Porphyra yezoensis Sauces Fermented With Lactic Acid Bacteria: Fermentation Properties, Flavor Profile, and Evaluation of Antioxidant Capacity in vitro

The demand for roasted seaweed sandwich (Porphyra yezoensis) product has risen in recent years. The product slicing process has created a huge number of scraps that are not utilized effectively. Three lactic acid bacteria (LAB) strains were used to ferment P. yezoensis sauces in this study, including Lactobacillus fermentum, Lactobacillus casei, Streptococcus thermophilus, and the mixed strains (1:1:1, v/v). The fermentation characteristics, antioxidant capacity in vitro, sensory properties, and flavoring substances of fermented P. yezoensis sauces were analyzed. After 21 days of fermentation, all LAB strains grew well in the P. yezoensis sauces, with protease activity increased to 6.6, 9.24, 5.06, and 5.5 U/mL, respectively. Also, the flavors of P. yezoensis sauces fermented with L. casei and L. fermentum were satisfactory. On this premise, gas chromatography-mass spectrometry (GC-MS) was used to investigate the changes in gustatory compounds in P. yezoensis sauces fermented with L. casei and L. fermentum. In general, 42 and 41 volatile flavor chemicals were identified after the fermentation of L. casei and L. fermentum. Furthermore, the fermented P. yezoensis sauce possessed greater DPPH scavenging activity and ferric-reducing ability power than the unfermented P. yezoensis. Overall, the flavor and taste of P. yezoensis sauce fermented by L. casei was superior.

Study on Synergistic Antioxidant Effect of Typical Functional Components of Hydroethanolic Leaf Extract from Ginkgo Biloba In Vitro

The predicted anti-oxidation is related to apoptosis, proliferation, lipid metabolism, cell differentiation, and immune response. There are some differences in the antioxidant capacity of the four typical components of ginkgo biloba extract (EGb) including ginkgo flavone (GF), ginkgolide (G), procyanidins (OPC), and organic acids (OA), and any two members of them can exhibit apparent synergistic effects. The order of DPPH scavenging ability was: OPC > GF > OA > G. The scavenging ability of procyanidins was close to that of VC; the scavenging capacity of ABTS was GF > OPC > OA > G. The GF:OPC (1:9) showed the best synergism in scavenging DPPH and ABTS radicals. The 193 kinds of small molecules reported in EGb were obtained by analyzing the properties of EGb. In order to construct a corresponding biological activity target set, molecular docking and the network pharmacology method were employed to build the molecular action mechanism network of a compound target, and the main biological functions and signaling pathways involved with their antioxidant activities were predicted. The results displayed that the top ten compounds which belonged to the two broad categories, ginkgo flavonoids and proanthocyanidins, could interact closely with several important target proteins (CASP3, SOD2, MAPK1, HSPA4, and NQO1). This would be expected to lay a theoretical foundation for the deep development of Ginkgo biloba extract.

Production Process of a Carbonated Drink from Red Flesh Dragon Fruit (Hylocereus polyrhizus)

The purpose of this study is to present a suitable production process of a carbonated drink from ingredients originated from red flesh dragon fruits. Additionally, optimal parameters in the hydrolysis and pasteurization stages of the juice were determined so that the product could retain the highest bioactive ingredients while still maintaining favorable color. The investigated parameters of pectinase hydrolysis process included hydrolysis temperature (35, 40, 45 and 50oC), hydrolysis time (1 hour, 2 hours, 3 hours and 4 hours), concentration pectinase enzyme level (0.4; 0.6, 0.8 and 1%) and enzyme pectinase content (0.2, 0.4, 0.6 and 0.8%). Outcomes which were considered in optimization processes included polyphenol content, vitamin C content and DPPH scavenging activity. The results are expected to aid in diversification of products from dragon fruit raw materials to meet the increasing demand of consumers.

Physiological responses of resistant and susceptible pepper plants to exogenous proline application under Phytophthora capsici stress

Phytophthora capsici Leon. is the main pathogen that limits the production of peppers. In this study, the effects of 1 and 10 mM proline (Pro), prior to exposure of resistant (CM-334) and susceptible (SD-8) pepper seedlings to P. capsici, on some physiological parameters were investigated. A lower Pro concentration (1 mM) was found to be more effective than 10 mM Pro in increasing the stress tolerance of the CM-334 cultivar. Namely, in CM-334 cultivar, the highest chlorophyll a, chlorophyll b, carotenoid, glucose and fructose content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity percentage were detected on the seventh day after application of 1 mM Pro + P. capsici, while the lowest malondialdehyde (MDA) amount was measured on the third day in the same treatment. The highest ferric reducing antioxidant power (FRAP) increase was determined on the seventh day in the 10 mM Pro + P. capsici application. The effects of the same Pro treatments on the SD-8 cultivar somewhat differed; the highest amounts of chlorophyll a, chlorophyll b, anthocyanins, fructose, total protein and endogenous Pro were detected on the seventh day in the 1 mM Pro + P. capsici application, while the lowest MDA amount was measured on the third day after the 10 mM Pro + P. capsici application, the highest DPPH % and FRAP values were detected on the seventh day with 10 mM Pro + P. capsici application. Although some differences were detected between the cultivars, Pro application against the P. capsici stress in general resulted in a positive effect on photosynthetic pigments, soluble carbohydrates and antioxidant capacity in pepper. The exogenous application of Pro helped the non-resistant cultivar to overcome the stress.

Antioxidant and Antibacterial Activities of Four Underutilized Fruits of Bangladesh

Antioxidant and antibacterial activities of four underutilized fruits namely Jujube (Ziziphus mauritiana Lam.), Olive (Elaeocarpus serratus L.), Roselle (Hibiscus sabdariffa L.), and Taikor (Garcinia pedunculata Roxb.) commonly found in Bangladesh were evaluated. The highest total phenolic content (685.08 ± 27.65 mg GAE/100 ml) and total flavonoid content (148.18 ± 0.40 mg QE/100 ml) were found in Taikor extract, which compliance with its highest DPPH scavenging activity and antibacterial properties. It exerted a significantly higher (p ≤ 0.05) zone of inhibition against Escerichia coli, Staphylococcus spp. and Pseudomonas spp. than the other experimented fruit extracts. The antioxidant activity was found as Taikor (43.15 ± 1.61%)> Roselle (33.07 ± 1.61%) > Olive (28.68 ± 0.78%) > Jujube (24.81 ± 1.34%). Bacillus spp. are found to be more susceptible to the experimented sample extracts. Fruit samples studied may be utilized as potential sources of natural antioxidants and antibacterial compounds, and their extracts may be used as natural biopreservatives to extend the shelf life of foodstuffs. Bangladesh J. Bot. 50(4): 1035-1039, 2021 (December)

Antioxidant, Analgesic and CNS Depressant Activities of Commelina diffusa Burm. f.

Commelina diffusa Burm. f. is a member of Commelinaceae family, which is widely grown in crop land and treated as a weed. This plant has several important medicinal properties which have not been studied extensively. In this study, the crude powder of C. diffusa whole plant was extracted with 95% ethanol and different solvent fractions (n-hexane, chloroform and methanol) were prepared from the crude extract by solvent-solvent partitioning. All these plant samples were subjected to bioassays for evaluating the antioxidant, central analgesic, peripheral analgesic and CNS depressant activities. The crude extract and its methanol soluble fraction showed mild free DPPH scavenging property with IC50 values of 98.49- and 84.77-μg/ml, respectively as compared to the standard ascorbic acid (IC50 = 2.67 μg/ml). In the analgesic activity test, the n-hexane fraction of C. diffusa at doses of 200- and 400-mg/kg body weight exhibited significant (p<0.05) central analgesic activity (tail flick test) in mice. Similarly, all the test samples showed statistically significant (p<0.05) reduction in abdominal writhing induced by acetic acid. C. diffusa showed significant CNS depressant activity which was measured by ‘open field test’ and ‘hole cross test’. Considering the potential bioactivities, the plant materials can be further studied elaborately to explore the activities of the purified compounds to aid in future drug development. Dhaka Univ. J. Pharm. Sci. 20(2): 159-166, 2021 (December)

Evaluation of in-Vitro antioxidant and antidiarrheal activities of Peperomia Pellucida methanol extracts on Albino mice

Peperomia pellucida also known as shiny bush is a common plant wildly distributed in the tropical regions of the world including Nigeria. In ethnomedicine, it is used to treat hemorrhages, fevers, lower cholesterol levels and serves as a cough suppressant, emollient, and diuretic. This study evaluated the in vitro and antidiarrhea activities of Peperomia pellucida. For the in vitro antioxidant assay the following methods were used: 2-diphenyl-2-pierylhydrazylhydrate (DPPH) scavenging activity, Superoxide scavenging activity, Hydrogen peroxide scavenging activity, Lipid Peroxidation Assay, Total Antioxidant Capacity, 2,2’-Azinobis (3-Ethylbenzothiazoline-6-sulphonic Acid) (ABTS) radical scavenging activity and Hydroxyl radical scavenging activity. Antidiarrheal activities were studied using Castor Oil-Induced and Intestinal Transit in Mice models. Methanol and aqueous plant extract of Peperomia pellucida at various concentration demonstrated impressive in vitro antioxidant scavenging activities. The onset of diarrheal (**P<0.01) and the % of charcoal travel (*P<0.05) in the mice was reduced at 200 mg/kg compared to the control. Conclusively, this study showed that the aqueous and methanol extract of Peperomia pellucida has in vitro free radical scavenging activities. The plant demonstrated antidiarrheal activities.

Chemical Composition and Antiproliferative and Antioxidant Activities of Methanolic Extract of Alcea setosa A. Malvaceae

Alcea setosa A. (Malvaceae) is a wild plant that grows in Jordan and have several traditional medicinal uses. This study aims to collect and chemically analyze the methanolic extract from Alcea setosa A. from Jordan and to evaluate its cytotoxic and antioxidant activity against human breast cancer cells (T47D), colorectal adenocarcinoma cells (CACO2), and normal human fibroblasts (MRC5). The extract was extracted by methanol solvent and analyzed by liquid chromatography coupled with a mass spectrometer. Cell viability was assessed using trypan blue, neutral red, and MTT assays, and antioxidant activity was evaluated using DPPH scavenging activity assay. A total of 290 compounds, 12 among which were identified when compared to available standards, the extract contained six flavons derivatives, Two fatty acids, one ketone derivative, one flavonol derivative, one organic acid, and one coumarin derivative. The results also revealed that the IC50 values of the viability assays were higher among normal cells compared to the human cancer cell lines, and the viability inhibition was significant at higher concentrations compared to untreated cells. Nevertheless, moderate antioxidant activity was observed for the extract in the DPPH scavenging activity test. To sum up, this study indicates that samples of A. setosa collected from Jordan is likely to be an effective antioxidant, is optimistically potential to be utilized in breast and colon cancers treatment due to its preferential cytotoxicity against cancer cells.

Antioxidant p-terphenyl compound, isolated from edible mushroom, Boletopsis leucomelas

A new acetyl p-terphenyl derivative, boletopsin 15, was isolated from the ethyl acetate extract of fruit bodies of the Basidiomycete Boletopsis leucomelas, together with four known compounds. The structures of these compounds were elucidated by spectral analysis, as well as by directly comparing the spectral data of the new compound with those of known compounds. The free radical-scavenging activity of the compounds was assayed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The results showed that compounds 1 and 2 exhibited significant antioxidant activity (1: EC50 = 2.1 μM and 2: EC50 = 6.6 μM).

Effect of Preservation Methods on Physicochemical Quality, Phenolic Content, and Antioxidant Activity of Stevia Leaves

The effect of freeze-drying and gamma irradiation at 0.5, 1, and 2 kGy on the physicochemical composition (moisture, fat, ash, mineral, and chlorophyll contents), microstructure, total phenolic content, and antioxidant capacity of stevia leaves was investigated in the present study. The results obtained indicated that freeze-drying and gamma irradiation treatments caused significant reduction ( p ≤ 0.05) of moisture and fat contents in comparison with those of commercial leaves, while ash content was not significantly affected. Mineral composition was analysed. Among the analysed elements, potassium and iron levels were higher in the freeze-dried and irradiated samples, respectively. The microstructure was analysed using a scanning electron microscope. Micrographs revealed that a higher porous size structure was obtained by freeze-drying, and degradation of cell wall structure was more clearly visualized by irradiation at 2 kGy. However, the main functional groups were stable as confirmed by Fourier transform infrared spectroscopy analysis. The effects on chlorophyll content, phenolic profile, and antioxidant properties were evaluated before and after ten months of storage. In terms of chlorophyll contents, the freeze-dried leaves exhibited the highest content. Chlorophylls a and b decreased when storage progressed for freeze-dried leaves as well as for gamma-irradiated leaves. Both preservation methods gave significant advantages in increasing the total phenolic content and DPPH scavenging activity. Moreover, a significant increase of bioactive compounds and antioxidant activity was observed as the gamma irradiation dose increased. In addition, the storage time increased the amounts of polyphenols and DPPH scavenging activity. After 10 months of storage, gamma-irradiated leaves had the highest total phenolic content as well as the DPPH scavenging activity followed by freeze-dried leaves. The results indicate that freeze-drying and gamma irradiation at the studied doses could be effective postharvest methods for preservation of stevia leaf quality.