Microwave-assisted Extracts Research Articles

Effects of autoclave- and microwave-assisted Caulerpa lentillifera extracts on the growth rate, reproduction, immunity and oxidative stress of Daphnia magna

ABSTRACT Caulerpa lentillifera is a green alga that contains essential nutrients. This study investigated the effects of autoclave- and microwave-assisted C. lentillifera extracts (A-CLE and M-CLE) on the growth, reproduction, immunity, and oxidative stress in Daphnia magna. Both extracts were supplemented to D. magna at 1 to 5 g/L. The results showed that D. magna treated with 2 to 5 g/L of A-CLE produced juveniles faster than the control. Juveniles at 1 to 4 g/L A-CLE treatments increased. Moreover, juveniles in 1 g/L M-CLE treatment significantly increased, but the hatching time was not affected. A-CLE also stimulated the immunity of D. magna by increasing hemocytes in the 3 g/L treatment. Furthermore, both extracts did not affect the growth rate, phenoloxidase activity, malondialdehyde level, and catalase activity in D. magna. Therefore, our results indicated that both extracts could enhance the reproduction and immunity of D. magna. Our study is useful for the health improvement of D. magna.

Enhancing bioactive phenolic extraction from unfermented Cabernet Sauvignon pomace through tailored synergies of pH, proteolysis, and microwave processing

The impact of enzyme-assisted (EAE), microwave-assisted (MAE), and microwave enzyme-assisted (MEAE) extractions using water were evaluated and compared to aqueous (AEP), conventional ethanolic (CSE), and microwave ethanolic (MSE) controls for the release of phenolics from Cabernet Sauvignon grape pomace. Optimization of extract total phenolic content (TPC) involved stepwise screening of time, temperature, slurry pH, solids-to-liquid ratio, and enzyme conditions. The use of 0.1 % alkaline protease in MEAE (1:10 g pomace/mL water, pH 11.5, 70 °C, 30 min) reduced extraction time by 50 % compared to AEP, EAE, and CSE methods, doubling the TPC of the extracts to 100.9 mg GAE/g dry weight pomace compared to ethanolic extractions. MAE and MEAE extracts exhibited in vitro antioxidant activities (ABTS and ORAC) similar to ethanolic extracts and had greater antioxidant activities than AEP/EAE extracts while boosting relative contents of catechins, procyanidins, trans-piceid, and malvidin-3,5-diglucoside as detected by untargeted metabolomics. Quantitation by HPLC showed increased levels of gallic acid, protocatechuic acid, syringic acid, p-coumaric acid, polymeric phenols, and polymeric pigments in MEAE compared to hydroethanolic methods. Scanning electron microscopy further supported the synergistic role of microwave processing and proteolysis in disrupting the grape cell structure to aid in releasing valuable bioactive phenolic compounds.

Development of Biologically Active Phytosynthesized Silver Nanoparticles Using Marrubium vulgare L. Extracts: Applications and Cytotoxicity Studies.

Metal nanoparticle phytosynthesis has become, in recent decades, one of the most promising alternatives for the development of nanomaterials using "green chemistry" methods. The present work describes, for the first time in the literature, the phytosynthesis of silver nanoparticles (AgNPs) using extracts obtained by two methods using the aerial parts of Marrubium vulgare L. The extracts (obtained by classical temperature extraction and microwave-assisted extraction) were characterized in terms of total phenolics content and by HPLC analysis, while the phytosynthesis process was confirmed using X-ray diffraction and transmission electron microscopy, the results suggesting that the classical method led to the obtaining of smaller-dimension AgNPs (average diameter under 15 nm by TEM). In terms of biological properties, the study confirmed that AgNPs as well as the M. vulgare crude extracts reduced the viability of human gingival fibroblasts in a concentration- and time-dependent manner, with microwave-assisted extracts having the more pronounced effects. Additionally, the study unveiled that AgNPs transiently increased nitric oxide levels which then decreased over time, thus offering valuable insights into their potential therapeutic use and safety profile.

Green Approach to Enhance the Recovery of Polyphenols from Blackcurrant and Bilberry Leaves: Evaluation of Microwave-Assisted and Pressurized Liquid Extraction.

The aim of the present study was to evaluate microwave-assisted (MAE) and pressurized liquid extraction (PLE) for the recovery of polyphenols from blackcurrant and bilberry leaves and the preservation of their antioxidant activity. The extractions were carried out varying the solvent/solid (SS) ratio, temperature and time. During MAE, increasing the SS ratio increased the polyphenol concentration in the extracts from blackcurrant and bilberry leaves, while increasing the temperature had a positive effect only on bilberry polyphenols. During PLE, only a temperature increase was a determining factor for the isolation of blackcurrant leave polyphenols. Based on polyphenol recovery, optimal extraction parameters were established resulting in a yield of 62.10 and 56.06 mg/g dw in the blackcurrant and bilberry MAE extracts and 78.90 and 70.55 mg/g dw in the PLE extracts. The optimized extracts were profiled by UPLC ESI MS2, and their antioxidant capacity was evaluated through FRAP, DPPH, ABTS and ORAC assays. The characterization of the extracts by UPLC ESI MS2 confirmed flavonols as the predominant compounds in both blackcurrant and bilberry leaves, while flavan-3-ols and procyanidins were the main compounds responsible for high antioxidant capacity as confirmed by the ABTS and ORAC assays. Due to the extract composition and antioxidant capacity, PLE proved to be a technique of choice for the production of blackcurrant and bilberry leave extracts with high potential for use as value-added ingredients in the food and nutraceutical industry.

Effect of Microwave-Assisted Extract (MAE) on Functional Properties, Digestibility, and Glycemic Index of Arrowroot Starch (Maranta arundinacea)

Effect of Microwave-Assisted Extract (MAE) on Functional Properties, Digestibility, and Glycemic Index of Arrowroot Starch (Maranta arundinacea)

Effect of maceration, ultrasound, and microwave-assisted method of extraction on antioxidant activity and phenolic profile of free, esterified, and bound phenolics of Tulaipanji rice

Abstract The present work was designed to investigate the effect of maceration, ultra-sound, and microwave-assisted extraction on free, esterified, and bound phenolics of Tulaipanji rice (Oryza sativa L.) flour. Antioxidant activity was measured by DPPH, ABTS, SOD, and reducing power assays. HPTLC analysis was performed for identification and quantification of phenolics in different extracts. Total phenolic (TPC) and total flavonoid contents (TFC) were found significantly high (p < 0.05) in microwave-assisted extraction of bound phenolics compared with other methods. Microwave-assisted extracts showed highest DPPH radicals, ABTS radicals, SOD, and reducing power activity. Further, Pearson’s correlation study exhibited a significant positive correlation within % yield, TPC, and TFC. Significant negative correlation was found within % yield, TPC, TFC, and antioxidant activity. The study found that extractive value, antioxidant activity, and phenolic contents varied with the extraction methods. Microwave-assisted extraction technique showed the best performance for extraction as compared to other methods.

Teucrium montanum L.-Unrecognized Source of Phenylethanoid Glycosides: Green Extraction Approach and Elucidation of Phenolic Compounds via NMR and UHPLC-HR MS/MS.

Health-oriented preferences, a demand for innovative food concepts, and technological advances have greatly influenced changes in the food industry and led to remarkable development of the functional food market. Incorporating herbal extracts as a rich source of bioactive compounds (BC) could be an effective solution to meet the high demand of consumers in terms of expanding the high-quality range of functional foods. The aim of this study is the valorization of the bioactive potential of T. montanum L., an understudied Mediterranean plant species, and the in-depth elucidation of a polyphenolic profile with a UHPLC-HR MS/MS and NMR analysis. The total phenolic content (TPC) and antioxidant capacity (AC) were determined on heat-assisted (HAE), microwave-assisted (MAE) and subcritical water (SWE) extracts. In terms of antioxidant capacity, SWE extracts showed the most notable potential (ABTS: 0.402-0.547 mmol eq Trolox g-1 dw, DPPH: 0.336-0.427 mmol eq Trolox g-1 dw). 12 phenolic compounds were identified in the samples of T. montanum from six microlocations in Croatia, including nine phenylethanoid glycosides (PGs) with total yields of 30.36-68.06 mg g-1 dw and 25.88-58.88 mg g-1 dw in HAE and MAE extracts, respectively. Echinacoside, teupolioside, stachysoside A, and poliumoside were the most abundant compounds HAE and MAE extracts, making T. montanum an emerging source of PGs.

Green Synthesis of ZnO and Black TiO2 Materials and Their Application in Photodegradation of Organic Pollutants.

ZnO and black TiO2 have been selected as the most efficient materials for organic pollution abatement due to their increased efficiency when compared to other materials. However, the concept of green chemistry makes it desirable to design green synthesis approaches for their production. In this study, black TiO2 was synthesized using an environmentally safe synthetic technique with glycerol as a reductant. ZnO was prepared by using ionic-liquid-based microwave-assisted extracts of Polygonum minus. To investigate the materials' potential to photodegrade organic pollutants, methylene blue (MB) and phenol were chosen as model organic pollutants. Both materials were found to exhibit spherical morphologies and a mesoporous structure and were efficient absorbers of visible light. ZnO exhibited electron-hole pair recombination lower than that of black TiO2. Black TiO2 was discovered to be an anatase phase, whereas ZnO was found to have a hexagonal wurtzite structure. In contrast to black TiO2, which had a surface area of 239.99 m2/g and a particle size of 28 nm, ZnO had a surface area of 353.11 m2/g and a particle size of 32 nm. With a degradation time of 60 min, ZnO was able to eliminate 97.50% of the 40 mg/L MB. Black TiO2, on the other hand, could reduce 90.0% of the same amount of MB in 60 min. When tested for phenol degradation, ZnO and black TiO2 activities were reduced by nearly 15 and 25%, respectively. A detailed examination of both ZnO and black TiO2 materials revealed that ZnO has more potential and versatility for the degradation of organic pollutants under visible light irradiation.

Effect of Microwave and Ultrasound-Assisted Extraction on the Phytochemical and In Vitro Biological Properties of Willow (Salix alba) Bark Aqueous and Ethanolic Extracts.

White willow (Salix alba) is a medicinal plant used in folk medicine. In this study, aqueous and ethanolic willow bark extracts were obtained via ultrasonic-assisted extraction (UAE) and microwave-assisted extraction (MAE), and analyzed regarding their phytochemical (total phenolics, phenolic acids, flavonoids, and tannins) content and in vitro biological properties (antibacterial and antifungal activity, acetylcholinesterase AChE inhibitory activity and anti-inflammatory effects). The highest phenolic, tannin, and flavonoid contents were found for willow bark extracts obtained via microwave-assisted extraction using ethanol as a solvent (SA-ME). The polyphenol load of all MAE and UAE extracts was higher when conventional solid-liquid extraction was applied (ρ < 0.05). The antioxidant capacities were stronger for microwave-assisted ethanolic extracts, with the lowest IC50 values of 12 μg/mL for DPPH• and a value of 16 μg/mL for ABTS•+, whereas the conventional extraction had the highest IC50 values (22 μg/mL and 28 μg/mL, respectively). Willow bark extract showed antibacterial activity against Gram-positive bacteria S. aureus and P. aeruginosa. AChE inhibitory activity was dependent on the extraction method and solvent used, and the highest inhibition among samples was observed for SA-ME. Taken altogether, our findings suggest that willow (Salix alba) bark extract obtained via ethanolic microwave-assisted extraction is a phytochemical-rich resource with in vitro, anti-inflammatory, and AchE inhibitory properties and, therefore, potential multiple medicinal end-uses.

A Bioactive Compound-Loaded Zinc-Aminoclay Encapsulated, Pickering Emulsion System for Treating Acne-Inducing Microbes.

Acne is a common skin condition caused by the growth of certain bacteria. Many plant extracts have been investigated for their potential to combat acne-inducing microbes, and one such plant extract is microwave-assisted Opuntia humifusa extract (MA-OHE). The MA-OHE was loaded onto zinc-aminoclay (ZnAC) and encapsulated in a Pickering emulsion system (MA-OHE/ZnAC PE) to evaluate its therapeutic potential against acne-inducing microbes. Dynamic light scattering and scanning electron microscopy were used to characterize MA-OHE/ZnAC PE with a mean particle diameter of 353.97 nm and a PDI of 0.629. The antimicrobial effect of MA-OHE/ZnAC was evaluated against Staphylococcus aureus (S. aureus) and Cutibacterium acnes (C. acnes), which contribute to acne inflammation. The antibacterial activity of MA-OHE/ZnAC was 0.1 and 0.025 mg/mL to S. aureus and C. acnes, respectively, which were close to naturally derived antibiotics. Additionally, the cytotoxicity of MA-OHE, ZnAC, and MA-OHE/ZnAC was tested, and the results showed that they had no cytotoxic effects on cultured human keratinocytes in a range of 10-100 μg/mL. Thus, MA-OHE/ZnAC is suggested to be a promising antimicrobial agent for treating acne-inducing microbes, while MA-OHE/ZnAC PE is a potentially advantageous dermal delivery system.

A new strategy to achieve high antimicrobial activity: green synthesised silver nanoparticle formulations with Galium aparine and Helichrysum arenarium.

Silver nanoparticles (AgNPs), which have recently gained attention due to their antimicrobial activity, can also be produced by green synthesis. The aims of this study were to (i) characterise green synthesized AgNPs using microwave-assisted aqueous extracts of Galium aparine (G-AgNPs) and Helichrysum arenarium (H-AgNPs) and (ii) investigate the combined antimicrobial effects of the G- and H-AgNPs in different ratios. Nanoparticle formation and reactions were determined with UV-Vis spectroscopy. The G-AgNPs were 52.0±10.9 nm in size, with a 0.285±0.034 polydispersity index (PDI), and a -17.9±0.9 mV zeta potential. For H-AgNPs these characteristics were 23.9±1.0 nm, 0.280±0.032, and -21.3±2.7 mV, respectively. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirmed that the particles were monodisperse and spherical. The Fourier transform-infrared spectroscopy (FT-IR) results showed the presence of reducing agents that stabilised the AgNPs. Three different nanoformulations (NF-1, NF-2, and NF-3) were prepared by combining these two synthesised nanoparticles in different ratios and their antimicrobial activity was tested against E. coli, S. aureus, C. albicans, and A. flavus. Our study is the first to show that combining AgNPs from two different biological sources can produce effective nanoformulations with improved antibacterial activity against E. coli and S. aureus. These nanoformulations showed lower minimum inhibitory concentrations (31.25 µg/mL against E. coli with all NFs; 62.5 µg/mL for NF-1 and 125 µg/mL for NF-2/3 against S. aureus) than G-AgNPs (62.5 µg/mL for E. coli) or H-AgNPs (125 µg/mL for S. aureus) alone. Their high combined inhibitory effect against E. coli (NF-1-3) was synergistic and against S. aureus (NF-2 and NF-3) potentially additive. Considering such promising results, we believe our study provides some direction for new research and strategies in antimicrobial therapeutics.

Microwave-assisted extract of rhodomyrtone from rhodomyrtus tomentosa leaf: Anti-inflammatory, antibacterial, antioxidant, and safety assessment of topical rhodomyrtone formulation

ABSTRACT Series of works on the biological properties of rhodomyrtone, a major active component of Rhodomyrtus tomentosa leaf has been reported. In this study, rhodomyrtone-rich microwave-assisted extract from R. tomentosa leaf (RT-MAE) before formulation was profiled for phytochemical composition using gas chromatography-mass spectrometry (GC-MS) and targeted for anti-inflammatory activity with topical application. The formulation was assessed for bioactivity, biocompatibility, and safety on human volunteers. The GC-MS spectra indicated a rich content of phytosterols, sesquiterpenes, and acylphloroglucinols. At concentrations 50–600 ng/mL, RT-MAE before formulation treated macrophages showed >86% cell viability. Nitric oxide production significantly decreased by 19.26–88.36% following the treatment with 50–600 ng/mL RT-MAE before formulation (p < 0.001). Moreover, a significant (p < 0.01) concentration-dependent downregulation of lipopolysaccharide-induced IL-6, IL-1β, iNOS, and COX-2 mRNA was observed in RT-MAE before formulation treated macrophages. The extract demonstrated minimum inhibitory (MIC) and minimum bactericidal concentration (MBC) at 0.25–4 and 1–16 μg/mL, respectively. The antioxidant activity of RT-MAE before formulation indicated IC50 of 0.16 and 0.06 ug/mL for DPPH and ABTS assays, respectively. Ex-vivo diffusion of rhodomyrtone from formulation showed steady-state flux 64.935 ng/cm2 h, with >80% viability on HaCaT cells. Safety assessment of formulation containing RT-MAE after formulation was conducted on healthy volunteers. Hematological and biochemical analysis showed no significant difference between test and baseline (p < 0.05). The results suggested that the formulation can be effectively employed as a topical inflammatory agent.

Microwave-assisted sustainable exploration of cocklebur leaves (Xanthium strumarium L.) as a novel source of distinct yellow natural colorant for dyeing cotton fabric.

During current times, the use of bio-colorants attained public acceptance as a sustainable alternative to synthetic ones which in turn reduced the environmental contamination. The present study focused on the green, safe, and clean technology for the resurgence of natural colorant from cocklebur (Xanthium strumarium L.) leaves and their application to cotton fabric. Natural colorants were extracted by employing an eco-friendly microwave-assisted extraction process using an aqueous and alkaline medium. Dyeing of cotton fabric was carried out using irradiated and unirradiated cotton fabric with irradiated and unirradiated natural dyes of cocklebur leaves. The results of extraction experiments revealed that 4min microwave-assisted alkaline extract exhibited significantly outstanding color strength onto microwave-treated cotton fabric compared to aqueous one. Further to investigate the optimum dyeing conditions for cotton fabric, various dyeing variables such as dyeing time, dyeing temperature, dye concentration, and exhausting agent were monitored and found a superior result using a dye concentration of 45ml, for dyeing cotton fabric at 75°C for 50min in the presence of 4g/100ml of table salt. For improvement in color strength and color fastness properties, the effects of various bio-mordants, such as eucalyptus bark, acacia bark, turmeric rhizome, and onion shells, and chemical mordants (aluminum and copper) on dyed cotton fabric were also evaluated. It was also observed that cotton fabric dyed with alkaline extract of cocklebur leaves using bio-mordants as pre-mordants (4% acacia, 4% eucalyptus, 2% onion) and post-mordants (3% onion, 3% eucalyptus, 4% acacia) exhibited the highest color strength and various hues with acceptable colorfastness properties against light, washing, and rubbing in comparison to chemical mordants. The ISO standard for fastness also revealed that bio-mordanting has enhanced the rating from good to excellent in comparison to chemical mordants. The results provide ample scope for the extraction of yellow natural dye from the cocklebur leaves for eco-friendly coloration of fabrics using bio-mordants.

Microwave- and Ultrasound-Assisted Extraction of Cannabinoids and Terpenes from Cannabis Using Response Surface Methodology.

Limited studies have explored different extraction techniques that improve cannabis extraction with scale-up potential. Ultrasound-assisted and microwave-assisted extraction were evaluated to maximize the yield and concentration of cannabinoids and terpenes. A central composite rotatable design was used to optimize independent factors (sample-to-solvent ratio, extraction time, extraction temperature, and duty cycle). The optimal conditions for ultrasound- and microwave-assisted extraction were the sample-to-solvent ratios of 1:15 and 1:14.4, respectively, for 30 min at 60 °C. Ultrasound-assisted extraction yielded 14.4% and 14.2% more oil and terpenes, respectively, compared with microwave-assisted extracts. Ultrasound-assisted extraction increased cannabinoid concentration from 13.2-39.2%. Considering reference ground samples, tetrahydrocannabinolic acid increased from 17.9 (g 100 g dry matter-1) to 28.5 and 20 with extraction efficiencies of 159.2% and 111.4% for ultrasound-assisted and microwave-assisted extraction, respectively. Principal component analyses indicate that the first two principal components accounted for 96.6% of the total variance (PC1 = 93.2% and PC2 = 3.4%) for ultrasound-assisted extraction and 92.4% of the total variance (PC1 = 85.4% and PC2 = 7%) for microwave-assisted extraction. Sample-to-solvent ratios significantly (p &lt; 0.05) influenced the secondary metabolite profiles and yields for ultrasound-assisted extracts, but not microwave-assisted extracts.

Metabolite Profiling of Microwave-Assisted Sargassum fusiforme Extracts with Improved Antioxidant Activity Using Hybrid Response Surface Methodology and Artificial Neural Networking-Genetic Algorithm.

Sargassum fusiforme (SF) is a popular edible brown macroalga found in Korea, Japan, and China and is known for its health-promoting properties. In this study, we used two sophisticated models to obtain optimized conditions for high antioxidant activity and metabolite profiling using high-resolution mass spectrometry. A four-factor central composite design was used to optimize the microwave-assisted extraction and achieve the maximum antioxidant activities of DPPH (Y1: 28.01 % inhibition), ABTS (Y2: 36.07 % inhibition), TPC (Y3: 43.65 mg GAE/g), and TFC (Y4: 17.67 mg CAE/g), which were achieved under the optimized extraction conditions of X1: 47.67 %, X2: 2.96 min, X3: 139.54 °C, and X4: 600.00 W. Moreover, over 79 secondary metabolites were tentatively identified, of which 12 compounds were reported for the first time in SF, including five phenolic (isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoate, 3,4-dihydroxyphenylglycol, scopoletin, caffeic acid 4-sulfate, and cinnamoyl glucose), two flavonoids (4',7-dihydroxyisoflavone and naringenin), three phlorotannins (diphlorethohydroxycarmalol, dibenzodioxin-1,3,6,8-tetraol, and fucophlorethol), and two other compounds (dihydroxyphenylalanine and 5-hydroxybenzofuran-2(3H)-one) being identified for the first time in optimized SF extract. These compounds may also be involved in improving the antioxidant potential of the extract. Therefore, optimized models can provide better estimates and predictive capabilities that would assist in finding new bioactive compounds with improved biological activities that can be further applied at a commercial level.

Guaianolide Derivatives from the Invasive Xanthium spinosum L.: Evaluation of Their Allelopathic Potential.

Ziniolide, xantholide B (11α-dihydroziniolide), and 11β-dihydroziniolide, three sesquiterpene lactones with 12,8-guaianolide skeletons, were identified as volatile metabolites from the roots of Xanthium spinosum L., an invasive plant harvested in Corsica. Essential oil, as well as hydrosol and hexane extracts, showed the presence of guaianolide analogues. The study highlights an analytical strategy involving column chromatography, GC-FID, GC-MS, NMR (1D and 2D), and the hemi-synthesis approach, to identify compounds with incomplete or even missing spectral data from the literature. Among them, we reported the 1H- and 13C-NMR data of 11β-dihydroziniolide, which was observed as a natural product for the first time. As secondary metabolites were frequently involved in the dynamic of the dispersion of weed species, the allelopathic effects of X. spinosum root's volatile metabolites were assessed on seed germination and seedling growth (leek and radish). Essential oil, as well as hydrosol- and microwave-assisted extracts inhibited germination and seedling growth; root metabolite phytotoxicity was demonstrated. Nevertheless, the phytotoxicity of root metabolites was demonstrated with a more marked selectivity to the benefit of the monocotyledonous species compared to the dicotyledonous species. Ziniolide derivatives seem to be strongly involved in allelopathic interactions and could be the key to understanding the invasive mechanisms of weed.

In Vitro and In Vivo Antidiabetic Activity, Phenolic Content and Microscopical Characterization of Terfezia claveryi.

Terfezia claveryi (T. claveryi) is used by traditional healers in the Middle East region to treat several diseases, including diabetes. The present study evaluated the total phenolic and investigated the blood-glucose-lowering potential of different aqueous extracts of this selected truffle using in vitro and in vivo models. The phytochemical profile was examined using UPLC-MS. The macerate and the microwave-assisted extract were the richest in phenolic compounds. All T. claveryi extracts exhibited a remarkable α-glucosidase inhibitory effect in vitro, with an IC50 of 2.43, 3.26, 5.18 and 3.31 mg/mL for the aqueous microwave-assisted extract macerate, infusion and decoction, respectively. On the other hand, in the high-fat diet alloxan-induced diabetic mice model, all tested crude aqueous extracts exhibited a significant antihyperglycemic activity (p < 0.05). Four hours after the administration of the 250 mg/kg dose, the macerate was able to induce a 29.4% blood-glucose-lowering effect compared to a 24.8% reduction induced by the infusion, which was sustained for a further two hours. The hypoglycemic effect (29.3% and 32.4%) was also recorded six hours after the administration of the single dose 500 mg/kg of the macerate and the infusion, respectively. Truffle extracts exhibited antidiabetic activity both in vitro and in vivo, providing a rationale for the traditional use as a natural hypoglycemic.

Microwave-Assisted Dendropanax morbifera Extract for Cosmetic Applications

Recently, utilizing natural bioactive compounds for active ingredients in cosmetics has become a growing worldwide trend. More and more studies aim to identify the sources of herbal ingredients for applications in the pharmaceutical and cosmetic fields. Additionally, in order to optimize the safety of natural ingredients, choosing an environmentally friendly extraction method also plays an important role. In this work, an eco-friendly extraction technique for Dendropanax morbifera using microwave treatment and microwave-assisted Dendropanax morbifera extract (MA-DME) was investigated. The results indicate that higher yields of MA-DME were obtained than with conventional methods and that D. morbifera’s antioxidant properties were enhanced. Moreover, we found that MA-DME exhibited extraordinary antioxidant, anti-aging, and skin-whitening activities. We suggest MA-DME as a potential cosmeceutical ingredient than could be utilized for comprehensive protection of human skin.

In Vitro Inhibitory and Proliferative Cellular Effects of Different Extracts of Struthanthus quercicola: A Preliminary Study.

Struthanthus quercicola, a hemiparasitic plant known as “seca palo,” is used by Nahuatl traditional healers against diabetes, wounds, and rashes. We aimed to investigate the effects of different S. quercicola extracts, which were selected based on their traditional use in Tamazunchale, San Luis Potosí, on the cell viability and antioxidant activity in HeLa cell cultures. S. quercicola growing on Guazuma ulmifolia and Citrus sp. hosts was collected, and methanolic and ethanolic extracts as well as decoctions, infusions, and microwave-assisted extracts were obtained. The terpenoid, alkaloid, flavonoid, saponin, and tannin contents of each extract were evaluated qualitatively and quantitatively. The effects of different extracts on the viability of cervical adenocarcinoma (HeLa) cells were tested using an MTT assay. The differences in the total flavonoid and phenolic contents and free-radical scavenging activity in relation to the host and the extract were also determined. In assessments of the effects of the extracts on cell viability, eight organic extracts (4 from G. quercicola grown on Host 1 and 4 from G. quercicola grown on Host 2) were shown to decrease cell viability significantly in comparison with the control. However, the extract obtained by percolation (PMeOH) caused a significant increase in cell viability (p < 0.05), especially with the plant grown on Host 1. The microwave aqueous and methanolic extracts of the plants grown on both hosts showed a significant increase in the percentage of apoptosis (p < 005). In conclusion, different extracts of Struthanthus quercicola showed variable effects on cell viability and apoptosis. Isolation of the molecule or molecules with inhibitory and proliferative effects on cells should be conducted to evaluate their possible use as antineoplastic agents.

Ultrasound-Assisted and Microwave-Assisted Extraction, GC-MS Characterization and Antimicrobial Potential of Freeze-dried L. camara Flower

Lantana camara is known to have anti-bacterial properties which can be exploited to develop a natural food preservative. There is huge demand for natural preservatives in food industry due to the increased health risks associated with synthetic preservatives, development of effecient extraction methods are essential to retain heat sensitive bioactive compounds. This aim of this study was to compare the performance of microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and conventional solvent extraction (CSE) methods for extraction of freeze-dried lantana flower. The phytochemicals in freeze-dried flowers were characterized by GC-MS analysis and antibacterial properties were tested at different concentrations (50, 100, and 150 µl) against E.coli, Salmonella, and S. aureus. It was evident that the UAE offered the highest yield (64%), followed by MAE (53%) and CSE (49%) with distilled water as solvent. The freeze-dried extract possessed a high amount of tannins (417 µg/g), followed by flavonoids such as catechol (88 µg/g) and quercetin (9.2 µg/g). The antibacterial potential results revealed that only distilled water-based extraction techniques offered positive inhibition zones of 2.0-2.67 mm (MAE), 1.67-2.67 mm (UAE), and 1.67-2.17 mm (CSE) against all three organisms, while the chloroform based extracts had no inhibition effect. The microwave-assisted extract at 150 µl concentration offered a significant inhibitory effect against all three pathogens. The GC-MS profiling of bioactive compounds in flower extract revealed the presence of hexadecanoic acid as the major phytochemical compound in all three extraction techniques. The study revealed that the chloroform extract failed to exhibit an antibacterial effect due to the absence of alkaloids, saponins, and anthraquinones as a result of its neutralizing effect.