BackgroundThe fruit of Elaeagnus umbellata has high medicinal values and is an excellent source of phytochemicals. This study was aimed to evaluate the antioxidant, enzyme inhibitory and antidiabetic potential of Elaeagnus umbellata.MethodsThe antioxidant potential of the crude extract and subfractions of E. umbellata fruit were determined using DPPH (2, 20-diphenyl-1-picrylhydrazyl) and ABTS (2, 2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) assays. The enzyme inhibitory potentials of extracts against α-amylase and α-glucosidase enzymes were also determined. The in vivo anti-hyperglycemic effects of the extract in STZ-induced type 2 diabetes were determined using Sprague Dawley adult rats. HPLC system (Agilent 1260) was used for the identification of bioactive compounds present in extracts. Molecular docking was used to identify and compare the interaction between the compounds (active constituents) and standard inhibitor acarbose with the α-amylase and α-glucosidase active sites.ResultsThe chloroform, ethyl acetate, and butanol fractions showed significant antioxidant potential with IC50 values of 40, 45 and 60 μg/mL against DPPH and 57, 70 and 120 μg/mL against ABTS free radicals respectively. The chloroform and ethyl acetate were highly active against α-amylase and α-glucosidase (IC50 values 58 and 200 μg/ml against α-amylase 60 and 140 μg/ml against α-glucosidase. The crude extract, chloroform, and ethyl acetate fractions were more potent in controlling the hyperglycemia in STZ-induced type 2 diabetes in rats and considerable reduction of glucose level was observed compared to the non-treated group. Furthermore, the extracts were also found useful in controlling the secondary complications associated with type 2 diabetes mellitus which was evident from the observed substantial reduction in the blood level of serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, alkaline phosphatase, total cholesterol, low-density lipoproteins, and triglycerides. The molecular docking approach indicated the favorable inhibitory interaction between the docked compounds and the active sites of the α-amylase and α-glucosidase. All docked compounds occupied the same binding site as occupied by acarbose.ConclusionIt was concluded that E. umbellata can be used in the treatment of type 2 diabetes and oxidative stress. The extracts were also found to be effective in relieving the secondary complications associated with type 2 diabetes.Graphical abstract Electronic supplementary materialThe online version of this article (10.1186/s12906-018-2381-8) contains supplementary material, which is available to authorized users.

Background Elaeagnus umbellata is abundantly found in Himalayan regions of Pakistan which is traditionally used to treat various health disorders. However, the experimental evidence supporting the anti-amnesic effect is limited. Therefore the study was aimed to evaluate the prospective beneficial effect of E. umbellata on learning and memory in mice. Objectives To assess neuroprotective and anti-amnesic effects of E. umbellata fruit extracts and isolated compounds on the central nervous system. Methods Major phytochemical groups present in methanolic extract of E. umbellata were qualitatively determined. The total phenolic and flavonoid contents were also determined in extract/fractions of E. umbellata. On the basis of in vitro promising anticholinesterases (AChE & BChE) and antioxidant activities observed for CHF. Ext and isolated compound-I (Chlorogenic acid = CGA), they were further evaluated for learning and memory in normal and scopolamine-induced cognitive impairment in mice using memory behavioral tests such as the Y maze and Novel object recognition using standard procedures. The test sample were further assessed for in vivo anticholinesterases (AChE & BChE) and DPPH free radical scavenging activities in mice brain sample and finally validated by molecular docking study using GOLD software. Results The extract/fractions and isolated compounds were tested for their anticholinesterase and antioxidant potentials. The CHF. Ext and CGA showed maximum % inhibition of tested cholinesterases and free radicals. The CHF. Ext and CGA reversed the effects of scopolamine in mice. The CHF. Ext and CGA significantly increased the alternate arm returns and % spontaneous alteration performance while escape latency times (second) significantly decreased in Y maze test. The CHF. Ext and CGA significantly increased the time spent with novel object and also increased the discrimination index in the Novel object recognition test. Furthermore, molecular docking was used to validate the mechanism of cholinesterases inhibition of isolated compounds. Conclusion The data obtained from behavioral and biochemical studies (AChE/BChE and DPPH/ABTS inhibition) have shown that E. umbellata possessed significant memory enhancing potency. These results suggest that E. umbellata extract possess potential antiamnesic effects and amongst the isolated compounds, compound I could be more effective anti-amnesic therapeutics. However, further studies are needed to identify the exact mechanism of action. Graphical abstract

Recent developments in nanoscience have appreciably modified how diseases are prevented, diagnosed, and treated. Metal nanoparticles, specifically silver nanoparticles (AgNPs), are widely used in bioscience. From time to time, various synthetic methods for the synthesis of AgNPs are reported, i.e., physical, chemical, and photochemical ones. However, among these, most are expensive and not eco-friendly. The physicochemical parameters such as temperature, use of a dispersing agent, surfactant, and others greatly influence the quality and quantity of the synthesized NPs and ultimately affect the material’s properties. Scientists worldwide are trying to synthesize NPs and are devising methods that are easy to apply, eco-friendly, and economical. Among such strategies is the biogenic method, where plants are used as the source of reducing and capping agents. In this review, we intend to debate different strategies of AgNP synthesis. Although, different preparation strategies are in use to synthesize AgNPs such as electron irradiation, optical device ablation, chemical reduction, organic procedures, and photochemical methods. However, biogenic processes are preferably used, as they are environment-friendly and economical. The review covers a comprehensive discussion on the biological activities of AgNPs, such as antimicrobial, anticancer anti-inflammatory, and anti-angiogenic potentials of AgNPs. The use of AgNPs in water treatment and disinfection has also been discussed in detail.

Background Elaeagnus umbellata Thunb. (autumn olive) is a high valued medicinal plant. It belongs to Elaeagnaceae family and is widely distributed in Himalayan regions of Pakistan. In the present study essential oil were extracted from the fruit of this plant and their antioxidant, anticholinesterase and antidiabetic potentials were also evaluated. Methods Essential oils were extracted from the fruit of E. umbellata using hydro-distillation method and were characterized by GC-MS. The extracted oil were tested for its antioxidant, anticholinesterase, and antidiabetic potentials using standard protocols. Results About 68 compounds were identified by GC-MS. The extracted oil exhibited a fairly high free radical scavenging activities against DPPH and ABTS radicals with IC50 values of 70 and 105 μg/mL respectively (for ascorbic acid, used as standard, the IC50 values were 32 and 29 μg/mL, respectively against the mentioned radicals). The essential oil also exhibited anticholinesterase activities with IC50 values of 48 and 90 μg/mL respectively against AChE and BChE (for galantamine used as standard, the IC50 values were 25 and 30 μg/mL respectively). The essential oil also exhibited antidiabetic potential with IC50 values of 120 and 110 μg/mL respectively against α-glucosidase and α-amylase (IC50 values for standard acarbose = 28 and 30 μg/mL respectively). Conclusion Essential oil extracted from the fruits of E. umbellata exhibited reasonable antioxidant, anticholinesterase, and antidiabetic potentials that could be used as alternative medicine in treating diabetes and neurodegenerative disorders. However, further studies are needed to isolate responsible compounds and evaluate the observed potential in animal models. Graphical abstract

In this study, an attempt was made to synthesize silver nanoparticles (Ag-NPs) using Grewia optiva leaf extract and isolated compounds. The bioreductant capacity of Grewia optiva leaf extract for the synthesis of Ag-NPs was assessed using various confirmatory techniques like thermogravimetric analysis (TGA), particle size analysis (PSA), energy-dispersive X-ray (EDX), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and UV-Visible spectroscopy. The presence of various bioactive compounds in leaf aqueous extract was confirmed through HPLC analysis, and 8 compounds were identified among the different peaks present in the chromatogram. Biopotencies like antioxidant, antibacterial, and effect on hair growth were determined for extract and NPs. Antioxidant capacities were assessed through standard ABTS and DPPH methods. The antibacterial potential was evaluated in terms of zone of inhibition, minimum bactericidal concentration, and minimum inhibitory concentration of the Ag-NPs and the leaf extract against selected strains of bacteria, whereas the effect on growth of rabbit hair was studied through topical treatment for a specific period of time. Better antibacterial and DPPH and ABTS free radical inhibition was observed for the formulated Ag-NPs as compared to leaf extract. The previously isolated eight compounds from this plant’s chloroform and ethyl acetate extracts were also tested for their bioreductant capacities. Out of them, the highest amount of precipitates was obtained with compound VII ((2,5-dihydroxyphenyl)-3 ′ ,6 ′ ,8 ′ -trihydroxyl-4H-chromen-4 ′ -one). The study implies that the biogenically engineered nanoscale particles could have promising biological activities in comparison to parental extract and they need to be investigated further as potential therapeutic agents to be used as antibacterial and antioxidant agents and for hair growth enhancement.