Search Results (333)

Aizoon africanum (L.) Klak (Synonym Galenia africana L.) is traditionally used for a variety of medicinal purposes; however, it has been reported to cause liver damage and severe ascites, particularly in sheep and Angora goats in the arid regions of the Western Cape. This study explores its cytotoxic properties to identify potential cytotoxic compound(s) in the plant. The methanolic extract of A. africanum was re-investigated and subjected to various chromatographic techniques, including preparative HPLC, resulting in the isolation of eight compounds (1–8). Structural elucidation was primarily based on NMR data. Among the isolated compounds, four were flavanones, one was a flavonone, and three were chalcones. Notably, compound 8 was identified as a new chalcone, while compounds 2 and 3 were reported for the first time from this plant. The toxicity of these isolated compounds was evaluated against the HepG2 and SH-SY5Y cancer cell lines using the MTT assay. We further investigated markers of cell death using spectrophotometric and luminometric methods. Among the isolated compounds, 7 and 8 exhibited cytotoxic activities within the range of 3.0–20.0 µg/mL. Notably, the compounds demonstrated greater cytotoxicity towards liver-derived HepG2 cells compared to the neuronal SH-SY5Y cell line. Compound 7 (2′,4′-dihydroxychalcone) was identified as inducing apoptosis through the intrinsic pathway without causing overt necrosis. The findings indicate that the phytochemicals derived from A. africanum exhibit differential cytotoxic effects based on cell type, suggesting potential for developing novel anticancer agents, particularly compound 7. Additionally, the identification of compound 8 provides insight into the liver toxicity of this plant observed in sheep in South Africa. Full article

Volcanic rock is a natural mineral material which has garnered interest for its potential application in water treatment due to its unique physicochemical properties. In this study, we prepared a polysilicate aluminum chloride (PSAC) coagulant using volcanic rock which exhibited good coagulation–flocculation performance. Further investigation into the influence of synthetic parameters, such as calcination temperature, reaction time, and alkali types, on the structure and performance of a volcanic rock-derived coagulant was conducted. Techniques including Scanning Electron Microscopy, Energy-Dispersive Spectroscopy, Fourier-Transform Infrared Spectroscopy, and X-Ray Diffraction were utilized to characterize it. Also, a ferron-complexation timed spectrophotometric method was used to study the distribution of aluminum species in the coagulant. Results indicated that the volcanic rock that was treated with acidic and alkaline solutions had the potential to form PSAC with Al-OH, Al-O-Si, Fe-OH, and Fe-O-Si bonds, which influenced the coagulation–flocculation efficiency. An acid leaching temperature of 90 °C, 8 mL of 2 mol/L NaOH, a reaction time of 0.5 h, and a reaction temperature of 60 °C were conducive to the preparation. A higher temperature could result in a higher proportion of Alb species, and, at 100 °C, the Ala, Alc, and Alb were 29%, 24%, and 47%, respectively, achieving a residual turbidity lower than 1 NTU at an appropriate dosage, as well as a reduction of over 0.1 to 0.018 in the level of UV₂₅₄. The findings of this study provide a feasible method to prepare a flocculant using volcanic rock. Further application is expected to yield good results in wastewater/water treatment. Full article

Tanacetum parthenium (Asteraceae) has been traditionally used worldwide for medicinal purposes, and some of its therapeutic uses have been attributed to the pharmacological effects of its secondary metabolites. The root culture of this species might represent a sustainable source of several pharmacologically active compounds. The biomass of a root T. parthenium culture was extracted with methanol and fractionated using column chromatography. Three selected fractions (4TP, 5TP, and 8TP) were analyzed via spectrophotometric, chromatographic, and mass spectrometry techniques and in vitro pharmacological assays. The greatest values for total phenolic and phenolic acid contents and antibacterial activity against Escherichia coli were determined for 4TP. The highest values for total flavonoid and sesquiterpene lactone contents, antioxidant potential, and α-amylase inhibitory effect were determined for 8TP. The antibacterial effect against Staphylococcus aureus was not significantly different among the three fractions. The root culture of T. parthenium is a potential source of several metabolites, such as phenolic acids, fatty acids, coumarins, sesquiterpenoids, and triterpenoids, which are capable of exerting α-amylase inhibition and antioxidant, antibacterial, and cytotoxic effects. Among eight phenolic compounds detected and quantified in the fractions, chlorogenic acid was the most abundant. Full article

To overcome the complexity of yarn color measurement using spectrophotometry with yarn winding techniques and to enhance consistency with human visual perception, a yarn color measurement method based on digital photography is proposed. This study employs a photographic colorimetry system to capture digital images of single yarns. The yarn and background are segmented using the K-means clustering algorithm, and the centerline of the yarn is extracted using a skeletonization algorithm. Spectral reconstruction and colorimetric principles are then applied to calculate the color values of pixels along the centerline. Considering the nonlinear characteristics of human brightness perception, the final yarn color is obtained through a nonlinear texture-adaptive weighted computation. The method is validated through psychophysical experiments using six yarns of different colors and compared with spectrophotometry and five other photographic measurement methods. Results indicate that among the seven yarn color measurement methods, including spectrophotometry, the proposed method—based on centerline extraction and nonlinear texture-adaptive weighting—yields results that more closely align with actual visual perception. Furthermore, among the six photographic measurement methods, the proposed method produces most similar to those obtained using spectrophotometry. This study demonstrates the inconsistency between spectrophotometric measurements and human visual perception of yarn color and provides methodological support for developing visually consistent color measurement methods for textured textiles. Full article

Dragon fruit peel is a by-product rich in bioactive compounds, such as polyphenols and betalains. In this study, ultrasound-assisted enzyme extraction (UAEE) was proposed to exploit this, combining the advantages of the enzymatic hydrolysis and ultrasound extraction. The effect of extraction time, temperature, and enzyme quantity were evaluated using a Box–Behnken design. Total betalains and polyphenol contents were determined spectrophotometrically. The results show that the extraction of total polyphenols was significantly affected (p ≤ 0.05) by the enzyme quantity, while temperature had a significant effect (p ≤ 0.05) on the extracted betalains. The optimal conditions for the extraction of total betalains and polyphenols were a temperature of 20 °C, an extraction time of 20 min, and an enzyme/substrate ratio of 400 mg/g. Under optimized conditions, the extraction efficiency reached 565.6 ± 12.9 µg/g for total betalains and 14.9 ± 2.4 mg/g for total polyphenols. In addition, UAEE showed the best extraction yields compared to other methodologies, such as microwave, ultrasound, and enzymatic hydrolysis extraction (p ≤ 0.05). This study helps us to understand how the temperature, time, and amount of enzymes affect the extraction of total polyphenols and betalains present in the peel of the dragon fruit using the UAEE technique. Full article

Farmers commonly throw away tomato leaves when they harvest tomatoes, although they are a good source of vital biomolecules. ZnO nanoparticles (ZnO NPs) enhance plant growth by regulating abiotic stress and scavenging reactive oxygen species. In the current article, the activities of five antioxidant enzymes—glutathione reductase (GR), peroxidase (POX), glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT)—were determined spectrophotometrically to study the interaction between foliar fertilization of ZnO NPs and salt stress in tomato plants. We employed the next-generation sequencing (NGS) technique to investigate the gene expression. It was also used to generate a de novo supertranscript and then determine the sequences modulated by treatments. Differential expression analysis was used to identify increased and reduced gene clusters, and gene enrichment analysis was used to identify over- and under-expressed genes under the treatment. Gene Ontology (GO) was used to identify the functions and regulatory pathways of the differentially expressed genes (DEGs). It was found that ZnO nanoparticles had the capability to overcome the reduction in antioxidant enzyme production levels in the case of the salinity-stressed treatments and enhance the secretion of those enzymes in the non-stressed but sprayed treatments. The ZnO NPs also enhanced the reduction in stress-responsive genes associated with salt stress resistance. The results revealed the impact of ZnO nanoparticles on alleviating the salinity stress reductive effects in antioxidative enzymes and regulating the mechanism by which metabolically relevant genes adaptively respond to salt stress in tomato plants. So, spraying tomato plants (stressed or not) with ZnO NPs is a promising agricultural technique in improving different metabolic pathways that are responsible for plants’ resistance. Full article

Vegetables are usually thermally processed before consumption to improve their flavor and safety. In this work, the effect of boiling (BO), blanching (BL), steaming (ST), air-frying (AF), and pan-frying (PF)on the nutritional value and bioactivity of broccoli (Brassica oleracea var. italica) heads was investigated, including a comparative analysis of the tissue and the cooking water remaining after the treatments. Using spectrophotometric methods, AF broccoli was found to have the highest levels (p ≤ 0.05) of hydroxycinnamic acids (1.58 ± 0.71 mg CAE/g fw), total glucosinolates (3.76 ± 2.09 mg SinE/g fw), carotenoids (6.73 ± 2.89 mg/kg fw), and lycopene (0.91 ± 0.19 mg/kg fw). Steamed and AF broccoli had the highest total phenolics (0.72 ± 0.12 mg GAE/g fw and 0.65 ± 0.15 mg GAE/g fw, respectively; p ≤ 0.05). ST broccoli also had the highest levels of soluble sugars (11.04 ± 2.45 mg SucE/g fw) and total tannins (0.46 ± 0.19 mg GAE/g fw). The water remaining after cooking broccoli (BOW) had the highest total flavonoids (2.72 ± 0.59 mg QE/g fw) and antioxidant capacity (ABTS and FRAP, 57.57 ± 18.22% and 79.34 ± 3.28%, respectively; p ≤ 0.05). The DPPH assay showed that AF (36.12 ± 15.71%) and ST (35.48 ± 2.28%) had the strongest antioxidant potential. DNA nicking assay showed that BOW and BLW were the most effective in preserving plasmid DNA supercoiled form (99.51% and 94.81%, respectively; p ≤ 0.05). These results demonstrate that thermal processing significantly affects the phytochemical composition and functional properties of broccoli, with steaming and air-frying generally preserving the highest nutritional quality. Additionally, cooking water, often discarded, retains high levels of bioactive compounds and exhibits strong antioxidant and DNA-protective effects. To the best of our knowledge, this is the first study to investigate how different thermal processing techniques of vegetables influence their ability to protect plasmid DNA structure. Furthermore, this is the first study to compare the DNA-protective effects of broccoli tissue extracts and the water remaining after cooking broccoli. Full article

Cannabis (Cannabis sativa L.) contains numerous secondary metabolites with different bioactivities. Extraction methods differ in their efficiency in recovering metabolites from plant material, and thus cannabis extracts vary significantly in their composition and activity. We aimed to develop a repeatable and accurate HPLC-MS method for the determination of nine common cannabinoids and compare two widely used extraction techniques: ultrasound-assisted extraction (UAE) with methanol and supercritical CO₂ extraction (SFE). Inflorescences of the Kompolti cultivar were used as the plant material. On a polar C18 column, more than thirty compounds were well separated within 25 min; thirteen cannabinoids were identified and eight of them were quantified, with cannabidiol and its acidic precursor being the most abundant. Additionally, three spectrophotometric assays were employed for extract characterization: the total phenolic content, total flavonoid content, and DPPH radical scavenging capacity. The SFE extract, obtained using ethanol as a co-solvent under low pressure (<100 bar) and temperature (<45 °C), was more enriched than the UAE extract (181.62 ± 2.90 vs. 140.64 ± 13.24 mg quercetin equivalents/g of dry extract) and cannabinoids (446.29 ± 22.66 vs. 379.85 ± 17.16 mg/g of dry extract), especially cannabinoid acids. However, UAE achieved greater recovery from the plant material (cannabinoids: 83.42 ± 5.15 vs. 68.84 ± 3.49 mg/g of plant material) and showed superior antioxidant capacity (DPPH IC₅₀: 2.50 ± 0.18 vs. 3.37 ± 0.07 mg/mL). Notwithstanding the observed partial decarboxylation, the high repeatability (RSD < 15%, n = 11) of the entire analytical workflow involving UAE extraction and LC-MS analysis renders it suitable for routine analyses. This study contributes to the ongoing efforts toward the quality control and valorization of C. sativa. Full article

Background: The presence of C. perfringens in chicken meat products leads to significant economic losses for the industry and is associated with human food poisoning. It inspires creative answers for novel substances and techniques, such natural antibacterials, for improved prospects in the future. The objective of this study was to examine the antibacterial properties of thymus and star anise extracts for the suppression of Clostridium perfringens in products made from chicken meat. Methods: Thymus and star anise extracts were phytochemically analyzed using the Folin–Ciocalteu spectrophotometric method, High-Performance Liquid Chromatography (HPLC) to determine the phenolic compounds, DPPH to determine the antioxidant activity, and the agar disk diffusion assay to determine the antibacterial effect of the star anise. Following treatment with the mixture extract, an experimental application was conducted on chicken burgers. C. perfringens was also found in poultry samples. Lastly, the sensory evaluation of the chicken burger was detected. Results: The findings showed that Clostridium perfringens was present in a large number of chicken meat products, with a significant concentration in chicken thighs (84%), as well as in the mixture extract has the largest concentration of phytochemical components (TPC:123.88 ± 7.42 mg GAE/g, TFC: 69.04 ± 6.37 mg quercetin/g) with strong antibacterial action (the minimum inhibitory concentration (MIC) of the mixed extract was 3.12 mg/mL, with an inhibition zone of 13.06 ± 0.91 mm). Also, the addition of mix. extract to chicken burgers extends their shelf life, particularly when the mix content is high. Additionally, the mix. extract shows non-significant effect (p < 0.05) on the chicken burger’s sensory qualities. Conclusions: Finally, we can make use of the mix. extract of thymus and star anise as a natural preservative in chicken meat products especially the chicken burger. Full article

Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, synaptic dysfunction, and neuronal loss. Identifying reliable biomarkers for early diagnosis and disease monitoring remains a critical need. Objective: This study aimed to investigate the serum levels of NPAS-4 (Neuronal PAS Domain Protein 4) and NPTX-2 (Neuronal Pentraxin 2) in patients with Alzheimer’s disease, exploring their potential roles in disease pathophysiology and their relationship with lipid parameters. Methods: This was a cross-sectional study that included 63 patients diagnosed with Alzheimer’s disease and 56 age- and sex-matched healthy controls. Venous blood samples were collected from all participants. NPAS-4 and NPTX-2 levels were measured using the ELISA method, while lipid parameters were analyzed via spectrophotometric techniques. Cognitive assessment was performed using the Standardized Mini-Mental Test (SMMT). Comparative analyses between groups, correlation studies, logistic regression, and ROC analyses were conducted. Results: Serum NPAS-4 and NPTX-2 levels were significantly lower in Alzheimer’s patients compared to healthy controls (p < 0.001 and p = 0.001, respectively). Additionally, total cholesterol and LDL levels were lower in the patient group. Logistic regression analysis identified NPAS-4 as an independent risk predictor for Alzheimer’s disease (OR = 0.313, p < 0.001). ROC analyses demonstrated that both biomarkers had significant diagnostic discrimination power. However, no significant correlation was found between NPAS-4 and NPTX-2 levels and SMMT scores or lipid parameters. Conclusions: The decreased levels of NPAS-4 and NPTX-2 in Alzheimer’s patients may reflect biochemical manifestations of impaired synaptic plasticity. These findings suggest that NPAS-4 and NPTX-2 may serve as potential early biomarkers in the diagnosis and monitoring of Alzheimer’s disease. Full article

Spectrophotometric antioxidant assays can generally be divided into two fundamental categories: single electron transfer (SET)-based assays and hydrogen atom transfer (HAT)-based methods. In SET-based assays, the progression of the electron exchange reaction is determined by the redox potential of the substrates. In contrast, HAT-based methods assess the antioxidant’s ability to transfer a hydrogen atom to a radical, thereby stabilizing it. The objective of this article is to provide a critical evaluation of antioxidant spectrophotometric assays. Assessing the antioxidant potential of food should involve multiple assays to ensure accuracy and reliability. A positive correlation among different methods enhances the validity of the results. Moreover, antioxidants may interact with other food components, such as amino acids, potentially leading to inaccurate outcomes—as observed in the Folin–Ciocalteu assay. Among the various techniques, CUPRAC and ORAC exhibit greater repeatability and reagent stability compared to other assays. Furthermore, these methods are considered superior due to their closer resemblance to in vivo conditions. In contrast, approaches such as ABTS⁺, DPPH, FRAP, and Folin–Ciocalteu are often criticized for their non-physiological environments. There is a pressing need to establish a standardized method that, to the greatest extent possible, reflects in vivo conditions and can serve as a reference standard for other assays. Full article

Background: The plant extract of quercetin possesses valuable pharmacological properties. However, its high instability, poor water solubility, and low cell bioavailability has limited its medical applications. An innovative approach used to overcome these limitations is the QUE incorporation in suitable polymer carriers. Methods: In the present study, fibrous materials based on PLA or PLA/PEG loaded with the flavonoid quercetin (QUE) were obtained by the electrospinning technique. Diverse morphological, spectroscopic, physico-mechanical, and spectrophotometric methods were used to characterize the prepared electrospun mats. Results: The addition of hydrophilic PEG to the polymer matrix improved its wettability and assisted the more rapid release of QUE from the PLA/PEG fibrous mat than from the PLA one. The obtained fibrous mats possess good mechanical properties. Moreover, QUE-loaded electrospun mats exhibited high anticancer activity against HeLa cervical cancer cells, but lower toxicity to normal cells. Conclusions: The obtained perspective results revealed the potential of the obtained QUE-loaded materials to find applications for wound healing and cancer treatment. Full article

Honey is a multifaceted substance whose composition is intricately affected by various biotic and abiotic elements generated in the bee colony’s surroundings, including botanical and geographical origins, climatic conditions, soil characteristics, and beekeeping techniques. Monofloral honeys are identified by pollen analysis and are derived from the nectar of a predominant plant species, exhibiting rich sensory and nutritional profiles, making them food matrices with unique characteristics and excellent qualities. To explore the monofloral honey potential harvested in different regions of Portugal, a comprehensive study was conducted including the determination of phenolic composition and the assessment of biological activities. In addition to this evaluation, the inter simple sequence repeat (ISSR) was used to help differentiate honeys by botanical origin. The phenolic content and the antioxidant capacity were evaluated by spectrophotometric methods, observing, in general, differences between monofloral honeys. The honey from Citrus sinensis (Silves) exhibited the lowest phenolic content, including total phenols, ortho-diphenols, and flavonoids, whereas honeydew (Vinhais) showed the highest values. Regarding the antioxidant capacity, honey from Lavandula stoechas (Almodôvar) presented the lowest values, while honeydew (Vinhais) displayed the highest values for both DPPH and FRAP assays. In relation to the ABTS assay, the honey from Metrosideros excelsa (Aveiro) exhibited the lowest values, whereas the honey from Eucalyptus spp. (Arouca) showed the highest. The ISSR marker analysis allows the distribution of the samples based on the honey’s botanical origin, suggesting its potential role in honey authentication. Full article

This review presents an in-depth analysis of the latest methods used for the determination of sucralose (E955), focusing on research conducted over the past 10 years. As a widely used sugar substitute in the food and pharmaceutical industries, sucralose has raised concerns about its environmental persistence, potential genotoxicity, and health impacts. This study examines several spectrophotometric, chromatographic, and electrochemical techniques, evaluating their sensitivity, selectivity, and limitations in differentiating sucralose from natural carbohydrates and other sweeteners. The review highlights the pressing need for novel detection methods that not only improve accuracy in trace detection but also address growing concerns about its bioaccumulation and conversion into harmful metabolites. Advancing these analytical techniques is essential for enhancing food safety, public health surveillance, and environmental risk assessment. Chromatographic methods are dominant in sucralose determination in foods and environmental objects, as they allow the determination of sucralose at micro- and nanomolar levels. However, spectrophotometric and electrochemical methods are frequently used as complementary to chromatographic methodologies, sensitizing them. On the other hand, purely spectrophotometric methods are less popular, and electrochemical methods remain underdeveloped. Therefore, the advancement of sucralose determination must be due to cheaper chromatographic and classical electrochemical methods. Full article

Shea butter (SB) is a raw material fat obtained from Vitellaria paradoxa C.F. Gaertn kernels. We investigated the direct and indirect protective effects of 10 traditional and industrial SBs and their polar extracts on cell-free systems using ABTS and DPPH radical scavenging assays as well as on singlet oxygen (¹O₂) produced by Rose Bengal (RB) photosensitization. Their effects against RB-induced HaCaT cell phototoxicity were also explored. A spectrophotometric assay and HPLC were performed to quantify and identify phenolic content, which was between 14.16 and 82.99 ppm pyrogallol equivalent. These variations could be due to the SB origin and extraction process. These polar fractions exhibited moderate DPPH and strong ABTS radical-scavenging activity. By applying the UV–visible technique, we demonstrated that SBs and their phenolic compounds behave as ¹O₂ quenchers in a dose-dependent manner. Moreover, using a UVR-like model after the irradiation of RB, both polar extracts and crude SB exhibited photoprotective effects, highlighting the indirect protective action. In acellular and cellular models, SB and its polar extracts can act as a free radical scavenger against reactive oxygen species and ¹O₂ quenchers. Due to the maximum absorbance of SB at 280 nm and the antioxidant effect of ¹O₂ quenching, SB polar extracts exhibit photoprotective properties. Full article