Antioxidant potential and α-glucosidase inhibitory activity of onion (Allium cepa L.) peel and bulb extracts

Allium cepa L. is a commonly consumed vegetable that belongs to the Amaryllidaceae family and contains nutrients and antioxidants in ample amounts. In spite of the valuable food applications of onion bulb, its peel and outer fleshy layers are generally regarded as waste and exploration of their nutritional and therapeutic potential is still in progress with a very slow progression rate. The present study was designed with the purpose of doing a comparative analysis of the antioxidant potential of two parts of Allium cepa, i.g., bulb (edible part) and outer fleshy layers and dry peels (inedible part). Moreover, the inhibitory effect of the onion bulb and peel extracts on rat intestinal α-glucosidase and pancreatic α-amylase of porcine was also evaluated. The antioxidant potential of onion peel and bulb extracts were evaluated using 2,2-diphenyl- 1-picryl hydrazyl (DPPH), ferric-reducing antioxidant power assay (FRAP), 2,2’-azino-bis- 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay, H2O2 radical scavenging activity and Fe2+ chelating activity. Total flavonoids and phenolic content of ethanolic extract of onion peel were significantly greater as compared to that of onion bulb. Ethanolic extract of onion peel also presented better antioxidant and free-radical scavenging activity as compared to the ethanolic extract of bulb, while the aqueous extract of bulb presented weakest antioxidative potential. Onion peel extract’s α-glucosidase inhibition potential was also correlated with their phenolic and flavonoid contents. The current findings presented onion peel as a possible source of antioxidative agents and phenolic compounds that might be beneficial against development of various common chronic diseases that might have an association with oxidative stress. Besides, outer dry layers and fleshy peels of onion exhibited higher phenolic content and antioxidant activities, compared to the inner bulb. The information obtained by the present study can be useful in promoting the use of vegetable parts other than the edible mesocarp for several future food applications, rather than these being wasted.

Antioxidant and antimicrobial activities of Thymus vulgaris essential oil contained and synthesis thymus (Vulgaris) silver nanoparticles

Several species of thymus have therapeutic properties, so they are used in traditional medicine. In this work was carried out to synthesize Thymus vulgalis silver nanoparticles (TSNPS) and evaluate antioxidant and antimicrobial activities of TSNPS and T. vulgalis essential oil extract (TEOE). The essential oils analyzed by GC-MS and were characterized. Major compounds of phenol, 2 methyl 5 (1 methylethyle) (CAS), thymol and 1,2 Benzene dicarboxylic acid, 3 nitro (CAS) (48.75%, 32.42% and 8.12%, respectively) were detected. Results demonstrated that the TSNPS gave a highest DPPH radical scavenging activity, it was obtained 97.2 at 1000 ug/ml. TSNPS, Thymus + Hexane (T+H), Thymus + Ethanol (T+E) gave the greatest antimicrobial activity than amoxicillin (AM) and ciprofloxacin (CIP). In conclusion: The essential oil of thymus (Vulgaris) and thymus (Vulgaris) silver nanoparticles can be a good source of natural preservatives as an antioxidant and antimicrobial agents for increasing the shelf life of foodstuffs.

Antioxidant Extract from Cleistocalyx nervosum var. paniala Pulp Ameliorates Acetaminophen-Induced Acute Hepatotoxicity in Rats

The indigenous purplish red fruit, Cleistocalyx nervosum var. paniala (CN), is grown in northern Thailand. The aqueous extract of CN pulp is known to exhibit antioxidant and anticarcinogenic properties. To search for an antioxidant fraction separated from CN, various hydroalcoholic extractions were performed. The acidified ethanolic extract of CN obtained from 0.5% (v/v) citric acid in 80% (v/v) ethanol yielded greater polyphenol content and DPPH radical scavenging activity when compared with other hydroethanolic extracts. Cyanidin-3-glucoside is a major anthocyanin present in the acidified ethanolic extract of CN (AECN). At a dose of 5000 mg/kg bw, an anthocyanin-rich extract was found to be safe when given to rats without any acute toxicity. To examine the hepatoprotective properties of AECN, an overdose of acetaminophen (APAP) was induced in a rat model, while silymarin was used as a standard reference. The administration of AECN at a dose of 300 mg/kg bw for 28 days improved hepatocyte architecture and modulated serum alanine aminotransferase levels in APAP-induced rats. Furthermore, it significantly decreased serum and hepatic malondialdehyde levels but increased hepatic glutathione content, as well as glutathione peroxidase and UDP-glucuronosyltransferase activities. In conclusion, AECN may effectively reduce oxidative stress induced acute hepatotoxicity in overdose APAP-treated rats through the suppression of oxidative stress and the enhancement of the antioxidant system in rat livers.

Analyses of the oil content, fatty acid composition, and antioxidant activity in seeds of Thlaspi arvense L. from different provenances and correlations with environmental factors

Background Pennycress (Thlaspi arvense L.) is an annual herbaceous plant of the Cruciferae family that has attracted attention as an oil crop and interseeded cover crop. We collected seeds of pennycress from five provenances in Northeast China, compared their characteristics, i.e. oil content, fatty acid composition, physical, chemical and antioxidant properties, their correlations with environmental factors were also analysed. Results There were significant differences in the seed characteristics, oil content, quality indicators and composition among different provenances (P < 0.05). The 1000-seed weight ranged from 0.80 to 1.03 g; seed oil content from 28.89 to 42.57%; iodine from 79.19 to 99.09; saponification value from 186.51 to 199.60; peroxide value from 0.07 to 10.60; and acid value from 0.97 to 13.02. The range of seed oil colours were 66.53–78.78 (L*), 4.51–10.29 (a*), and 105.68–121.35 (b*). Erucic acid (C22:1) was the fatty acids with the highest content in pennycress seed oils (31.12–35.31%), followed by linoleic acid (C18:2 16.92–18.95%) and α-linolenic acid (C18:3 14.05–15.34%). The fatty acid 8,11,14-eicosatrienoic acid (C20:3) was detected for the first time in seed oils from Beian city, Panshi city and Kedong county, with contents of 1.13%, 0.84% and 1.03%, respectively. We compare and report for the first time on the radical-scavenging activity of the seed oils of pennycress. The EC50 values of the DPPH radical-scavenging activity and ABTS+ radical-scavenging activity of the seed oils from different provenances were 8.65–19.21 mg/mL and 6.82–10.61 mg/mL, respectively. The ferric ion reduction antioxidant capacity (FRAP) ranged from 0.11 to 0.30 mmol Fe2+/g, which is equivalent to 4 mg/mL FeSO4 of pennycress seed oils. Conclusions There was a significant correlation between seed characteristics and changes in geographical factors. With increasing longitude, the thickness of seeds, 1000-seed weight, and seed oil content increased, while the acid and peroxide values of the seed oil decreased. As the latitude increased, the 1000-seed weight and seed oil content increased, while the seed oil peroxide value decreased. Furthermore, mean annual temperature and annual rainfall are the two key environmental factors affecting the quality of pennycress. Graphical Abstract

Synthesis of Silver Nanoparticles Using Flavonoid Hesperidin and Pharmacological Evaluation of its Free Radical Scavenging Activity

Background: Silver Nanoparticles are drawing significant attention from the scientific community to explore a wide range of its medical applications. Human body is under constant stress due to free radicals generated by the physiological and pathological conditions in the body. Scavenging systems or Antioxidants can help alleviate the damages caused by these radicals which can influence the course of progress in several chronic diseases with an inflammatory background. External antioxidants supplement and facilitate the overwhelmed scavenging systems in the body.Silver Nanoparticles can enhance the therapeutic effects of phytochemicals. Aim: To Synthesize silver nanoparticles using the phytochemical Hesperidin and studying its Free radical scavenging activity. Methods: Silver Nanoparticles are synthesized using chemical reduction method. The synthesis is confirmed using spectrophotometric studies. Free Radical scavenging activity is detected using 1, 1-diphenyl-2-picrylhydrazyl (DPPH •) free radical scavenging assay. Results: Silver nanoparticles were successfully synthesized which was confirmed by the change in color of the solution and peak absorbance peak at 420 nM on spectrophotometric studies.Hesperidin Silver Nanoparticles exhibited higher free radical scavenging activity when compared with pure hesperidin and standard Ascorbic acid. Conclusion: Hesperidin can ideally be used for the synthesis of silver nanoparticles and the synthesized Silver Nanoparticles enhances the free radical scavenging activity of Hesperidin which can further be evaluated by In Vivo studies.

Radical scavenging activity of fruit extracts Tribulus Terrestris with natural antioxidant Ascorbic acid: A comparative study

The main aim of this work was to analyze through a systematic review the ability of Tribulusterrestris to promote the increase of hormonal levels as a mechanism for the relief of menopausal symptoms. The criteria used for the selection were: studies involving menopausal women and use of Tribulusterrestris as a treatment for sexual dysfunction and / or other menopausal symptoms. The survey of literature shows that women who used Tribulusterrestris had drastic improvement in symptoms such as vaginal lubrication, sensation in the genitals during intercourse and other constructive activities. In this study, we have found a significant increase in bioavailable testosterone after the use of the plant extracts which has great potential in the treatment of sexual intercourse and unique symptoms of menopause.

Comparative Study of the Characterisation and Extraction Techniques of Polyphenolic Compounds from Acacia seyal gum

Abstract Acacia seyal gum is an abundant source of natural polyphenolic compounds (NPPCs) and antioxidant activity with numerous benefits and is often used in cancer treatment. The type of extraction technique can significantly impact the yield and isolation of NPPCs from Acacia seyal gum (ASG). The traditional use of maceration extraction reportedly yields fewer NPPCs. Objectives This study investigates five extraction techniques for NPPCs and ASG antioxidant activity, namely: homogenisation, shaking, ultrasonication, magnetic stirring, and maceration. Materials and Methods The evaluation of the antioxidant activity (AoA) of the extracted NPPCs from ASG used five assays, namely: Total Flavonoids Content (TFC), Folin-Ciocalteu index (FCI), 2,2-Diphenyl-1-Picrylhydrazyl radical scavenging activity (DPPH), Ferric Reducing Antioxidant Power (FRAP), and Cupric Reducing Antioxidant Capacity (CUPRAC). Results To minimise the dataset dimensionality requires Principal Component Analysis. The ultrasonic and maceration techniques were the best techniques to extract NPPCs and examine the AoA of ASG, with a high correlation between the NPPCs and AoA. However, the maceration process was slow (12 h) compared to ultrasonication (1 h). Slow extraction can result in a decline of the NPPCs due to polyphenol oxidase-enzyme and impact productivity. Conclusions These findings provide an essential guide for the choice of extraction techniques for the effective extraction of NPPCs from ASG and other plant materials.

Decreased Human Platelet Activation and Mouse Pulmonary Thrombosis by Rutaecarpine and Comparison of the Relative Effectiveness with BAY11-7082: Crucial Signals of p38-NF-κB

Platelets play a critical role in arterial thrombosis. Rutaecarpine (RUT) was purified from Tetradium ruticarpum, a well-known Chinese medicine. This study examined the relative activity of RUT with NF-κB inhibitors in human platelets. BAY11-7082 (an inhibitor of IκB kinase [IKK]), Ro106-9920 (an inhibitor of proteasomes), and RUT concentration-dependently (1–6 μM) inhibited platelet aggregation and P-selectin expression. RUT was found to have a similar effect to that of BAY11-7082; however, it exhibits more effectiveness than Ro106-9920. RUT suppresses the NF-κB pathway as it inhibits IKK, IκBα, and p65 phosphorylation and reverses IκBα degradation in activated platelets. This study also investigated the role of p38 and NF-κB in cell signaling events and found that SB203580 (an inhibitor of p38) markedly reduced p38, IKK, and p65 phosphorylation and reversed IκBα degradation as well as p65 activation in a confocal microscope, whereas BAY11-7082 had no effects in p38 phosphorylation. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay shows that RUT and BAY11-7082 did not exhibit free radical scavenging activity. In the in vivo study, compared with BAY11-7082, RUT more effectively reduced mortality in adenosine diphosphate (ADP)-induced acute pulmonary thromboembolism without affecting the bleeding time. In conclusion, a distinctive pathway of p38-mediated NF-κB activation may involve RUT-mediated antiplatelet activation, and RUT could act as a strong prophylactic or therapeutic drug for cardiovascular diseases.

Variations in the Composition, Antioxidant and Antimicrobial Activities of Cystoseira compressa during Seasonal Growth

The underexplored biodiversity of seaweeds has recently drawn great attention from researchers to find the bioactive compounds that might contribute to the growth of the blue economy. In this study, we aimed to explore the effect of seasonal growth (from May to September) on the in vitro antioxidant (FRAP, DPPH, and ORAC) and antimicrobial effects (MIC and MBC) of Cystoseira compressa collected in the Central Adriatic Sea. Algal compounds were analyzed by UPLC-PDA-ESI-QTOF, and TPC and TTC were determined. Fatty acids, among which oleic acid, palmitoleic acid, and palmitic acid were the dominant compounds in samples. The highest TPC, TTC and FRAP were obtained for June extract, 83.4 ± 4.0 mg GAE/g, 8.8 ± 0.8 mg CE/g and 2.7 ± 0.1 mM TE, respectively. The highest ORAC value of 72.1 ± 1.2 µM TE was obtained for the August samples, and all samples showed extremely high free radical scavenging activity and DPPH inhibition (>80%). The MIC and MBC results showed the best antibacterial activity for the June, July and August samples, when sea temperature was the highest, against Listeria monocytogenes, Staphylococcus aureus, and Salmonella enteritidis. The results show C. compressa as a potential species for the industrial production of nutraceuticals or functional food ingredients.