Regia Leaf Extract Research Articles

Phytochemical Profiling and in Vitro Antioxidant Activity Assessment of Lawsonia Inermis and Juglans Regia Leaf Extracts

This study aimed to profile the phytochemicals present in Lawsonia inermis and Juglans regia leaf extracts and assess their in vitro antioxidant activity using three different assays. Phytochemical screening revealed the presence of carbohydrates, glycosides, triterpenes, flavonoids, saponins, and alkaloids in both plant extracts. These compounds are known to possess various pharmacological properties, including antimicrobial, anti-inflammatory, antiviral, and anticancer activities. The in vitro antioxidant activity of the extracts was evaluated using the phosphomolybdenum, FeCl3 radical scavenging, and DPPH radical scavenging assays. The results showed that Lawsonia inermis extract had a higher total antioxidant capacity, as measured by the phosphomolybdenum assay, compared to Juglans regia extract. Similarly, it had a higher ability to prevent the formation of free radicals, as measured by the FeCl3 radical scavenging assay. Additionally, Lawsonia inermis extract exhibited a higher capacity to neutralize free radicals, as measured by the DPPH radical scavenging assay. Overall, the study suggests that both Lawsonia inermis and Juglans regia leaf extracts contain various phytochemicals with potential health benefits. However, Lawsonia inermis extract exhibited a stronger antioxidant activity compared to Juglans regia extract. These findings could have significant implications in the development of natural antioxidants for various industrial and therapeutic applications

Antioxidant, antimicrobial, and α-glucosidase inhibitory activities of saponin extracts from walnut (Juglans regia L.) leaves

Objective: To investigate the relationship between triterpenoid saponin content and antioxidant, antimicrobial, and α-glucosidase inhibitory activities of 70% ethanolic, butanolic, aqueous, supernate and precipitate extracts of Juglans regia leaves. Methods: Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method. Antioxidant activity was evaluated against DPPH and ABTS free radicals. We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts. Pearson's correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities. Results: The butanolic extract was most effective against DPPH with an IC50 of 6.63 μg/mL, while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50 of 42.27 μg/mL. Pearson's correlation analysis indicated a strong negative correlation (r = -0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined. In addition, the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts. All the extracts had fair antibacterial activity against Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae except for the aqueous extract. Conclusions: Juglans regia extracts show potent antioxidant, antimicrobial, and α-glucosidase inhibitory activities. There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities. However, additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.

Effect of the Juglans Regia (Walnut) leaf extract concentration on the biosynthesis of ZnO nanoparticles: Characterisation and antimicrobial activity

ABSTRACT In the present article, we have developed an eco-friendly, phytosynthetic, cost-effective, and straightforward method for the synthesis of ZnO nanoparticles using leaf extracts of Juglans Regia (JR) as green reducing agents. The powder X-ray diffraction pattern revealed the high crystalline nature of synthesised ZnO nanoparticles also rivalled with ICSD no. 98–009-4004. The SEM images of the samples showed the spherical and irregularly distributed rod and plate-like structures. The EDS spectrum filed only Zn and O peaks revealed that the sample has good purity in ZnO nanoparticles. The HRTEM analysis explained the formed ZnO nanoparticles by biogenic reduction were hexagonal shape with definite edges and the average grain size was obtained as 33.18 ± 6.2 nm for the 50JR sample. The d-spacings of fringes and SAED pattern got also rivalled with XRD d-spacings. According to the UV-Visible analysis, the values of peak absorbance wavelength decreased (blue shift) with the increase in the leaf extract concentrations. The bandgap values were calculated in the range of 2.74–3.17 eV. The Fourier Transform Infra-Red study explicated the biomolecules for the reduction of nanoparticles and also ZnO bonding. These results also proved the presence of ZnO nanoparticles synthesised using Juglans Regia extract. Regarding the antimicrobial effects of ZnO NPs, ZnO NP which was using 50 mL JR extracts was detected as highly efficient nanoparticles against test microorganisms. In particular, the highest antimicrobial activity was measured with 15.66 ± 1.15 mm against Candida albicans 10,231 and revealed data compared with fluconazole, as reference antifungal, recorded 69% antimicrobial index. The findings demonstrated that ZnO NPs can be evaluated for use in biomedical applications.

Valorization of Juglans regia Leaves as Cosmeceutical Ingredients: Bioactivity Evaluation and Final Formulation Development

The cosmetic industry is constantly searching for bioactive ingredients, namely, those obtained from natural sources with environmentally friendly connotations and less toxic effects. A previous study of our research group optimized the extraction of phenolic compounds from Juglans regia by heat-assisted extraction. Due to its richness in different phenolic compounds, the present work aimed to develop a formulation containing J. regia leaf extract. The extract’s antioxidant, anti-tyrosinase, antimicrobial, anti-inflammatory, wound healing, cytotoxicity, and photostability properties were evaluated. The extract was then incorporated into an O/W base cream, followed by characterization of the final formulation in terms of its antioxidant properties, phenolic composition, and stability over time and at different storage conditions. The most abundant compounds in the hydroethanolic extract were 3-O-caffeoylquinic acid (18.30 ± 0.04 mg/g), quercetin-O-pentoside (9.64 ± 0.06 mg/g), and quercetin 3-O-glucoside (6.70 ± 0.19 mg/g). Besides those, the extract presented antioxidant, anti-inflammatory, wound closure, and antibacterial effects against several skin pathogens. In addition, HaCaT cell viability was maintained up to 98% at 400 µg/mL. Within Proteus vulgaris-infected HaCaT cells, the extract also presented an over 40% bacterial mortality rate at its nontoxic concentration (200 µg/mL). After incorporating the extract, the obtained formulation presented a good physicochemical profile over time and at different storage conditions while also maintaining its antioxidant effect; as such, it can be considered stable for topical application. Future work to evaluate its performance in terms of skin permeation and detailed toxicological studies with a focus on regulatory requirements, involving skin irritation, eye irritation, genotoxicity, photo-irritation, and dermal absorption, should be conducted, as the prepared formulation demonstrated relevant properties that deserve to be further explored.

Allelopathic effects of Juglans regia leaf extract on seed germination and seedling growth of wheat (Triticum aestivum) and rye (Secale cereale)

This investigation was conducted to study the allelopathic effects of Juglans regia (Walnut) leaf extract on seed germination and seedling growth of wheat (Triticum aestivum) and rye (Secale cereale). For this J. regia leaves extract was selected to analyze its allelopathic effects on seed germination and seedling growth of wheat and rye seeds. Applied seeds was treated with J. regia leaves extract using 2%, 4% and 6% concentrations. Different parameters i.e., seed germination, seedling growth, mortality percentage, fresh and dry weight of plumule and radicle was observed after the experiments. The higher seed germination percentage (50%) was recorded at 2% level, in both the applied seeds, which is followed by 4% in comparison to control. Almost higher concentration showed deleterious effects than the lower doses on germination percentage and seedling growth. The highest mortality percentage (70%) has been recorded at 4% level in wheat and 6% level in both wheat and rye seeds. Therefore, the results indicated that the growing weeds in high quantity between crops can affect the productivity rate of crops due to its allelopathic effects. The allelopathic compounds can be used as natural herbicides and other pesticides; they are less disruptive of the global ecosystem than are synthetic agrochemicals.

The Effect of Walnut (Juglans regia) Leaf Extract on Glycemic Control and Lipid Profile in Patients With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

Numerous clinical trials have examined the beneficial effects of Juglans regia leaf extract (JRLE) in patients with type 2 diabetes mellitus (T2DM); however, the results of these studies are inconsistent. Therefore, we conducted the current systematic review and meta-analysis to evaluate the effect of JRLE on glycemic control and lipid profile in T2DM patients. We searched online databases including PubMed, Scopus, EMBASE, and Web of Science for randomized controlled clinical trials that examined the effect of JRLE on glycemic and lipid indices in T2DM patients. Data were pooled using both fixed and random-effect models and weighted mean difference (WMD) was considered as the overall effect size. Of the total records, 4 eligible studies, with a total sample size of 195 subjects, were included. The meta-analysis revealed that JRLE supplementation significantly reduces fasting blood glucose (WMD, −18.04; 95% confidence interval [CI], −32.88 mg/dL, −3.21 mg/dL; p = 0.017) and significantly increases fasting insulin level (WMD, 1.93; 95% CI, 0.40 U/L, 3.45 U/L; p = 0.014). Although the overall effect of JRLE supplementation on hemoglobin A1c was not significant, a significant reduction was seen in studies with an intervention duration of > 8 weeks (WMD, −0.64; 95% CI, −1.16%, −0.11%; p = 0.018). Moreover, we also found no significant change in lipid parameters. Our findings revealed a beneficial effect of JRLE supplementation on glycemic indices in T2DM patients, but no significant improvement was found for lipid profile parameters.

Is Juglone the Only Naphthoquinone in Juglans regia L. with Allelopathic Effects?

We investigated whether juglone is the only allelochemical in a leaf extract from the walnut (Juglans regia L.). This was achieved through comparisons of the effects of pure juglone (1 mM, 100 μM, 10 μM control juglone) and J. regia leaf extract (prepared as 1 mM, 100 μM leaf juglone) on seed germination, seedling growth, and secondary metabolism of the selected crop vegetables. Two control treatments were also applied, as extraction medium and water. For inhibition of seed germination, S. lycopersicum, B. rapa var. japonica, and V. locusta were more sensitive to 1 mM leaf juglone, and L. sativa was more sensitive to 1 mM control juglone. This suggests that this walnut leaf extract contains specific phenolic substance(s) that can stimulate seed germination in some species and inhibit it in others. Seedling length was more sensitive to 1 mM leaf juglone than 1 mM control juglone, with selective strong inhibition of root length versus shoot length by 1 mM control juglone. Juglone also had significant effects on the secondary metabolism of L. sativa, in particular for seedlings treated with 100 μM control juglone, with marked decreases in all secondary metabolites studied. Flavonols constituted the majority of these metabolites in L. culinaris, which showed the least sensitivity to both control juglone and leaf juglone treatments. Thirty compounds were identified and quantified in S. lycopersicum, L. culinaris, and L. sativa, some for the first time in these plants, and all for the first time in the seedlings of these crop vegetables.

Enhancing the antibacterial activity of the biosynthesized silver nanoparticles by “püse”

Background and Aims: The silver nanoparticles (Ag NPs) synthesized by green synthesis have antimicrobial properties and their potential to be used in the medical field is quite high. Püse, also called “black doctor”, is widely used as a treatment for the health problems of animals and in folk medicine in Turkish nomad culture. It has been reported that Ag NPs biosynthesized with Juglans regia leaf extracts have antibacterial activity. The aim and importance of this study is the preparation of a mixture of "püse" and Ag NPs for the first time and the investigation of its antibacterial activity. Methods: In this paper, Ag NPs were synthesized by using J. regia leaves and morphological characteristics of the NPs obtained were determined using TEM. The formation of NPs was identified using an UV-Vis spectrophotometer. The antibacterial activity was investigated by combining the obtained and characterized Ag NPs with the "püse". The antibacterial activity of the mixture was tested on Gram (+) bacteria and Gram (-) bacter. Results: The mixture that was prepared with püse and Ag NPs showed higher antibacterial activity than antibiotics. Conclusion: The positive results showed that this mixture has the potential to be used as a preparation especially in the treatment of animal wounds and the skin infections caused by bacteria.

Bioreduction synthesis of zinc oxide nanoparticles using Delonix regia leaf extract (Gul Mohar) and its agromedicinal applications

The bioreduction of Zinc nitrate hexahydrate using crude leaf extract of Gulmohar, by a combustion method at 400 °C was carried out to form the ZnO nanostructures. The structural, morphological and optic properties of the nanostructures were characterized by UV- Visible spectroscopy, XRD analysis, FTIR spectroscopy, SEM, and TEM. The antibacterial activity of pure wurtzite ZnO NPs was carried out by the Resazurin plate assay method followed by antifungal evaluation utilizing the food poisoning technique using bavistin as a positive control. The anticancer potential was performed using the HeLa cell line for the quantitative evaluation of MTT and apoptosis assay. Antibacterial effect of ZnO NPs on Escherichia coli and Staphylococcus aureus was in the range 0.25–0.0025 μg/ml and antifungal effect on Fusarium oxysporum and Phomposis azadirachtae was in the range of 100–700 μg/ml. The MTT assay and apoptosis analysis on the HeLa cell line particularized optimal cell uptake and cell toxicity on 24 h of exposure. This biogenic method based ZnO NPs synthesis flags the way indicating the significant microbicidal potential against selected plant and animal pathogenic microorganisms and also proved to have an optimal cytotoxic effect against HeLa cell lines. Therefore, these nanomaterials can act as promising nanoantibiotics for application in medicine.

Green synthesis of silver nanoparticles from Delonix regia leaf extracts: In-vitro cytotoxicity and interaction studies with bovine serum albumin

Biogenic synthesis is an effective, nontoxic, clean, eco-friendly and cost-effective green chemistry approach to synthesize metal nanoparticles having significant properties and applications in various fields. Herein, we have approached an environment-friendly protocol for the biogenic synthesis of silver nanoparticles (AgNPs) using Delonix regia (D. regia) leaf aqueous extract as bio-reducing and capping agent. The initial reaction progress was observed by the colour change in the reaction mixture and the AgNPs formation was confirmed by the appearance of surface resonance plasmon (SRP) band at 455 nm by UV–visible spectroscopy. The morphology of the biosynthesized AgNPs was further confirmed by using different techniques such as transmission electron microscopy (TEM), selected area electron diffraction (SAED) and scanning electron microscopy (SEM). The crystalline nature of the biogenic AgNPs was analyzed by X-ray diffraction (XRD) technique. We have further shown the in-vitro cytotoxicity of biogenic AgNPs against A459 and SiHa cell line. We have also investigated the esterase like activity of BSA with synthesized AgNPs. Fluorescence results suggested the contribution of static quenching in the complex formation between AgNPs and BSA. The AgNPs are seen to interact with BSA effectively resulting in structural changes of BSA confirmed by far UV-CD and FT-IR techniques.

Environmentally Benign and Economical Phytofabrication of Silver Nanoparticles Using Juglans regia Leaf Extract for Antibacterial Study

The present study deals with the phytofabrication of silver nanoparticles (SNPs) from the leaf extract of Juglans regia and their antibacterial efficacy. The characterization of SNPs was achieved by UV–visible spectroscopy, scanning electron microscopy, x-ray diffraction analysis and Fourier transform infrared spectroscopy. It has been found that synthesized nanoparticles were crystalline, within the size range of 20–30 nm while having spheroid shape. Fourier transform infrared spectroscopy has confirmed the involvement of functional groups of bio-compounds in the capping and stabilization of the silver nanoparticles which further has been supported by quantitative phytochemical analysis of leaf extract. Phytochemical screening confirmed the involvement of alkaloids and flavonoids. These silver nanoparticles were applied against the commonly found human pathogens for their bactericidal activity. Statistical analysis showed that SNPs have significant antibacterial activity against these bacterial strains. The highest activity was recorded against Staphylococcus aureus (16 mm). This work supports the capability of using biomaterials towards the synthesis of SNPs, by adopting the principles of green chemistry and the application of nanoparticles as an antibacterial material.

Green synthesis of copper oxide nanoparticles using Juglans regia leaf extract and assessment of their physico-chemical and biological properties

AbstractCopper oxide nanoparticles (CuO NPs) were green synthesized using walnut leaf extract. Effects of three synthesis parameters namely; amount copper salt (1-4 g), amount of walnut leaf extract (10-40 mL) and furnace temperature (300-500°C), on the particle size as manifested in broad absorption peak (λmax, nm), concentration (absorbance), antioxidant activity and antibacterial activity as minimum inhibitory concentration (MIC) of the fabricated CuO NPs were studied using response surface methodology, based on Box behnken experimental design. The spherical and crystalline monodispersed fabricated CuO NPs with mean particle size of 80 nm, were achieved using optimum synthesis parameters including 1 g copper salt, 14 mL walnut leaf extract and 490°C of furnace temperature. The fabricated CuO NPs at these conditions had maximum antioxidant activity of 83.64% and minimum MIC value of 1.78% w/v againstE. coli, with λmaxand absorbance values of 226 nm, 4.44% a.u., respectively.

Microwave-Assisted Green Synthesis of Silver Nanoparticles Using Juglans regia Leaf Extract and Evaluation of Their Physico-Chemical and Antibacterial Properties.

Silver nanoparticles (Ag NPs) were synthesized using Juglans regia (J. regia) leaf extract, as both reducing and stabilizing agents through microwave irradiation method. The effects of a 1% (w/v) amount of leaf extract (0.1–0.9 mL) and an amount of 1 mM AgNO3 solution (15–25 mL) on the broad emission peak (λmax) and concentration of the synthesized Ag NPs solution were investigated using response surface methodology (RSM). Fourier transform infrared analysis indicated the main functional groups existing in the J. regia leaf extract. Dynamic light scattering, UV-Vis spectroscopy and transmission electron microscopy were used to characterize the synthesized Ag NPs. Fabricated Ag NPs with the mean particle size and polydispersity index and maximum concentration and zeta potential of 168 nm, 0.419, 135.16 ppm and −15.6 mV, respectively, were obtained using 0.1 mL of J. regia leaf extract and 15 mL of AgNO3. The antibacterial activity of the fabricated Ag NPs was assessed against both Gram negative (Escherichia coli) and positive (Staphylococcus aureus) bacteria and was found to possess high bactericidal effects.

Effects of a hydroalcoholic extract of Juglans regia (walnut) leaves on blood glucose and major cardiovascular risk factors in type 2 diabetic patients: a double-blind, placebo-controlled clinical trial

BackgroundWe aimed to evaluate the effects of a hydroalcoholic extract of Juglans regia L. leaves on blood glucose level and cardiovascular risk factors in type 2 diabetic patients.MethodsIn this randomized, double-blind, placebo-controlled, parallel-group (2 arms) clinical trial, 50 diabetic patients were divided into two groups: treatment group (receive the capsules containing 100 mg J. regia leaf extract) and control group (receive the capsules containing placebo, microcrystallin cellulose). Baseline participant data were matched between the two arms of the study. We administered the prepared capsules to the patients twice daily for 8 weeks. Blood glucose level, glycosylated hemoglobin (HbA1c) level, body weight, body mass index, blood pressure, lipid profile, serum insulin, and insulin resistance were compared between the two groups before and after the intervention. P < 0.05 was considered significant.ResultsAfter excluding eleven patients, 20 received J. regia leaf extract and 20 patients received placebo. The J. regia leaf extract did not significantly change the blood glucose and insulin resistance condition. However, in this group, body weight, body mass index, and systolic blood pressure significantly decreased compared with the baseline measurements (P = 0.028, P = 0.030, and P = 0.005, respectively). The lipid profile did not change significantly compared with the baseline measurements. In the control group, postprandial glucose and HbA1c levels significantly decreased after the intervention (P = 0.030 and P = 0.028, respectively). The other variables were not significantly different in this group. At the end of the study, the variables were not significantly different between the two groups.ConclusionIn this double-blind study, 200 mg/d of J. regia leaf extract had no significant effect on blood glucose level and HOMA-IR score in patients with type 2 diabetes. However, the J. regia leaf extract was effective in reducing body weight and blood pressure. An accidental finding of our study was that microcrystalline cellulose, a widely used placebo in clinical trials, led to a reduction in blood glucose level.Trial registrationIranian Registry of Clinical Trials (IRCT: 138901203180 N2, 2010/6/6); retrospectively registered.

Delonix regia Leaf Extract (DRLE): A Potential Therapeutic Agent for Cardioprotection.

Delonix regia (Boj. Ex. Hook) is a flowering plant in the pea family found in tropical areas and its leaves are used informally to treat diseases in folk medicine. However, the cardioprotective effects in this plant are still unclear. In this study, we found that the Delonix regia leaf extract (DRLE) (400 mg/kg/d) can reduce the mortality rate in an isoproterenol (ISO)-induced heart injury and hypertrophy mouse model. Decreased serum levels of creatine phosphokinase, LDH, GOT, TNF-alpha and increased nitric oxide levels were found in DRLE-treated ISO-injured mice. In the in vitro study, the porcine coronary artery exhibited vasodilation effect induced by DRLE in a dose-dependent manner. In the DRLE toxic test, overdose of DRLE showed the high safety in normal mice and may have the ability to remove the metabolic wastes in blood. In conclusion, we demonstrated for the first time that DRLE has the cardioprotective effects by activating the vasodilation through NO pathway and preventing the myocyte injury via inhibition of TNF-alpha pathway. We suggest that DRLE may act as a promising novel herbal medicine for cardioprotection.

Phyto-synthesis and structural characterization of catalytically active gold nanoparticles biosynthesized using Delonix regia leaf extract

Biological methods of nanoparticles synthesis are ecologically sound and sustainable alternative to the conventional methods. On the basis of aforesaid premise, the present study deals with the optimization and fabrication of gold nanoparticles (Au-NPs) using easily available bio-resource, Delonix regia leaf extract. The use of practically nontoxic natural extracts and water allows the synthesis pathways presented to be considered as ‘‘green’’ and so permitting the synthesized Au-NPs to be used in sensitive areas, such as bioremediation. Various characterization techniques are adopted for the evaluation of size, stability, morphology, crystal nature, and purity of nanoparticles. Ultraviolet–visible spectroscopy analysis showed a surface Plasmon resonance peak for prepared Au-NPs at 542 nm, and its absorbance increased with increasing the interaction time. Transmission electron microscopy analysis showed that the particles were spherical and 4–24 nm in size. Energy dispersive X-ray spectroscopy analysis displayed a 2.2 keV peak corresponding to the pure phase gold nanocrystal. X-ray diffraction analysis proved the fabrication of crystalline Au-NPs with face-centered cubic geometry within 10 min. Furthermore, ζ potential (−15 mV) and Fourier transform infrared data suggested the role of polar polyphenolic compounds of leaf extract in fabrication and stabilization process. Biofabricated nanoparticles are demonstrated to have catalytic activity for the reduction of toxic nitro-organic pollutant o-nitroaniline. Therefore, the present study offers a straightforward, cost-efficient, eco-friendly, and sustainable alternative for the fabrication of catalytically active Au-NPs.

&lt;i&gt;Juglans regia&lt;/i&gt; Hexane Extract Exerts Antitumor Effect, Apoptosis Induction and Cell Circle Arrest in Prostate Cancer Cells &lt;i&gt;In vitro&lt;/i&gt;

Purpose: To elucidate the anticancer activity of Juglans regia leaf extract and its effect on cell cycle analysis, apoptosis and cancer cell morphology.Methods: Hexane extract of the leaves of Juglans regia was prepared by hot extraction. The anticancer activity of Juglans regia extract against human prostate cancer (PC3) cells was evaluated by MTT assay. Flow cytometry, using propidium iodide as a staining agent, was used to study the effect of the extract on cell cycle phase distribution. Apoptosis induced by the extract was evaluated by Annexin V binding assay using flow cytometer. Alterations in cell morphology following apoptosis were studied by inverted phase contrast microscope.Results: The extract of Juglans regia exhibited a potent and dose-dependent anti-proliferative activity against human prostate cancer cells in vitro. The extract also induced significant apoptosis in these PC3 cancer cells as revealed by annexin V binding assay as well as inverted phase contrast microscopy. It triggered a significant formation of apoptotic bodies after treatment with varying concentrations of the extract. Within 48 h of incubation, approximately 9.5, 15.5 and 26.3 % of the cells underwent early apoptosis after treatment with 5, 50 and 100 μg/mL of the extract, respectively. Similarly, 5.2, 11.2 and 18.9 % of the cells underwent late apoptosis after treatment with 5, 50 and 100 μg/mL of the extract, respectively. Treatment with different concentrations of the extract for 48 h induced an increase in the population of cells in the sub-G1 phase and a slight decrease in the G2/M phase.Conclusion: The hexane extract of Juglans regia inhibits growth of human prostate cancer cells by inducing apoptosis with concomitant alterations in cell cycle phase distribution.Keywords: Prostate cancer, Juglans regia, Apoptosis, Flow cytometry, Cell cycle phase, Sub-G1 phase

Walnut leaf extract inhibits PTP1B and enhances glucose-uptake in vitro

Ethnopharmacological relevanceWalnut, Juglans regia L. (Juglandaceae), is one of the medicinal plants used to treat diabetic symptoms in Austrian folk medicine. The air-dried green leaves are either used as aqueous decoctions or liquor preparations and are consumed on a daily basis. We investigated the hypoglycemic effect of a methanolic Juglans regia leaf extract on glucose uptake, protein tyrosine phosphatase 1B (PTP1B) inhibition and peroxisome proliferator-activated receptor gamma (PPARγ) activation. Material and methodsHypoglycemic activity was assessed by glucose-uptake in C2C12 myocytes, inhibition of PTP1B and activation of PPARγ. Phytochemical characterization of the extract was carried out by LC–MS and GC–MS. ResultsMethanolic Juglans regia leaf extract enhanced the glucose uptake rate in C2C12 myocytes at concentrations of 25µg/mL compared to untreated cells. This activity may partly be explained by the inhibition of PTP1B but not PPARγ agonism. LC–MS analyses revealed chlorogenic acid (1), 3-p-coumaroylquinic acid (2), a trihydroxynaphthalene-hexoside (3), as well as eight flavonoids (4–11) as main phenolic constituents in the active extract. ConclusionsThe finding that Juglans regia leaf extract enhances glucose uptake and inhibits PTP1B provides an in vitro-based rationale for the traditional use of walnut leaf preparations against elevated blood-glucose levels.

Effects of Juglans regia L. leaf extract on hyperglycemia and lipid profiles in type two diabetic patients: A randomized double-blind, placebo-controlled clinical trial

Ethnopharmacological relevanceThe Juglans regia L. leaf has been traditionally used for treatment of diabetes mellitus in Iran. But yet, no controlled human study has determined its efficacy in diabetic patients. The present study was designed to investigate the effects of the Juglans regia leaf extract on hyperglycemia and lipid profiles in type II diabetic patients. Materials and methodTotal 61 patients, suffering from type II diabetes with fasting blood glucose (FBG) between 150 and 200mg/dL, glycated hemoglobin (HbA1c) between 7% and 9% and aged between 40 and 60 years were selected, and randomly divided in to two groups of Juglans regia and placebo. First group received 100mg Juglans regia leaf extract in capsules form two times a day for 3 months and other group received 100mg placebo capsule with the same dosage. The standard anti-diabetic therapy (metformin and glibenclamide, and nutritional regimen) was continued in both groups. At the baseline and after three months the FBG, insulin, HbA1c, cholesterol, triglyceride, HDL, LDL and liver and renal function tests were determined. In addition general satisfaction with the treatment was identified using health questionnaires. ResultsThe results indicated that FBG, HbA1c, total cholesterol and triglyceride levels in Juglans regia treated patients significantly decreased compared with the baseline and with placebo group. Patients in Juglans regia group were significantly satisfied with Juglans regia treatment compared with the placebo group. No liver, kidney and other side effects were observed in the groups, except more GI events (specially a mild diarrhea) associated with extract treatment at the beginning of the study. ConclusionIn conclusion, treatment of type II diabetic patients with 100mg Juglans regia leaf extract two times a day for three months improves lipid profile and glycemic control without any tangible adverse effects.

Biosynthesis of Palladium Nanoparticles Using Delonix regia Leaf Extract and Its Catalytic Activity for Nitro-aromatics Hydrogenation

This work presents the biosynthesis of palladium nanoparticles (Pd-NPs) using Delonix regia (D. regia) leaf extract, and their catalytic activity was evaluated for 2-nitrophenol (2-NP) and 2-nitroaniline (2-NA) hydrogenation reactions. The appearance of a broad continuous absorption spectrum in the visible–ultraviolet region in UV–visible spectra confirmed the synthesis of Pd-NPs. The crystalline structure of Pd-NPs (with size range of 2–4 nm) was confirmed by X-ray diffraction and transmission electron microscopy analysis, respectively. The appearance of an optical absorption peak at 2.80 keV in energy dispersive spectra further confirmed the presence of Pd-NPs. Fourier transform infrared analysis suggested the role of water-soluble polyols present in the D. regia leaf extract in mediating the synthesis of Pd-NPs. Moreover, the catalytic activity of Pd-NPs for hydrogenation reactions was studied by UV–visible spectroscopy. Pd-NPs showed catalytic activity through electron relay effect. The hydrogenation ...