Antioxidant characterization of oak extracts combining spectrophotometric assays and chemometrics

Characterization of some Fagaceae kernels nutritional composition for potential use as novel food ingredients

The present study attempts to characterise Fagaceae kernels as a promising source of nutritional compounds for potential use as novel food ingredients. Thus, the proximate and mineral composition of some kernels (beech achene-BA, sessile oak acorn-SOA, turkey oak acorn-TOA, and red oak acorn-ROA), total phenolic content, individual polyphenols, and cytotoxicity of their aqueous extracts, respectively, the fatty acid composition of kernel oils were investigated using physicochemical and analytical techniques. Results revealed that BAK is rich in lipid and protein, OAKs in carbohydrates. All tested kernels contain high oleic-linoleic acid oils. BAK is abundant in phenolic acids, OAKs in hydrolysable tannins. Only BA and SOA kernels exert cytotoxicity against human fibroblasts. In all kernels, macroelements are dominated by K and microelements by Cu, Mn, and Fe. In conclusion, BA and OA kernels could be alternatively used as protein-rich, respectively, starch-rich ingredients in food.

In vitro and in vivo glycemic responses and antioxidant potency of acorn and chickpea fortified gluten-free breads

Gluten-free (GF) breads, based on rice flour and corn starch (50:50), were fortified with a mixture of acorn flour (ACF) - chickpea flour (CPF) at 30% substitution level of corn starch (i.e., rice flour:corn starch:ACF-CPF 50:20:30) using different flour blends of ACF:CPF at weight ratios of 5:25, 7.5:22.5, 12.5:17.5, and 20:10 in order to improve the nutritional quality and antioxidant potential as well as the glycemic responses of the GF breads; a control GF bread with rice flour:corn starch 50:50 ratio was also prepared. ACF was richer in total phenolic content than CPF, whereas CPF was characterized by higher amounts of total tocopherols and lutein compared to ACF. For both ACF and CPF as well as the fortified breads, the most abundant phenolic compounds were gallic (GA) and ellagic (ELLA) acids as found by HPLC-DAD analysis, while a hydrolysable tannin, valoneic acid dilactone, was also identified and quantified by HPLC-DAD-ESI-MS in high amount in the ACF-GF bread having the highest level of ACF (ACF:CPF 20:10), even though it seemed to decompose during breadmaking, possibly into GA and ELLA. Therefore, the inclusion of these two raw materials as ingredients in GF bread formulations resulted in baked products with enhanced concentrations of such bioactive compounds and higher antioxidant activities, as indicated by three different assays (DPPH, ABTS and FRAP). The extent of glucose release, as evaluated by an in vitro enzymic assay, was negatively correlated (r = -0.96; p = 0.005) with the level of added ACF, and was significantly reduced for all ACF-CPF fortified products when compared with their non-fortified GF counterpart. Furthermore, the GF bread containing a flour mixture of ACP:CPF at a weight ratio of 7.5:22.5, was subjected to an in vivo intervention protocol to assess the glycemic response when consumed by 12 healthy volunteers; in this case, white wheat bread was used as reference food. The glycemic index (GI) of the fortified bread was significantly lower compared to the control GF bread (97.4 versus 159.2, respectively), which along with its lower amount of available carbohydrates and the higher level of dietary fibers, resulted in a significantly reduced glycemic load (7.8 versus 18.8 g per serving of 30 g). The present findings underlined the effectiveness of acorn and chickpea flours in improving the nutritional quality and glycemic responses of fortified GF breads with these flours.

Valorization of Quercus suber L. Bark as a Source of Phytochemicals with Antimicrobial Activity against Apple Tree Diseases

Cork, an anatomic adaptation of the bark of Quercus suber L. through its suberization process, finds its main application in the production of bottle stoppers. Its processing results in a large waste stream of cork fragments, granulates, and dust, which may be susceptible to valorization. The work presented here explored the use of its extracts to inhibit the growth of phytopathogenic microorganisms associated with apple tree diseases. The in vitro antimicrobial activity of cork aqueous ammonia extract was assayed against four fungi, viz. Monilinia fructigena and M. laxa (brown rot), Neofussicoccum parvum (dieback), and Phytophthora cactorum (collar and root rot), and two bacteria, viz. Erwinia amylovora and Pseudomonas syringae pv. syringae, either alone or in combination with chitosan oligomers (COS). Effective concentration values of EC₉₀ in the 675-3450 μg·mL^-1 range, depending on the fungal pathogen, were obtained in growth inhibition tests, which were substantially improved for the conjugate complexes (340-801 μg·mL^-1) as a result of strong synergism with COS. Similar enhanced behavior was also observed in antibacterial activity assays, with MIC values of 375 and 750 μg·mL^-1 for the conjugate complexes against P. syringae pv. syringae and E. amylovora, respectively. This in vitro inhibitory activity was substantially higher than those exhibited by azoxystrobin and fosetyl-Al, which were tested for comparison purposes, and stood out among those reported for other natural compounds in the literature. The observed antimicrobial activity may be mainly attributed to the presence of glycerin and vanillic acid, identified by gas chromatography-mass spectroscopy. In the first step towards in-field application, the COS-Q. suber bark extract conjugate complex was further tested ex situ against P. cactorum on artificially inoculated excised stems of the 'Garnem' almond rootstock, achieving high protection at a dose of 3750 μg·mL^-1. These results suggest that cork industrial leftovers may, thus, be a promising source of bioactive compounds for integrated pest management.

Optimization of Microwave Assisted Extraction Conditions to Improve Phenolic Content and In Vitro Antioxidant and Anti-Microbial Activity in Quercus cerris Bark Extracts

The species of the Quercus genus, including Quercus cerris L., are widely used and their wood represents a valuable material utilized for various purposes. The intense industrial processing of wood results in a considerable amount of poorly-used natural by-products, such as bark, and a loss of potentially useful raw materials. Thus, the aim of our study was to evaluate the phytochemical characteristics and potential biological activities of Quercus cerris bark extracts obtained by optimizing the parameters of microwave assisted extraction (MAE). The optimum conditions for MAE were determined using a design of experiments (DoE) model, which set the experimental variables (irradiation time and microwave power) and their values. Aqueous and hydroalcoholic extractions were performed and the optimum parameters of extraction were determined for both solvents. The total polyphenolic and tannin contents were determined. The biological activities representative of antioxidant capacity were determined using two free radical scavenging methods, the DPPH and ABTS methods, and the antibacterial activity was assessed with the microdilution method. The results showed different optimal extraction conditions for aqueous (30 min at 850 W) and hydroalcoholic (18 min at 650 W) extracts. A higher yield of total polyphenols was observed in the hydroalcoholic bark extract (403.73 ± 7.35 mg gallic acid equivalents/g dried weight); however a lower level of tannins was registered in comparison to the aqueous extract. In addition, both extracts exerted high antioxidant activities, with the aqueous extracts having a stronger inhibitory effect against the DPPH radical. Moreover, the extracts exhibited antibacterial activity against the tested bacterial strains, especially against the Gram-positive strains and Klebsiella pneumoniae, with the hydroalcoholic extracts being more efficient overall. To conclude, the optimized MAE was an efficient method to extract phytochemical compounds with potential biological effects from Quercus cerris bark.

The Influence of Locality on Phenolic Profile and Antioxidant Capacity of Bud Extracts

Gemmotherapy represents the most recent therapeutic technique that uses the properties of extracts from fresh meristematic plant tissues, mainly buds and sprouts, by macerating them in ethanol and glycerol. The harvesting time and the location can significantly affect the chemical composition of the buds. Therefore, this work aimed to point out the possible variability in the phenolic content and the antioxidant potential of extracts prepared from commonly grown trees in the Czech Republic. Extracts from buds collected during autumn and spring in three different localities were analysed using UHPLC-MS (ultra-high-pressure liquid chromatography) for the phenols profile. Five tests assays were used for the evaluation of the extract antioxidant potential. The sampling time positively affected the content of total phenols, flavonoids, and phenolic acids. The increased levels of total phenols and flavonoids in localities with high and medium pollution may be the result of the higher levels of NO and SO_2, the main air pollutants. However, surprisingly, the content of phenolic acid showed the highest values in the area with the lowest pollution. The results of antioxidant tests did not completely correlate with the levels of phenolic metabolites, which may be due to the involvement of other active molecules (e.g., ascorbate, tocopherol, or proline) in the antioxidant machinery.

Polyglycerol Ester-Based Low Energy Nanoemulsions with Red Raspberry Seed Oil and Fruit Extracts: Formulation Development toward Effective In Vitro/In Vivo Bioperformance

This study focuses on the development of biocompatible oil-in-water (O/W) nanoemulsions based on polyglycerol esters, as promising carriers for natural actives: red raspberry seed oil—RO and hydro-glycolic fruit extracts from red raspberry—RE and French oak—FE. Nanoemulsions were obtained via phase inversion composition (PIC) method at room temperature by dilution of microemulsion phase, confirmed by visual appearance, percentage of transmittance, microscopic, rheological and differential scanning calorimetry (DSC) investigations. The results have shown that the basic RO-loaded formulation could be further enriched with hydro-glycolic fruit extracts from red raspberry or French oak, while keeping a semi-transparent appearance due to the fine droplet size (Z-ave: 50 to 70 nm, PDI value ≤ 0.1). The highest antioxidant activity (~92% inhibition of the DPPH radical) was achieved in the formulation containing both lipophilic (RO) and hydrophilic antioxidants (FE), due to their synergistic effect. The nanoemulsion carrier significantly increased the selective cytotoxic effect of RO towards malignant melanoma (Fem-X) cells, compared to normal human keratinocytes (HaCaT). In vivo study on human volunteers showed satisfactory safety profiles and significant improvement in skin hydration during 2 h after application for all nanoemulsions. Therefore, polyglycerol ester-based nanoemulsions can be promoted as effective carriers for red raspberry seed oil and/or hydro-glycolic fruit extracts in topical formulations intended for skin protection and hydration.

The Antioxidant and Anti-Inflammatory Effects of Quercus brantii Extract on TNBS-Induced Ulcerative Colitis in Rats

Objectives

Ulcerative colitis is a common subtype of persistent inflammatory bowel disease with high morbidity consequences. Despite unknown definite pathogenesis, multiple anti-inflammatory medications are used for its treatment. Traditionally, Quercus brantii (QB), mostly available in the Middle East, has been used for gastrointestinal disorders. Other beneficial effects associated with QB include reduction of oxidative stress, inflammations, homeostatic instability, and improvement in clinical conditions.

Materials and Methods

This experimental study was designed to assess the possible therapeutic effects of QB on UC and compare its effects with those of sulfasalazine. Of the 70 Wistar rats clustered in seven groups, ten received only alcohols and sixty were confirmed to be suffering from trinitrobenzene sulfonic acid- (TNBS-) induced colitis. Four groups received different dosages of QB extract via oral and rectal routes, one received sulfasalazine, and the other remaining two groups received nothing. The effects of QB were evaluated by assessing macroscopic and histologic scoring, measuring inflammatory mediators, and determining oxidative stress markers.

Results

Comparing to the untreated TNBS-induced control groups, QB-treated groups showed a dose- and route-dependent improvement comparable with sulfasalazine. Treating rats with QB reduced the microscopic and macroscopic damage, decreased TNF-α, IL-6, NO, MPO activity, and MDA content, increased superoxide dismutase (SOD) activity, and reduced body weight loss.

Conclusions

Our data recommended the anti-inflammatory and antioxidant effects of QB extract in a dose-dependent manner.

A Comprehensive Review of Phytochemistry and Biological Activities of Quercus Species

The Quercus genus provides a large amount of biomaterial with many applications in fields like pharmaceutics, cosmetics, and foodstuff areas. Due to the worldwide dissemination of the genus, many species were used for centuries in traditional healing methods or in the wine maturing process. This review aims to bring together the results about phytoconstituents from oak extracts and their biological applicability as antioxidants, antimicrobial, anticancer, etc. The literature data used in this paper were collected via PubMed, Scopus, and Science Direct (2010–June 2020). The inclusion criteria were papers published in English, with information about phytoconstituents from Quercus species (leaves, bark and seeds/acorns) and biological activities such as antioxidant, antibacterial, antiobesity, anti-acne vulgaris, antifungal, anticancer, antiviral, antileishmanial, antidiabetic, anti-inflammatory. The exclusion criteria were the research of other parts of the Quercus species (e.g., galls, wood, and twigs); lack of information about phytochemistry and biological activities; non-existent Quercus species reported by the authors. The most studied Quercus species, in terms of identified biomolecules and biological activity, are Q. brantii, Q. infectoria and Q. robur. The Quercus species have been reported to contain several phytoconstituents. The main bioactive phytochemicals are phenolic compounds, volatile organic compounds, sterols, aliphatic alcohols and fatty acids. The, Quercus species are intensely studied due to their antioxidant, anti-inflammatory, antimicrobial, and anticancer activities, provided by their phytochemical composition. The general conclusion is that oak extracts can be exploited for their biological activity and can be used in research fields, such as pharmaceutical, nutraceutical and medical.

Low-energy nanoemulsions as carriers for red raspberry seed oil: Formulation approach based on Raman spectroscopy and textural analysis, physicochemical properties, stability and in vitro antioxidant/ biological activity

Considering a growing demand for medicinal/cosmetic products with natural actives, this study focuses on the low-energy nanoemulsions (LE-NEs) prepared via the Phase inversion composition (PIC) method at room temperature as potential carriers for natural oil. Four different red raspberry seed oils (ROs) were tested, as follows: cold-pressed vs. CO2-extracted, organic vs. non-organic, refined vs. unrefined. The oil phase was optimized with Tocopheryl acetate and Isostearyl isostearate, while water phase was adjusted with either glycerol or an antioxidant hydro-glycolic extract. This study has used a combined approach to formulation development, employing both conventional methods (pseudo-ternary phase diagram - PTPD, electrical conductivity, particle size measurements, microscopical analysis, and rheological measurements) and the methods novel to this area, such as textural analysis and Raman spectroscopy. Raman spectroscopy has detected fine differences in chemical composition among ROs, and it detected the interactions within nanoemulsions. It was shown that the cold-pressed, unrefined, organic grade oil (RO2) with 6.62% saturated fatty acids and 92.25% unsaturated fatty acids, was optimal for the LE-NEs. Textural analysis confirmed the existence of cubic gel-like phase as a crucial step in the formation of stable RO2-loaded LE-NEs, with droplets in the narrow nano-range (125 to 135 nm; PDI ≤ 0.1). The DPPH test in methanol and ABTS in aqueous medium have revealed a synergistic free radical scavenging effect between lipophilic and hydrophilic antioxidants in LE-NEs. The nanoemulsion carrier has improved the biological effect of raw materials on HeLa cervical adenocarcinoma cells, while exhibiting good safety profile, as confirmed on MRC-5 normal human lung fibroblasts. Overall, this study has shown that low-energy nanoemulsions present very promising carriers for topical delivery of natural bioactives. Raman spectroscopy and textural analysis have proven to be a useful addition to the arsenal of methods used in the formulation and characterization of nanoemulsion systems.

Chemical Composition and In Vitro Bioaccessibility of Antioxidant Phytochemicals from Selected Edible Nuts

The ultimate health benefits of peanuts and tree nuts partially depend on the effective gastrointestinal delivery of their phytochemicals. The chemical composition and in vitro bioaccessibility of tocopherols, tocotrienols and phenolic compounds from peanuts and seven tree nuts were evaluated by analytical and chemometric methods. Total fat and dietary fiber (g 100 g-1) ranged from 34.2 (Emory oak acorn) to 72.5 (pink pine nut; PPN) and from 1.2 (PPN) to 22.5 (pistachio). Samples were rich in oleic and linoleic acids (56-87 g 100 g-1 oil). Tocopherols and tocotrienols (mg·kg-1) ranged from 48.1 (peanut) to 156.3 (almond) and 0 (almond, pecan) to 22.1 (PPN) and hydrophilic phenolics from 533 (PPN) to 12,896 (Emory oak acorn); flavonoids and condensed tannins (mg CE.100 g-1) ranged from 142 (white pine nut) to 1833 (Emory oak acorn) and 14 (PPN) to 460 (Emory oak acorn). Three principal components explained 90% of the variance associated with the diversity of antioxidant phytochemicals in samples. In vitro bioaccessibility of tocopherols, tocotrienols, hydrophilic phenolics, flavonoids, and condensed tannins ranged from 11-51%, 16-79%, 25-55%, 0-100%, and 0-94%, respectively. Multiple regression analyses revealed a potential influence of dietary fiber, fats and/or unsaturated fatty acids on phytochemical bioaccessibility, in a structure-specific manner.

Antioxidant properties of coffee substitutes rich in polyphenols and minerals

The analysis of general content of polyphenols, minerals and antioxidant activity of infusions from selected coffee substitutes is presented. The obtained results showed that the coffee infusions prepared from acorns exhibit the highest radical scavenging capacities for DPPH (EC₅₀ = 0.063-0.066 mg_d.w./mL), ABTS (EC₅₀ = 0.021-0.029 mg_d.w./mL), OH(EC₅₀ = 2.050-2.378 mg_d.w./mL) as well as the highest ability to Fe³⁺ reduction (FRAP) (∼1.1 mmolFe/g_d.w). These coffee substitutes also contain the greatest values of polyphenols (45-50 mgGA/g_d.w). Analyzed coffee substitutes differ in both quality and quantity of polyphenols, but all tested coffees contain gallic and chlorogenic acids. The most of phenolic compounds was found in herbal-cereal coffee substitute. The quantitative results and PCA analysis indicated a good correlation between the antioxidant activity and total polyphenols, flavonoids and gallic acid content. Using the obtained data on the composition and antioxidant properties of extracts the cluster analysis (CA) was performed to distinguish similar or close types of coffee.

Effect of the combined action of Quercus cortex extract and probiotic substances on the immunity and productivity of broiler chickens

Aim:

This study was designed to investigate the synergistic effect of the combined action of probiotic bacterial strains (Bifidobacterium adolescentis and Lactobacillus acidophilus) and Quercus cortex extract as biologically active substances in the feed on the immunity and productivity of Gallus gallus domesticus.

Materials and Methods:

For the experiment, 120 7-day-old broiler chickens were selected (4 groups, n=30, 3 replicates with 10 birds in each group). The groups were as follows: The reference group - basic diet (BD); experimental Group I - BD + Q. cortex extract (Q. cortex), 2.5 ml/kg of body weight; experimental Group II - BD + probiotic preparation based on B. adolescentis, 80.0 million colony-forming units (CFU), and L. acidophilus, 1.0 million CFU (dosage in accordance with the recommendations of the manufacturer); and experimental Group III - BD + probiotic + extract of Q. cortex. The following methods of study were used: Chemiluminescence and biochemical and hematological analysis.

Results:

The results of the experiment showed a slight decrease in the level of leukocytes in Groups II (p≤0.05) and III, and of hemoglobin in Group III (p≤0.05), compared to the reference group. The level of alanine aminotransferase and aspartate aminotransferase in Group II was higher than both the reference group (p≤0.05) and the other groups. Introduction of Q. cortex extract into the diet increased the level of triglycerides (p≤0.05) and urea in the blood serum. The combined use of probiotic preparations and the extract resulted in an increase in the level of iron in the blood serum by 78.1% (p≤0.05) in Group III. An increase in indicators of the antioxidant system (catalase increased in Group I by 27.2% (p≤0.05) and by 3.0–12.7% in other groups; superoxide dismutase increased by 3.0–13.2%) and nonspecific immunity (β-lysine increased by 8.8–16.0%) was noted. Introduction of the extract and probiotic preparation into the diet contributed to increasing the live weight of chickens at the age of 15 days by 5.9 and 7.4%, respectively (p≤0.05). In experimental Group II, this trend continued, and by the end of the period, the weight of animals exceeded that of their peers in other groups by 0.7-7.0%. Given the high preservation rate of poultry in the II and III Groups, and the low feed consumption per 1 kg of live weight gain (by 3.1–6.7%), the efficiency of growth was higher than in the reference group.

Conclusion:

Thus, the combined use of probiotic strains of bacteria and Q. cortex extract helped to increase the antioxidant activity of the organism and antimicrobial components of blood plasma compared with broiler chickens with similar growth rates but without the supplementation of this combination.

Quercus Brantii Lindl. Vaginal Douche Versus Clotrimazole on Vaginal Candidiasis: A Randomized Clinical Trial

Objectives

Vaginal Candidiasis with an approximate prevalence of 30% is the second cause of vaginal infections. Antifungal azole is the first treatment for Vaginal Candidiasis; however, some side effects have been reported for this chemical medicine. Based on the antifungal activity of Inner Stratum of Quercus Brantii (Q. Brantii), the aim of our study was to compare the effects of vaginal douche of Q. Brantii extract and clotrimazole on vaginal candidiasis symptoms before and after the treatments, in women.

Methods

89 non-pregnant women with positive KOH test which is capable of identifying the presence of hyphae and mycelium by adding KOH (10%), and a positive vaginal candidiasis culture were randomly divided into two experimental groups, using permuted block randomization method. One group received clotrimazole vaginal cream (1%) and the other group received vaginal douche of Q. Brantii extract. Groups were treated for 7 days and KOH tests and cultures were evaluated again. Data were analyzed via chi-square and independent t-test, using SPSS software.

Results

According to the results, there were no significant differences between experimental groups for demographic characteristics like age (p=0.403), BMI (p=0.911), educational levels (p=0.862) and contraceptive methods (p=0.702). Moreover, significant differences were seen in vaginal discharge between the groups after the treatments (P=0.043).

Conclusion

The results suggested that the therapeutic effect of vaginal douche of Q. Brantii extract was approximately similar to that of clotrimazole vaginal cream.

In Vitro Evaluation of Antioxidant Activity and Antibacterial Effects and Measurement of Total Phenolic and Flavonoid Contents of Quercus brantii L. Fruit Extract

Plant-based extracts, as alternatives to chemical compounds, are commonly use in pharmaceutical and food industries. Antibacterial properties of extracts are mainly considered in medicine. Because of the high incidence of infectious diseases, it is helpful to identify more agents that are able to treat diseases. Antioxidant effects have been reported for different plant extracts. We aimed to investigate antioxidant activity, total phenolic and flavonoid contents, and antibacterial effect of Quercus brantii L. fruit extract. In this study, Q. brantii L. fruit was extracted by maceration using ethanol 70%. Total phenolic content was determined by Folin-Ciocalceu reagent and gallic acid equivalence, and antioxidant activity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) compared to butylated hydroxytoluene (BHT). Antibacterial effects were investigated by broth microdilution and measurement of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Then the effects of different concentrations of extract on Staphylococcus aureus and Enterococcus faecalis growth were investigated in comparison with vancomycin and nitrofurantoin. Our findings demonstrate that antioxidant activity of hydroalcoholic extract of Q. brantii L. fruit was more than that of BHT. Total phenolic content was derived (3.010 mg GAE/g DW). Flavonol and flavonoid contents were 1.813 and 0.654 mg/g, respectively. The extract was found to exert significant inhibitory effects on both studied bacteria. S. aureus was more susceptible than E. faecalis to Q. brantii L. fruit extract. Q. brantii L. fruit extract can exert considerable antioxidant effects, contains high amounts of phenolic, flavonol, and flavonoid compounds, and inhibits bacterial growth.

Antioxidant Properties of Polyphenolic Extracts from Quercus Laurina, Quercus Crassifolia, and Quercus Scytophylla Bark

The objective of this work was to determine the concentration of total phenols, total flavonoids, hydroxycinnamic acids, and proanthocyanidins present in crude extracts of Quercus laurina, Q. crassifolia, and Q. scytophylla bark. They were extracted by ethanol (90%) maceration and hot water. The antioxidant capacity was determined by the ability to capture OH•, O₂•^−, ROO•, H₂O₂, NO•, and HClO. The hot water crude extract of Q. crassifolia was chosen to be concentrated and purified due to its higher extraction yield (20.04%), concentration of phenol compounds (747 mg gallic acid equivalent (GAE)/g, 25.4 mg quercetin equivalent (QE)/g, 235 mg ChAE/g, 25.7 mg chlorogenic acid equivalents (ChAE)/g), and antioxidant capacity (expressed as half maximal effective concentration (EC₅₀, µg/mL): OH• = 918, O2•^− = 80.5, ROO• = 577, H₂O₂ = 597, NO• ≥ 4000, HClO = 740). In a second stage, Q. crassifolia extracted with hot water was treated with ethyl acetate, concentrating the phenol compounds (860 mg GAE/g, 43.6 mg QE/g, 362 ChAE/g, 9.4 cyanidin chloride equivalents (CChE)/g) and improving the scavenging capacity (OH• = 467, O2•^− = 58.1, ROO• = 716, H₂O₂ = 22.0, NO• ≥ 4000, HClO = 108). Q. crassifolia had the highest polyphenolic concentration and the better capacity for scavenging reactive species, being a favorable candidate to be considered in the development of new products.

Polarity directed optimization of phytochemical and in vitro biological potential of an indigenous folklore: Quercus dilatata Lindl. ex Royle

BACKGROUND

Plants have served either as a natural templates for the development of new chemicals or a phytomedicine since antiquity. Therefore, the present study was aimed to appraise the polarity directed antioxidant, cytotoxic, protein kinase inhibitory, antileishmanial and glucose modulatory attributes of a Himalayan medicinal plant- Quercus dilatata.

METHODS

Total phenolic and flavonoid contents were determined colorimetrically and various polyphenols were identified by RP-HPLC analysis. Brine shrimp lethality, SRB and MTT assays were employed to test cytotoxicity against Artemia salina and human cancer cell lines respectively. Antileishmanial activity was determined using standard MTT protocol. Glucose modulation was assessed by α-amylase inhibition assay while disc diffusion assay was used to establish protein kinase inhibitory and antifungal spectrum.

RESULTS

Among 14 extracts of aerial parts, distilled water-acetone extract demonstrated maximum extract recovery (10.52% w/w), phenolic content (21.37 ± 0.21 μg GAE/mg dry weight (DW)), total antioxidant capacity (4.81 ± 0.98 μg AAE/mg DW) and reducing power potential (20.03 ± 2.4 μg/mg DW). On the other hand, Distilled water extract proficiently extracted flavonoid content (4.78 ± 0.51 μg QE/mg DW). RP-HPLC analysis revealed the presence of significant amounts of phenolic metabolites (0.049 to 15.336 μg/mg extract) including, pyrocatechol, gallic acid, catechin, chlorogenic acid, p-coumaric acid, ferulic acid and quercetin. Highest free radical scavenging capacity was found in Methanol-Ethyl acetate extract (IC₅₀ 8.1 ± 0.5 μg/ml). In the brine shrimp toxicity assay, most of the tested extracts (57%) showed high cytotoxicity. Among these, Chloroform-Methanol extract had highest cytotoxicity against THP-1 cell line (IC₅₀ 3.88 ± 0.53 μg/ml). About 50% of the extracts were found to be moderately antiproliferative against Hep G2 cell line. Methanol extract exhibited considerable protein kinase inhibitory activity against Streptomyces 85E strain (28 ± 0.35 mm bald phenotype at 100 μg/disc; MIC = 12.5 μg/ disc) while, Chloroform extract displayed maximum antidiabetic activity (α-amylase inhibition of 21.61 ± 1.53% at 200 μg/ml concentration). The highest antileishmanial potential was found in Ethyl acetate-Acetone extract (12.91 ± 0.02% at 100 μg/ml concentration), while, Q. dilatata extracts also showed a moderate antifungal activity.

CONCLUSION

This study proposes that multiple-solvent system is a crucial variable to elucidate pharmacological potential of Q. dilatata and the results of the present findings prospects its potential as a resource for the discovery of novel anticancer, antidiabetic, antileishmanial and antioxidant agents.

In vitro antiproliferative and apoptosis-inducing activities of crude ethyle alcohole extract of Quercus brantii L. acorn and subsequent fractions

Cancer cell resistance to widely used chemotherapeutic agents is gradually developed. Natural products, mainly isolated from medicinal plants, have been considered as valuable sources for herbal anticancer drugs. The present study aimed to evaluate in vitro antiproliferative and apoptosis-inducing activities of crude ethyle alcohole extract and four fractions of Q. brantii acorn. Crude ethyle alcohole extract of Q. brantii acorn was prepared and subjected to fractionation with different polarity. Subsequently, the extract and the fractions wereevaluated for their in vitro antiproliferative activity in two cancerous (Hela and AGS) and one normal (HDFs) cell lines using MTT [3-(4, 5-dimethylthiazol-2ol) 2, 5 diphenyltetrazoliumbromide] assay. To determine whether the cytotoxicity of these compounds involved the induction of apoptosis, Hela cells were treated with IC50 concentrations of test compounds, stained with both propidium iodide (PI) and Annexin V-fluorescein isothiocyanate (FITC), and analyzed by flow cytometry. In vitro cytotoxicity assay showed that the cell viability was significantly reduced in a dose-dependent manner following treatment with crude ethyle alcohole extract and Cholophorm and n-Butanol fractions. Based on the probit regression model, antiproliferative activities of crude ethyle alcohole extract, Cholophorm fraction, and n-Butanol fraction on Hela and AGS cells and HDFs cells were significantly different (P < 0.001). The results of flow cytometric analysis showed that crude ethyle alcohole extract and two fractions of Q. brantii acorn induced early apoptotic cell death. These findings suggest that crude ethyle alcohole extract and Cholophorm and n-Butanol fractions of Q. brantii acorn suppress the proliferation of cancer cells through induction of early apoptosis.

Anti-Herpes Simplex Virus Type-1 Activity and Phenolic Content of Crude Ethanol Extract and Four Corresponding Fractions of Quercus brantii L Acorn

This research was aimed to evaluate anti–herpes simplex virus type-1 (anti-HSV-1) activity of crude ethanol extract and 4 corresponding fractions of Quercus brantii acorn in vitro. Crude ethanol extract was prepared and subjected to fractionation with different polarity. Anti-HSV-1 activity was evaluated on baby hamster kidney cell line using MTT assay. The inhibitory effect of the plant materials on adsorption and/or post-adsorption stages of HSV-1 replication cycle were determined. Regression analysis was used to determine 50% inhibitory concentration and 50% cytotoxicity concentration, from which selective index was calculated. Based on our results, the chloroform fraction and the crude extract had the highest effect against HSV-1 with selectivity indices of 53.8 and 48.4, respectively. The n-hexane, n-butanol, and chloroform fractions inhibited HSV-1 replication in postadsorption stage (P < .001). The results obtained indicated that the chloroform fraction of Q brantii acorn with high inhibitory effect against HSV-1 replication could be a new promising anti-HSV-1 agent.

Anti-oxidant and anti-adipogenic effects of acorn (Quercus acutissima CARR.) shell extracts via regulation of wnt signaling in 3T3-L1 cells

Acorn (Quercus acutissima CARR.) is a nut from the Fagaceae family that has been used in traditional medicine for many years. However, shells from acorns are regarded as a by-product and are mostly discarded. Anti-adipogenic activities of acorn shells were investigated using 3T3-L1 cells and methanol shell extracts (AE-M). AE-M demonstrated Cu²⁺-chelation activities and anti-oxidant activities via reduction of oxidative stress levels induced using AAPH. Six days after adipocyte differentiation, 50 and 100 μg/mL AE-M completely suppressed 3T3-L1 adipogenesis and the anti-adipogenic effect was stronger than for the positive control 50 μM quercetin. Treatment with AE-M in 3T3-L1 cells reduced mRNA expression levels of adipogenic genes. AE-M-inhibition was found in pre-adipogenic, early, and intermediate stages of adipogenesis in 3T3-L1 cells. The Wnt/β-catenin signaling pathway is required for AE-M-inhibition of 3T3-L1 adipogenesis.

Antioxidant Capacity and Phenolic Contents of Three Quercus Species

The antioxidant capability and phenolic contents of ethanol extracts (free phenolics) and ethyl acetate extracts (bound phenolics) of three Quercus species were estimated in this work. The antioxidant activities were examined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical, reducing power and b-carotene bleaching methods. HPLC was employed to detect major phenolic acids. The leaf extract of Q. salicina contained maximum total phenolics while the highest total flavonoid content was found in the leaf extract of Q. serrata. The antioxidant activities varied among three species. Bark extract of Q. salicina was the most potential and it was closed to levels of the standard antioxidative dibutyl hydroxytoluene (BHT). The bark extract of Q. serrata also showed promising antioxidant activities despite their eminence was negligibly lower than Q. salicina. Stronger antioxidant activities of free phenolics than those of the bound phenolics may be attributed to higher quantities of free phenolics in the barks of Quercus species, however total flavonoids may not contribute a critical role. By HPLC analysis, thirteen phenolic acids were detected in the leaf and bark extracts. Of them, Q. salicina showed maximum in number (ten compounds) and quantities of detected phenolic acids. Ellagic, chlorogenic and benzoic acids were dominant in Quercus species. Findings of this study revealed that leaves and barks of three Quercus species are rich source of antioxidants, and Q.salicina is the most promising and should be elaborated to exploit its pharmaceutical properties.

Antioxidant activity of phytoestrogen type isoflavones in biomimetic environments

Oxidation of phytoestrogen type isoflavones in lecithin lipidic bi-layers and in silver nanoparticle complexes by the chemiluminescence method.