Source Of Natural Antioxidants Research Articles

In Vitro Test of Antioxidant Activity of Leilem Leaf Ethanol Extract (Clerodendrum minahassae) Using DPPH and FRAP Methods

The risk of degenerative diseases is increasing due to unhealthy lifestyles. Many people consume junk food, smoke, and do not protect themselves from sun exposure and pollution, exposing their bodies to free radicals. Free radicals can cause oxidative stress, necessitating the need for antioxidants to neutralize them. The leilem plant (Clerodendrum minahassae) is an endemic plant from North Sulawesi that is often used in traditional dishes and medicine. Moreover, leilem leaves are believed to be a source of natural antioxidants. This study aimed to determine the efficacy of leilem leaf ethanol extract as a source of antioxidants. The antioxidant potential was evaluated using phytochemical screening and antioxidant assays such as 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) methods, with ascorbic acid as a comparison. The level of antioxidant activity was measured by determining the IC50 value, which corresponds to the concentration of extract required to inhibit 50% of free radicals. The results of phytochemical screening showed that the ethanol extract of leilem (Clerodendrum minahassae) leaves contains active compounds such as phenols, flavonoids, saponins, tannins, steroids/triterpenoids, and alkaloids, indicating a high potential for antioxidant activity. The IC50 value for the DPPH method was 78.799 ppm, and the IC50 value for the FRAP method was 92.127 ppm. These results demonstrate that the ethanol extract of leilem leaves has strong antioxidant activity in both the DPPH and FRAP methods.

Characterization and antioxidant activity of peel extracts from three varieties of citrus sinensis

High volume of postharvest materials including peels from citrus fruits is periodically generated, which contributes to environmental pollution. Investigating the chemical composition cum antioxidant property of these ‘wastes’ would be instructive in achieving value addition in the food and pharmaceutical value chain. On this premise, this study carried out phytochemical screening and antioxidant activity of three (3) commonly cultivated citrus varieties namely Citrus sinensis ‘valencia’, Citrus sinensis ‘washinton’ and Citrus sinensis ‘thompson navel’. The peels were extracted using ethanol and hexane in a Soxhlet extractor and thereafter subjected to phytochemical and Gas Chromatography/Mass Spectrometry (GC/MS) analyses, ferric ion reducing antioxidant power (FRAP), hydrogen peroxide scavenging and cupric ion reducing antioxidant capacity (CUPRAC) assays to evaluate their antioxidant potentials. Results show that Citrus sinensis peel extracts contain alkaloids, flavonoids, phenols, phytosterols, diterpenes, tannins and glycosides. GC/MS analysis identified about 48 compounds in each extract; with the predominant bioactive compounds being limonene (16.5%), ascorbic acid (17.7%), stearic acid (26.3%), linalool (4.7%), linoleic acid (16.18%), palmitic acid (15.23%), pentadecyclic acid (1.1%). Ethanol and hexane extracts of Valencia exhibited higher FRAP (9.09 ± 0.13) and CUPRAC (2.04 ± 0.06) values while the ethanol extract of Ibadan sweet demonstrated greater hydrogen peroxide scavenging activity (1.39 ± 0.00). Citrus peels are rich in bioactive compounds with excellent antioxidant activity and may serve as potential sources of natural antioxidants for food products or pharmaceutical formulations.

Exploring the Impacts of Angelica purpurascens Extracts on Anticholinergic, Antidiabetic, Antibacterial Potential, and Antioxidant Capacity

In Kars-Sarıkamış-Soğanlı, Angelica purpurascens (A. purpurascens) emerges as a promising natural antioxidant source. Extracts from its leaves, branches, and flowers underwent thorough bioanalytical assessments. The leaf extract exhibited the highest concentrations of herbal flavonoids (45.22 µg QE/mg extract) and total phenolics (28.96 µg GAE/mg extract). Branch extracts demonstrated significant enzymatic activity against AChE and BChE with IC50 values of 37.26 mg/mL and 9.08 mg/mL respectively. The flower extract displayed notable antibacterial properties. This study sheds light on the therapeutic potential of A. purpurascens ethanol extracts, suggesting benefits for Alzheimer’s, cell damage-induced diseases, and diabetes mellitus. It pioneers new enzymatic and antioxidant insights and contributes to understanding this abundant Türkiye species. A. purpurascens holds promise for pharmaceutical exploration, offering potential solutions for challenging health conditions

Effect of regional disparities and solvent variations on the phenolic composition, antioxidant activity, and antibacterial efficacy of Cupressus sempervirens extracts

ABSTRACT The ethyl acetate, ethanol, methanol, and water extracts of cypress from three Tunisian regions (Bizerte, Ben Arous, and Nabeul) were reported for their phenolic content, antioxidant, and antibacterial activities. Cypress extract had an important antiradical and antibacterial potential which was strongly related to the organoleptic quality of the extract which appeared strongly region dependent. The highest contents of polyphenols were obtained in the methanol extract at the region of Bizerte (315.75 mg GAE/g DW). Cupressuflavone was the major compound with high proportions in methanol extract of Bizerte (68%). Amentoflavone also constituted an important flavonoid compound presented in higher proportion in the ethyl acetate extract of Ben Arous (21.2%). For Gram-positive bacteria strains, Staphylococcus aureus was sensitive to the ethanol extract of Nabeul with IZ = 40 mm. This study suggests cypress as potential natural source of antioxidants and antibacterial agents.

Effect of Dietary Incorporation of Hemp Seeds Alone or with Dried Fruit Pomace on Laying Hens' Performance and on Lipid Composition and Oxidation Status of Egg Yolks.

The present study was conducted to investigate the effects of introducing hemp seeds, as a source of PUFAs, into a standard diet with or without dried fruit pomace (dried blackcurrant (DB) or dried rosehip (DR)), as a source of natural antioxidants, on the laying performance of hens and the FA profile, cholesterol level, antioxidant content, and lipid oxidative status in the yolks of fresh eggs or eggs stored at 4 °C for 28 days. The experiment used 128 Tetra SL hens at 35 weeks of age, which were divided into four groups and randomly assigned to four dietary treatments: a standard corn-wheat-soybean meal diet (C), standard diet containing 8% ground hemp seed (H), hemp seed diet containing 3% dried blackcurrant pomace (HB), and hemp seed diet containing 3% dried rosehip pomace (HR). The laying rate, feed conversion ratio (FCR), egg weight, and yolk weight were improved by the use of hemp seeds. The yolks of the H, HB, and HR eggs had a lower cholesterol (p ˂ 0.01) and SFA content, while the concentration of total and individual PUFAs (n-6 and n-3 FAs) was significantly higher (p ˂ 0.01) compared to C. In addition, the introduction of hemp seeds into the diets alone or with dried fruit pomace (DB or DR) led to increased (p ˂ 0.001) content of α-linolenic acid (ALA, 18:3n-3), eicosapentaenoic acid (EPA, 20:5n-3), and docosahexaenoic acid (DHA, 22:6n-3) and hypo-/hypercholesterolemic FA ratio and decreased arachidonic acid (AA, 20:4n-6) content, n-6/n-3 ratio, and thrombogenicity index (TI) compared to the control eggs. The introduction of dried fruit pomace (DB or DR) into the diets had no effect on the laying performance of the hens or the cholesterol content and FA profile of the egg yolks, compared to the diet supplemented only with hemp seeds. The dried fruit pomace improved the color, accumulation of antioxidants, and oxidative stability of fats in the yolks of the fresh eggs and eggs stored at 4 °C for 28 days. The DR was found to have the most desirable effects, producing the most intense color of egg yolks, the highest content of natural antioxidants, and the best oxidative stability of yolk lipids.

Biochemical analysis of Justicia carnea leaves used as a hematinic

Justicia carnea is the largest genus of Acanthaceae and is a medicinal plant used widely in Nigeria, reported to have diverse functions, including blood-boosting potential. The phytochemicals, vitamins, minerals, amino acid and proximate compositions of the leaf extract of Justicia carnea were determined using standard methods. Results of the quantitative phytochemical analyses on the leaves of Justicia carnea recorded appreciable presence of flavonoids, alkaloids, saponins, tannins, cyanogenic glycosides, oxalate, and phytate using GC-FID. Ribalinidine with 42.08±0.03 mg/kg was the highest alkaloid, Flavan -3-ol was 21.18±0.02 mg/kg, presented the highest amount of flavonoids, and phytate with 25.69±0.07 mg/kg as the highest antinutrient. Analysis of Justicia carnea leaves recorded iron (8.61mg/kg) as the major elemental content followed by potassium (5.29±0.11mg/kg). The concentrations of vitamins in Justicia carnea leaves showed vitamin C, with the highest value of (232.32±12.26 mg/100g) followed by Vitamin A (22.16±2.12 mg/kg). The results of proximate composition on Justicia carnea leaves showed a high concentration of carbohydrate (60.35±3.05%) and appreciable amounts of ash (15.02±1.01%), fibre (9.29±0.93%), protein (8.40±0.41%), and low amount of lipid (1.50±0.09%). The amino acid results showed the presence of both essential and non-essential amino acids with their concentrations in increasing and decreasing orders. These results obtained showed that leaves of Justicia carnea may serve as rich source of natural antioxidants, this may be attributed to its rich phytochemicals, nutrients and vitamin compositions and could be recommended as a potential source of useful bioactive constituents as vegetable supplement and has no toxic effect and as an effective hematinic supplement when prepared adequately.

Phenolic composition and bioactivities of sea buckthorn (Hippophae rhamnoides L.) fruit and seeds: an unconventional source of natural antioxidants in North America.

Sea buckthorn (Hippophae rhamnoides L.) was introduced into Canada in the early 2000s. This plant bears fruits with high commercial value in other countries due to its premium oil. Nevertheless, sea buckthorn berries are also a rich source of bioactives with nutraceutical potential, especially the variety grown in Newfoundland (Canada), which has not previously been characterized. As such, this study evaluated the composition of polyphenols in sea buckthorn pomace and seeds, as well as their prospective health-promoting effects. Polyphenolic identification by high-performance liquid chromatography-ultraviolet-mass spectrometry-time of flight revealed the presence of 24 compounds in the seeds and 16 compounds in the pomace, including phenolic acids, flavonoids, and tannins, with ellagic acid derivative IV (pomace, 52.13 μg g-1) and (+)-catechin (seeds, 690.8 μg g-1) being the most dominant. Sea buckthorn extracts displayed in vitro antidiabetic and anti-obesity potential by inhibiting α-glucosidase (71.52-99.31%) and pancreatic lipase (15.80-35.61%) enzymes, respectively. The extracts also protected low-density-lipoprotein cholesterol (50.97-89.67%) and supercoiled DNA (35.11-79.84%) from oxidative damage. Sea buckthorn berries grown in Canada showed promising health benefits induced by their rich and diverse polyphenolic profile and need to be considered for further commercial expansion as a bioactive-loaded superfruit. © 2024 Society of Chemical Industry.

Chemical profiling of endangered Citrus macroptera leaf extracts and evaluation of its cytotoxic activity

The main component of drug production and formulation, with minimal to no adverse effects, is plant-based medicine. Citrus macroptera is an endangered species of North-Eastern India and has a diverse array of pharmaceutical applications owing to the presence of several bioactive compounds. The study aimed to evaluate the presence of bioactive metabolites, antioxidants, and cytotoxic mechanisms of the in vitro and ex-vitro leaf extracts of C.macroptera. Gas chromatography–mass spectrometry (GC-MS) profiling was performed using the ethanolic leaf extracts. Methanolic and aqueous extracts were profiled using High-performance thin-layer chromatography (HPTLC). Moreover, the cytotoxicity of the methanolic leaf extracts was assessed using the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test against SH-SY5Y, human neuroblastoma cell lines. GC-MS analysis revealed the existence of numerous pharmacologically significant components such as esters, hydrocarbons, fatty alcohols, and ester compounds. The presence of flavonoids and stigmasterol was exhibited by the HPTLC profile. The in-situ HPTLC analysis revealed white fluorescence after derivatization under white light that explicitly confirms the antioxidant potential of the extracts and can serve as a lead source of natural antioxidants. The cytotoxic efficacy of the extracts was observed in a concentration-dependent manner. However, the in vitro leaf extract displayed better suppressive effects against the SH-SY5Y cells with a 24-h IC50 of 167.71?g/mL compared to the ex-vitro leaf extract. Further, a comprehensive study is necessary to identify the cytotoxic compounds and their mode of action. The outcome of our investigation provides empirical evidence that phytoconstituents present in the leaf extracts of C. macroptera can be used as an effective pharmaceutical agent to combat several diseases.

Analytical Assessment of the Antioxidant Properties of the Coneflower (Echinacea purpurea L. Moench) Grown with Various Mulch Materials.

Antioxidants are added to foods to decrease the adverse effect of reactive species that create undesirable compounds that destroy essential nutrients and, therefore, lower the nutritional, chemical and physical properties of foods. This study was carried out to determine the antioxidant properties of flowers and plant stems with leaves of Echinacea purpurea grown with mulches of different colours and thicknesses. Coneflowers were grown in the Experimental Station of the Agricultural University in Kraków, Poland. The mulching materials used were black, green and brown colours of 100 g/m2 and 80 g/m2 density. In plant material, e.g., flowers or plant stems plus leaves the proximate analysis, the total polyphenol content and the ability to scavenge free radicals (ABTS, DPPH and FRAP) were determined. The results show that flower samples had a higher content of compound proteins, ash and phenolic compounds. The mulching colour and density did not affect the proximate analysis of the E. purpurea plant. Based on the result of this study, E. purpurea is a potential source of natural antioxidants and can be used to improve the antioxidant activity of various food products as well as in cosmetics within the pharmaceutical industry.

Comparative analysis of phytochemical profile and antioxidant and anti-inflammatory activity of four Gentiana species from the Qinghai-Tibet Plateau

Ethnopharmacological relevanceGentiana species, known as the traditional Tibetan medicine “Bangjian,” have been integral to clinical practice for millennia. Despite their longstanding use, our understanding of the variation in chemical constituents and bioactive effects among different species is limited. Aim of the studyIn the present study, we aimed to assess the differences in chemical profiles and bioactivities among four Gentiana species (G. veitchiorum, G. trichotoma, G. crassuloides, and G. squarrosa) and explore potential bioactive markers. Materials and methodsThe chemical composition of the four Gentiana species was analyzed using UPLC-QE-Orbitrap-MS. The antioxidant activity of the extracts was compared through DPPH, ABTS, and reducing power assays. The anti-inflammatory activity was evaluated by measuring the inhibitory effects on lipopolysaccharide-induced secretion of nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) by RAW264.7 macrophages. Additionally, compounds strongly correlated with anti-inflammatory and antioxidant activities were identified through spectrum–effect relationship analysis. ResultsA total of 50 compounds were identified across the four Gentiana species. In vitro antioxidant assays demonstrated DPPH and ABTS scavenging abilities and reducing power within the concentration range of 62.5–2000 μg/mL. All four species inhibited the production of NO, IL-6, and TNF-α in RAW264.7 cells. Spectrum–effect relationship analysis revealed that gentiascabraside A, gentiatibetine, tachioside, lutonarin, and isotachioside were associated with the highest antioxidant activity; and swertiamarin, tarennoside, eleganoside C, and alpigenoside were associated with the highest anti-inflammatory activity. ConclusionsThis study presents, for the first time, the chemical profiles and bioactivities of G. trichotoma, G. crassuloides, and G. squarrosa, which were comprehensively compared with those of G. veitchiorum. The findings provide novel insights to understand the traditional use and/or expand the current use of Gentiana species. Additionally, this research highlights the potential of Gentiana species as natural sources of antioxidants and anti-inflammatory agents, suggesting promising applications in tea production or medicinal contexts in the near future.

Phytochemical Profile and In Vitro Bioactivities of Wild Asparagus stipularis.

In this study, Asparagus stipularis was characterized concerning its phytochemical composition, antioxidant potential, cytotoxicity, and pancreatic lipase inhibitory activities. Twenty-seven compounds were identified and quantified by HPLC-DAD-MS in the leaf, stem, pericarp, and rhizome of ethanolic extracts. Seven steroidal saponins were detected, and the highest content was quantified in rhizome and pericap. A. stipularis also contained significant amounts of flavonoids in the aerial part. Isorhamnetin tetra-glycoside, quercetin-3-glucosyl-rutinoside, and rutin were the main flavonoid derivatives in leaf, stem, and pericarp extracts, respectively. In addition, eleven phenolic acids were also detected; among them, caffeic acid, protocatechuic acid, p-hydroxybenzoic acid, and ferulic acid were the predominant phenolics, with these having the highest amounts quantified in the rhizome extracts. All the tested extracts possessed antioxidant capacities, with pericarp and rhizome extracts exhibiting the highest activity in DPPH, ABTS, and FRAP assays. The extracts from pericarp and rhizome were revealed to also be the strongest inhibitors of pancreatic lipase. The rhizome extracts exhibited potent cytotoxic activity against HCT-116 and HepG2 with IC50 values of 30 and 54 µg/mL after 48 h of treatment. The present study demonstrated that A. stipularis can be used as a new source of natural antioxidants and potential anticancer and antiobesity compounds.

Optimization of Bioactive Compound Extraction from Saffron Petals Using Ultrasound-Assisted Acidified Ethanol Solvent: Adding Value to Food Waste.

The saffron industry produces large by-products, including petals with potential bioactive compounds, which are cheap and abundant, making them an attractive alternative to expensive stigmas for extracting bioactive components. This study aimed to optimize the extraction conditions of bioactive compounds from vacuum-dried saffron petals using an ultrasound-assisted acidified ethanol solvent. Three factors were considered: ethanol concentration (0-96%), citric acid concentration in the final solvent (0-1%), and ultrasound power (0-400 watt). This study examined the effects of these factors on parameters like maximum antioxidant activity, total anthocyanin content, total phenolic content, and the total flavonoid content of the extraction. This study found that saffron petal extract's antioxidant activity increases with higher ethanol concentration, citric acid dose, and ultrasound power, but that an increased water content leads to non-antioxidant compounds. Increasing the dosage of citric acid improved the extraction of cyanidin-3-glucoside at different ultrasound power levels. The highest extraction was achieved with 400 watts of ultrasound power and 1% citric acid. Ethanol concentration did not affect anthocyanin extraction. Higher ethanol concentration and greater citric acid concentration doses resulted in the maximum extraction of total phenolic content, with a noticeable drop in extraction at higher purity levels. This study found that increasing the proportion of citric acid in the final solvent did not affect flavonoid extraction at high ethanol concentration levels, and the highest efficiency was observed at 200 watts of ultrasound power. The optimum values of the independent parameters for extracting bioactive compounds from saffron petals included 96% ethanol concentration, 0.67% citric acid concentration, and 216 watts of ultrasound power, resulting in a desirability value of 0.82. This ultrasound-assisted acidified ethanolic extract can be used in the food industry as a natural antioxidant and pigment source.

Process optimization and identification of antioxidant peptides from enzymatic hydrolysate of bovine bone extract, a potential source in cultured meat

Bone protein is a significant secondary product of the meat industry, comprising a substantial quantity of protein. These proteins could be broken down through enzymatic hydrolysis to generate antioxidant peptides. This study aimed to produce antioxidant peptides from bovine bone extract by enzymatic hydrolysis utilizing Flavourzyme and Protamex by optimizing enzyme amounts and time using the Box–Behnken design. The final optimized conditions obtained through the model were as follows: The amount of Flavourzyme was 1,100 U, the amount of Protamex was 2,814 U, and the time was 3.77 (h). Bovine bone extract hydrolysate (BBEH) was purified stepwise using ultrafiltration membranes with molecular cutoffs of 5, 3, and 1 kDa. To assess the antioxidant capacity of the fractions, several methods were used, including radical scavenging activity “1,1-diphenyl-2-picrylhydrazyl (DPPH),” “2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS),” metal chelating activity (MCA), reducing power (RP), and thiobarbituric acid assay (TBA). The results indicated that the ultrafiltration fraction with a molecular weight of less than 1 kDa showed significant antioxidant activity, with 48, 42, and 50% inhibition rates for DPPH, ABTS, and metal chelating, respectively. Using size exclusion chromatography, the fraction with a molecular weight less than 1 kDa was further separated into five sub-fractions: Frac-I, Frac-II, Frac-III, Frac-IV, and Frac-V. Sub-Frac-III, which exhibits significant DPPH radical scavenging activity (55%) and a reducing power of 0.8 at 700 nm, was separated into six sub-sub-fractions using reversed-phase HPLC (RP-HPLC) based on molecular weight and hydrophobicity. The sub-sub-fraction with the highest value for DPPH radical scavenging activity was sub-Fra-III-6, which exhibited approximately 69.45% activity. The sub-Fra-III-6 was analyzed using LC–MS/MS, which identified two specific peptides: Ala-Pro-Phe with a mass of 333.12 Da and Asp-His-Val with a mass of 369.14 Da. These two peptides are likely the primary peptides that might have a crucial role in antioxidant capacity. It can be concluded that BBEH is a valuable source of natural antioxidants and has the potential to serve as a viable resource in the cultured meat industry.

Molecular Mechanism of Natural Food Antioxidants to Regulate ROS in Treating Cancer: A Review.

Cancer is the second-highest mortality rate disease worldwide, and it has been estimated that cancer will increase by up to 20 million cases yearly by 2030. There are various options of treatment for cancer, including surgery, radiotherapy, and chemotherapy. All of these options have damaging adverse effects that can reduce the patient's quality of life. Cancer itself arises from a series of mutations in normal cells that generate the ability to divide uncontrollably. This cell mutation can happen as a result of DNA damage induced by the high concentration of ROS in normal cells. High levels of reactive oxygen species (ROS) can cause oxidative stress, which can initiate cancer cell proliferation. On the other hand, the cytotoxic effect from elevated ROS levels can be utilized as anticancer therapy. Some bioactive compounds from natural foods such as fruit, vegetables, herbs, honey, and many more have been identified as a promising source of natural antioxidants that can prevent oxidative stress by regulating the level of ROS in the body. In this review, we have highlighted and discussed the benefits of various natural antioxidant compounds from natural foods that can regulate reactive oxygen species through various pathways.

Secondary metabolite estimation and antioxidant potential assessment of purple bell Thunbergia erecta (Benth.) T. Anderson

To quantify the aqueous and methanolic extracts for primary and secondary metabolites, and the antioxidant potential of leaf extracts of the Thunbergia erecta plant and to adopt them in Ayurvedic medications for various illnesses. Primary metabolites like carbohydrates, proteins, and secondary metabolites such as flavonoids, alkaloids, total phenols, and tannins were estimated using standard procedures. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), hydrogen peroxide, and phosphomolybdenum free radical scavenging activities were employed to evaluate the antioxidative potential. The phytochemical examination of T. erecta exhibited the presence of carbohydrates, proteins, amino acids, alkaloids, total polyphenolics, flavonoids, and tannins in significant quantity. The in vitro antioxidant potential of the species, clearly verifies that methanolic extract shows prominent antioxidant properties followed by the hydroalcoholic extract. From this study, it can be concluded that this species is effective in scavenging free radicals and may be a powerful antioxidant. The T. erecta leaf extract showed the existence of bioactive components which are known to exhibit medicinal activities. The findings of this study suggest that these plant leaves could be a potential source of natural antioxidants that could have great importance as therapeutic agents in preventing various diseases.

Bioactive compounds and DPPH antioxidant activity of underutilized macroalgae (Sargassum spp.) from coastal water of Makassar, Indonesia

Abstract. Widyaswari SG, Metusalach, Kasmiati, Amir N. 2024. Bioactive compounds and DPPH antioxidant activity of underutilized macroalgae (Sargassum spp.) from coastal water of Makassar, Indonesia. Biodiversitas 25: 176-182. This study focuses on determining the chemical component and potential of two species of macroalgae (seaweed) Sargassum spp., i.e., Sargassum polycystum and Sargassum ilicifolium from the coastal waters of Makassar City, South Sulawesi, Indonesia. Several macroalgae are highly cultivated and exported; however, these species of Sargassum remain underutilized due to limited studies on their potential. Brown algae (Phaeophyceae), especially Sargassum spp., contain secondary metabolites known for their health-promoting properties, including antioxidant effects, inhibiting oxidative stress, lowering blood pressure, and improving the immune system. The investigation analyzes the nutritional components and bioactive substances in Sargassum spp. harvested from the Makassar City coastal waters, South Sulawesi, Indonesia. Nutritional content was analyzed using proximate analysis. Phytochemical screening was conducted based on the method by Harborne method. Antioxidant activity was performed using the DPPH method. Total phenolic/flavonoid content based on spectrophotometric method. The investigation reveals the primary chemical composition of Sargassum polycystum showing the presence of valuable secondary metabolites such as alkaloids, flavonoids, phenol hydroquinone, and reactive saponins. Sargassum ilicifolium contains flavonoids, phenol hydroquinone, tannins, and steroids. The IC50 values for the antioxidant activity of S. polycystum and S. ilicifolium were 51.34 ppm and 51.25 ppm, respectively. The compounds in these seaweeds might be beneficial in promoting health. These findings suggest the possibility of underutilized seaweeds as a natural source of antioxidants in food and non-food industries.

Optimizing the Solvent Selection of the Ultrasound-Assisted Extraction of Sea Buckthorn (Hippophae rhamnoides L.) Pomace: Phenolic Profiles and Antioxidant Activity

Sea buckthorn pomace (SBP) is a by-product of sea buckthorn processing that is rich in bioactive compounds. In this study, different active ingredients were extracted by using different solvents (water, methanol, ethanol, glycerol, ethyl acetate, and petroleum ether) combined with an ultrasonic assisted method. The correlation between the active ingredients and antioxidant properties of the extract was studied, which provided a research basis for the comprehensive utilization of SBP. This study revealed that the 75% ethanol extract had the highest total phenolic content (TPC) of 42.86 ± 0.73 mg GAE/g, while the 75% glycerol extract had the highest total flavonoid content (TFC) of 25.52 ± 1.35 mg RTE/g. The ethanol extract exhibited the strongest antioxidant activity at the same concentration compared with other solvents. The antioxidant activity of the ethanol, methanol, and glycerol extracts increased in a concentration-dependent manner. Thirteen phenolic compounds were detected in the SBP extracts using UPLC-MS/MS analysis. Notably, the 75% glycerol extract contained the highest concentration of all identified phenolic compounds, with rutin (192.21 ± 8.19 μg/g), epigallocatechin (105.49 ± 0.69 μg/g), and protocatechuic acid (27.9 ± 2.38 μg/g) being the most abundant. Flavonols were found to be the main phenolic substances in SBP. A strong correlation was observed between TPC and the antioxidant activities of SBP extracts. In conclusion, the choice of solvent significantly influences the active compounds and antioxidant activities of SBP extracts. SBP extracts are a valuable source of natural phenolics and antioxidants.

Effect of Time of Harvest on the Chemical Composition and Antioxidant Potential of Leaf Essential Oil of Syzygium guineense Growing in North Central Nigeria (Willd.) Dc. Var.

Abstract. The use of synthetic antioxidants to ameliorate oxidative stress goes with side effects. Some plants are known to be sources of natural antioxidants and, hence, could be used as alternatives to synthetic antioxidants without side effects. Meanwhile, the presence of the phytochemicals that exhibit antioxidant activity in plants depends on environmental conditions that vary with the time of harvest of plant materials. This study, therefore, investigated the effect of time of harvest on the chemical composition and antioxidant potential of leaf essential oil of Syzygium guineense native to North central Nigeria. To accomplish these, pulverized (500 g) leaves of S. guineense harvested in the morning and afternoon were separately hydrodistilled and yielded 0.25 ± 0.002 % (w/w) and 0.27 ± 0.003 % (w/w) of essential oils. Characterization of the oils using GC-MS revealed the presence of twenty-two and twenty-three compounds in the oils from morning and afternoon harvests. The most abundant compound in the oils was β-bergamotene (30.1 % and 27.3 %). D-limonene (2.9 % and 5.6 %), β-ocimene (4.2 % and 10.2 %), α-santalene (7.4 % and 7.7 %), α-cedrene (8.6 % and 9.0 %), β-farnesene (9.1 % and 10.2 %) and calamenene (7.1 % and 5.2 %) were detected in significant quantities in the oils. DPPH radial scavenging assay was used to evaluate the antioxidant activity of the oils with butylated hydroxyl toluene (BHT) as standard. The oils exhibited antioxidant activity with IC50 of 41.92 μg/mL and 33.12 μg/mL for the oils from morning and afternoon harvests. Although the oils exhibited lower antioxidant activity than the standard (IC50 of 28.63 μg/mL), but the oils could be used to ameliorate oxidative stress after clinical trials.

GC-MS profile, total phenolic, and DPPH radical scavenging activity of Saurauia minahassae stembark ethyl acetate extract

Several species of the genus Saurauia have been traditionally used as remedies. However, Saurauria minahassae, as an endemic plant, is still understudied. This study aims to reveal the total phenolics, GC-MS profile, and bioactivity as DPPH free radical scavengers of ethyl acetate extract of S.minahassae collected from Banggai Island, Indonesia. Determination of Total Phenolic Content (TPC) was conducted using the colorimetry method by spectrophotometer. Thin layer chromatography (TLC) and TLC-bioautography performed analysis of secondary metabolites and qualitative DPPH free radical scavenging activity, respectively. GC-MS analysis was conducted to identify the chemical compounds of the extract. The extract’s IC50 value and Antioxidant activity index (AAI) were performed by serial microdilution method on the 96-microwell plate. The results showed that TPC was 432.33 mg GAE/g extract. TLC analysis revealed several metabolites, and TLC-bioautography also revealed several compounds active as DPPH free radical scavengers. The ethyl acetate extract of S. minahassae is categorized as a very strong DPPH free radical scavenger or potent antioxidant with an IC50 value of 3.29 ug/ml and AAI of 9.32. GC-MS profile of the ethyl acetate extract of S.minahassae stembark contained several compounds with antioxidant activity. The potential antioxidant activity of S. minahassae stembark extract was contributed by phenolic content and several compounds with antioxidant activity in the extract. This extract could be a good source of natural antioxidants, and S. minahassae sustainability as an endemic plant should be maintained.

Screening and characterization of bioactive compounds from two epiphytic microlichen and evaluation of their in vitro antioxidant activity

BackgroundLichens in symbiosis produce a wide range of primary and secondary fine compounds in extreme environmental conditions that have a broad range of biological properties as well as antioxidant potential and can be used in future pharmaceuticals as a natural source of antioxidant molecules.ResultsThe two microlichen species collected are identified based on morphological and molecular techniques; further studies are carried out by analyzing phytochemicals (FTIR, GC MS), and antioxidant assays are evaluated. The non-enzymatic antioxidant activity is evaluated by DPPH and FRAP assays. The methanol extract of both lichens showed virtuous DPPH scavenge with IC50 of P. nitida (125.76 ± 0.023 µg/ml) and G. scripta IC50 (176.90 ± 0.058 µg/ml). FRAP activity was prominent in the methalonic extract. The enzymatic antioxidant activity is observed by SOD and catalase activity. The cytosolic (Cu–Zn-SOD and Fe-SOD) and mitochondrial SOD (Mn-SOD) are detected in lichens, though P. nitida shows mitochondrial Mn-SOD and cytosolic Cu–Zn-SOD and Fe-SOD, whereas G. scripta has a single cytosolic Cu–Zn-SOD; however, two isoforms of catalase were reported. GC–MS analysis screened bioactive metabolites such as phenols, Quinons, heterocyclic compounds, benzofurans, fatty acids, pyrans, carboxylic acid, aliphatic aldehydes, organic alcohol, fluorinated aliphatic substances, ketones, terpenes and fatty alcohols in P. nitida, whereas, in G. scripta screened fatty acids, alcohols, hydrocarbons, carbonyl compounds, polyols, terpenes, glycosides, phenols, and sugar alcohols detected in the chromatogram peak. FTIR analysis revealed functional groups like Alcohols, Amines, Amides, Alkanes, Aldehydes, Carboxylic acid, Alkynes, Esters, Ketones, Anhydrides, Acid chlorides, Alkenes, Aromatic compounds, Nitro compounds, Alkyl and Aryl Halides in both lichens.ConclusionsThe results obtained in the present study proved that P. nitida and G. scripta have promising antioxidant activity owing to the presence of polyphenols and terpenes, as evidenced by DPPH and FRAP assay along with enzymatic analysis (SOD and CAT). Thus both the lichens may be used as natural sources of new bioactive molecules having pharmaceutical interest.