Concentration-dependent Antioxidant Activity Research Articles

Cell-free fat extract regulates oxidative stress and alleviates Th2-mediated inflammation in atopic dermatitis.

Atopic dermatitis (AD) is a common inflammatory skin disease that significantly affects patients' quality of life. This study aimed to evaluate the therapeutic potential of cell-free fat extract (FE) in AD. In this study, the therapeutic effect of DNCB-induced AD mouse models was investigated. Dermatitis scores and transepidermal water loss (TEWL) were recorded to evaluate the severity of dermatitis. Histological analysis and cytokines measurement were conducted to assess the therapeutic effect. Additionally, the ability of FE to protect cells from ROS-induced damage and its ROS scavenging capacity both in vitro and in vivo were investigated. Furthermore, we performed Th1/2 cell differentiation with and without FE to elucidate the underlying therapeutic mechanism. FE reduced apoptosis and cell death of HaCat cells exposed to oxidative stress. Moreover, FE exhibited concentration-dependent antioxidant activity and scavenged ROS both in vitro and vivo. Treatment with FE alleviated AD symptoms in mice, as evidenced by improved TEWL, restored epidermis thickness, reduced mast cell infiltration, decreased DNA oxidative damage and lower inflammatory cytokines like IFN-γ, IL-4, and IL-13. FE also inhibited the differentiation of Th2 cells in vitro. Our findings indicate that FE regulates oxidative stress and mitigates Th2-mediated inflammation in atopic dermatitis by inhibiting Th2 cell differentiation, suggesting that FE has the potential as a future treatment option for AD.

Structure characterization and protective effect against UVB irradiation of polysaccharides isolated from the plateau plant Gentiana dahurica Fisch

Gentiana dahurica Fisch. (G. dahurica) is one of the legitimate sources of Qinjiao in Traditional Chinese Medicine (TCM) and grows on high-altitude plateaus. Plants develop unique biochemical accumulations to resist plateau conditions, especially the strong UV irradiation. Thus, this study aimed to investigate the polysaccharide of G. dahurica (GDP), its structure and its activity against UVB irradiation. Four GDPs were isolated and two of them were subjected to structural elucidation. The results suggested that GDP-1 has 53.5 % Ara and 30.8 % GalA as its main monosaccharides, with a molecular weight (Mw) of 23 kDa; the GDP-2 has 33.9 % Ara and 48.5 % GalA, with a Mw of 82 kDa. Methylation and NMR spectroscopy analysis revealed that GDP-1 contains →5)-α-Araf-(1 → 5)-α-Araf-(1 → 3,5)-α-Araf-(1 → 3,4)-α-GalpA-(6-OMe)-(1→ as the main chain, the branches of GalA (with esterification), and the terminal Ara; the GDP-2 contains →4)-α-GalpA-(1 → 4)-α-GalpA-(6-OMe)-(1 → 5)-α-Araf-(1 → 3,5)-α-Araf-(1→ as the main chain, the branches of →5)-α-Araf-(1–5)-α-Araf, and the terminal GalA. Both GDP-1 and GDP-2 exhibited concentration-dependent antioxidant activity against DPPH, ABTS and hydroxyl radicals. Moreover, GDPs significantly attenuated the decreases in viability and proliferation of HaCaT cells after UVB irradiation. They can scavenge reactive oxygen species (ROS) and improve the activities of endogenous antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GSH). The potential mechanism explored by flow cytometry assays of cell apoptosis and cell cycle distribution suggested that GDPs exert protective effects against UVB irradiation by reducing ROS and attenuating S phase cell arrest. In brief, the GDP-1 and GDP-2 are α-1,3- and α-1,4- arabinogalacturonan, respectively. The high content of Ara could be attributed to biochemical accumulation in resisting to the plateau environment and to prevent UVB irradiation-related damage in cells. These findings provide insight into authentic medicinal herbs and the development of GDPs in the modern pharmaceutical and cosmetics industry.

Amino-Functionalized Pluronic F127 micelles as a dual drug delivery nanostructure for controlled therapeutics release

Bacterial infection is one of the serious leading causes of hospitalization. The development of a novel dual drug delivery nanostructure based on polymeric micelles is presented here for the treatment of Staphylococcus aureus-associated infections. The nanostructure was composed of quercetin (QC)-encapsulated in the core of F127 micelles (FQ micelles) which was later shell cross-linked using 3-amisinopropyl triethoxysilane (APTES) molecules through condensation reaction. The functionalization of the head groups of FQ micelles with APTES (FQA NPs) facilitated the covalent linkage of vancomycin (Vanc) drug and consequent formation of FQA-Vanc NPs with the hydrodynamic size of 133 nm. FQA-Vanc NPs demonstrated prolong release of QC and Vanc over a period of 168 h. The core–shell structure offered sustainable release of Vanc and QC to the FQA-Vanc NPs during 96 h and 48 h, respectively. The co-administration of Vanc and QC not only enhanced the antibacterial performance of FQA-Vanc NPs, but also induced time and concentration-dependent antioxidant activities. Overall, the Vanc immobilized-FQA NPs together with antibacterial and antioxidant activities could potentially provide a new therapeutic platform for bacterial infection treatment.

Study on Chemical Composition and Biological Activity of Psidium guajava Leaf Extracts.

Guava (Psidium guajava) is a plant widely distributed in tropical and subtropical regions. Its leaves contain a large amount of physiological molecules such as flavonoid, sesquiterpene, triterpenoid, coumarin, alkaloid, and tannin molecules with antioxidative and anti-inflammatory effects. In this study, the use of concentrated P. guajava leaf extract molecules as a functional natural material was evaluated by confirming the extract's antioxidative, antibacterial, tyrosinase activity inhibition, and collagenase activity inhibition effects and its trans-2-nonenal removal ability. As a result of the analysis of the antioxidant and antibacterial components of concentrated P. guajava leaf extract molecules through GC-MS, a large amount of aromatic hydrocarbon molecules were detected. When different concentrations of ethanol were used for extraction, the leaf extract concentrated with 70% ethanol showed the most effective active molecules. As a result of measuring DPPH radical scavenging activity, a concentration-dependent antioxidant activity was confirmed. The antioxidant activity tended to increase when the ethanol content used for extraction was increased. Molecules such as 2,4-di-tert-butylphenol, caryophyllene oxide, and γ-muurolene in P. guajava leaf extract concentrate appeared to have antibacterial activities against S. aureus bacteria known to cause atopy. As ethanol content increased, the inhibitory effect on tyrosinase activity was increased. In addition, when ethanol content was 50%, the concentrated leaf extract was able to remove trans-2-nonenal by 52.4%. As a result of determining the concentrated leaf extract's collagenase inhibition activity, an inhibition rate close to that of ascorbic acid, a positive control, was confirmed. The concentrated guajava leaf extract molecules were confirmed to have whitening and wrinkle-improving functionality. Thus, the P. guajava leaf extract has high potential as a food and natural cosmetic material.

Centella asiatica improves memory and executive function in middle-aged rats by controlling oxidative stress and cholinergic transmission

Ethnopharmacological relevanceCentella asiatica (L.) Urban, is a medicinal herb with rich history of traditional use in Indian subcontinent. This herb has been valued for its diverse range of medicinal properties including memory booster, and also as a folk treatment for skin diseases, wound healing and mild diuretic. Aim of studyAging is a gradual and continuous process of natural decay in the biological systems, including the brain. This work aims to evaluate the effectiveness of ethanolic extract of Centella asiatica (CAE) on age-associated cognitive impairments in rats, as well as the underlying mechanism. Material and methodsRats were allocated into five distinct groups of 5 animals each: Young rats (3 months old rats), middle-aged (m-aged) rats (13–14 months old), and the remaining three groups were comprised of m-aged rats treated with different concentrations of CAE, viz., 150, 300, and 450 mg/kg b. w., orally for 42 days. Y-maze, open field, novel object recognition, and elevated plus maze tests were used to assess animal behavior. The malondialdehyde (MDA), superoxide dismutase (SOD), and acetylcholinesterase (AChE) assays; and H&E staining were done in the rat brain to assess the biochemical and structural changes. CAE was also subjected to HPLC analysis, in vitro antioxidant and anti-cholinergic activity. The active compounds of CAE were docked with AChE and BuChE in molecular docking study. ResultsThe results showed that CAE treatment improves behavioral performance; attenuates the age-associated increase in MDA content, SOD, and AChE activity; and reduces neuronal loss. In vitro study showed that CAE has concentration-dependent antioxidant and anti-AChE activity. Furthermore, the presence of Asiatic acid and Madecassic acid in CAE and their good binding with cholinergic enzymes (in silico) also suggest the anticholinergic effect of CAE. ConclusionThe findings of the current study show that the anticholinergic and antioxidant effects of CAE are attributable to the presence of Asiatic acid and Madecassic acid, which not only provide neuroprotection against age-associated cognitive decline but also reverse it.

Structural Characterization and Antioxidant Activity of β-Glucans from Highland Barley Obtained with Ultrasonic-Microwave-Assisted Extraction.

In order to efficiently extract β-glucan from highland barley (HBG) and study its structural characterization and antioxidant activity, ultrasonic-microwave-assisted extraction (UME) was optimized by the response surface method (RSM). Under the optimal extraction conditions of 25.05 mL/g liquid-solid ratio, 20 min ultrasonic time, and 480 W microwave intensity, the DPPH radical scavenging activity of HBG reached 25.67%. Two polysaccharide fractions were purified from HBG, namely HBG-1 and HBG-2. Structural characterization indicated that HBG-1 and HBG-2 had similar functional groups, glycosidic linkages, and linear and complex chain conformation. HBG-1 was mainly composed of glucose (98.97%), while HBG-2 primarily consisted of arabinose (38.23%), galactose (22.01%), and xylose (31.60%). The molecular weight of HBG-1 was much smaller than that of HBG-2. Both HBG-1 and HBG-2 exhibited concentration-dependent antioxidant activity, and HBG-1 was more active. This study provided insights into the efficient extraction of HBG and further investigated the structure and antioxidant activities of purified components HBG-1 and HBG-2. Meanwhile, the results of this study imply that HBG has the potential to be an antioxidant in foods and cosmetics.

Exploring marine algae-derived phycocyanin nanoparticles as a safe and effective adjuvant for sunscreen systems

BackgroundUV radiation (UV) exposure risks skin damage and cancer due to DNA damage and oxidative stress. Synthetic chemical sunscreens that protect against UV radiation can have health and environmental concerns. This study explores phycocyanin (PC), a marine algae-derived natural photoprotective compound, and its crosslinked nanoparticles (PCNP) as safe and effective adjuvants for sunscreen systems.MethodsPCNP was synthesized via genipin-crosslinking. PC and PCNP biocompatibility were assessed on mouse embryonic fibroblast cells. ABTS evaluated antioxidant activity, and the UV absorption capacity of PC and PCNP were analyzed. PCNP skin permeability was tested in vitro and in vivo. Gel formulations with PCNP were examined for UV absorption effects.ResultsPCNP showed good biocompatibility, maintaining cell viability above 90% across concentrations. Both PC and PCNP demonstrated concentration-dependent antioxidant activity, efficiently scavenging free radicals. PCNP exhibited enhanced UV absorption in the UVB range compared to PC alone. Skin permeation studies displayed limited PCNP penetration through skin layers. In vivo, absorption assessments indicated PCNP localized mainly in the stratum corneum. PCNP-containing gels displayed improved UV absorption compared to gels without PCNP.ConclusionThis study showcases PCNP’s potential as a natural and safe adjuvant for sunscreen with enhanced UV protection capabilities. PCNP preserved antioxidant activity, displayed limited skin penetration, and enhanced UV absorption. The findings suggest PCNP’s promise as a viable alternative to synthetic sunscreen agents, delivering effective photoprotection while minimizing health and environmental concerns.

Phytochemical Constituents of Adansonia digitata L. (Baobab) Fruit Pulp from Tekeze Valley, Tigrai, Ethiopia.

Baobab (Adansonia digitata L) is a large tree species growing in semiarid and arid lowlands of Ethiopia and other places. The plant is valued by natives for its contributions as a cash crop and livelihood tree. Previous studies using samples from different countries have documented their phytochemical profiles and nutritional and health benefits. This study explored the phytochemical constituents and biological activities of fruit pulp extracts of baobab collected from Tekeze Valley, Tigrai, Ethiopia. To this end, qualitative phytochemical screening tests, quantitative phytochemical analyses, and gas chromatography-mass spectrometry (GC-MS) analysis were carried out using aqueous extract. Analyses of antioxidant activities were also conducted with aqueous- and methanol-extracts using of 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), and hydroxyl (OH) radical scavenging activity assays. The qualitative screening tests showed the presence of flavonoids, phenols, saponins, tannins, and terpenoids. Quantitative analyses of these phytochemicals at 25, 50, and 100 g/mL aqueous extract resulted in 0.0252 to 0.1000% yields. Yields of flavonoids, phenols, and saponins were higher at 50 g/mL extract, while that of tannins and terpenoids were higher at 100 g/mL. GC-MS analysis resulted in 15 predominant compounds including (1,2bis(trimethylsilyl)benzene (13.17%), 2-methyl-7-phenylindole (11.75%), 2-ethylacridine (10.11%), and benz[b]-1,4-oxazepine-4(5H)-thione,2,3-dihydro-2,8-dimethyl (10.11%). Aqueous and methanol extracts showed concentration-dependent antioxidant activities. In all the assays and concentrations, the antioxidant activities of both extracts were lower than that of the ascorbic acid standard. At equal extract concentrations (e.g., 100 and 250 μg/mL), methanol extract had higher antioxidant activities than aqueous extract. The findings can encourage future initiatives towards large-scale research for compiling a complete phytochemical profile of the fruit pulp of the Ethiopian baobab.

Assessment of antioxidant activity of pure graphene oxide (GO) and composite V2O5/GO using DPPH radical and H2O2 scavenging assays

In this research, the Co precipitation method was utilized to synthesize a nanocomposite of vanadium oxide (V2O5) and graphene oxide (GO). Pure GO was synthesized by the modified hammers method. Using a 1:2 ratio of GO and V2O5 and heating in the oven at 70 °C leading to the formation of V2O5/GO nanocomposite. By grafting of GO on V2O5 surface, a high range of graphene oxidation in V2O5/GO allowed for better reduction with V2O5 metal-oxide. The scanning electron microscope (SEM) images and X-ray diffraction (XRD) spectra provide evidence of the distinct phase of graphene oxide formation. The antioxidant activity of V2O5/GO nanocomposite was conducted in two vitro assays, focusing on neutralization of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and H2O2 radicals. The uniqueness of the nanocomposite was evident from its concentration-dependent antioxidant activities. Interestingly, the V2O5/GO samples has showed 60% antioxidant performance in the H2O2 assays compared to its constituent.

Exploration and Evaluation of In-vitro Antioxidant Activity of ABANA: A Polyherbal Formulation

Objective: The purpose of this study was to determine the antioxidant capacity of Abana® (a poly-ingredient formulation with natural constituents). Methods: Extensive ethanol extraction of polyherbal formulations was followed by fractionation into petroleum ether, chloroform, and ethyl acetate extracts. Various fractions were further analyzed using this conventional method for phytochemical composition and concentration dependent antioxidant activity. Due to the presence of phenolic compounds in the formulation, extracts were analyzed for total phenolic content, flavonoid content, and in- vitro antioxidant activity. Antioxidant capacity was determined using total reducing potential, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis-ethyl-benzothiozoline-sulphonic acid diammonium salt (ABTS) and nitric oxide inhibition assays. Results: Primitive phytochemical screening revealed the presence of steroids, saponins, flavonoids, alkaloids and tannins which were confirmed using thin-layer chromatography. The antioxidant activity of Abana tablet extracts decreased in the order ethyl acetate > ethanolic > chloroform > petroleum ether comparable to that of ascorbic acid and butylated hydroxytoluene. Conclusion: The current investigation suggests that the ethanolic extract and fractions of Abana polyherbal formulations exhibit significant antioxidant activity. Our results strongly imply that polyherbal compounds are a potential source of antioxidants capable of scavenging free radicals. The strong positive connection between antiradical scavenging activity and overall polyphenolic concentration in polyherbal drugs demonstrates that polyphenols are significant components capable of scavenging free radicals. Additional research is required to isolate and characterize the active moiety responsible for biological activity and treat it under various stress conditions.

Effect of Oil Pollution on the Antioxidant Activity of the Methanolic Extracts of Polluted and Unpolluted Leaves of Hyptis suaveolens (L)

Hyptis suaveolens (L.) Poit, an aromatic weed known as pignut or daddoya-ta-daji in the Hausa language, has a longstanding history of usage as food and medicine in Kaduna state. This plant is interestingly found thriving in environments with or without oil pollution. In our modern industrial society, it's practically inevitable that these medicinal plants come in contact with oil contamination. This is largely because oil pipelines, often aged and susceptible to corrosion or illicit activities leading to leakages, are scattered across urban and rural settlements, influencing the plants' phytochemical composition. This study is focused on examining if oil pollution alters the antioxidant activity of this plant. An evaluation of the antioxidant properties of methanol extracts from Hyptis suaveolens (L.) leaves, both from polluted and unpolluted areas, was carried out using the 2,2-Diphenyl-1-Picrylhydrazyl-hydrate (DPPH) free radical scavenging assay. The outcomes showed that the extracts have significant (p < 0.05) concentration-dependent antioxidant activity. Yet, the unpolluted H. suaveolens leaves' methanol extract exhibited superior DPPH radical scavenging action compared to the extract from the polluted leaves. The median inhibitory concentrations (IC50) for the polluted and unpolluted leaves' methanol extracts were 35 µg/ml and 20 µg/ml respectively. Therefore, the contamination had a detrimental impact on the plant extract's antioxidant capacity.

In vivo antioxidant activity of rabbiteye blueberry (Vaccinium ashei cv. 'Brightwell') anthocyanin extracts.

Blueberries are rich in phenolic compounds including anthocyanins which are closely related to biological health functions. The purpose of this study was to investigate the antioxidant activity of blueberry anthocyanins extracted from 'Brightwell' rabbiteye blueberries in mice. After one week of adaptation, C57BL/6J healthy male mice were divided into different groups that were administered with 100, 400, or 800 mg/kg blueberry anthocyanin extract (BAE), and sacrificed at different time points (0.1, 0.5, 1, 2, 4, 8, or 12 h). The plasma, eyeball, intestine, liver, and adipose tissues were collected to compare their antioxidant activity, including total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity and glutathione-peroxidase (GSH-PX/GPX) content, and the oxidative stress marker malondialdehyde (MDA) level. The results showed that blueberry anthocyanins had positive concentration-dependent antioxidant activity in vivo. The greater the concentration of BAE, the higher the T-AOC value, but the lower the MDA level. The enzyme activity of SOD, the content of GSH-PX, and messenger RNA (mRNA) levels of Cu,Zn-SOD, Mn-SOD, and GPX all confirmed that BAE played an antioxidant role after digestion in mice by improving their antioxidant defense. The in vivo antioxidant activity of BAE indicated that blueberry anthocyanins could be developed into functional foods or nutraceuticals with the aim of preventing or treating oxidative stress-related diseases.

THE INFLUENCE OF CATHARANTHUS ROSEUS (L.) G. DON. ETHANOL EXTRACT IN CLOVE OIL NANOEMULSION: PHYSICAL CHARACTERIZATION, ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES

Objective: This study aimed to develop a topical nanoemulsion using clove oil and ethanol extract of catharanthus roseus (L.) G. for antioxidant and antibacterial dosage form. Methods: The nanoemulsion was produced using a spontaneous emulsification method. The formulation was carried out using tween 80 and pluronic 127 as surfactants with different extract concentrations (0.5–2%). The characterizations of the formula included organoleptic test, homogeneity, pH determination, emulsion type, viscosity, particle size determination, zeta potential, and stability test were evaluated. Antioxidant activity was conducted using DPPH method and antibacterial activity was determined against propionibacterium acnes and Staphylococcus epidermidis. Results: The result showed that all the formulations produced a stable nanoemulsion with semisolid, clarity, transparent and homogenous characteristic. The nanoemulsion had pH of 5.5-6.5 and belong to oil in water (O/W) type of emulsion. The formula showed viscosity ranged from 121.33±0.29 until 211.01±1.00 cps, had particle size below than 300 nm, and were stable for 3 mo of storage and after accelerated evaluation. nanoemulsion contained 2% of c. roseus extract showed moderate antioxidant activity with IC50 value of 96.29±3.64 and antibacterial activity with 10.65±0.15 and 13.27±0.21 mm of inhibition zones for propionibacterium acnes and Staphylococcus epidermidis, respectively. Conclusion: Clove oil combined with the ethanol extract of c. roseus produced a stable nanoemulsion, which demonstrated concentration-dependent antioxidant and antibacterial activities.

Antioxidant and Antimalarial Activities of Methanol Extract of Picralima nitida Root Bark

Ethnomedically, the root, stem bark, seed or leaves of Picralima nitida are relevant in local preparations as antimalaria, antipyretic, antihypertensive and gastrointestinal agents. This study was therefore designed to determine the antimalarial and antioxidant effects of the methanol extract of the root bark of Picralima nitida using standard procedures. The antioxidant activity of the methanol root bark extract was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method and ferric reducing antioxidant power (FRAP) assay. The antimalarial activity of the methanol root bark extract was investigated using the 4-day suppressive test in mice infected with Plasmodium berghei. The extract showed a concentration-dependent antioxidant activity with 50% inhibitory concentration (IC50) for free radical scavenging activity of 10.19 µg/mL, while the FRAP value was 0.17 ± 0.00 mM FSE/g Extract. The extract demonstrated significant antimalarial activity with 68.33% and 67.27% parasitaemia suppression at doses of 400 mg/kg and 800 mg/kg, respectively. The present study has shown that the root bark extract of P. nitida has antioxidant and antimalarial activities. This study does not only validate the claimed ethnomedicinal use of the plant as antimalaria but also has shown the plant as a potential source of active antimalarial agent.

One-pot synthesis, characterisation and biological activities of gold nanoparticles prepared using aqueous seed extract of Garcinia kola

Recently, biogenic synthesis of gold nanoparticles (AuNPs) has become a focus area in cancer research owing to the eco-friendliness and cost effectiveness of the synthetic method. In this study, aqueous extract of Garcinia kola seed (AEGKs) was used for the bio-reduction of Au3+ to Au0. The synthesised AEGKs-AuNPs was characterised by ultraviolet-visible (UV-Vis) spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscopy (HRTEM) and Fourier transform-infrared (FT-IR) spectroscopy. The in vitro antioxidant activity of the AEGKs and AEGKs-AuNPs was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability and ferric reducing antioxidant power assays. The AEGKs-AuNPs showed an absorption maximum at 512 nm, and the HRTEM images revealed mostly, spherical-shaped AuNPs in the size range of 2–17 nm. The FT-IR spectroscopy revealed that polyphenolic compounds and proteins were predominant, and responsible for the reduction and capping of the AuNPs. The AEGKs-AuNPs showed concentration dependent antioxidant activities, while dose-dependent in vitro anti-cancer activity of the AEGKs-AuNPs was demonstrated against lungs, prostrate, human cervical and human colon cancer cells, using the 3-(4,5-dimethylthiazol-2-yl)− 2,5-diphenyltetrazolium bromide tetrazolium reduction (MTT) assay. The antioxidant and anti-cancer activities of the AEGKs-AuNPs could be attributed to the presence of phytochemicals and physicochemical properties of the AuNPs.

Physicochemical Properties and In Vivo Hepatoprotective Effect of Polysaccharides from Grape Pomace.

Here, the polysaccharides from grape pomace, a by-product in the wine industry, were characterized and evaluated in vitro and in vivo. The polysaccharides were extracted and studied using spectroscopic and chemical methods. The results revealed that GPPs are rich in arabinose, galactose and glucuronic acid and are heteropolysaccharides without protein and nucleic acid, containing α-glycoside bonds with irregular clusters on the surface. In vitro antioxidant activity assays indicated that GPPs have concentration-dependent antioxidant activity. In vivo, GPPs markedly decreased the levels of TNF-a, IL-6, ALT, AST and MDA in serum and liver tissues and restored the levels of SOD, CAT and GSH. Additionally, further histopathological examination confirmed that GPPs could mitigate the injury of liver induced by CCl4. Our results demonstrate that GPPs had antioxidant and hepatoprotective effects, and they are expected to be a potential ingredient for functional foods or hepatoprotective drugs.

Fatty acids analysis, antioxidant, antimicrobial and biological activity of essential oil of Skimmia laureola Leaves

The Western Himalayas in India treasures a trove of fragrant medicinal herbs that are natural antioxidants and antibacterial. The essential oil of Skimmia laureola from Kedarnath Wildlife Sanctuary, Uttarakhand is studied for its phytochemical composition, antioxidant and antibacterial activities in order to develop novel natural medicines. The fresh leaves of Skimmia laureola were exposed to hydro-distillation and the mined essential oil was scrutinized using gas chromatography -mass spectrometric (GC-MS) techniques. The antioxidant effect was analyzed by DPPH method. The antibacterial activity was examined against pathogenic bacteria like Escherichia coli, Citrobacter brundii, Staphylococcus aureus, Enterococcus faecalis, Salmonella typhimurium, Proteus vulgaris, Bacillus subtilis, Klebsiella pneumonia, Salmonella enterica typhi, Staphylococcus epidermidis and Streptococcus pyogenes by agar well diffusion method. The obtained oil yield was 0.72% v/w on fresh weight basis having 24 components. The main phytoactive components found in Skimmia laureola essential oil are Linalyl anthranilate (1, 6-Octadien-3-ol, 3, 7-dimethyl-, 2-aminobenzoate) (46.93%) and L-linalool (18.52%). The in vitro antioxidant study revealed concentration-dependent antioxidant activity with $${\text{I}\text{C}}_{50}$$ value. The extracted oil also revealed strong antibacterial action against Escherichia coli and Staphylococcus aureus with the MIC of 6.25 mg ml−1 and ZOI of 19.00 mm for both. The antioxidant activity and sturdy antibacterial activity against bacteria like Escherichia coli and Staphylococcus aureus might be owing to the presence of Linalyl anthranilate, L-linalool etc. having antioxidant and antimicrobial effects. Thus, Skimmia laureola essential oil possesses significant natural antioxidant and antibacterial properties, making it a safer choice for managing resistant bacterial infections.

In vitro antioxidant activities of Carissa edulis ((Forssk) Vahl) and Pappea capensis (Eckyl. & Zeyh) extracts

Herbal medications are gaining popularity due to their long history of use in traditional medicine. They serve as a reservoir for a diverse array of phytocompounds linked to amelioration of oxidative stress. Oxidative stress is a disturbance in the balance between generation and elimination of reactive species in human body. Moreover, reactive species are implicated in the onset and progression of chronic disorders. The current therapeutic approaches despite showing efficacy are characterized by several limitations such as adverse effects and prohibitive costs. This drives the need to explore alternatives that can inhibit, ameliorate or reverse conditions caused by oxidative stress. Several studies have evaluated antioxidant effects of diverse plant extracts. C. edulis and P. capensis are used as traditional therapy among the African communities to manage oxidative stress-related ailments. However, there is limited research on the antioxidant effects of these medicinal plants. The current study, therefore, sought to evaluate the antioxidant and phytochemical profile, of C. edulis and P. capensis extracts. Samples were collected from Embu County, Kenya. In vitro antioxidant properties of the extracts were evaluated through ferric reduction, Iron chelating, hydroxyl radical, and DPPH radical scavenging activities. Activities of catalase, superoxide dismutase and glutathione reductases of the extracts were further determined. Phytochemical profiles were determined using Liquid Chromatography Mass Spectrophotometer (LC-MS) and Gas Chromatography Mass Spectrophotometer (GC-MS) analyses. The extracts displayed concentration dependent antioxidant activities. Phytochemical analyses revealed presence compounds which are associated with antioxidant activities including flavonoids, phenolics, tocopherols and terpenoids. The findings provide a scientific validation for the folklore use of C. edulis and P. capensis in management of oxidative stress. Nevertheless, there is a need for further purification and characterization of phytochemicals associated with antioxidant activities.

Leonotis nepetifolia Flower Bud Extract Mediated Green Synthesis of Silver Nanoparticles, Their Characterization, and In Vitro Evaluation of Biological Applications.

Biosynthesis of silver nanoparticles (AgNPs) using the green matrix is an emerging trend and is considered green nanotechnology because it involves a simple, low-cost, and environmentally friendly process. The present research aimed to synthesize silver nanoparticles from a Leonotis nepetifolia (L.) R.Br. flower bud aqueous extract, characterize these nanoparticles, and perform in vitro determination of their biological applications. UV-Vis spectra were used to study the characterization of biosynthesized L. nepetifolia-flower-bud-mediated AgNPs (LnFb-AgNPs); an SPR absorption maximum at 418 nm confirmed the formation of LnFb-AgNPs. The presumed phytoconstituents subjected to reduction in the silver ions were revealed by FTIR analysis. XRD, TEM, EDS, TGA, and zeta potential with DLS analysis revealed the crystalline nature, particle size, elemental details, surface charge, thermal stability, and spherical shape, with an average size of 24.50 nm. In addition, the LnFb-AgNPs were also tested for antimicrobial activity and exhibited a moderate zone of inhibition against the selected pathogens. Concentration-dependent antioxidant activity was observed in the DPPH assay. Further, the cytotoxicity increased proportionate to the increasing concentration of the biosynthesized LnFb-AgNPs with a maximum effect at 200 μg/mL by showing the inhibition cell viability percentages and an IC50 of 35.84 μg/mL. Subsequently, the apoptotic/necrotic potential was determined using Annexin V/Propidium Iodide staining by the flow cytometry method. Significant early and late apoptosis cell populations were observed in response to the pancreatic ductal adenocarcinoma (PANC-1) cell line, as demonstrated by the obtained results. In conclusion, the study's findings suggest that the LnFb-AgNPs could serve as remedial agents in a wide range of biomedical applications.

Antimicrobial, Total Phenolic Content and Free Radical Scavenging Activity Determination of the Centella asiatica extract

Centella asiatica is a popular medicinal plant that has a long history of usage as a traditional medicine that is used for neurological disease, skin disease, immune disease, and others. Nowadays, there is a wide array of Centella asiatica -based products. Although Centella asiatica was claimed to be having an established profile on the free radical scavenging activity, total phenolic content and antimicrobial activity of Centella asiatica but there is still a lack of detailed study that focuses on those properties. This study aims to fill the gap in the previous research, especially on the antimicrobial activity of C. asiatica. This study is worth examining because it helps to assure the effectiveness of C. asiatica medicinal products on the market. The antioxidant activity and total phenolic content of the plant extract were examined by using DPPH assay and Folin-Ciocalteu method respectively. Based on the findings, C. asiatica was found to be having concentration-dependent antioxidant activity with the highest radical scavenging activity recorded at 52.7% at 100 μg/mL. For total phenolic concentration wise, 1mg/ml maceration and soxhlet extract of C. asiatica were found to be having 20.74 and 27.48 μg/mL Gallic acid equivalent (GAE) respectively. The antimicrobial activity was determined by using the modified broth dilution method. Based on the findings, C. asiatica was found to be effective against E. coli, K. pneumonia, and S. epidermidis with the MIC recorded at 4mg/ml. On the other hand, B.pumilus did not portray sensitivity against C. asiatica at the tested concentration. This study is significant as it verifies the antioxidant activity, total phenolic content, and antimicrobial activity of the plant extract successfully.