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)

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.

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.

Antioxidant and antimicrobial studies of nanochitosan, carboxymethyl cellulose and graphene oxide binary and ternary composites

The present study aimed to prepare binary and ternary composites of nanochitosan (NCS), carboxymethyl cellulose (CMC) and graphene oxide (GO) for the biological and biomedical application. The prepared NCS/CMC, CMC/GO and NCS/CMC/GO composites were characterized using FTIR, XRD and SEM studies. The results revealed the suitability of the material for biological application with increased amorphous nature for cell adhesion. Antimicrobial studies were carried out against selected bacterial and fungal species. DPPH scavenging activity was done for the prepared biocomposites. NCS/CMC/GO ternary composite have the highest action against Bacillus sp (21 mm) followed by Klebsilla sp. (19 mm) and Proteus sp. (16 mm). For selected fungal species of Candida, Rhizopus and Aspergillus niger the ternary composites shows 28 mm, 26 mm and 24 mm inhibitory zone. The overall results exhibit the potential antioxidant and antimicrobial activity of the prepared composites.

Antioxidant Activity and Anti-Nutritional Factors in Acacia Nilotica Gum

The rapidly growing civilization and economy need the judicious usage of floral and faunal heritage. Acacia nilotica (Family: Fabaceae) is a beneficial plant species and each part of it exhibits numerous biological and pharmacological effects. The gum exudates of Acacia nilotica trees are underutilized plant products that can be explored for their potential as a therapeutic and curative agent. Its nutritional composition, interaction with anti-nutritional factors and antioxidants can determine its utility as a food. The present investigation was aimed to estimate the anti-nutritional factors and antioxidant activity of Acacia nilotica gum. It also focused on establishing a relationship of the obtained data with the ethnomedicinal and pharmacological properties claimed in the literature. The analysis was carried out using standard methods and protocols involving spectrophotometric and gravimetric principles. The anti-nutritional components like tannin, trypsin inhibitor, phytate, oxalate, total saponin, steroidal saponins, alkaloid content of Acacia nilotica gum was found to be 0.2369±0.0354 g tannic acid equivalent/100 g, 0.0108±0.0037 TIU/mg, 156.3333±9.4516 mg/100 g, 132.5±28.3152mg/100 g, 12.7183±6.7788 mg diosgenin equivalent /g, 0.0705±0.01 mg diosgenin equivalent /g, 0.1333±0.0577 g/100 g respectively. The amounts of total phenols and flavonoids was determined to be 8.0033±2.7211 mg of gallic acid equivalent/g sample, 0.0458±0.0186 mg quercetin equivalent /g sample respectively with a significant DPPH Scavenging activity. The results indicate that the quantity of anti-nutritional factors in gum is within the range of the contents of anti-nutritional factors found in commonly consumed foods. The substantial presence of phenol, flavonoids and DPPH activity in the gum indicates the presence of high antioxidant properties. The presence of anti-nutritional factors and antioxidants in favourable levels can impart diverse physiological responses. The present study concluded that Acacia nilotica gum can be used as a nutritious food commodity with a plethora of recuperative activities.

Antioxidant Activity and Anti-Nutritional Factors in Acacia Nilotica Gum

The rapidly growing civilization and economy need the judicious usage of floral and faunal heritage. Acacia nilotica (Family: Fabaceae) is a beneficial plant species and each part of it exhibits numerous biological and pharmacological effects. The gum exudates of Acacia nilotica trees are underutilized plant products that can be explored for their potential as a therapeutic and curative agent. Its nutritional composition, interaction with anti-nutritional factors and antioxidants can determine its utility as a food. The present investigation was aimed to estimate the anti-nutritional factors and antioxidant activity of Acacia nilotica gum. It also focused on establishing a relationship of the obtained data with the ethnomedicinal and pharmacological properties claimed in the literature. The analysis was carried out using standard methods and protocols involving spectrophotometric and gravimetric principles. The anti-nutritional components like tannin, trypsin inhibitor, phytate, oxalate, total saponin, steroidal saponins, alkaloid content of Acacia nilotica gum was found to be 0.2369±0.0354 g tannic acid equivalent/100 g, 0.0108±0.0037 TIU/mg, 156.3333±9.4516 mg/100 g, 132.5±28.3152mg/100 g, 12.7183±6.7788 mg diosgenin equivalent /g, 0.0705±0.01 mg diosgenin equivalent /g, 0.1333±0.0577 g/100 g respectively. The amounts of total phenols and flavonoids was determined to be 8.0033±2.7211 mg of gallic acid equivalent/g sample, 0.0458±0.0186 mg quercetin equivalent /g sample respectively with a significant DPPH Scavenging activity. The results indicate that the quantity of anti-nutritional factors in gum is within the range of the contents of anti-nutritional factors found in commonly consumed foods. The substantial presence of phenol, flavonoids and DPPH activity in the gum indicates the presence of high antioxidant properties. The presence of anti-nutritional factors and antioxidants in favourable levels can impart diverse physiological responses. The present study concluded that Acacia nilotica gum can be used as a nutritious food commodity with a plethora of recuperative activities.

Flavonoids from the Roots of Amomum compactum Soland Ex Maton (Zingiberaceae)

Amomum compactum Soland Ex Maton is one of the Zingiberaceae family plants which is the endemic plants from West Java, Indonesia. This study was aimed to determine the chemical structure of flavonoid compounds from n-hexane extract of A.compactum Sol. Ex Maton roots. Dried powder of the roots was extracted consecutively with n-hexane, ethyl acetate, and methanol solvents. Three flavonoids, 5-hydroxy-3,7,4`-trimethoxy kaempferol (1), 5-hydroxy-3,7,3',4'-tetra methoxy kaempferol (2) and 4'-hydroxy-3,5,7-trimethoxy kaempferol (3), have been isolated from the roots of A. compactum Sol. Ex Maton. The chemical structures of compounds 1-3 were identified by spectroscopy data including infrared 1D-NMR, 2D-NMR and HRTOF-MS as well as by comparison with previously reported spectral data. Compounds 1-3 were isolated from this plant for the first time and showed free radical DPPH scavenging activity.

Valorization of Fig (Ficus carica L.) Waste Leaves: HPLC-QTOF-MS/MS-DPPH System for Online Screening and Identification of Antioxidant Compounds

Fig (Ficus carica L.) leaves are produced each year and often disposed, resulting in a waste of resources. Fig waste leaves are rich in flavonoids, which have strong antioxidant activity; however, the variety and chemical structure of antioxidants in fig leaves have not been reported in detail. To take full advantage of fig waste leaves, antioxidant capacity of different extracts (petroleum ether, ethyl acetate, and water) was evaluated by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS), and ferric-ion-reducing antioxidant power (FRAP) methods. The results showed that flavonoids in ethyl acetate extraction had the highest content (83.92 ± 0.01 mg/g), maximum DPPH scavenging activity (IC50 0.54 mg/mL), highest ABTS scavenging rate (80.28%), and FRAP (3.46 mmol/g). Furthermore, an HPLC-QTOF-MS/MS-DPPH method was developed to identify 11 flavonoids in fig waste leaves. This rapid and efficient method can not only be used for screening the antioxidant components in fig waste leaves, but also can be combined with mass spectrometry to identify the compounds with antioxidant capacity. There are three flavonoids with significant antioxidant capacity, which are 3-O-(rhamnopyranosyl-glucopyranosyl)-7-O-(glucopyranosyl)-quercetin, isoschaftoside, and rutin. The results confirmed that fig waste leaves contain a variety of antioxidant components, which contributed to increase the value of fig waste leaves as antioxidants.