Phenolic and flavonoid compounds extraction from Calophyllum inophyllum leaves

Calophyllum inophyllum has been known as a part of the mangrove forest area. This species is distributed primarily in the coastal regions of Indonesia and Africa. It is rich in bioactive compounds and has been used as a traditional medication. This work employed a single replicate of the one-factor-at-a-time experiment method to investigate optimum conditions, which resulted in the highest TPC. The three factors studied were organic solvent type (acetone, ethanol, and methanol), organic solvent concentration in water (50–100%, v/v), and extraction temperature (30–60 °C). The extraction was conducted with the percolation method. The result shows that organic solvent type, organic solvent concentration in water, and extraction temperature significantly affect the TPC, TFC, and the yield of crude extract obtained. The highest TPC (289.12 mg GAE/g of the residue of C. inophyllum leaves) was achieved with 80% methanol in water at 30 °C for 48 h. Under this condition, TFC value of 410.4 mg QE/g of the residue of C. inophyllum leaves, the yield of 2.41%, and IC₅₀ value of 0.054 µg/mL were achieved. Moreover, bis (2-ethylhexyl) phthalate was firstly detected in the extract.     

Optimization Method for Phenolic Compounds Extraction from Medicinal Plant (Juniperus procera) and Phytochemicals Screening

Juniperus procera is a natural source of bioactive compounds with the potential of antitumor, antimicrobial, insecticidal, antifungal, and antioxidant activities. An optimization method was developed for total phenolic content (TPC), total flavonoid content (TFC), and total tannin content (TTC) in leaf and seed extract of Juniperus procera. Organic solvents (methanol (99.8%), ethanol (99%), and acetone (99.5%)), and deionized water (DI) were used for extraction. The estimation of TPC, TFC, and TTC in plant materials was carried out using UV-spectrophotometer and HPLC with the standards gallic acid, quercetin, and tannic acid. Recovery of TPC in leaf extract ranged from 2.9 to 9.7 mg GAE/g DW, TFC from 0.9 to 5.9 mg QE/g DW, and TTC ranged from 1.5 to 4.3 mg TA/g DW while the TPC value in the seed extract ranged from 0.53 to 2.6 mg GAE/g DW, TFC from 0.5 to 1.6 mg QE/g DW, and TTC ranged from 0.5 to 1.4 mg TA/g DW. This result revealed that methanol is the best solvent for recovery of the TPC value (9.7 mg) from leaf extract in comparison to other solvents. Ethanol recorded the highest result of TFC (5.9 mg) in leaf extract among the solvents whereas acetone was the best for TTC yield recovery from leaf extract (4.3 mg). In the case of the seed extract, ethanol was the best solvent for both TPC (2.6 mg), and TFC (1.6 mg) recovery in comparison to other solvents. Total tannin content in methanol resulted in significant recovery from seed extract (1.4 mg). Separation and quantification of gallic acid, quercetin, and tannic acid in plant materials were undertaken using HPLC. Gallic acid in leaf and seed of J. procera ranged from 6.6 to 9.2, 6.5 to 7.2 µg/g DW, quercetin from 6.3 to 18.2, 0.9 to 4.2 µg/g DW, and tannic acid from 16.2 to 29.3, 6.6 to 9.3 µg/g DW, respectively. Solvents have shown a significant effect in the extraction of phenolic compounds. Moreover, phytochemicals in plant materials were identified using GC-MS and resulted in very important bioactive compounds, which include anti-inflammatory, antibacterial, and antitumor agents such as ferruginol, phenanthrene, and n-hexadecanoic acid. In conclusion, the optimal solvent for extraction depends on the part of the plant material and the compounds that are to be isolated.     

Novel Processes for the Extraction of Phenolic Compounds from Olive Pomace and Their Protection by Encapsulation

Olive pomace, the solid by-product derived from olive oil production consists of a high concentration of bioactive compounds with antioxidant activity, such as phenolic compounds, and their recovery by applying innovative techniques is a great opportunity and challenge for the olive oil industry. This study aimed to point out a new approach for the integrated valorization of olive pomace by extracting the phenolic compounds and protecting them by encapsulation or incorporation in nanoemulsions. Innovative assisted extraction methods were evaluated such as microwave (MAE), homogenization (HAE), ultrasound (UAE), and high hydrostatic pressure (HHPAE) using various solvent systems including ethanol, methanol, and natural deep eutectic solvents (NADESs). The best extraction efficiency of phenolic compounds was achieved by using NADES as extraction solvent and in particular the mixture choline chloride-caffeic acid (CCA) and choline chloride-lactic acid (CLA); by HAE at 60 °C/12,000 rpm and UAE at 60 °C, the total phenolic content (TPC) of extracts was 34.08 mg gallic acid (GA)/g dw and 20.14 mg GA/g dw for CCA, and by MAE at 60 °C and HHPAE at 600 MPa/10 min, the TPC was 29.57 mg GA/g dw and 25.96 mg GA/g dw for CLA. HAE proved to be the best method for the extraction of phenolic compounds from olive pomace. Microencapsulation and nanoemulsion formulations were also reviewed for the protection of the phenolic compounds extracted from olive pomace. Both encapsulation techniques exhibited satisfactory results in terms of encapsulation stability. Thus, they can be proposed as an excellent technique to incorporate phenolic compounds into food products in order to enhance both their antioxidative stability and nutritional value.     

Extraction of Phenolic and Flavonoid Compounds from Mung Bean (Vigna radiata L.) Seed Coat by Pressurized Liquid Extraction

Mung bean seed coat (MBC) is a by-product of the mung bean processing industry. It contains a large number of phenolic compounds with therapeutic anti-inflammatory, anti-diabetic and antioxidant properties. This research aimed to investigate the optimum conditions for phenolic and flavonoid extraction from MBC by pressurized liquid extraction (PLE). Response surface methodology (RSM) was used to study the effects of temperature (80–160 °C), pressure (1200–1800 psi) and ethanol concentration (5–95%) on total phenolic content (TPC), total flavonoid content (TFC) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity (ABTS). Scale-up extraction was also performed. The optimum conditions for extraction were 160 °C, 1300 psi and 50% ethanol. Under optimum conditions, the TPC was 55.27 ± 1.14 mg gallic acid equivalent (GAE)/g MBC, TFC was 34.04 ± 0.72 mg catechin equivalent (CE)/g MBC and ABTS scavenging activity was 195.05 ± 2.29 mg trolox equivalent (TE)/g MBC. The TFC and ABTS scavenging activity of the extracts obtained at the pilot scale (10 L) was not significantly different from the laboratory scale, while TPC was significantly increased. The freeze-dried MBC extract contained vitexin and isovitexin 130.53 ± 17.89, 21.21 ± 3.22 mg/g extract, respectively. In conclusion, PLE was able to extract phenolics, flavonoids with ABTS scavenging activity from MBC with the prospect for future scale-up for food industry.     

Optimization and stabilization of the antioxidant properties from Alkanet (Alkanna tinctoria) with natural deep eutectic solvents

Natural Deep eutectic solvents (NaDESs) are promising green solvents for the extraction of phytochemical compounds with antioxidant properties. In this study, we aimed to evaluate the behavior of the antioxidant properties of Alkanet (Alkanna tinctoria) root in hydrophilic NaDESs. For this purpose, two NaDESs constituted of sodium acetate:lactic acid (SALA₁₂) and sodium acetate:formic acid (SAFA₁₂) were synthesized to evaluate the antioxidant properties of Alkanet. 70% ethanol, 80% methanol and water were used as conventional solvents for comparison. SALA₁₂ and SAFA₁₂ were characterized considering their viscosities and FITR spectra. The extracts obtained with SALA₁₂ and SAFA₁₂ presented the best results when compared to the conventional solvents. The NaDES presented the highest extraction performance was SAFA₁₂. This prominent NaDES was subjected to the response surface methodology using a Box-Behnken design to figure out the optimum conditions to have the maximum antioxidant activity of Alkanet root. For total phenolic content (TPC), total flavonoid content (TFC) and DPPH radical scavenging, the optimum conditions were 1:4 molar ratio, 45% water content and 25% mL solvent ratio. The confirmed responses at the optimum conditions were 390.16 mg GAE/g, 10.69 mg ECE/g and 444.68 mmol TE/g, respectively. NaDES molar ratio and water content were found to impact most significantly the antioxidant properties Alkanet. The thermal stability experimentation revealed that phytochemicals along with the antioxidant properties of Alkanet were more stable in NaDES. These findings revealed that novel NaDES is an efficient green solvent for the extraction of bioactive compounds with antioxidant properties from plants.     

Evaluation of antioxidants in Dong quai (Angelica sinensis) and its dietary supplements

The antioxidant activity (AA), total phenolic content (TPC) and total flavonoids content (TFC) in Dong quai (DQ, Angelica sinensis) raw materials and dietary supplements (DS) containing this plant were determined using the CUPRAC, FRAP and fluorescence methods. The antioxidant activity for DQ aqueous extracts revealed by CUPRAC was (1330.45 ± 1.30) μmol Trolox equivalent (TE) per 100 g of dry mass (DM), whereas the antioxidant activity as determined by FRAP was (1813.9 ± 2.0) μmol of TE per 100 g of DM. Lower values were noted for the fluorescence method than for CUPRAC and FRAP (ranging from (35.96 ± 0.3) to (304.6 ± 1.4) μmol of TE per 100 g of DM). The highest TPC values were determined for an aqueous extract of DQ ((3330.3 ± 2.3) μmol of TE per 100 g of DM), while TFC for ethanolic extracts of DQ was ((146.50 ± 0.5) mg of quercetin equivalent (QE) per 100 g of DM). Cinnamic acid, isomers of benzoic acid and derivatives of quercetin were analysed by HPLC-PDA. The ferulic acid concentration in an ethanolic extract of DQ was (21.83 ± 0.07) mg per 100 g of DM. Of the flavonols detected, rutin exhibited the highest concentration in ethanolic extract of DQ ((3.32 ± 0.13) mg of QE per 100 g of DM). Other phytochemicals (alkaloids, saponins, flavonoids, anthraquinones, tannins, steroids, etc.) were identified by phytoscreening colour reaction. The results were analysed by principal component analysis (PCA), cluster analysis and one-way ANOVA tests.     

Enzyme pretreatment improves the recovery of bioactive phytochemicals from sweet basil (Ocimum basilicum L.) leaves and their hydrodistilled residue by-products,and potentiates their biological activities

In the present study, the effect of enzyme pretreatment on essential oil recoveries from sweet basil (Ocimum basilicum L.) leaves was evaluated. Moreover, the consideration on the use of hydrodistilled residue by-products as a source of bioactive phytochemicals with antioxidant, antimicrobial, and repellent effects against the stored-grain pest Tribolium castaneum was examined. Results showed that the enzymatic pretreatment increased the extraction yield of essential oil by 400, 417, and 478% in hemicellulase-, cellulase-, and viscozyme-treated samples, respectively. Phenylpropanoids including methyl cinnamate, methyl eugenol, eugenol and estragol were found as the main components, and were particularly abundant in cellulase-treated samples. From the hydrodistilled residue of enzyme-treated samples, better recoveries of total phenols (TPC) (258.3–470.9 mg GAE/g extract) and flavonoids (TFC) (59.4–94.3 mg QE/g extract) were observed. Using the DPPH, ABTS, and FRAP assays, a strong antioxidant activity of the rosmarinic-rich extract was observed. Such an activity which was mediated through electron transfer mechanism was highly correlated with the TPC, TFC and rosmarinic acid content. The in vitro bioassay showed that methanol extract (6.29 and 12.58 µL/cm²) had repellent activity against the stored-grain pest Tribolium castaneum. These results suggest the potential of enzyme pretreatment to promote the use of hydrodistilled residue by-products as a valuable source of natural antioxidants and repellents ingredients.     

Determination and quantification of phenolic compounds in methanolic extracts of Solanum ferrugineum (Solanaceae) fruits by HPLC-DAD and HPLC/ESI-MS/TOF

Solanum ferrugineum Jacq. is a wild species that in previous analysis reported a significant antioxidant capacity. The aim of our research was to determine total phenolic content (TPC) and total flavonoid content (TFC), and the phenolic composition by HPLC-DAD and HPLC/ESI-MS/TOF of methanolic extracts of S. ferrugineum fruits, collected from Paredones, Jiquilpan, and Fray Dominguez, Pajuacarán in the Mexican state of Michoacán. TPC and TFC were determined by the spectrophotometric Folin–Ciocalteu reagent and the AlCl₃ method, respectively. TPC in S. ferrugineum fruit [31.41?±?0.91?mg gallic acid equivalent/g dry tissue (DT)] was similar to those reported for Turkey berry (Solanum torvum Sw.) and eggplant (Solanum melongena L.) fruits. The TFC values of S. ferrugineum fruits (29.14?±?4.99?mg catechin equivalent /g DT) corresponded to 80.24% of the TPC. Eight phenolic compounds (PC) were identified by HPLC analysis. The main PC identified in S. ferrugineum fruits were chlorogenic acid, caffeic acid, p-coumaric acid, gallic acid, quercetin, and kaempferol. S. ferrugineum fruits could be used as a starting material for the extraction of high-value PC with potential applications.     

Polyphenolic characterization and evaluation of multimode antioxidant,cytotoxic, biocompatibility and antimicrobial potential of selected ethno-medicinal plant extracts

IntroductionScientific evidence about biological profile of natural products can support their traditional uses. The current work was aimed to assess phytochemical and biological profile of nine medicinal plants collected from Herbalists.MethodsExtracts prepared in different solvents were subjected to phytochemical, antioxidant, enzyme inhibitory, cytotoxic, and antimicrobial activities. Reverse phase-high performance liquid chromatography (RP-HPLC) analysis was performed for the quantification of polyphenols.ResultsResults showed methanol extract (M) being potent as compared to others. Gentian lutea M showed maximum extract recovery (15.00 ± 0.11 % w/w) and TFC (30.82 ± 0.21 μg QE/mg extract). Nigella sativa M displayed highest TPC (44.99 ± 0.43 μg GAE/mg extract) and TAC (334.72 ± 0.35 μg AAE/ mg extract). Results showed noteworthy quantities of vanillic acid, rutin, kaempferol, emodin in ethyl acetate (EA) and methanol (M) extracts of plants assessed by RP-HPLC. Gentisic acid was highest (11.75 µg/mg extract) in T. arjuna M extract. Similarly, maximum %FRSA (82.28 ± 0.03 %) and TRP (160.40 ± 0.38 μg AAE/ mg extract) were depicted by Terminalia chebula and Chamomilla recutita, respectively. Moreover, Mentha longifolia and G. lutea M demonstrated noteworthy (p < 0.05) antibacterial activity against Staphylococcus aureus (14 ± 0.7 mm) and Klebsiella pneumoniae (12 ± 0.3 mm), respectively. Curcuma amada, C. recutita, Murraya koenigii and G. lutea M had significant α-glucosidase activity. Another good solvent for extraction was ethyl acetate (EA), whose extracts were secondary to methanol in producing significant biological profile. For example, EA of N. sativa (TPC: 1.46 ± 0.45 µg GAE/ mg extract), G. lutea (TRP: 160.33 ± 0.52 μg AAE/mg extract: ZOI of 12 ± 0.5 mm in K. pneumoniae) and Mormodica charantia (α-amylase inhibition: 39.5 ± 0.10 %) showed significant bioactivities. All extracts displayed mild antifungal protein kinase inhibition activities and were significantly (greater than80 %: p < 0.05) cytotoxic to brine shrimps with negligible hemolytic activity.ConclusionBriefly, variable polarity solvent extracts of studied plants will be processed for isolation of antioxidant, cytotoxic, carbohydrate enzyme inhibitory and antibacterial compounds.     

Umbu Fruit Peel as Source of Antioxidant,Antimicrobial and α-Amylase Inhibitor Compounds

Herein, the extraction of bioactive compounds from umbu fruit peel was optimized using thermal-assisted solid–liquid extraction. In parallel, antioxidant, antimicrobial, and inhibitory effects against α-amylase of optimized extract were also evaluated. The combination of operational conditions including the temperature (32–74 °C), ethanol concentration (13–97%), and solid/liquid ratio (1:10–1:60; w/v) was employed using a rotational central composite design for optimization. The extracts were evaluated for total phenolic compounds (TPC), total flavonoid compounds (TFC) and antioxidant capacity by ABTS^•+, DPPH^• and FRAP assays. The bioactive profile of the optimized extract was obtained by ultra-performance liquid chromatography coupled to quadrupole/time-of-flight mass spectrometry in electrospray ionization in both negative and positive modes. The statistically evaluated results showed that the optimal operational conditions for the recovery of bioactive compounds from umbu fruit peel included 74 °C, 37% ethanol, and a solid–liquid ratio of 1:38. Under these conditions, the obtained values were 1985 mg GAE/100 g, 1364 mg RE/100 g, 122 µmol TE/g, 174 µmol/TE g and 468 µmol Fe²⁺/g for TPC, TFC, ABTS^•+, DPPH^•, and FRAP assays, respectively. In addition, the optimized extract was effective against Gram-positive and Gram-negative bacteria (MBC ranged from 0.060 to 0.24 mg GAE/mL), as well as it was effective to inhibit α-amylase (IC₅₀ value of 0.076 mg GAE/mL). The optimized extract showed to be mainly constituted by phenolic acids and flavonoids.     

GC/MS and LC-MS/MS phytochemical evaluation of the essential oil and selected secondary metabolites of Ajuga orientalis from Jordan and its antioxidant activity

The current investigation aimed to shed light in the volatile and non-volatile secondary metabolites of Ajuga orientalis L. from Jordan. GC/MS and GC/FID analysis of the hydrodistilled essential oil obtained from aerial parts of the plant revealed tiglic acid (18.90 %) as main constituent. Each of the methanol and butanol fractions of A. orientalis were screened for their total phenol content (TPC), total flavonoid content (TFC), and antioxidant activity determined by DDPH and ABTS methods. The extracts were then analyzed by LC-ESI-MS/MS to unveil their chemical constituents, especially phenols and flavonoids. Results showed that the AO-B extract had the highest TPC (217.63 ± 2.65 mg gallic acid/g dry extract), TFC (944.41 ± 4.77 mg quercetin /g dry extract), highest DPPH and ABTS antioxidant activity ((4.00 ± 0.20) × 10^-2; (3.00 ± 0.20) × 10^-2 mg/mL, respectively) as compared to the AO-M extract. LC-ESI-MS/MS analysis of both extracts revealed the presence of several phenolics, flavonoids and nonphenolic acids.     

New mechanistic insights on Justicia vahlii Roth: UPLC-Q-TOF-MS and GC–MS based metabolomics,in-vivo,in-silico toxicological,antioxidant based anti-inflammatory and enzyme inhibition evaluation

Justicia vahlii Roth. (acanthaceae) is an important medicinal food plant used in pain relief and topical inflammation. The present study aimed to evaluate phytochemical composition, toxicity, anti-inflammatory, antioxidant and enzyme inhibition potential of n-butanol extract of J. vahlii (BEJv). The extract prepared through maceration was found rich in total phenolic contents (TPC) 196.08 ± 6.01 mg of Gallic acid equivalent (mg GAE/g DE) and total flavonoid contents (TFC) 59.08 ± 1.32 mg of Rutin equivalent (mg RE/g DE). The UPLC-Q-TOF-MS analysis of BEJv showed tentative identification of 87 compounds and 19 compounds were detected in GC–MS analysis. The HPLC-PDA quantification showed the presence of 14 polyphenols amongst which kaempferol (3.45 ± 0.21 µg/ mL DE) and ferulic acid (2.31 ± 1.30 µg/ mL DE) were found in highest quantity. The acute oral toxicity study revealed the safety and biocompatibility of the extract up to 3000 mg/kg in mice. There was no effect of BEJv on human normal liver cells (HL 7702) and very low cytotoxic effect on liver cancer cells (HepG2) and breast cancer cells (MCF-7). In anti-inflammatory evaluation, the BEJv treated groups showed significant inhibition (p < 0.001) of late phase carrageenan induced paw edema at 400 mg/kg and increased the levels of oxidative stress markers; catalase, superoxide dismutase (SOD) and glutathione (GSH) while decreased the inflammatory markers; interleukin-1beta (IL-β) and tumor necrosis factor alpha (TNF-α) in paw tissue of mice. BEJv displayed highest results in Ferric reducing antioxidant power (FRAP) assay 97. 21 ± 2.34 mg TE (trolox equivalent)/g DE, and highest activity 3.32 ± 0.31 mmol ACAE (acarbose equivalent)/g D.E against α-glucosidase. Docking study showed good docking score by the tested compounds against the various clinically significant enzymes. Conclusively the current study unveiled J. vahlii as novel non-toxic source with good antioxidant-mediated anti-inflammatory potential which strongly back the traditional use of the species in pain and inflammation.     

Antioxidant potential in the leaves of grape varieties (Vitis vinifera L.) grown in different soil compositions

Grape plant (Vitis vinifera L.) is a species of the family Vitaceae. It is an economically important fruit plant abundantly grown all over the world. Vitaceae comprised of 900 species distributed across tropical, sub-tropical and partially temperate sorts of climatic zones. In the current study we aimed to evaluate the antioxidant activities of grape leaves extract from different Pakistani varieties.We have analyzed the crude methanolic extract from the leaves of Pakistani grape varieties (i.e. NARC Black, Sundar Khani, Shogran-1, Shogran-2, Haita, Sheghali, Perlette, and Sultania-C) cultivated in various soil compositions. Total phenolic contents (TPC) of the extract were determind by using Folin-ciocalteu reagent method. Total flavonoid contents (TFC) were determind by the Aluminum Chloride Calorimetric method. Antioxidant activities of the extracts of different concentration were evaluated using Phosphomolybdenum method, Reducing power and DPPH (2, 2-disphenyl-1-picryl-hydrazyl) assays. Assays performed for grape varieties showed great antioxidant potential. All varieties significantly depicted with variation in polyphenolic contents and antioxidant potential with changes in the soil conditions. The highest TPC and TFC were quantified in Shogran-1 97.58 ± 0.09 (GAE, g⁻¹) and Sultania-C 97.47 ± 0.12 (µg QE/g DE) varieties respectively which were grown in (T6) and (T5), while lower were recorded in Sundar khani 5.16 ± 0.23 in (T6). Likewise, Shogran-1 128.26 ± 0.23 (µg AAE/g extract) variety grown in (T6) depicted highest total antioxidant capacity, NARC black 182.06 ± 0.24 (µg AAE/g extract) variety grown in (T6) resulted in maximum reducing power while DPPH free radical scavenging potential were determinded in Sultania-C 80.91 ± 0.10 (T4) equivalent µg/g. In the terms of bioassays, the promising results were showed by compost + sand + clay (T4), compost + clay + dung (T5) and sand + clay + dung (T6). Therefore, we conclude that variation in soil composition has a significant contribution in the quantity of phytochemicals and antioxidants expression. Our study further suggest that use of organic fertilizer (Compost) and loamy sort of soil enhance functioning of most of the varieties in terms of important phytochemicals.     

Phytochemical,Antimicrobial, Antidiabetic,Thrombolytic, anticancer Activities,and in silico studies of Ficus palmata Forssk

Ficus palmata Forssk. (Moraceae family) is medicinally valuable plant that is mostly used as folk medicine for the treatment of different diseases. Phytochemical composition was evaluated by preliminary phytochemical investigation, GCMS analysis, and total bioactive contents (TPC and TFC). The antioxidant, enzyme inhibition, antimicrobial, thrombolytic and anticancer activities were performed for biological evaluation. The extract exhibited the maximum total phenolic (49.24 ± 1.21 mg GAE/g) and total flavonoid contents (29.9 ± 1.13 mg QE/g) which may be correlated to higher antioxidant potential of extract. The GCMS investigation identified the presence of 27 phytocompounds of different classes related to aldehydes, esters of fatty acids, triterpenes, steroids, triterpenoid. The extract possessed the strong α-glucosidase (73.4 ± 4.65 %) and moderate α-amylase inhibition activity (47.1 ± 3.29 %). Significant results were observed in case of antiviral, antifungal, and antibacterial activities. F. palmata extract inhibited the growth of HepG2 cancer cells in a dose-dependent manner. The extract also exhibited moderate in vitro thrombolytic activity. In addition, the phytocompounds identified by GCMS were subjected to in silico molecular docking studies to analyze the binding affinity between phytocompounds and enzymes (α-glucosidase and α-amylase). Moreover, the best docked compounds were selected for ADMET studies which provide information about pharmacokinetics, physicochemical properties, drug-likeness, and toxicity of identified phytocompounds. The outcome of our research revealed that ethanolic extract of F. palmata possessed good antidiabetic, antimicrobial, thrombolytic and anticancer potential. This plant should be further explored to isolate the bioactive compounds for new drug development.     

Investigation of phytochemicals and antioxidant capacity of selected <Emphasis Type="Italic">Eucalyptus</Emphasis> species using conventional extraction

Eucalyptus species have found their place in traditional medicine and pharmacological research and they have also been shown to possess a large number of phenolic compounds and antioxidants. The present study sought to implement conventional extraction to yield maximal total phenolic content (TPC), total flavonoid content (TFC), proanthocyanidins, antioxidants, and saponins from E. robusta using different solvents. The most suitable extraction solvent was further employed for extracting phytochemicals from E. saligna, E. microcorys, and E. globulus to select the Eucalyptus species with the greatest bioactive compound content. The results emphasised the efficiency of water in extracting TPC ((150.60 ± 2.47) mg of gallic acid equivalents per g), TFC ((38.83 ± 0.23) mg of rutin equivalents per g), proanthocyanidins ((5.14 ± 0.77) mg of catechin equivalents per g), and antioxidants ABTS ((525.67 ± 1.99) mg of trolox equivalents (TE) per g), DPPH ((378.61 ± 4.72) mg of TE per g); CUPRAC ((607.43 ± 6.69) mg of TE per g) from E. robusta. Moreover, the aqueous extract of E. robusta had the highest TPC, TFC and antioxidant values among the other Eucalyptus species tested. These findings highlighted the efficiency of conventional extraction in extracting natural bioactive compounds from Eucalyptus species for pharmaceutical and nutraceutical applications.     

Anti-pathogenic,anti-diabetic,anti-inflammatory,antioxidant, and wound healing efficacy of Datura metel L. leaves

Datura metel L. is an important medicinal plant of Solanaceae family which has extensive pharmacological properties. The present investigation was aimed to identify the presence of phytoconstituents and assess in vitro antibacterial, anti-biofilm, anti-diabetic, anti-inflammatory, antioxidant, cytotoxicity, and wound healing efficacy of D. metel leaves extract. Among different solvent extracts, methanolic extract showed higher amount of phenolic (124.61 ± 0.68 mg GAE/g), alkaloid (88.77 ± 1.01 mg AE/g), flavonoids (42.24 ± 0.18 mg QE/g), and tannins contents (38.72 ± 0.51 mg GAE/g). The extract exhibited not only significantly (P < 0.05) different antibacterial activities against pathogens tested but also showed maximum biofilm inhibition of 94, 88, and 92% against B. subtilis, MRSA, and E. coli, respectively. Anti-diabetic assay depicted 22.55 ± 0.62–79.41 ± 1.13% and 24.31 ± 1.47–72.59 ± 0.22% of α-amylase and α-glucosidase inhibition abilities of methanolic extract, respectively at varied concentrations. The methanolic extract showed potential anti-inflammatory effect (P < 0.05) by showing 28.11 ± 0.13, 34.94 ± 1.11, 55.73 ± 0.42, 73.28 ± 0.72, and 92.62 ± 1.33% of inhibition of protein denaturation at different concentrations with an IC₅₀ value of 52.45 µg/mL. The extract revealed significant (P < 0.05) rate of ABTS scavenging, DPPH degradation, and reducing power assay in a concentration dependent manner. The cytotoxicity assay was demonstrated on L929 mouse fibroblast cell line and found > 90% of cell viability in the presence of methanolic extract, thereby indicating its non-toxicity effect. Wound healing assay indicated that methanolic extract at 50 µg/mL closed 100% of wound gap after 24 h with high rate of migration and proliferation. Furthermore, GC–MS chromatogram revealed the presence of several components in methanolic extract, including neophytadiene, hexadecanoic acid, and hentriacontane as principal phytoconstituents. In conclusion, methanolic extract of D. metel leaves could be used as potent therapeutic agent not only for treating metabolic diseases but also superficial chronic diabetic wounds.     

Improving antioxidant scavenging effect of fruit peel waste extracts and their applicability in biodiesel stability enhancement

The increasing popularity of fruit peel extracts as effective sources of natural antioxidants is primarily attributed to their affordability, easy availability, and high phenolic contents that readily dissolve in solutions. However, most natural antioxidants demonstrate a lesser free radical scavenging effect when applied in mono blends compared to their synthetic counterparts. To address this problem, this work aims to improve the antioxidant capacities of palm fruit, banana, and mango peel liquid extracts recovered using supercritical fluid extraction (SFE). Firstly, a reverse-phase high-performance liquid chromatography (RP-HPLC) was used to isolate three (3) target bioactive compounds from the extracts, whose estimated quantities ranged between 1.2983–4.6841, 1.1469–3.6987, and 0.0254–0.0489 mg/g for quercetin, beta-carotene, and gallic acid respectively. Subsequently, blends of the recovered extracts were formulated in mono, binary, and ternary dosage ratios (S.₁–S.₁₀) to assess their free radical scavenging efficiency (RSE) in terms of inhibitory concentration at 50% (IC₅₀) using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, total phenolic content (TPC), total flavonoid content (TFC), and total carotenoid content (TCC). Based on the results obtained, the highest RSE was exhibited by the ternary blend (S.₉), with an IC₅₀ value of 76.21 ± 032 µg/mL and a TPC value of 242.38 ± 0.26 mg gallic acid equivalent (GAE/g). The fastest kinetics for the extracts’ reaction with DPPH corresponding to a rate constant (K) of 1.2351 M^−1.min⁻¹ and activation energy ($E_a)$ of 0.55 KJ/mol were presented by the same sample blend (S.₉), indicating the ease of hydrogen atom release for radical scavenging. Finally, the peel extracts demonstrate an improved antioxidative performance by prolonging the biodiesel’s induction period of the extracts-blended samples as obtained from Rancimat analysis.     

Effects of Orange Leaves Extraction Conditions on Antioxidant and Phenolic Content: Optimization Using Response Surface Methodology

In the last few years, bioactive components or their extraction techniques are gaining special interest in scientific areas. In this framework, orange leaves were used for preparation of extracts with high content of biologically active compounds. To optimize the extraction process, three levels and three variables of Box–Behnken design with response surface methodology were applied. Investigated responses were the total phenolic content (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, cupric ion reducing antioxidant capacity (CUPRAC), and ferric reducing antioxidant power (FRAP). Independent variables were methanol concentration (10–90%), temperature (20–60°C), and extraction time (60–180?min). Experimentally obtained results were fit into a second-order polynomial model with multiple regression. Analysis of variance was used to estimate model fitness and determine optimal conditions for processing. Estimated optimal conditions were 90% methanolic solution, 60°C and 180?min using these parameters; the predicted values of investigated responses were 43.19?mg GAE/g (GAE: gallic acid equivalents), 43.04?mg TE/g (TE: trolox equivalents), 139.34 and 93.76?mg TE/g for TPC, DPPH, CUPRAC, and FRAP, respectively. The obtained optimal conditions could be considered as an alternative strategy for developing novel functional products.     

Phenolic composition,antioxidant and enzyme inhibitory activities of Parkia biglobosa (Jacq.) Benth., Tithonia diversifolia (Hemsl) A. Gray,and Crossopteryx febrifuga (Afzel.) Benth

Medicinal plants from Chad grow under special climatic conditions in between the equatorial forest of Central Africa and the desert of North Africa and are understudied. Three medicinal plants from Chad (T. diversifolia, P. Biglobosa and C. Febrifuga) were evaluated for their phenolic composition, antioxidant and enzyme inhibition activities. The total phenolic composition varied from 203.19 ± 0.58 mg GAE/g DW in the ethyl acetate extract of P. biglobosa, to 56.41 ± 0.89 mg GAE/g DW in the methanol extract of C. febrifuga while the total flavonoid content varied from 51.85 ± 0.91 mg QE/g DW in the methanol extract of P. biglobosa to 08.56 ± 0.25 mg QE/g DW in the methanol extract of C. febrifuga. HPLC-DAD revealed that rutin, gallic acid and protocatechuic acid were the most abundant phenolics in T. diversifolia, P. Biglobosa and C. Febrifuga respectively. The antioxidant activity assayed by five different methods revealed very good activity especially in the DPPH^?, ABTS^?+ and CUPRAC assays where the extracts were more active than the standard compounds used. Good inhibition was exhibited against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with methanol (IC₅₀: 15.63 ± 0.72 µg/mL), ethyl acetate (IC₅₀: 16.20 ± 0.67 µg/mL) extracts of P. biglobosa, and methanol (IC₅₀: 21.53 ± 0.65 µg/mL) and ethyl acetate (IC₅₀: 30.81 ± 0.48 µg/mL) extracts of T. diversifolia showing higher inhibition than galantamine (IC₅₀: 42.20 ± 0.44 µg/mL) against BChE. Equally, good inhibition was shown on α-amylase and α-glucosidase. On the α-glucosidase, the ethyl acetate (IC₅₀ = 12.47 ± 0.61 µg/mL) and methanol extracts (IC₅₀ = 16.51 ± 0.18 µg/mL) of P. biglobosa showed higher activity compared to the standard acarbose (IC₅₀ = 17.35 ± 0.71 µg/mL) and on α-amylase, the ethyl acetate (IC₅₀ = 13.50 ± 0.90 µg/mL) and methanol (IC₅₀ = 18.12 ± 0.33 µg/mL) extracts of P. biglobosa showed higher activity compared to acarbose (IC₅₀ = 23.84 ± 0.25 µg/mL). The results indicate that these plants are good sources of antioxidant phenolics and can be used to manage oxidative stress linked illnesses such as Alzheimer’s disease and diabetes.     

Efficient green extraction of polyphenols from post-harvested agro-industry vegetal sources in Piedmont

A study of the polyphenols content and antioxidant capacity of grapevine waste and hazelnut skins (roasted material) from post-harvest products that originate from Piedmont (Italy) has been carried out and the results herein presented. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) were used to achieve process intensification in shorter extraction times, with lower environmental impact and higher selectivity compared to classic maceration. Besides classic solvents, the aqueous β-cyclodextrin solution (1.5%) showed to be an excellent extraction medium for grapevine waste. Total phenolic content (TP) from grapevine waste ranged from 18.23 ± 2.4 to 198 ± 3 mg gallic acid equivalents (GAE)/g dry weight, while total antioxidant capacity (TAC) expressed as EC₅₀ ranged from 0.0902 ± 0.08 mg/mL to 0.0041 ± 0.02 mg/mL. For hazelnut skins, TP ranged from 61.68 ± 0.8 to 200.79 ± 3.0 mg GAE/g dry weight, while TAC ranged from 0.0021 ± 0.0004 to 0.0002 ± 0.0001 mg/mL extract. We have shown that, compared to maceration, the use of UAE and MAE methods can enhance polyphenols recovery and antioxidant capacity.