantification of flavonoids, amino acids and saponins, analysis of tannins and organoleptic properties of powder and tincture of Echinacea purpurea (L.) and Rhapónticum carthamoídes

Medicinal plants are one of the main sources of vitamins, minerals salts, macro-and microelements, and other biologically active substances that have a health and protective effect on the human body. The current study was aimed to appraise the heavy metals contents in the powder materials of two medicinally important plants Echinacea purpurea (L.)  and Rhapónticum carthamoídes collected from the Semipalatinsk nuclear test site using atomic absorption spectrophotometer. Flavonoids, saponins, amino acid contents quantification were done both in raw materials as well as tincture prepared from both plants via GCMS-QP 2010 Ultra chromatomass spectrometer. Further, tannins concentrations and organoleptic properties of the tincture were elucidated using previously reported standard procedures. In the current study, the concentrations of heavy metals were within the permitted range i.e. lead (0.0027 mg.100g-1), cadmium (0.00012 mg.100g-1), arsenic (ND), mercury (ND). In the crude powder, flavonoids were observed to be in the highest concentration in E. purpurea (L.) (5.5 ±0.20 mg.100g-1), whereas, its concentration was 3.1 ±0.346 mg.100g-1 in R. carthamoídes powder. Tannin concentration was higher in R. carthamoídes (5.5 ±0.115 mg.100g-1) and 3.1 ±0.46 mg.100g-1 in E. purpurea. Likewise, saponins concentrations were 4.1 ±0.40 mg.100g-1 and 5.6 ±0.17 mg.100g-1 in E. purpurea and R. carthamoídes powder respectively. Concentrations of these active metabolites in the resultant tincture were flavonoids (7.6 ±0.23), tannins (7.5  ±0.28), and saponins (8.5 ±0.16) mg.100g-1. In the current study, we observed highest concentrations of these essential amino acids in the tincture including leucine/isoleucine (78.00 ±1.15 mg.100g-1), histidine (14.00 ±1.44 mg.100g-1), lysine (49.33 ±2.02 mg.100g-1), methionine (18.66 ±2.90 mg.100g-1), cystine (29.00 ±0.57 mg.100g-1), phenylalanine (24.16 ±1.87 mg.100g-1) and threonine (32.50 ±1.22 mg.100g-1) respectively. The resultant tincture has a pleasant agreeable taste coupled with acceptable herbal flavor which are important organoleptic properties for any product.

Treating Hyperglycemia From Eryngium caeruleum M. Bieb: In-vitro α-Glucosidase, Antioxidant, in-vivo Antidiabetic and Molecular Docking-Based Approaches

Natural-based drugs are believed to be safe, effective and economical. Based on the medicinal importance of the genus Eryngium and unexplored nature of Eryngium caeruleum, we have evaluated its antidiabetic and antioxidant potentials. Both in-vitro and in-vivo assays have been carried out for antidiabetic assays. The antioxidant activity was determined by using different free radicals [i.e., 1,1-diphenyl,2-picrylhydrazyl (DPPH), 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS), and hydrogen peroxide (H₂O₂)]. Moreover, different phytoconstituents were identified in the most active solvent fraction by GC-MS analysis. Furthermore, comparative fingerprints of methanolic extract and chloroform fraction were also analyzed via High Performance Liquid Chromatography coupled with Diode Array Detector (HPLC-DAD). The crude methanolic extract of E. caeruleum (Ec.Cr) and its sub-fractions [i.e., n-hexane (Ec.Hex), chloroform (Ec.Chf), ethyl acetate (Ec.EtAc), and aqueous (Ec.Aq) were employed in this study]. In the α-glucosidase inhibition assay, a concentration-dependent inhibitory response was observed against the enzyme. The most active sample was Ec.Chf which revealed an IC₅₀ of 437 μg/ml in comparison to the standard acarbose (IC₅₀ 25 μg/ml). The rest of the samples showed moderate inhibition of α-glucosidase. In antioxidant assays, Ec.Chf and Ec.Cr exhibited a considerable scavenging effect against all the free radicals. The IC₅₀ values recorded for Ec.Chf were 112, 109, and 150 μg/ml against DPPH, ABTS, and H₂O₂ respectively. Based on the in-vitro potential of Ec.Chf, this was subjected to the in-vivo model experiment. The Ec.Chf lowered the blood glucose level up to 10.3 mmol/L at 500 μg/Kg. The Ec.Chf was also subjected to GC-MS analysis. The GC-MS analysis confirmed the presence of 60 compounds. The identified phytoconstituents consist of some essential compounds previously reported with antidiabetic and antioxidant studies, which include thymol, tocopherol, phytol, nerolidol, (I)-neophytadiene, linolenic acid, and falcarinol. Similarly, the HPLC-DAD chromatograms of Ec.Cr and Ec.Chf exhibited a variety of peaks, which further demonstrates the possibility of important phytochemicals. In a nutshell, we can conclude that Eryngium caeruleum is a potential source of bioactive compounds which may be beneficial for the management of ailments like diabetes and free radicals mediated disorders. Molecular docking was performed to explore the possible role of all the identified bioactive compounds in the chloroform fraction of Eryngium caeruleum into active sites of the homology model of α-glucosidase.

Comparative Cholinesterase, α-Glucosidase Inhibitory, Antioxidant, Molecular Docking, and Kinetic Studies on Potent Succinimide Derivatives

Introduction

The current study was designed to synthesize derivatives of succinimide and compare their biological potency in anticholinesterase, alpha-glucosidase inhibition, and antioxidant assays.

Methods

In this research, two succinimide derivatives including (S)-1-(2,5-dioxo-1-phenylpyrrolidin-3-yl) cyclohexanecarbaldehyde (Compound 1) and (R)-2-((S)-2,5-dioxo-1-phenylpyrrolidin-3-yl)-2-phenylpropanal (Compound 2) were synthesized using Michael addition. Both the compounds, ie, 1 and 2 were evaluated for in-vitro acetylcholinesterase (AChE), butyrylctcholinesterase (BChE), antioxidant, and α-glucosidase inhibitory potentials. Furthermore, molecular docking was performed using Molecular Operating Environment (MOE) to explore the binding mode of both the compounds against different enzymes. Lineweaver-Burk plots of enzyme inhibitions representing the reciprocal of initial enzyme velocity versus the reciprocal of substrate concentration in the presence of synthesized compounds and standard drugs were constructed using Michaelis-Menten kinetics.

Results

In AChE inhibitory assay, compounds 1 and 2 exhibited IC₅₀ of 343.45 and 422.98 µM, respectively, against AChE enzyme. Similarly, both the compounds showed IC₅₀ of 276.86 and 357.91 µM, respectively, against BChE enzyme. Compounds 1 and 2 displayed IC₅₀ of 157.71 and 471.79 µM against α-glucosidase enzyme, respectively. In a similar pattern, compound 1 exhibited to be more potent as compared to compound 2 in all the three antioxidant assays. Compound 1 exhibited IC₅₀ values of 297.98, 332.94, and 825.92 µM against DPPH, ABTS, and H₂O₂ free radicals, respectively. Molecular docking showed a triple fold in the AChE and BChE activity for compound 1 compared with compound 2. The compound 1 revealed good interaction against both the AChE and BChE enzymes which revealed the high potency of this compound compared to compound 2.

Conclusion

Both succinimide derivatives exhibited considerable inhibitory activities against cholinesterases and α-glucosidase enzymes. Of these two, compound 1 revealed to be more potent against all the in-vitro targets which was supported by molecular docking with the lowest binding energies. Moreover, compound 1 also proved to have antiradical properties.

SAR based in-vitro anticholinesterase and molecular docking studies of nitrogenous progesterone derivatives

Progesterone is a steroidal hormone that has been described with pathogenic features of brain dysfunction, realized with advanced age-related neurodegenerative diseases such as Alzheimer's disease. In this study, sixteen nitrogenous derivatives of progesterone which we previously synthesized have been used for Alzheimer targets. The progesterone derivatives (1-16) were screened for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potentials in a dose-dependent manner. All the compounds exhibited overwhelming AChE inhibitions, with IC₅₀ values ranging from 14.40 to 40.37 μM. Similarly, the BChE inhibitory potentials of our compounds were also dominant with IC₅₀values between 20.08 and 46.84 μM. In comparison to our compounds, the standard drug galantamine attain IC₅₀ values of 12.03 and 18.20 μM against AChE and BChE respectively. Molecular docking studies suggested that the compounds exerted their inhibitory activity by binding to the active site of the enzyme. The cholinergic system plays an important role in the regulation of learning and memory processes and has been a major target for the design of anti-Alzheimer's drugs. Therefore, these nitrogen-containing progesterone derivatives will be of potential interest to researchers working in AD for developing new drugs or chemical tools to study the disease.

Antioxidant properties of eugenol, butylated hydroxylanisole, and butylated hydroxyl toluene with key biomolecules relevant to Alzheimer's diseases-In vitro

This research work examined and likened effect of eugenol a natural phenolic compound with butylated hydroxylanisole (BHA) and butylated hydroxyl toluene (BHT) synthetic phenolic compounds with key biomolecules [acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and monoamine oxidase (MAO)] relevant to Alzheimer's diseases (AD) in vitro. Ten millimolar each sample was prepared in a mixture of ethanol and water (1:1 v/v), and the interactions with AChE, BChE, and MAO were evaluated. Still, ferric reducing antioxidant property, ABTS radicals scavenging ability and lipid peroxidation were carried out. The results revealed eugenol, BHT, and BHA inhibited AChE, BChE, and MAO activities dose-dependently. Though, eugenol had greater inhibitory effect against AChE and BChE activities. Also, eugenol demonstrated higher antioxidant potential compared to BHT and BHA. The potent enzymatic inhibitory and antioxidant effects of eugenol indicate eugenol could be promising as an alternative food additive and neuromodulator in AD management. PRACTICAL APPLICATION: BHT and BHA are synthetic antioxidant employed industrially as food preservative. BHT and BHA are employed in food packaging, drugs, and cosmetics. Although BHT and BHA are widely in use but have been found were associated with alteration in sleeping, induced changes in brain serotonin and norepinephrine levels with increased cholinesterase activity. Endocrine disrupting effects, reproductive disorder is more side effects associated with the use of BHT and BHA. However, eugenol a natural compound found in plants compares favorably with BHT and BHA as antioxidant with many more health promoting benefits such as neuroprotective effects, antiapoptotic effects, and prevent aluminum toxicity. Eugenol being a natural antioxidant with no side effects showing more promising effects over the synthetic phenolic compounds and could be an alternative for the BHT and BHA.

An Upcoming Approach to Alzheimer's Disease: Ethnopharmacological Potential of Plant Bioactive Molecules

BACKGROUND

Neurodegenerative disorders have achieved epidemic levels in the last decades; not only the elderly but also adult individuals have been increasingly affected. Among them, Alzheimer's disease is one of the most prevalent and crippling diseases, associated with high rates of multi-morbidities and dependency. Despite the existence of a wide variety of drugs used as the symptomatic treatment, they have some side effects and toxicity, apart from their limited effectiveness. Botanical preparations have a secular use, being widely recommended for a multitude of purposes, such as for the improvement of brain health.

OBJECTIVE

The aim of the present report is to systematize the knowledge on plant-food derived bioactive molecules with promising in vitro enzymatic inhibitory activities.

RESULTS

Alkaloids, phenolic compounds and terpenes are the most studied phytochemicals, both derived from natural and commercial sources. In spite of their efficient activity as enzymatic inhibitors, the number of in vivo studies and even clinical trials have confirmed that their real bioactive potential remains scarce.

CONCLUSION

Thus, it is of the utmost importance to deepen knowledge in this area, once those relevant and informative tools can significantly contribute to the promising advances in the field of Alzheimer's disease treatment.

Pharmacological Evaluation of Aldehydic-Pyrrolidinedione Against HCT-116, MDA-MB231, NIH/3T3, MCF-7 Cancer Cell Lines, Antioxidant and Enzyme Inhibition Studies

Purpose

The current work was designed to synthesize a bioactive derivative of succinimide and evaluate it for anti-Alzheimer, anticancer and anti-diabetic potentials.

Methods

The compound was synthesized by Michael addition of butyraldehyde with N-phenylmaleimide. The synthesized compound was screened for biological potentials including anti-cholinesterase, in-vitro anti-diabetic, antioxidant and anthelmintic potentials. The anti-cholinesterase potential was evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), anti-diabetic potential against α-glucosidase, antioxidant potential against ABTS, DPPH and H₂O₂ and anthelmintic potential against Perethima posthuma and Ascaridia galli respectively.

Results

The compound demonstrated significant AChE and BChE inhibition i.e., 71.34±1.92 and 73.42 ±1.92 at the concentration of 1000 µg/mL respectively. Other dilutions exhibited concentration-dependent inhibitory activity against both enzymes. In the MTT assay, the newly synthesized compound was found active against all of the cell lines viz, HCT-116, MDA-MB231, NIH/3T3 and MCF-7 and the highest cytotoxicity potential was observed against the colon cancer cell line (HCT-116) with an IC₅₀ value of 78 µg/mL exhibiting its highest potential. Moreover, the compound exhibited prominent α-glucosidase inhibitory potentials (79.86±2.54% at 1000 µg/mL) with IC₅₀ value of 156.23 µg/mL. Further, our test compound exhibited considerable scavenging activity against DPPH, ABTS and H₂O₂ free radicals with percent inhibitions of 75.84±1.58, 72.85±1.17 and 54.82±1.82 and IC₅₀ values of 84.36, 139.74 and 752.21 µg/mL respectively. Our test sample exhibited significant anthelmintic potentials. It demonstrated significant paralysis and death of the test worms in an unbelievably short time in comparison with albendazole.

Conclusion

Going into the detail of all observations, it may be deduced that the newly synthesized succinimide derivative could be an important drug candidate against neurodegenerative disorders like Alzheimer's disease, cancer, diabetes mellitus and worms. Further detailed studies in animal models are required for in-vivo analysis of the compound.

Isodon rugosus (Wall. ex Benth.) Codd In Vitro Cultures: Establishment, Phytochemical Characterization and In Vitro Antioxidant and Anti-Aging Activities

Isodon rugosus (Wall. ex Benth.) Codd accumulates large amounts of phenolics and pentacyclic triterpenes. The present study deals with the in vitro callus induction from stem and leaf explants of I. rugosus under various plant growth regulators (PGRs) for the production of antioxidant and anti-ageing compounds. Among all the tested PGRs, thidiazuron (TDZ) used alone or in conjunction with α-napthalene acetic acid (NAA) induced highest callogenesis in stem-derived explants, as compared to leaf-derived explants. Stem-derived callus culture displayed maximum total phenolic content and antioxidant activity under optimum hormonal combination (3.0 mg/L TDZ + 1.0 mg/L NAA). HPLC analysis revealed the presence of plectranthoic acid (373.92 µg/g DW), oleanolic acid (287.58 µg/g DW), betulinic acid (90.51 µg/g DW), caffeic acid (91.71 µg/g DW), and rosmarinic acid (1732.61 µg/g DW). Complete antioxidant and anti-aging potential of extracts with very contrasting phytochemical profiles were investigated. Correlation analyses revealed rosmarinic acid as the main contributor for antioxidant activity and anti-aging hyaluronidase, advance glycation end-products inhibitions and SIRT1 activation, whereas, pentacyclic triterpenoids were correlated with elastase, collagenase, and tyrosinase inhibitions. Altogether, these results clearly evidenced the great valorization potential of I. rugosus calli for the production of antioxidant and anti-aging bioactive extracts for cosmetic applications.

Chemical Characterization, Analgesic, Antioxidant, and Anticholinesterase Potentials of Essential Oils From Isodon rugosus Wall. ex. Benth

Isodon rugosus Wall. ex. Benth is an important species and is used in folk medicine for different types of pains such as abdominal pain, earache, toothache, gastric, and generalized body pain. Recently, we also have reported the antinociceptive potential of chloroform fraction of I. rugosus. In this research, we have investigated the antinociceptive, antioxidant and anti-cholinesterase potentials of essential oils from I. rugosus (Ir.EO), and have determined a possible mechanism of anti-nociception. The Ir.EO was subjected to gas chromatography-mass spectroscopy analysis to find out its chemical constituents. The Ir.EO was assayed for analgesic potential following acetic acid induced writhing, formalin test and hot plate method in animal models. The antioxidant activity was conducted against DPPH and ABTS free radicals following spectroscopic analysis. The cholinesterase inhibitory assays were performed using Ellman's assay. The GC-MS analysis of Ir.EO revealed the identification of 141 compounds. Ir.EO demonstrated strong antinociceptive potential in all three in-vivo models. With the use of nalaxone, it was confirmed that the essential oil was acting on the central pathway of nociception. The Ir.EO also exhibited strong free radicals scavenging potential, exhibiting IC₅₀ values of 338 and 118 μg/ml for DPPH and ABTS free radicals respectively. In AChE and BChE inhibitory assays, the observed IC₅₀ values were 93.56 and 284.19 μg/ml respectively. The encouraging antinociceptive, antioxidant and anticholinesterase results revealed that Ir.EO is a rich source of bioactive compounds as obvious from the GC-MS results.

Extraction Process, Component Analysis, and In Vitro Antioxidant, Antibacterial, and Anti-Inflammatory Activities of Total Flavonoid Extracts from Abutilon theophrasti Medic. Leaves

The flavonoid fraction was extracted from the leaves of Abutilon theophrasti Medic., which are usually used as a traditional Chinese herbal medicine for the treatment of inflammation and joint pain. The current study focused on the extraction process, component analysis, and in vitro antioxidant, antibacterial, and anti-inflammatory activities of the flavonoid fraction as a part of ongoing research on bioactive substances from natural plant sources. This study evaluated the antioxidant activities via assays of DPPH radical scavenging capacity, ABTS radical scavenging capacity, and reducing power and investigated inhibitory activities against Escherichia coli, Salmonella, Staphylococcus aureus, and Streptococcus. Moreover, the inflammatory activity of the flavonoid fraction was estimated by measurement of the content of tumor necrosis factor alpha, interleukin-1-beta, interleukin-6, interleukin-10, nitric oxide, and cyclooxygenase-2 and the gene expression levels of several inflammation markers, such as inducible nitric oxide synthase and cyclooxygenase-2, in RAW 264.7 macrophages after LPS treatment. In addition, the underlying anti-inflammatory mechanisms, that is, the activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, were also revealed from the gene and protein expression levels. Taken together, these results suggested that the flavonoid fraction might exert in vitro antioxidant, antibacterial, and anti-inflammatory effects on LPS-stimulated RAW 264.7 macrophages and will be potentially useful as an adjuvant treatment for oxidative stress and bacterial and inflammatory diseases.

Anticholinesterase and antioxidant potentials of Nonea micrantha Bioss. & Reut along with GC-MS analysis

BACKGROUND

Nonea micrantha Boiss. & Reut . being an unexplored member of Boraginaceae was investigated for GC/MS analysis, acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory and antioxidant activities in an attempt to find its effectiveness in neurological disorders.

METHODS

The AChE and BChE inhibitory activities of crude methanolic extract (Nm.Cr), subsequent fractions; n-hexane (Nm.Hex), chloroform (Nm.Cf), ethyl acetate (Nm.EtAc), aqueous (Nm.Aq) and crude saponins (Nm.Sp) from N. micrantha were conducted using Ellman's assay. The antioxidant activity of the plant samples using DPPH and ABTS free radical scavenging potential following quantitative spectrophotometric and qualitative TLC method were also studied. Moreover the total reducing power (TRP) of all the samples was also figured out.

RESULTS

The GC/Ms analysis confirmed that the plant is rich in bioactive molecules. Among different fractions, Nm.Hex, Nm.EtAc and Nm.Cf exhibited highest AChE inhibitory activities causing 75.51 ± 0.73, 68.54 ± 0.59 and 63.48 ± 0.59% enzyme inhibition respectively and IC50 of 44, 100 and 144 μg/mL respectively. In BChE inhibiton assay, Nm.Aq, Nm.Sp and Nm.Cr showed highest activity causing 83.49 ± 0.27, 81.49 ± 0.89 and 75.31 ± 0.56% enzyme inhibition with IC50 of 90, 110 and 44 μg/mL respectively. In DPPH assay, Nm.Aq, Nm.Cf, Nm.Hex and Nm.Cr were most potent exhibiting IC50 values of 3, 5, 93 and 120 μg/ml respectively. In ABTS assay Nm.EtAc, Nm.Aq, Nm.Sp and Nm.Cr showed IC50 values of 60, 95, 100 and 150 μg/mL respectively. Likewise ABTS inhibition was most prominent for Nm.Sp, Nm.EtAc and Nm.Aq causing 78.26 ± 0.49, 67.67 ± 0.73 and 63.58 ± 0.45% inhibition respectively at 1 mg/mL. These results were further confirmed by qualitative screening using DPPH and ABTS staining.

CONCLUSIONS

Our anticholinesterase and antioxidant results signify the N. micrantha as a potential source of natural bioactive compounds. Moreover isolation of natural bioactive compounds from this plant may lead to novel drug candidates against neurodegenerative disorders.

Neurologically Potent Molecules from Crataegus oxyacantha; Isolation, Anticholinesterase Inhibition, and Molecular Docking

Crataegus oxyacantha is an important herbal supplement and famous for its antioxidant potential. The antioxidant in combination with anticholinesterase activity can be considered as an important target in the management of Alzheimer’s disease. The compounds isolated from C. oxyacantha were evaluated for cholinesterases inhibitory activity using Ellman’s assay with Galantamine as standard drug. Total of nine (1–9) compounds were isolated. Compounds 1 and 2 were isolated for the first time from natural source. Important natural products like β-Sitosterol-3-O-β-D-Glucopyranoside (3), lupeol (4), β-sitosterol (5), betulin (6), betulinic acid (7), oleanolic acid (8), and chrysin (9) have also been isolated from C. oxyacantha. Overall, all the compounds exhibited an overwhelming acetylcholinesterase (AChE) inhibition potential in the range 5.22–44.47 μM. The compound 3 was prominent AChE inhibitor with IC₅₀ value of 5.22 μM. Likewise, all the compounds were also potent in butyrylcholinesterase (BChE) inhibitions with IC₅₀s of up to 0.55–15.36 μM. All the compounds, except 3, were selective toward BChE. Mechanism of the inhibition of both the enzymes were further studied by docking procedures using Genetic Optimization for Ligand Docking suit v5.4.1. Furthermore, computational blood brain barrier prediction of the isolated compounds suggest that these are BBB+.

Demonstration of biological activities of extracts from Isodon rugosus Wall. Ex Benth: Separation and identification of bioactive phytoconstituents by GC-MS analysis in the ethyl acetate extract

Background

Since long, natural sources have been explored for possible managements of various diseases. In this context, the study is designed to evaluate Isodon rugosus Wall. ex Benth for biological potentials including antibacterial, anthelmintic, insecticidal, anti-termites and anti-Pharaoh activities followed by GC-MS analysis of active fraction to identify various bioactive compounds.

Methods

I. rugosus was investigated against eight bacterial strains using well diffusion method and microdilution method with ceftriaxone as positive control. Similarly, the insecticidal activity was carried out against Tribolium castaneum, Rhyzopertha dominica, Monomorium pharaonis and Heterotermis indicola following contact toxicity method. Likewise, anthelmintic activity was performed against Ascaridia galli and Pherethima posthuma using albendazole as positive control, in which the paralysis and death times of the worms were observed. The GC-MS analysis of the most active solvent fraction was performed for identifications of various bioactive compounds.

Results

Among the tested samples of I. rugosus, flavonoids and ethyl acetate fraction exhibited high antibacterial activities. The crude saponins showed highest anthelmintic activity against Pherethima posthuma and Ascaridia galli with death times of 27.67 and 29.22 min respectively at concentrations of 40 mg/ml. In insecticidal activity, chloroform fraction and saponins exhibited notable results against R. dominica (60 and 70%) and T. castaneum (70 and 76%) at concentration of 200 mg/ml. In anti-termite assay, all the plant samples showed overwhelming results, i.e. all the 25 termites were killed on the 3rd day. Similarly, in anti-Pharaoh activity, the chloroform, ethyl acetate and saponins fractions were most potent, each exhibiting LD₅₀ of <0.1 mg/ml. In GC-MS analysis, total of 57 compounds were identified. Some of the bioactive compounds identified in GC-MS analysis are palmitic acid, hinokiol, α-amyrin, phytol, ethyl linolate, cyclohexanone, hinokione, methyl palmitate, ethyl palmitate and stigmasterol acetate.

Conclusions

Based on our current results, it can be concluded that I. rugosus possess strong antibacterial, insecticidal and anthelmintic potentials having crude saponins and ethyl acetate as the most active fractions. The GC-MS analysis and biological assays reveal that ethyl acetate fraction is a suitable target for the isolation of diverse array of bioactive compounds.

Chemical profiling, antimicrobial and insecticidal evaluations of Polygonum hydropiper L

Background

The emergence of multidrug resistant (MDR) pathogens is of great concern to the global health community. Our ability to effectively treat diseases is based on the discovery of potent drugs for the treatment of these challenging diseases. Traditional medicines are one of the major sources for the discovery of safe, effective and economical drug candidates. In order to validate its antibacterial, antifungal and insecticidal potentials with respect to traditional uses, we have screened for the first time Polygonum hydropiper against pathogenic bacterial, fungal strains and a variety of insects.

Methods

Polygonum hydropiper samples including crude extract (Ph.Cr), subsequent fractions; n-hexane (Ph.Hex), chloroform (Ph.Chf), ethyl acetate (Ph.EtAc), n-Butanol (Ph.Bt), aqueous (Ph.Aq) and crude saponins (Ph.Sp) were tested against pathogenic bacterial and fungal strains. Insecticidal activities were performed against Tribolium castaneum and Rhyzopertha dominica and Monomorium pharaonis. Ph.Cr was analyzed by gas chromatography–mass spectrometry (GC-MS) for preliminary identification of chemical constituents.

Results

In disc diffusion assay, Ph.Chf, Ph.Hex, Ph.EtAc and Ph.Sp exhibited highest activity against Enterococcus faecalis. MICs of Ph.Chf against Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli, P. mirabilis, Staphylococcus aureus, Salmonella typhi and Pseudomonas aeruginosa were 32.00, 13.33, 10.66, 5.33, 64.00, 8.66 and 10.66 μg/ml respectively. MFC’s of Ph.Chf against Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger and Fusarium oxysporum were 16.66, 23.33, 125.00 and 46.66 μg/ml respectively. Ph.EtAc, Ph.Sp, Ph.Chf and Ph.Bt were most active fractions against T. castaneum and R. dominica. Ph.Sp being most active against A. punctatum exhibited LC₅₀ of < 0.01 mg/ml. In GC-MS analysis of Ph.Cr, 124 compounds were identified among which several bioactive antibacterial, antifungal and insecticidal compounds were found.

Conclusions

P. hydropiper samples exhibited broad spectrum of activity against bacterial and fungal strains. Our results support previously reported insecticidal properties of saponins and may provide scientific justification for the ethno-medicinal uses of the plant.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1491-4) contains supplementary material, which is available to authorized users.

Antibacterial and antifungal potentials of the solvents extracts from Eryngium caeruleum, Notholirion thomsonianum and Allium consanguineum

BACKGROUND

Herbal medicines have long been used for various ailments in various societies and natural bioactive compounds are gaining more and more importance due to various factors. In this context, three plant species i.e., Eryngium caeruleum, Notholirion thomsonianum and Allium consanguineum have been aimed for the scientific verification of their purported traditional uses against various infectious diseases.

METHODS

In this study, three plants were assayed for antibacterial and antifungal potentials. The antibacterial investigations were performed via well diffusion method and nutrient broth dilution method. The bacterial strains used in the study were Enterococcus faecalis, Proteus mirabilis, Escherichia coli, Salmonella typhi, Klebsiella pneumonia and Pseudomonas aeruginosa. The antifungal potential was investigated by dilution method of Muller-Hinton agar media of the plants' samples. The fungal strains used were Aspergillis fumigatus, Aspergillis flavus and Aspergillis niger. Ceftriaxone and nystatin were used as standard drugs in antibacterial and antifungal assays respectively.

RESULTS

Different fractions from N. thomsonianum were tested against five bacterial strains while the samples from A. consanguineum and E. caeruleum were tested against six bacterial strains. All the samples exhibited prominent antibacterial activity against the tested strains. Overall, chloroform and ethyl acetate fractions were found most potent among the three plants' samples. N. thomsonianum excelled among the three plants in antibacterial activity. Similarly, in antifungal assay, N. thomsonianum exhibited strong antifungal activity against the fungal strains. The chloroform fraction displayed MFCs of 175.67 ± 5.20***, 29.33 ± 5.48*** and 63.00 ± 4.93*** μg/ml against Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger respectively. The whole study demonstrates that all the three plant species were active against tested bacterial and fungal strains.

CONCLUSION

It can be concluded from our findings that N. thomsonianum, A. consanguineum and E. caeruleum have broad antibacterial and antifungal potentials. In all of the plants' samples, chloroform and ethyl acetate fractions were more active. Furthermore, being the potent samples, the chloroform and ethyl acetate fractions of these plants can be subjected to column chromatography for the isolation of more effective antimicrobial drugs.

Evaluation of Rumex hastatus D. Don for cytotoxic potential against HeLa and NIH/3T3 cell lines: chemical characterization of chloroform fraction and identification of bioactive compounds

Background

The importance of Rumex genus and the renowned ethnopharmacological and biological potentials of Rumex hastatus is evident from the previous reports. Recently the R. hastatus has been evaluated for anticancer potential against HepG2, MCF7 or LNCaP cell lines with considerable cytotoxicity. We also reported the anti-tumor and anti-angiogenic potentials of R. hastatus. The current study has been arranged to evaluate cytotoxic potential of this plant against HeLa and NIH/3T3 cell lines and sort out the most active fraction of R. hastatus along with the identification of bioactive compounds responsible for cytotoxicity.

Methods

The cytotoxic potential of methanolic extract and sub-fractions of R. hastatus was performed following (3-[4, 5-dimethylthiazole-2-yl]-2, 5-diphenyl-tetrazolium bromide) MTT calorimetric assay. Four concentrations (500, 250, 125 and 62.5 μg/ml) of each sample were used against both cell lines. Two cell lines i.e. HeLa and NIH/3T3 were used in the assay. Furthermore, chemical characterization of chloroform fraction was performed by GC-MS analysis.

Results

The current investigational study demonstrates that all the solvent fractions of R. hastatus were active against HeLa and NIH/3T3 cell lines. Among all the fractions, chloroform fraction was dominant in activity against both cell lines. The observed IC₅₀ values of chloroform fraction were 151.52 and 53.37 μg/ml against HeLa and NIH/3T3 respectively. The GC-MS analysis of chloroform fraction revealed the identification of 78 compounds with the identification of bioactive ones like ar-tumerone, phytol, dihydrojasmone, sitostenone etc.

Conclusion

It can be concluded from our results that Rumex hastatus D. Don possess strong cytotoxic potential. Moreover, the observed IC₅₀ values and GC-MS analysis of chloroform fraction reveal that most of the bioactive compounds are in chloroform fraction. It can be further deduce that the chloroform fraction is a suitable target for the isolation of compounds having potential role in cancer therapy.

Anti-nociceptive Activity of Ethnomedicinally Important Analgesic Plant Isodon rugosus Wall. ex Benth: Mechanistic Study and Identifications of Bioactive Compounds

Isodon rugosus Wall. ex Benth. is extensively used as traditional medicine for the management of various types of pain including tooth ache, gastric pain, abdominal pain, ear ache, and generalized body pain. The current study is designed to scientifically verify the purported uses of I. rugosus as analgesic agent and to figure out its possible mechanism of action. Bioactive compounds responsible for analgesic activity were identified using GC and GC-MS analysis. Analgesic potentials were evaluated using acetic acid induced writhing, hot plate test, and formalin induced paw licking test. In acetic acid induced writhing chloroform fraction (Ir.Chf) exhibited 53% analgesia while formalin test displayed 61% inhibition at phase-I and 45% at phase-II respectively at a dose of 100 mg/kg. Similarly, in hot plate test Ir.Chf displayed average reaction time of 7 min at 15, 30, 45, and 60 min intervals. The possible mechanism of action was found to be the central pathway via opioidergic receptors as the mice showed morphine like analgesic activity at pre-administration of naloxone (opioid antagonist) in hot plate and formalin tests. In GC-MS analysis, 83 compounds were identified among which eight compounds including benzyl alcohol, sebacic acid, myristic acid, phytol, sugiol, Tocopherol, α-Amyrin, and stigmasterol were sorted out as previously reported analgesic compounds. Current study revealed that analgesic potential of I. rugosus can attributed to the presence of analgesic compounds. It may also be concluded that opioids receptors are involved in the analgesic mechanism of I. rugosus due to effective antagonism of nalaxone.

Antitumor and anti-angiogenic potentials of isolated crude saponins and various fractions of Rumex hastatus D. Don

Background

Cancer, being the foremost challenge of the modern era and the focus of world-class investigators, gargantuan research is in progress worldwide to explore novel therapeutic for its management. The exploitation of natural sources has been proven to be an excellent approach to treat or minify the excessive angiogenesis and proliferation of cells. Similarly, based the ethnomedicinal uses and literature survey, the current study is designed to explore the anti-tumor and anti-angiogenic potentials of Rumexhastatus. Anti-tumor and anti-angiogenic activities were carried out using potato-disc model and chorioallantoic membrane (CAM) assay respectively. Moreover, R. hastatus was also assessed for antibacterial activity against Agrobacteriumtumefaciens (tumor causing bacterial strain). The positive controls used in anti-tumor, anti-angiogenic and antibacterial activities were vincristine sulphate, dexamethasone and cefotaxime respectively.

Results

The crude saponins (Rh.Sp), methanolic extract (Rh.Cr) and other solvent extracts like n-hexane (Rh.Hex), chloroform (Rh.Chf), ethylacetate (Rh.EtAc) and aqueous fraction (Rh.Aq) exhibited notable anti-tumor and anti-angiogenic activities. In potato tumor assay, the chloroform and saponin fractions were observed to be the most effective showing 86.7 and 93.3 % tumor inhibition at 1000 µg/ml with IC₅₀ values 31.6 and 18.1 µg/ml respectively. Similarly, these two samples i.e., chloroform and saponins also excelled among the entire test samples in anti-angiogenic evaluation exhibiting 81.6 % (IC₅₀ = 17.9 µg/ml) and 78.9 % (IC₅₀ = 64.9 µg/ml) at 1000 µg/ml respectively. In contrast, the antibacterial investigations revealed a negligible potential against A. tumefaciens.

Conclusion

Based on our results we can claim that R. hastatus possesses both anti-tumor and anti-angiogenic potentials. In all of the solvent fractions, Rh.Chf and Rh.Sp were most effective against tumor and angiogenesis while having negligible activity against A. tumefaciens. It can be concluded that Rh.Chf and Rh.Sp might be potential targets in the isolation of natural product having anti-neoplastic action.

Chemical composition, antioxidant and anticholinesterase potentials of essential oil of Rumex hastatus D. Don collected from the North West of Pakistan

Background

Ethnomedicinally Rumex hastatus D. Don has been used since long for various ailments especially in neurological disorders. The reported data and the importance of Rumex genus demonstrate the vital medicinal value of R. hastatus.

Methods

In the current investigational study, isolation of essential oil and its antioxidant and anticholinesterase assays were performed. The essential oil of R. hastatus was analyzed by GC-MS for the first time. The essential oil was evaluated for anticholinesterase and antioxidant assays. The anticholinesterase assay was conducted at various concentrations (62.5 to 1000 μg/ml) against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Similarly, the antioxidant potential was determined using DPPH and ABTS free radicals.

Results

The GC-MS analysis of essential oil showed 123 components. The result recorded for the anticholinesterase assays demonstrated a marked potential against AChE and BChE with IC₅₀ values of 32.54 and 97.38 μg/ml respectively which were comparable with the positive control i.e., galanthamine (AChE, IC₅₀ = 4.73 μg/ml and BChE, IC₅₀ = 11.09 μg/ml). The antioxidant assays against DPPH and ABTS free radicals also exhibited significant scavenging potential with IC₅₀ values of 3.71 and 6.29 μg/ml respectively, while for ascorbic acid the IC₅₀ value was <0.1 μg/ml against both free radicals.

Conclusions

Based on the current investigational studies, it may be concluded that R. hastatus is an effective source of essential oil's components having anticholinesterase and antioxidant potentials, which after subjecting to drug development may lead to novel drug candidates against neurodegenerative disorders.

Comparative chemical profiling, cholinesterase inhibitions and anti-radicals properties of essential oils from Polygonum hydropiper L: a preliminary anti- Alzheimer's study

Background

Cholinesterase inhibition is a vital target for the development of novel and mechanism based inhibitors, owing to their role in the breakdown of acetylcholine (ACh) neurotransmitter to treat various neurological disorders including Alzheimer’s disease (AD). Similarly, free radicals are implicated in the progression of various diseases like neurodegenerative disorders. Due to lipid solubility and potential to easily cross blood brain barrier, this study was designed to investigate the anticholinesterase and antioxidant potentials of the standardized essential oils from the leaves and flowers of Polygonum hydropiper.

Methods

Essential oils from the leaves (Ph.LO) and flowers (Ph.FO) of P. hdropiper were isolated using Clevenger apparatus. Oil samples were analyzed by GC-MS to identify major components and to attribute the antioxidant and anticholinesterase activity to specific components. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potentials of the samples were determined following Ellman’s assay. Antioxidant assays were performed using 1,1-diphenyl,2-picrylhydrazyl (DPPH), 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS) and hydrogen peroxide (H₂O₂) free radical scavenging assays.

Results

In the GC-MS analysis 141 and 122 compounds were indentified in Ph.LO and Ph.FO respectively. Caryophylene oxide (41.42 %) was the major component in Ph.FO while decahydronaphthalene (38.29 %) was prominent in Ph.LO. In AChE inhibition, Ph.LO and Ph.FO exhibited 87.00** and 79.66***% inhibitions at 1000 μg/ml with IC₅₀ of 120 and 220 μg/ml respectively. The IC₅₀ value for galanthamine was 15 μg/ml. In BChE inhibitory assay, Ph.LO and Ph.FO caused 82.66*** (IC₅₀ 130 μg/ml) and 77.50***% (IC₅₀ 225 μg/ml) inhibitions respectively at 1000 μg/ml concentration. In DPPH free radical scavenging assay, Ph.LO and Ph.FO exhibited IC₅₀ of 20 and 200 μg/ml respectively. The calculated IC₅₀s were 180 & 60 μg/ml for Ph.LO, and 45 & 50 μg/ml for Ph.FO in scavenging of ABTS and H₂O₂ free radicals respectively.

Conclusions

In the current study, essential oils from leaves and flowers of P. hydropiper exhibited dose dependent anticholinesterase and antioxidant activities. Leaves essential oil were more effective and can be subjected to further in-vitro and in-vivo anti-Alzheimer’s studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-015-0145-8) contains supplementary material, which is available to authorized users.

Synthesis, anticholinesterase and antioxidant potentials of ketoesters derivatives of succinimides: a possible role in the management of Alzheimer's

Background

Based on the pharmacological potency and structural features of succinimides, this study was designed to synthesize new ketoesters derivatives of succinimides. Furthermore, the synthesized compounds were evaluated for their possible anticholinesterase and antioxidant potentials. The compounds were synthesized by organocatalytic Michael additions of α-ketoesters to N-aryl maleimides. Acetyl and butyrylcholinesterase inhibitory activities were determined using Ellman’s spectrophotometric assay. The antioxidant activity was performed with DPPH and ABTS free radicals scavenging assay.

Results

The Michael additions of α-ketoesters to maleimides was promoted by 8-hydroxyquinoline. The organocatalyst (8-hydroxyquinoline, 20 mol %) produced the compounds in relatively shorter time (20–24 h) and with excellent isolated yields (84-98 %). The synthesized compounds (1–4) showed outstanding acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potentials, i.e., 98.75 and 90.00 % respectively for compound 2, with IC₅₀ < 0.1 μg/mL. Additionally, compounds 1–4 revealed moderate antioxidant activity at different concentrations. In DPPH free radical scavenging assay, compound 1 showed dominant result with 72.41 ± 0.45, 52.49 ± 0.78 and 35.60 ± 0.75 % inhibition at concentrations of 1000, 500 and 250 μg/mL respectively, IC₅₀ value of 440 μg/mL. However, the free radical scavenging was better when used ABTS free radicals. In ABTS free radicals scavenging assay compound 1 exhibited 88.51 ± 0.62 % inhibition at highest tested concentration i.e., 1000 μg/mL.

Conclusions

Herein, we have synthesized four ketoesters derivatives of succinimides in a single step reaction and high yields. As a highlight, we have showed a first report on the anticholinesterase and antioxidant potentials of succinimides. All the compounds showed overwhelming enzyme inhibitions and moderate antioxidant potentials.

Graphical Abstract

Anticholinesterase and antioxidant investigations of crude extracts, subsequent fractions, saponins and flavonoids of atriplex laciniata L.: potential effectiveness in Alzheimer's and other neurological disorders

Background

Atriplex laciniata L. was investigated for phenolic, flavonoid contents, antioxidant, anticholinesterase activities, in an attempt to explore its effectiveness in Alzheimer’s and other neurological disorders. Plant crude methanolic extract (Al.MeF), subsequent fractions; n-hexane (Al.HxF), chloroform (Al.CfF), ethyl acetate (Al.EaF), aqueous (Al.WtF), Saponins (Al.SPF) and Flavonoids (Al.FLVF) were investigated for DPPH, ABTS and H₂O₂ free radical scavenging activities. Further these extracts were subjected to acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities using Ellman’s assay. Phenolic and Flavonoid contents were determined and expressed in mg Gallic acid GAE/g and Rutin RTE/g of samples respectively.

Results

In DPPH free radicals scavenging assay, Al.FLVF, Al.SPF and Al.MeF showed highest activity causing 89.41 ± 0.55, 83.37 ± 0.34 and 83.37 ± 0.34% inhibition of free radicals respectively at 1 mg/mL concentration. IC₅₀ for these fractions were 33, 83 and 82 μg/mL respectively. Similarly, plant extracts showed high ABTS scavenging potential, i.e. Al.FLVF (90.34 ± 0.55), Al.CfF (83.42 ± 0.57), Al.MeF (81.49 ± 0.60) with IC₅₀ of 30, 190 and 70 μg/ml respectively. further, H₂O₂ percent scavenging was highly appraised in Al.FLVF (91.29 ± 0.53, IC₅₀ 75), Al.SPF (85.35 ± 0.61, IC₅₀ 70) and Al.EaF (83.48 ± 0.67, IC₅₀ 270 μg/mL). All fractions exhibited concentration dependent AChE inhibitory activity as; Al.FLVF, 88.31 ± 0.57 (IC₅₀ 70 μg/mL), Al.SPF, 84.36 ± 0.64 (IC₅₀ 90 μg/mL), Al.MeF, 78.65 ± 0.70 (IC₅₀ 280 μg/mL), Al.EaF, 77.45 ± 0.46 (IC₅₀ 270 μg/mL) and Al.WtF 72.44 ± 0.58 (IC₅₀ 263 μg/mL) at 1 mg/mL. Likewise the percent BChE inhibitory activity was most obvious in Al.FLVF 85.46 ± 0.62 (IC₅₀ 100 μg/mL), Al.CfF 83.49 ± 0.46 (IC₅₀ 160 μg/mL), Al.MeF 82.68 ± 0.60 (IC₅₀ 220 μg/mL) and Al.SPF 80.37 ± 0.54 (IC₅₀ 120 μg/mL).

Conclusions

These results stipulate that A. laciniata is enriched with phenolic and flavonoid contents that possess significant antioxidant and anticholinestrase effects. This provide pharmacological basis for the presence of compounds that may be effective in Alzheimer’s and other neurological disorders.

Antioxidant and anticholinesterase investigations of Rumex hastatus D. Don: potential effectiveness in oxidative stress and neurological disorders

BACKGROUND

Rumex species are traditionally used for the treatment of neurological disorders including headache, migraine, depression, paralysis etc. Several species have been scientifically validated for antioxidant and anticholinestrase potentials. This study aims to investigate Rumex hastatus D. Don crude methanolic extract, subsequent fractions, saponins and flavonoids for acetylcholinestrase, butyrylcholinestrase inhibition and diverse antioxidant activities to validate its folkloric uses in neurological disorders. Rumex hastatus crude methanolic extract (Rh. Cr), subsequent fractions; n-hexane (Rh. Hex), chloroform (Rh. Chf), ethyl acetate (Rh. EtAc), aqueous fraction (Rh. Aq), crude saponins (Rh. Sp) and flavonoids (Rh. Fl) were investigated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) at various concentrations (125, 250, 500, 1000 μg/mL) using Ellman's spectrophotometric analysis. Antioxidant potentials of Rh. Sp and Rh. Fl were evaluated using DPPH, H2O2 and ABTS free radical scavenging assays at 62.5, 125, 250, 500, 1000 μg/mL.

RESULTS

All the test samples showed concentration dependent cholinesterase inhibition and radicals scavenging activity. The AChE inhibition potential of Rh. Sp and Rh. Fl were most prominent i.e., 81.67 ± 0.88 and 91.62 ± 1.67 at highest concentration with IC50 135 and 20 μg/mL respectively. All the subsequent fractions exhibited moderate to high AChE inhibition i.e., Rh. Cr, Rh. Hex, Rh. Chf, Rh. EtAc and Rh. Aq showed IC50 218, 1420, 75, 115 and 1210 μg/mL respectively. Similarly, against BChE various plant extracts i.e., Rh. Sp, Rh. Fl, Rh. Cr, Rh. Hex, Rh. Chf, Rh. EtAc and Rh. Aq resulted IC50 165, 175, 265, 890, 92, 115 and 220 μg/mL respectively. In DPPH free radical scavenging assay, Rh. Sp and Rh. Fl showed comparable results with the positive control i.e., 63.34 ± 0.98 and 76.93 ± 1.13% scavenging at 1 mg/mL concentration (IC50 312 and 104 μg/mL) respectively. The percent ABTS radical scavenging potential exhibited by Rh. Sp and Rh. Fl (1000 μg/mL) were 82.58 ± 0.52 and 88.25 ± 0.67 with IC50 18 and 9 μg/mL respectively. Similarly in H2O2 scavenging assay, the Rh. Sp and Rh. Fl exhibited IC50 175 and 275 μg/mL respectively.

CONCLUSION

The strong anticholinesterase and antioxidant activities of Rh. Sp, Rh. Fl and various fractions of R. hastatus support the purported ethnomedicinal uses and recommend R. hastatus as a possible remedy for the treatment of AD and neurodegenerative disorders.