Flavonoids in Juglans regia L. leaves and evaluation of in vitro antioxidant activity via intracellular and chemical methods

Evaluation of anthelmintic efficacy of ethanolic leaf extract of Juglans regia L. on Ascaridia galli: a comprehensive in vitro and in vivo study

Anthelmintic resistance in livestock animals has been spreading across the world in prevalence and severity. As a result, researchers are exploring alternative strategies to combat this issue, and one promising avenue is the utilization of medicinal plants. This study aims to investigate the anthelmintic efficacy of the crude ethanolic extract (CEE) derived from the leaves of Juglans regia against one of the most detrimental nematode parasites affecting poultry, namely Ascaridia galli (A. galli). For the in vitro studies, adult A. galli worms were collected from the naturally infected chickens and the efficacy of CEE was measured at the concentration of 25, 50, and 100 mg/ml using adult worm motility inhibition (WMI) assay. In addition, levamisole (0.55 mg/ml) was used as the positive control. Likewise, Phosphate buffered saline (PBS) was used as the negative control. For the in vivo studies, CEE of J.regia at the doses of 500, 1000, and 2000 mg/kg were evaluated in chickens experimentally infected with A. galli. The anthelmintic efficacy was monitored using faecal egg count reduction (FECR) and worm count reduction (WCR) assays. In vitro studies revealed significant (P < 0.001) anthelmintic effects of CEE of J.regia on the motility of A. galli worms at different hours post-exposure. At the concentration of 100 mg/ml, CEE resulted in 96.5% inhibition of worm motility at 24 h post-exposure. While the synthetic anthelmintic drug, levamisole caused the highest inhibition of worm motility (100%) at the same time period. The in vivo anthelmintic activity of CEE of J. regia demonstrated a maximum effect on day 14 post-treatment by inducing 67.28% FECR and 65.03% WCR. We observed no significant difference (P > 0.05) in worm counts between the negative control group and the chickens treated with CEE at the dosage of 500 mg/kg. Together, the results of the present study suggest that CEE of J. regia leaves possess anthelmintic properties and could be a potential source of novel anthelmintic compounds for controlling helminth parasites.

Chemical Profiling, Bioactive Properties, and Anticancer and Antimicrobial Potential of Juglans regia L. Leaves

The aim of this study was to assess the biological potential of the polyphenolic fraction isolated from J. regia leaves, collected in the Subcarpathian region (Poland). The phenolic profile was determined using the UPLC-PDA-MS/MS method. Biological activity was determined by evaluating the antioxidant, anticancer, antibacterial, and antifungal effects. Prior to this study, the purified polyphenolic fraction was not been tested in this regard. A total of 40 phenolic compounds (104.28 mg/g dw) were identified, with quercetin 3-O-glucoside and quercetin pentosides dominating. The preparation was characterized by a high ability to chelate iron ions and capture O₂^•- and OH^• radicals (reaching IC₅₀ values of 388.61, 67.78 and 193.29 µg/mL, respectively). As for the anticancer activity, among the six tested cell lines, the preparation reduced the viability of the DLD-1, Caco-2, and MCF-7 lines the most, while in the antibacterial activity, among the seven tested strains, the highest susceptibility has been demonstrated against K. pneumoniae, S. pyogenes, and S. aureus. Depending on the needs, such a preparation can be widely used in the design of functional food and/or the cosmetics industry.

7.0T cardiac magnetic resonance imaging of right ventricular function in rats with high-altitude deacclimatization

Background

High-altitude deacclimatization syndrome (HADAS) is a severe public health issue. The study of the changes in right ventricular function caused by high-altitude deacclimatization (HADA) is of great significance for the prevention and treatment of HADAS.

Methods

Six-week-old, male Sprague Dawley (SD) rats were randomly divided into the plain, plateau and the HADA group. Rats in the plateau and plain group were exposed to altitudes of 3,850 and 360 m, respectively, for 12 weeks. Rats in HADA group were exposed to the plateau altitude of 3,850 m for 12 weeks and subsequently transported to the plain altitude of 360 m for 4 weeks. Right ventricular ejection fraction (RVEF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and myocardial strain parameters, including the global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS), were evaluated by 7.0T cardiac magnetic resonance (CMR). The levels of red blood cell (RBC), hemoglobin (HGB), and hematocrit (HCT) in the blood were measured, and hematoxylin-eosin (HE) staining was used to observe the pathological changes in the myocardium.

Results

In rats in the plateau group, the right ventricular fibrous space was slightly widened, and partial focal steatosis were observed. However, in the HADA group, only a few focal steatoses were found. Rats in the plateau group had elevated levels of RBC, HGB and HCT, increased right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV) and right ventricular stroke volume (RVSV), and decreased right ventricular global longitudinal strain (RVGLS), right ventricular global circumferential strain (RVGCS), and right ventricular global radial strain (RVGRS) compared to rats in the plain group (P<0.001). The RVEDV, RVGCS, and RVGRS in the HADA group basically returned to the plain state. Interestingly, the RVESV in the HADA group was higher, while the RVSV, RVEF, and RVGLS were lower than those in the other two groups.

Conclusions

After 12 weeks of exposure to high-altitude environment, there were some pathological changes and the whole contractile strain of the right ventricle was observed. Some pathological changes in the myocardial tissue and stroma recovered after returning to the plain for 4 weeks. However, the right ventricular systolic function and strain did not recover completely.

Topical administration of Juglans regia L. leaf extract accelerates diabetic wound healing

Background

Diabetic wounds are one of the most important issues in diabetic patients. It seems that Juglans regia L. leaf with antioxidant and anti-inflammatory potentials can be profitable for healing of diabetic wounds. The aim of present study was to investigate the topical administration of Juglans regia L. leaf extract in diabetic wound healing.

Methods

Seventy-five diabetic male rats were randomly divided into 5 groups (n = 15), including: untreated (Control) group, Eucerin group, 2% Juglans regia L. ointment (JRL 2%) group, 5% Juglans regia L. ointment (JRL 5%) group, and Phenytoin group as a reference drug. Sampling was performed at days 7, 14, and 21 after surgery. Evaluation tests included stereology, immunohistochemistry, molecular, and biomechanical.

Results

Our results showed that the wound closure rate, volumes of newly formed of epidermis and dermis, density of fibroblasts and blood vessels, collagen deposition, density of proliferation cells, expression levels of TGF-β and VEGF genes, and biomechanical characteristics were significantly higher in extract groups compared to control and eucerin groups, however, these changes were considerable in the JRL 5% group (P < 0.05). This is while that the density of neutrophils and expression levels of TNF-α and IL-1β genes in the extract groups, especially in the JRL 5% group, were significantly reduced compared to control and eucerin groups (P < 0.05).

Conclusion

Topical administration of Juglans regia L. leaf extract, especially in 5% concentration, considerably accelerates diabetic wound healing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03735-6.

The influence of in vitro gastrointestinal digestion and fecal fermentation on the flowers of Juglans regia: Changes in the active compounds and bioactivities

The objective of the research was to investigate the digestion and fecal fermentation characteristics of the flowers of Juglans regia (FJR), by using in vitro simulated digestion model (oral, gastric, and intestine) as well as colonic fermentation. As a result, the contents of most active substances and functional activities of FJR were decreased as the digestion proceeded, and showed a trend of first increasing and then decreasing in the fecal fermentation phase. In the oral digestion phase, the total phenolic and total flavonoid contents were released most with the values of 11.43 and 9.41 μg/mg, respectively. While in the gastric digestion phase, the antioxidant abilities, α-glucosidase and α-amylase inhibitory abilities were the weakest. By using high-performance liquid chromatography, 13 phenolic acids and 3 flavonoids were detected. Of these, the highest number of identified compounds were found in the undigested and the oral digestion stages, which were mainly salicylic acid, epicatechin, 3,5-dihydroxybenoic acid, vanillic acid, and protocatechuic acid. However, great losses were observed during the gastric and intestinal digestion stages, only epicatechin, salicylic acid, and protocatechuic acid were found. Surprisingly, fecal fermentation released more abundant phenolic substances compared to gastric and intestinal digestion. Additionally, FJR reduced the pH values in the colonic fermentation system, significantly promoted the production of short-chain fatty acids, and regulated the microbe community structure by improving the community richness of beneficial microbiota. This indicated that FJR had the benefit to improve the microorganismal environment in the intestine. Further Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that FJR could suppress the metabolic pathways related to diseases, such as infectious diseases, metabolic diseases and neurodegenerative diseases. In conclusion, although the bioactivities of FJR decreased significantly after in vitro gastrointestinal digestion and fecal fermentation, it still maintained certain antioxidant and hypoglycemic ability in vitro. This study described the detailed changes in the active compounds and bioactivities of FJR during in vitro gastrointestinal digestion and fecal fermentation, and its effects on microbiota composition and SCFAs levels in feces. Our results revealed the potential health benefits of FJR, and could provide a reference for its further research and development.

Investigation of the Antinociceptive Activity of the Hydroethanolic Extract of Junglas nigra Leaf by the Tail-Immersion and Formalin Pain Tests in Rats

Background

Juglans (J.) nigra leaf is obtained from a plant that is used in traditional medicine in some countries to alleviate inflammatory diseases.

Aim

The aim of this study was to compare the effects of J. nigra extract on acute nociceptive and inflammatory pain in rats.

Methods

Antinociceptive activity was examined in Wistar rats by the tail-immersion and formalin tests. Motor function was assessed using the rotarod test. Plant extract was administered intraperitoneally.

Results

In the tail-immersion test, the maximal antinociceptive effect of the plant extract (100–330 mg/kg) was about 24–30% and is the result of the effect of a high concentration of ethanol. In the formalin test, the plant extract (41.3–330 mg/kg) significantly and dose-dependently inhibited nociception in both phases of the test with similar maximal effects of about 76% and 85%. Only the plant extract at the dose of 330 mg/kg caused a significant time-dependent reduction in time spent on the rotarod.

Conclusions

In rats, the preventive systemic administration of the hydroethanolic extract of J. nigra leaf reduced chemically but not thermally induced pain. Higher efficacy was obtained in pain associated with inflammation and tissue injury. The antinociceptive effect is dose-dependent and may be limited by motor impairment.

Mineral Composition, Antioxidant, Anti-Urease, and Antibiofilm Potential of Juglans Regia Leaves and Unripe Fruits

The leaves and unripe fruits from 5 walnut clones were tested in terms of mineral composition, antioxidant activity, and the inhibitory effect on model urease. It has been shown that the leaves are richer in minerals and also have higher antioxidant potential than unripe fruits. HPTLC polyphenolic profiles of leaves extract were found more abundant in flavonoids regardless of the sample origin. Only green walnut extracts showed an effect as urease inhibitors. Higher antibacterial activity was observed against Staphylococcus aureus in comparison with Staphylococcus epidermidis. Both leaf and fruit extracts showed antibiofilm activity, up to 95% of biofilm inhibition. It was shown that all tested Juglans regia extracts can serve as a valuable antibacterial agent against staphylococci infections.

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.

Euphorbia characias: Phytochemistry and Biological Activities

The aim of this review is to summarize all the compounds identified and characterized from Euphorbia characias, along with the biological activities reported for this plant. Euphorbia is one of the greatest genera in the spurge family of Euphorbiaceae and includes different kinds of plants characterized by the presence of milky latex. Among them, the species Euphorbia characias L. is an evergreen perennial shrub widely distributed in Mediterranean countries. E. characias latex and extracts from different parts of the plant have been extensively studied, leading to the identification of several chemical components such as terpenoids, sterol hydrocarbons, saturated and unsaturated fatty acids, cerebrosides and phenolic and carboxylic acids. The biological properties range between antioxidant activities, antimicrobial, antiviral and pesticidal activities, wound-healing properties, anti-aging and hypoglycemic properties and inhibitory activities toward target enzymes related to different diseases, such as cholinesterases and xanthine oxidase. The information available in this review allows us to consider the plant E. characias as a potential source of compounds for biomedical research.

Flower Development of Heterodichogamous Juglans mandshurica (Juglandaceae)

Juglans mandshurica is a monoecious heterodichogamous species with protogynous and protandrous mating strategies that occur at a 1:1 ratio and are randomly distributed in the population. The inconsistent male and female flowering periods of the same mating type result in an imbalance of the ratio of male and female flowers, contributing to the low yield of this species. However, little more is known about its floral development. Following three consecutive years of observations, histological analysis, and scanning electron microscopy, we found that the morphological and anatomical development of the male and female flowers were synchronous. The male floral morphological development of J. mandshurica was divided into seven phases, while that of the female flower was nine. Four stages were shared between the male and female flower's anatomical development. Our findings indicate that there was minimal overlap between sexual functions within the same mating type, guaranteeing synchronization, mutual non-interference, outcrossing, and avoidance of self-fertilization. These results provide a theoretical basis for the improvement of fruit yield and quality through the reasonable allocation of protogynous and protandrous individuals in a population, and for artificial pollination control. Further, these findings lay a foundation for further research on the genetic mechanisms and environmental effects on flower development of heterodichogamous J. mandshurica.

Effects of Juglans regia L. leaf extract supplementation on testicular functions in diabetic rats

Testicular dysfunction is a complication of diabetes mellitus (DM). Juglans regia L. (JRL) leaf extract is a source of phenolic compounds that exhibits hypoglycemic and antioxidative properties. We investigated whether JRL leaf extract could inhibit the adverse effects of DM on oxidative stress, testis histology and testosterone hormone production. We used four groups of male rats: control group (non-diabetic) given saline, diabetic group, diabetic + JRL group that received JRL leaf extract, and JRL group (nondiabetic) that received JRL leaf extract only. To evaluate the effects of JRL leaf extract on testicular functions in diabetic animals, we evaluated histopathological and histomorphometric changes; serum testosterone; and malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) levels. Decreased of MDA along with improved antioxidant status in the testis of diabetic rats; these abnormalities were attenuated by JRL leaf extract. We detected significantly decreased antioxidant biomarkers (GSH, SOD, CAT) and testosterone levels in the diabetic rats; these levels were normalized after JRL leaf extract administration. The MDA level and improved antioxidant status in the testis of diabetic rats was detected after JRL leaf extract administration. Our findings suggest that JRL leaf extract exerts preventive effects against diabetic dysfunction in the testis, which might be due to its antioxidant, anti-inflammatory and anti-apoptotic properties.

F. R. Ferreira I, Ferreira O. Insights on the Extraction Performance of Alkanediols and Glycerol: Using Juglans regia L. Leaves as a Source of Bioactive Compounds

Glycerol and alkanediols are being studied as alternative solvents to extract phytochemicals from plant material, often as hydrogen bond donors in deep eutectic solvents (DESs). Many of those alcohols are liquid at room temperature, yet studies of their use as extraction solvents are scarce. In this work, glycerol and a series of alkanediols (1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, and 1,2-hexanediol) were studied for the extraction of phenolic compounds from Juglans regia L. leaves, a rich source of this class of bioactive compounds. The extraction yield was quantified, and the bioactivity of both extracts and pure solvents was evaluated by measuring the anti-inflammatory and cytotoxic activities. The solvents showing the best combined results were 1,2 and 1,3-propanediol, as their extracts presented a high amount of phenolic compounds, close to the results of ethanol, and similar cytotoxicity against cervical carcinoma cells, with no impact on non-tumor porcine liver cells in the studied concentration range. On the other hand, none of the extracts (and solvents) presented anti-inflammatory activity. Overall, the results obtained in this work contribute to the study of alternative solvents that could potentially be used also as formulation media, highlighting the importance of walnut leaves as a source of bioactive compounds.

Probing the effect of quercetin 3-glucoside from Dianthus superbus L against influenza virus infection- In vitro and in silico biochemical and toxicological screening

Investigation of antiviral and cytotoxic effect of quercetin 3-glucoside (Q3G) from Dianthus superbus L over influenza virus infection and replication were studied. Moreover, anti-influenza mechanism was screened by time-dependent antiviral assay, virus-induced symptoms and related gene expressions. The blockade of cap-binding domain of polymerase basic protein subunit were analysed by molecular docking study. The Q3G demonstrated potent antiviral activity showing 4.93, 6.43, 9.94, 8.3, and 7.1 μg/mL of IC₅₀ for A/PR/8/34, A/Victoria/3/75, A/WS/33, B/Maryland/1/59, and B/Lee/40, respectively. The cellular toxicity of Q3G and oseltamivir (control) were tested and >100 μg/mL of CC₅₀ value considered as nontoxic. Influenza A virus infection induced a higher ROS production, however potentially reduced by Q3G treatment and significantly blocked virus infection induced acidic vesicular organelles (AVO). Moreover, Q3G has no inhibitory effect for neuraminidase activity but blocked virus replication through time dependent assay and showed more competitive binding affinity (-8.0 kcal/mal) than GTP (-7.0 kcal/mol) to block polymerase basic protein-2 subunit of influenza virus. Q3G from D. superbus showed potent antiviral activity against influenza A and B viruses with suppressive effect on virus-induced cellular ROS generation and AVO formation. Thus, this study provided a new line of research for Q3G to develop possible natural anti-influenza drug.

Efficacy of Shenqi Pollen Capsules for High-Altitude Deacclimatization Syndrome via Suppression of the Reoxygenation Injury and Inflammatory Response

High-altitude deacclimatization syndrome (HADAS) is involved in hypoxia-reoxygenation injury and inflammatory response, induced a series of symptoms, and has emerged as a severe public health issue. Here, we investigated the mechanism as well as potential means to prevent HADAS using Shenqi pollen capsules (SPCs) in subjects with HADAS in a multicenter, double-blinded, randomized, placebo-controlled study. All subjects were at the same high altitude (3650 m) for 4-8 months before returning to lower altitudes. Subjects (n = 288) in 20 clusters were diagnosed with mild or moderate HADAS on the third day of the study. We randomly allocated 20 clusters of subjects (1 : 1) to receive SPCs or a placebo for 7 weeks, and they were then followed up to the 14^th week. The primary endpoints were subjects' HADAS scores recorded during the 14 weeks of follow-up. Compared with the placebo, SPC treatment significantly decreased the subjects' HADAS scores and reduced the incidence of symptom persistence. SPC therapy also reduced the serum levels of CK, CK-MB, LDH, IL-17A, TNF-α, and miR-155 and elevated IL-10 and miR-21 levels. We thus demonstrate that SPCs effectively ameliorated HADAS symptoms in these subjects via suppression of the hypoxia-reoxygenation injury and inflammatory response.

Carrier oils in dermatology

Wounds are a common medical infliction. With the increase in microbial resistance and a shift of interest towards complementary medicines, essential oils have been shown to be beneficial in suppressing microbial growth. However, in practice, essential oils are more often diluted into a base due to the risk of topical adverse effects, such as dermatitis. There is a lack of collated evidence-based information on toxicity and efficacy of carrier oils. The current information on the subject matter is restricted to generic, aroma-therapeutic books and pamphlets, based on anecdotal evidence rather than an experimental approach. Therefore, this review aimed at identifying the recommended carrier oils used in dermatology and thereafter collating the scientific evidence to support the use of carrier oils together with essential oils recommended for dermatological use. Aloe vera gel had multiple studies demonstrating the ability to enhance wound healing; however, several other carrier oils have been largely neglected. It was observed that the extracts for certain plant species had been used to justify the use of the carrier oils of the same plant species. This is an inaccurate cross assumption due to the difference in chemical composition and biological activities. Lastly, despite these carrier oils being recommended as a base for essential oils, very little data was found on the interactive profile of the carrier oil with the essential oil. This review provides a platform for further studies, especially if essential oils are to receive credence in the scientific field.

A Comparative Review on the Extraction, Antioxidant Content and Antioxidant Potential of Different Parts of Walnut (Juglans regia L.) Fruit and Tree

As a valuable tree nut, walnut is a well-known member of the Juglandaceae family. The fruit is made up of an outer green shell cover or husk, the middle shell which must be cracked to release the kernel, a thin layer known as skin or the seed coat, and finally, the kernel or meat. The nutritional importance of walnut fruit is ascribed to its kernel. The shell and husk are burned as fuel or discarded away as waste products. In the past two decades, the evaluation of the phenolic content and antioxidant activity of different parts of walnut has received great interest. In this contribution, the recent reports on the extraction and quantification of phenolic content from each part of the walnut tree and fruit using different solvents were highlighted and comparatively reviewed. The current review paper also tries to describe the antioxidant content of phenolic extracts obtained from different parts of the walnut tree and fruit. Additionally, the antioxidant and antiradical activities of the prepared extracts have also been discussed.

Juglans Regia L. Leaf Extract Attenuates Diabetic Nephropathy Progression in Experimental Diabetes: An Immunohistochemical Study

BACKGROUND

There is accumulating evidence that Juglans regia L. (GRL) leaf extract has hypoglycemic and antioxidative properties. The present study aimed to investigate the protective effects of GRL leaf extract against diabetic nephropathy (DN).

METHODS

In total, 28 male adult Sprague-Dawley rats were used. The DN rat model was generated by intraperitoneal injection of a single 55 mg/kg dose of streptozotocin (STZ). A subset of the STZ-induced diabetic rats received intragastric administration of GRL leaf extract (200 mg/kg/day) starting 1 week (preventive group) and 4 weeks (curative group) after the onset of hyperglycemia up to the end of the 8th week, whereas other diabetic rats received only isotonic saline (diabetic group) as the same volume of GRL leaf extract. To evaluate the effects of GRL leaf extract on the diabetic nephropathy, various parameters of apoptosis and inflammation were assessed. Statistical analysis was performed using the SPSS software, version 15.0. The data were compared between the groups using the Tukey's multiple comparison test and the analysis of the variance. P values ˂0.05 were considered statistically significant.

RESULTS

Fasting blood sugar (FBS) levels (P=0.001) and histopathological changes in the kidney of diabetic rats attenuated after GRL leaf extract consumption. Greater caspase-3 (P=0.004), COX-2 (P=0.008), PARP (P=0.007), and iNOS (P=0.005) expression could be detected in the STZ-diabetic rats, which were significantly (P=0.009) attenuated after GRL leaf extract consumption. In addition, attenuation of lipid peroxidation in the diabetic rats was detected after GRL consumption (P=0.01).

CONCLUSION

GRL leaf extract exerts preventive and curative effects against diabetic nephropathy.

Phytochemical profile and biological activity of Juglans regia

Juglans regia Linn. (Juglandaceae), popularly known as English or Persian walnut, is a valuable medicinal plant with a potency to cure various diseases in traditional medicine. Since ancient time, different local ethnic groups have used various part of J. regia for a wide array of ailments including helminthiasis, diarrhea, sinusitis, stomach ache, arthritis, asthma, eczema, scrofula, skin disorders, diabetes mellitus, anorexia, thyroid dysfunction, cancer and infectious diseases. Biological activities of J. regia have been reported in several peer review journals and scientific attention is increasing. The present review attempts to provide comprehensive information on plant description, ethnobotanical use, toxicity, phytochemical profile, pharmacology, clinical studies and current research prospective of the J. regia. Currently, there is an immense interest on isolation/identification of active constituents from walnut and screening those active compounds for pharmacological activities. In addition, researchers are performing clinical trials as well as screening various solvent extracts or fractions of J. regia in several animal diseases models to identify promising therapeutic benefits. In the present work, we review the latest information based on published scientific investigations of J. regia.

Juglans regia L. protects against UVB induced apoptosis in human epidermal keratinocytes

The present study was aimed to investigate the photoprotective effect of the male flower of J. regia L. (MEJR) against ultraviolet-B induced apoptosis in human skin cells. Human skin epidermal keratinocytes were pretreated with the MEJR (80 µg/ml, has been selected after MTT assay), prior to 30 min UVB-irradiation at a dose of 20 mJ/cm². Mitochondrial membrane potential was evaluated using Rhodamine-123 staining; the % apoptosis by Hoechst staining and acridine orange staining; DNA damage was measured by comet assay. The levels of p53, Bax, Bcl-xL, Bcl-2, Cytochrome c, Caspase-9 and Caspase-3 expression in HaCaT cells were analyzed by western blotting and RT-PCR. Pretreatment with MEJR 80 µg/ml prior to UVB-irradiation significantly prevents apoptotic characteristics, DNA damage and loss of mitochondrial membrane potential. Thus, MEJR protects UVB-mediated human skin cells, by modulating the expression of apoptotic markers and UVB-induced DNA damage in HaCaT cells.

Protective effects of methanolic extract of Juglans regia L. leaf on streptozotocin-induced diabetic peripheral neuropathy in rats

Background

Oxidative stress has a pivotal role in the pathogenesis and development of diabetic peripheral neuropathy (DPN), the most common and debilitating complications of diabetes mellitus. There is accumulating evidence that Juglans regia L. (GRL) leaf extract, a rich source of phenolic components, has hypoglycemic and antioxidative properties. This study aimed to determine the protective effects of Juglans regia L. leaf extract against streptozotocin-induced diabetic neuropathy in rat.

Methods

The DPN rat model was generated by intraperitoneal injection of a single 55 mg/kg dose of streptozotocin (STZ). A subset of the STZ-induced diabetic rats intragastically administered with GRL leaf extract (200 mg/kg/day) before or after the onset of neuropathy, whereas other diabetic rats received only isotonic saline as the same volume of GRL leaf extract. To evaluate the effects of GRL leaf extract on the diabetic neuropathy various parameters, including histopathology and immunohistochemistry of apoptotic and inflammatory factors were assessed along with nociceptive and biochemical assessments.

Results

Degeneration of the sciatic nerves which was detected in the STZ-diabetic rats attenuated after GRL leaf extract administration. Greater caspase-3, COX-2, and iNOS expression could be detected in the STZ-diabetic rats, which were significantly attenuated after GRL leaf extract administration. Also, attenuation of lipid peroxidation and nociceptive response along with improved antioxidant status in the sciatic nerve of diabetic rats were detected after GRL leaf extract administration. In other word, GRL leaf extract ameliorated the behavioral and structural indices of diabetic neuropathy even after the onset of neuropathy, in addition to blood sugar reduction.

Conclusion

Our results suggest that GRL leaf extract exert preventive and curative effects against STZ-induced diabetic neuropathy in rats which might be due to its antioxidant, anti-inflammatory, and antiapoptotic properties.

Graphical abstract

Protection against neuropathy

Nature nominee quercetin's anti-influenza combat strategy-Demonstrations and remonstrations

Nature's providences are rather the choicest remedies for human health and welfare. One such is quercetin, which is nature's nominee for cancer cure and recently demonstrated against influenza attack. Quercetin is highly recognized for its anticancer applications. This review emphasizes on yet another gift that this compound has to offer for mankind, which is none other than combating the deadly evasive influenza virus. The chemistry of this natural bioflavonoid and its derivatives and its modus operandi against influenza virus is consolidated into this review. The advancements and achievements made in the anti-influenza clinical history are also documented. Further, the challenges facing the progress of this compound to emerge as a predominant anti-influenza drug are discussed, and the future perspective for breaking its limitations through integration with nanoplatforms is envisioned.

A Review Study on Phytochemistry and Pharmacology Applications of Juglans Regia Plant

In recent years, the use of medicinal plants increased considerably; so that today, the use of traditional medicine, as well as medicinal plants is necessary for the aim of producing more effective drugs with fewer side effects and determining the effective doses. With the scientific name of Juglans regia, walnut plant is a medicinal plant with different properties that is considered less, despite having great therapeutic potential in the traditional medicine. The aim of this study was to review the dispersal of walnut plants, the chemical compounds, and therapeutic effects of walnuts on antioxidant activity, antidiabetic, hypolipidemic, antimicrobial, and antihypertensive activities, as well as liver protection. Data of this review study have been collected from the books and scientific articles published in databases such as Science Direct, Web of Science, Scopus, PubMed, and Scientific Information Database. While this plant having high antioxidant capabilities, walnuts are composed of many chemical compounds such as ascorbic acid, flavonoids, quercetin, and caffeic acid. Experimental studies have shown that walnuts reduced blood glucose and lipids and also decreased blood pressure. They have antioxidant, antidiabetic, antimicrobial, and liver-protective properties. The use of walnuts in traditional medicine and review of experimental studies demonstrated the presence of multiple, effective, and useful compounds which may provide the opportunity for the production of lipid-lowering, antidiabetes, and liver protective drugs. Due to the effects of walnuts on improving the complications of various diseases, the need for doing comprehensive clinical trials for the use of walnuts in the treatment of diseases is necessary.

Transcriptome-guided gene isolation and functional characterization of UDP-xylose synthase and UDP-D-apiose/UDP-D-xylose synthase families from Ornithogalum caudatum Ait

The present study first identified the involvement of OcUAXS2 and OcUXS1-3 in anticancer polysaccharides biosynthesis in O. caudatum. UDP-xylose synthase (UXS) and UDP-D-apiose/UDP-D-xylose synthase (UAXS), both capable of converting UDP-D-glucuronic acid to UDP-D-xylose, are believed to transfer xylosyl residue to anticancer polysaccharides biosynthesis in Ornithogalum caudatum Ait. However, the cDNA isolation and functional characterization of genes encoding the two enzymes from O. caudatum has never been documented. Previously, the transcriptome sequencing of O. caudatum was performed in our laboratory. In this study, a total of six and two unigenes encoding UXS and UAXS were first retrieved based on RNA-Seq data. The eight putative genes were then successfully isolated from transcriptome of O. caudatum by reverse transcription polymerase chain reaction (RT-PCR). Phylogenetic analysis revealed the six putative UXS isoforms can be classified into three types, one soluble and two distinct putative membrane-bound. Moreover, the two UAXS isoenzymes were predicted to be soluble forms. Subsequently, these candidate cDNAs were characterized to be bona fide genes by functional expression in Escherichia coli individually. Although UXS and UAXS catalyzed the same reaction, their biochemical properties varied significantly. It is worth noting that a ratio switch of UDP-D-xylose/UDP-D-apiose for UAXS was established, which is assumed to be helpful for its biotechnological application. Furthermore, a series of mutants were generated to test the function of NAD⁺ binding motif GxxGxxG. Most importantly, the present study determined the involvement of OcUAXS2 and OcUXS1-3 in xylose-containing polysaccharides biosynthesis in O. caudatum. These data provide a comprehensive knowledge for UXS and UAXS families in plants.

A simple and convenient method for the preparation of antioxidant peptides from walnut (Juglans regia L.) protein hydrolysates

Background

Walnut (Juglans regia L.), that belongs to the Juglandaceae family, is one of the nuts commonly found in Chinese diets. Researchers had obtained peptides from walnut protein hydrolysates, and these peptides exhibited the high antioxidant activities. The objective of this study was to develop a simple and convenient method for a facile and reproducible preparation of antioxidant peptides from walnut protein hydrolysates.

Results

Walnut proteins were extracted from walnut kernels using continuous countercurrent extraction process, and were separately hydrolyzed with six types of proteases (neutrase, papain, bromelain, alcalase, pepsin, and pancreatin). Then, hydrolysates were purified by ultrafiltration. The yields and purity of the peptides prepared using neutrase and papain were 16 and 81 % at least, respectively, higher than others, and had low molecular weight, 99 % of which were less than 1500 Da. Furthermore, the bioassay indicated that the two peptides exhibited the high antioxidant activities in the DPPH (IC₅₀ values: 59.40 and 31.02 µg/mL, respectively), ABTS (IC₅₀ values: 80.36 and 62.22 µg/mL, respectively), and superoxide radical scavenging assay (IC₅₀ values: 107.47 and 80.00 µg/mL, respectively).

Conclusions

The method combines the advantages of generality, rapidity, simplicity, and is useful for the mass production of walnut peptides.Graphical Abstract

Analysis of Flavonoids in Lotus (Nelumbo nucifera) Leaves and Their Antioxidant Activity Using Macroporous Resin Chromatography Coupled with LC-MS/MS and Antioxidant Biochemical Assays

Lotus (Nelumbo nucifera) leaves, a traditional Chinese medicinal herb, are rich in flavonoids. In an effort to thoroughly analyze their flavonoid components, macroporous resin chromatography coupled with HPLC-MS/MS was employed to simultaneously enrich and identify flavonoids from lotus leaves. Flavonoids extracted from lotus leaves were selectively enriched in the macroporous resin column, eluted subsequently as fraction II, and successively subjected to analysis with the HPLC-MS/MS and bioactivity assays. Altogether, fourteen flavonoids were identified, four of which were identified from lotus leaves for the first time, including quercetin 3-O-rhamnopyranosyl-(1→2)-glucopyranoside, quercetin 3-O-arabinoside, diosmetin 7-O-hexose, and isorhamnetin 3-O-arabino- pyranosyl-(1→2)-glucopyranoside. Further bioactivity assays revealed that these flavonoids from lotus leaves possess strong antioxidant activity, and demonstrate very good potential to be explored as food supplements or even pharmaceutical products to improve human health.