Shruti Shukla

In vitro antioxidant activity and total phenolic content of ethanolic leaf extract of Stevia rebaudiana Bert.

The aim of this study was to assess the in vitro potential of ethanolic leaf extract of Stevia rebaudiana as a natural antioxidant. The DPPH activity of the extract (20, 40, 50, 100 and 200 microg/ml) was increased in a dose dependent manner, which was found in the range of 36.93-68.76% as compared to ascorbic acid 64.26-82.58%. The IC(50) values of ethanolic extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 93.46 and 26.75 microg/ml, respectively. The ethanolic extract was also found to scavenge the superoxide generated by EDTA/NBT system. Measurement of total phenolic content of the ethanolic extract of S. rebaudiana was achieved using Folin-Ciocalteau reagent containing 61.50 mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The ethanolic extract also inhibited the hydroxyl radical, nitric oxide, superoxide anions with IC(50) values of 93.46, 132.05 and 81.08 microg/ml, respectively. However, the IC(50) values for the standard ascorbic acid were noted to be 26.75, 66.01 and 71.41 microg/ml respectively. The results obtained in this study clearly indicate that S. rebaudiana has a significant potential to use as a natural antioxidant agent.

Antioxidant activity and total phenolic content of ethanolic extract of Caesalpinia bonducella seeds

The aim of this study was to assess the in vitro potential of ethanolic extract of Caesalpinia bonducella seeds as a natural antioxidant. The DPPH activity of the extract (20, 40, 50, 100 and 200 microg/ml) was increased in a dose dependent manner, which was found in the range of 38.93-74.77% as compared to ascorbic acid (64.26-82.58%). The IC(50) values of ethanolic extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 74.73 and 26.68 microg/ml, respectively. The ethanolic extract was also found to scavenge the superoxide generated by EDTA/NBT system. Measurement of total phenolic content of the ethanolic extract of C. bonducella was achieved using Folin-Ciocalteau reagent containing 62.50mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The ethanolic extract also inhibited the hydroxyl radical, nitric oxide, superoxide anions with IC(50) values of 109.85, 102.65 and 89.84 microg/ml, respectively. However, the IC(50) values for the standard ascorbic acid were noted to be 70.79, 65.98 and 36.68 microg/ml respectively. The results obtained in this study clearly indicate that C. bonducella has a significant potential to use as a natural antioxidant agent.

Antioxidant ability and total phenolic content of aqueous leaf extract of Stevia rebaudiana Bert.

In the present study, we carried out a systematic research on relative antioxidant activity of aqueous leaf extract of Stevia rebaudiana. The DPPH activity of aqueous leaf extract (20, 40, 50, 100 and 200 μg/ml) was increased in a dose dependent manner, which was found in the range of 40.00-72.37% as compared to ascorbic acid 64.26-82.58%. The IC(50) values of aqueous extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 83.45 and 26.75 μg/ml, respectively. Measurement of total phenolic content of the aqueous leaf extract of S. rebaudiana was achieved using Folin-Ciocalteau reagent containing 56.73 mg/g of phenolic content, which was found significantly potent when compared to reference standard gallic acid. The aqueous extract also inhibited the hydroxyl radical, nitric oxide and superoxide anions with IC(50) values of 100.86, 98.73 and 100.86 μg/ml, respectively. The greater amount of phenolic compounds leads to more potent radical scavenging effects as shown by the aqueous leaf extract of S. rebaudiana.

Determination of biogenic amines in Korean traditional fermented soybean paste (Doenjang)

Biogenic amines, produced by bacterial decarboxylation of amino acids, have been associated with toxicological symptoms in food products. Twenty-three samples of traditionally available Korean fermented soybean paste samples (Doenjang) were analyzed in order to determine the content of biogenic amines. Amines were extracted with 0.4M perchloric acid and derivatized with dansyl chloride. Nine biogenic amines were separated from Doenjang samples by high performance liquid chromatography using gradient elution (acetonitrile and ammonium acetate), and detected with spectrophotometric UV-vis detection at 254 nm. The pH value of all the samples was ranged from 4.8 to 6.0, and the strong amino acid decarboxylase activity was found to be in an acidic environment. The mean values of biogenic amines (tryptamine, 2-phenyl-ethylamine, putrescine, cadaverine, agmatine, histamine, tyramine, spermidine and spermine) determined in 23 Doenjang samples were found to be 18.37, 82.03, 70.84, 34.24, 47.32, 26.79, 126.66, 74.41 and 244.36 mg%, respectively. The findings of this study enhance the safety of not only Doenjang but other salted and/or fermented food products.

Immunomodulatory activities of the ethanolic extract of Caesalpinia bonducella seeds.

UNLABELLED Caesalpinia bonducella FLEMING (Caesalpiniaceae) is a plant well known for its medicinal value in Indian Ayurveda. However, to prove its efficiency for the clinical utilization, more experimental data will be beneficial. AIMS OF THE STUDY The present study involved the investigation of immunomodulatory activities of ethanolic extract of Caesalpinia bonducella seeds. MATERIALS AND METHODS Neutrophil adhesion test, haemagglutinating antibody (HA) titre, delayed-type hypersensitivity (DTH) response, phagocytic activity and cyclophosphamide-induced myelosuppression were determined by in vivo experiments. RESULTS The evaluation of immunomodulatory potential by oral administration of ethanolic seed extract of Caesalpinia bonducella (200-500 mg/kg) evoked a significant increase in percent neutrophil adhesion to nylon fibers as well as a dose-dependent increase in antibody titre values, and potentiated the delayed-type hypersensitivity reaction induced by sheep red blood cells. Also it prevented myelosuppression in cyclophosphamide drug treated rats and good response towards phagocytosis in carbon clearance assay. CONCLUSIONS The results obtained in this study indicate that Caesalpinia bonducella possesses potential immunomodulatory activity and has therapeutic potential for the prevention of autoimmune diseases.

Studies on anti-inflammatory, antipyretic and analgesic properties of Caesalpinia bonducella F. seed oil in experimental animal models

Caesalpinia bonducella FLEMING (Caesalpiniaceae) plant is well known for its medicinal and therapeutic values in Indian Ayurveda. However, to be clinically useful, more scientific data are needed. Therefore, in the present study, we investigated the effects of C. bonducella seed oil on acute and chronic inflammation. To assess the anti-inflammatory, antipyretic and analgesic activities, varied concentrations of the seed oil of C. bonducella (100, 200 and 400mg/kg orally) were tested in carrageenan-induced rat paw oedema, brewers yeast-induced pyrexia, acetic acid-induced writhing and hot plate reaction time in experimental rats. The paw volumes, pyrexia and writhes in experimental rats were reduced significantly (p<0.05) as compared to that of control, and hot plate test showed significant licking effect in rats. These results clearly indicate that the oil of C. bonducella seeds could be a potential source for using as anti-inflammatory, antipyretic and analgesic agent.

Determination of non-volatile and volatile organic acids in Korean traditional fermented soybean paste (Doenjang)

Organic acids are formed in food as a result of metabolism of large molecular mass compounds. These organic acids play an important role in the taste and aroma of fermented food products. Doenjang is a traditional Korean fermented soybean paste product that provides a major source of protein. The quantitative data for volatile and non-volatile organic acid contents of 18 samples of Doenjang were determined by comparing the abundances of each peak by gas (GC) and high performance liquid chromatography (HPLC). The mean values of volatile organic acids (acetic acid, butyric acid, propionic acid and 3-methyl butanoic acid), determined in 18 Doenjang samples, were found to be 91.73, 29.54, 70.07 and 19.80 mg%, respectively, whereas the mean values of non-volatile organic acids, such as oxalic acid, citric acid, lactic acid and succinic acid, were noted to be 14.69, 5.56, 9.95 and 0.21 mg%, respectively. Malonic and glutaric acids were absent in all the tested samples of Doenjang. The findings of this study suggest that determination of organic acid contents by GC and HPLC can be considered as an affective approach to evaluate the quality characteristics of fermented food products.

Development of sandwich enzyme-linked immunosorbent assay for the detection of Cronobacter muytjensii (formerly called Enterobacter sakazakii)

This study aimed to produce a polyclonal antibody against Cronobacter muytjensii (C. muytjensii, formerly called Enterobacter sakazakii) and to develop an immunoassay for its detection. The optimum production of rabbit anti‐C. muytjensii immunoglobulin G (IgG) and chicken anti‐C. muytjensii IgY was reached in weeks 8 and 9, respectively. Purification of rabbit anti‐C. muytjensii IgG from immunized rabbit sera was accomplished using the caprylic acid and ammonium sulfate precipitation method. As a result, sodium dodecyl sulfate‐polyacrylamide gel electrophoresis produced two bands around 25 and 50 kDa, corresponding to a light and a heavy chain, respectively. The optimized conditions for sandwich enzyme‐linked immunosorbent assay were using rabbit anti‐C. muytjensii IgG (1 μg/mL) as a detection antibody and chicken anti‐C. muytjensii IgY (10 μg/mL) as a capture antibody. In this assay, no cross‐reactivity was observed with the other genera of pathogenic bacteria tested, which included Escherichia coli O157:H7, Salmonella typhimurium, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes. The developed assay did not show cross‐reactivity with other tested species of Cronobacter and Enterobacter genera such as C. turicensis, C. sakazakii, E. aerogenes, E. pulveris and E. helveticus. The detection limit of sandwich ELISA for C. muytjensii was found to be 2.0 × 104 colony forming units (CFU)/mL. In addition, detection of C. muytjensii in infant formula powder showed a low matrix effect on the detection curve of sandwich ELISA for C. muytjensii, the detection limit being found to be 6.3 × 104 CFU/mL. These findings demonstrate that the developed method is able to detect all strains of C. muytjensii. Hence, this ELISA technique has potent application for the rapid and accurate detection of C. muytjensii in dietary foods.

Immunoliposome-based immunomagnetic concentration and separation assay for rapid detection of Cronobacter sakazakii.

This study aimed to develop an immunoliposome-based immunomagnetic concentration and separation assay for the rapid detection of Cronobacter sakazakii (C. sakazakii), an acute opportunistic foodborne pathogenic bacterium, in both pure culture and infant formula. To develop the assay, magnetic nanoparticles (diameter 30 nm) were coated with immunoglobulin G (IgG), specifically anti-C. sakazakii IgG, and applied for the sensitive and efficient detection of C. sakazakii using immunoliposomes. The binding efficiency of anti-C. sakazakii IgG to the magnetic nanoparticles was 86.23 ± 0.59%. The assay developed in this study detected as few as 3.3 × 10(3) CFUmL(-1) of C. sakazakii in pure culture within 2h 30 min; in comparison, an indirect non-competitive enzyme-linked immunosorbent assay was able to detect 6.2 × 10(5) CFUmL(-1) of C. sakazakii in pure culture after 17 h. The developed assay did not show any cross-reactivity with other Cronobacter spp. or pathogens belonging to other genera. In addition, the method was able to detect 10(3) CFUmL(-1) of C. sakazakii in infant formula without any pre-incubation. These results confirm that the immunoliposome-based immunomagnetic concentration and separation assay may facilitate highly sensitive, efficient, and rapid detection of C. sakazakii.

Anti-Angiogenic Effect of Nelumbo nucifera Leaf Extracts in Human Umbilical Vein Endothelial Cells with Antioxidant Potential

Nelumbo nucifera Gaertn (Nymphaeaceae) has long been used as a traditional herb in Chinese, Japanese, Indian, and Korean medicinal practices since prehistoric times and flourishes today as the primary form of medicine. This study reports for the first time the potent ability of N. nucifera leaf extracts to inhibit vascular endothelial growth factor (VEGF)-induced angiogenesis in vitro and in vivo, as well as their antioxidant efficacy in various scavenging models and an analysis of their chemical composition. In vivo anti-angiogenic activity was evaluated in a chick chorioallantoic membrane (CAM) model using fertilized chicken eggs, in human umbilical vein endothelial cells (HUVECs) by using cell viability, cell proliferation and tube formation assays, and by determining intracellular reactive oxygen species (ROS) in vitro. The antioxidant efficacy of N. nucifera leaf extracts was determined in various scavenging models, including total phenolic and flavonoid content. The chemical composition of N. nucifera leaf extracts was determined by GC-MS analysis, which revealed the presence of different phytochemicals. The IC50 values for the DPPH radical scavenging activities of water and methanol extracts were found to be 1699.47 and 514.36 μg ml−1, and their total phenolic and flavonoid contents were 85.01 ± 2.32 and 147.63 ± 2.23 mg GAE g dry mass−1 and 35.38 ± 1.32 and 41.86 ± 1.07 mg QA g dry mass−1, respectively. N. nucifera leaf extracts (10–100 μg ml−1) exhibited significant dose-dependent inhibition of VEGF-induced angiogenesis, as well as VEGF-induced proliferation and tube formation in HUVECs. In this study, N. nucifera leaf extracts displayed potent antioxidant and inhibitory effects on VEGF-induced angiogenesis. N. nucifera exerted an inhibitory effect on VEGF-induced proliferation and tube formation, as well as CAM angiogenesis in vivo. Moreover, N. nucifera leaf extracts significantly blocked VEGF-induced ROS production in HUVECs, confirming their possible anti-angiogenic mechanism.