Potential Prophylactic Properties of Apple and Characterization of Potent Bioactive from cv. "Granny Smith" Displaying Strong Antimutagenicity in Models Including Human Lymphoblast TK6(+/-) Cell Line

Insights into the radioprotective efficacy of Pterocarpus santalinus L. aqueous extract

In the present study, we have attempted a comprehensive assessment of the possible radioprotective efficacy of Pterocarpus santalinus aqueous extract (PSAE). All the studied models were gamma-irradiated with prior treatment with PSAE. First, the content of total phenols (4.061 μg/mg gallic acid equivalents), flavonoids (6.616 μg/mg quercetin equivalents), and tannins (0.008 mg/L of PSAE) were determined spectrophotometrically. Second, UHPLC-HRMS analysis was performed to identify the possible radioprotectors. Of those, santalins A & B are known for their usage as natural color in foods and alcoholic beverages identified in PSAE. Treatment was well tolerated with no side effects from PSAE. Later, it was shown that radiation-induced lethality significantly amended in PSAE-treated spleen lymphocytes as evidenced by reduced elevated levels of ROS and lipid peroxidation, restored total thiols and GSH: GSSG, inhibited DNA DSBs and cell death. Furthermore, an immunomodulation study was carried out because radiation exposure induces an inflammatory response. Our study shows that PSAE suppressed concanavalin A-induced T-cell proliferation as evidenced by CFSE dye dilution and CD69 antibody staining methods. Taken together, the current study explored the protective efficacy of PSAE from gamma radiation-inflicted injuries and hence we recommend PSAE as a potent radioprotective formulation.

Granny Smith Apple Extract Lowers Inflammation and Improves Antioxidant Status in L-arginine-induced Exocrine Pancreatic Dysfunction in Rats

Objectives

Granny Smith is a cultivated hybrid variety of apple with a high antioxidant content relative to all other species of apple. Acute pancreatitis (AP) is an instantly emerging inflammatory condition with a high mortality rate. The preferred treatment is restricted to symptomatic relief and supportive care. The present study was undertaken to evaluate the favorable effects of Granny Smith apple extract (GSAE) as a prophylactic treatment for L-arginine-induced AP in rats.

Materials and Methods

Male Sprague Dawley rats were divided in to five groups (n=6): Normal control (saline), disease control (a single dose of L-arginine 2.5 g/kg I.P.), positive control (pelatonin 10 mg/kg I.P.), and GSAE I and II (200 mg/kg and 400 mg/kg, orally, respectively). All groups were treated for 7 days. At the end of the study, blood samples were collected from the retro-orbital plexus, serum separated, and subjected to estimation of biomarker enzymes such as amylase, lipase, antioxidant enzymes, etc. The animals were then sacrificed, and the pancreas was isolated and subjected to estimation of tissue biomarkers, DNA fragmentation assay, and histopathological studies.

Results

Serum levels of amylase and lipase were significantly (p<0.001) reduced in L-arginine-treated rats. Similar results were also observed with tissue inflammatory markers such as malondialdehyde, nitrate, etc. There was a dramatic increase (p<0.001) in the overall antioxidant enzyme levels when compared with disease control rats. Histopathological examination of pancreatic tissue showed an intact structural feature of acinar cells in the extract-treated group of rats, which was further in pact with the intact DNA found in the DNA fragmentation assay.

Conclusion

Thus, GSAE treatment was found to be beneficial in lowering the inflammatory conditions of AP by improving the overall antioxidant levels, and a further investigation into its exact molecular mechanism is needed.

Pterocarpus santalinus L. extract mitigates gamma radiation-inflicted derangements in BALB/c mice by Nrf2 upregulation

Plant-based natural extracts contain several nutrients and bioactive compounds, such as phenolics and flavonoids, that possess various health-promoting activities. This study investigated the effects of polyphenols from Pterocarpus santalinus hydroalcoholic extract (PSHE) against gamma radiation-induced derangements via the upregulation of Nrf2. Ultra High Performance Liquid Chromatography Coupled to High Resolution Mass Spectrometry (UHPLC-HRMS/MS) analysis was performed to identify the possible radioprotectors. In vivo and in vitro studies, namely Real-Time-PCR (RT-PCR) analysis, Reactive Oxygen Species (ROS) scavenging activity, lipid peroxidation and GSH levels, DNA damage and cell death studies, anti-inflammatory (Sandwich ELISA), immunomodulatory studies (antibody staining), and model free radical scavenging assays, were performed. Vanillic acid, protocatechuic acid, para-hydroxybenzoic acid, chlorogenic acid, TNF-α inhibitor (Eudesmin), isoflavone (Daidzein 7-o-glucoside), astragalin (Kaempferol 3-o-glycoside), and other polyphenols were identified in PSHE using UHPLC-HRMS/MS analysis. Prophylactic administration of PSHE (-1 h) rendered more than 33% survival in mice exposed to 8 Gy whole-body-irradiation with increased mice survival and recovery of bone marrow and spleen cellularity. Real-time RT-PCR analysis showed that PSHE treatment (50 µg/mL) upregulated Nrf2, HO-1, and GPX-1 in mice splenocytes. At 50 µg/mL, PSHE reduced ROSscavenging activity, mitochondrial and spleen membrane lipid peroxidation levels, DNA damage, and cell death, and increased GSH levels. At 10 µg/mL, PSHE treatment diminished the content of IL-6 and TNF-α. At 50 µg/mL, PSHE suppressed lymphocyte proliferation. These findings indicate that polyphenols of PSHE possess marked antioxidant, anti-inflammatory, and immunomodulatory capacities, which play important roles in the prevention of radiation damage.

Deuterium-depletion has no significant impact on the mutation rate of Escherichia coli, deuterium abundance therefore has a probabilistic, not deterministic effect on spontaneous mutagenesis

Deuterium (D), the second most abundant isotope of hydrogen is present in natural waters at an approximate concentration of 145-155 ppm (ca. 1.5E-4 atom/atom). D is known to influence various biological processes due to its physical and chemical properties, which significantly differ from those of hydrogen. For example, increasing D-concentration to >1000-fold above its natural abundance has been shown to increase the frequency of genetic mutations in several species. An interesting deterministic hypothesis, formulated with the intent of explaining the mechanism of D-mutagenicity is based on the calculation that the theoretical probability of base pairs to comprise two adjacent D-bridges instead of H-bridges is 2.3E-8, which is equal to the mutation rate of certain species. To experimentally challenge this hypothesis, and to infer the mutagenicity of D present at natural concentrations, we investigated the effect of a nearly 100-fold reduction of D concentration on the bacterial mutation rate. Using fluctuation tests, we measured the mutation rate of three Escherichia coli genes (cycA, ackA and galK) in media containing D at either <2 ppm or 150 ppm concentrations. Out of 15 pair-wise fluctuation analyses, nine indicated a significant decrease, while three marked the significant increase of the mutation/culture value upon D-depletion. Overall, growth in D-depleted minimal medium led to a geometric mean of 0.663-fold (95% confidence interval: 0.483-0.911) change in the mutation rate. This falls nowhere near the expected 10,000-fold reduction, indicating that in our bacterial systems, the effect of D abundance on the formation of point mutations is not deterministic. In addition, the combined results did not display a statistically significant change in the mutation/culture value, the mutation rate or the mutant frequency upon D-depletion. The potential mutagenic effect of D present at natural concentrations on E. coli is therefore below the limit of detection using the indicated methods.

Molecular mechanism of antimutagenicity by an ethoxy-substituted phylloquinone (vitamin K1 derivative) from spinach (Spinacea oleracea L.)

In our previous study, an antimutagenic compound from spinach (Spinacea oleracea L.), ethoxy-substituted phylloquinone (ESP) was isolated and characterized. The current study deals with elucidation of the possible mechanism of antimutagenicity of ESP against ethyl methanesulfonate (EMS) deploying model systems such as human lymphoblast (TK^+/- or TK6) cell line (thymidine kinase gene mutation assay) and Escherichia coli MG1655 (rifampicin resistance assay). Findings of the study ruled out the possibility of direct inactivation of EMS by ESP. DAPI competitive binding assay indicated the DNA minor groove binding activity of ESP. Interestingly, ESP did not display major groove binding or intercalating abilities. Further, proteomics study using 2-D gel electrophoresis in E. coli and subsequent studies involving single gene knockout strains revealed the possible role of tnaA (tryptophanase) and dgcP (diguanylate cyclase) genes in observed antimutagenicity. These genes have been reported to be involved in indole and cyclic-di-GMP biosynthesis, respectively, which eventually lead to cell division inhibition. In case of TK^+/- cell line system, ADCY genes (adenylate cyclase), a functional analogue of dgcP gene, were found to be transcriptionally up-regulated. The generation/doubling time were significantly higher in E. coli or TK^+/- cells treated with ESP than control cells. The findings indicated inhibition of cell proliferation by ESP through gene regulation as a possible mechanism of antimutagenicity across the biological system. Cell division inhibition actually provides additional time for the repair of damaged DNA leading to antimutagenicity.

Antioxidant and Enzyme Inhibitory Properties of the Polyphenolic-Rich Extract from an Ancient Apple Variety of Central Italy (Mela Rosa dei Monti Sibillini)

This study was undertaken to evaluate the nutraceutical potential of the Mela Rosa dei Monti Sibillini (MR), an ancient apple variety of the Sibillini Mountains, central Italy. The chemical profile of the apple’s polyphenolic-rich extract (MRE) obtained from first- and second-choice samples using the Amberlite^® XAD7HP resin was analyzed by High Performance Liquid Chromatography with Diode-Array and Mass spectrometry (HPLC-DAD-MS) and 21 phytochemicals were quali–quantitatively determined. For comparative purposes, the polyphenol-rich extract of Annurca (ANE), a southern Italian variety, was analyzed. The antioxidant capacity of MREs was evaluated by Folin–Ciocalteu, 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. The inhibitory capacity of MREs for the enzymes α-glucosidase, lipase, monoamine oxidase A, tyrosinase, and acetylcholinesterase was also determined. The MREs showed higher polyphenolic and triterpene profiles than the ANE. Their radical scavenging activity was higher than that of ANE and comparable to the reference trolox. The MRE from the second-choice apples displayed higher contents of the 21 phytochemicals investigated. Either MRE from second-choice or first-choice samples showed enzymatic inhibition with IC₅₀ values higher than those of reference inhibitors but worthy of nutraceutical consideration. Taken together, these results show the potential of MRE as a source of bioactive compounds to be used for pharmaceutical, nutraceutical, and cosmeceutical applications has been confirmed.

No induced mutagenesis in human lymphoblast cell line and bacterial systems upon their prolonged sub-culturing in irradiated food blended media

BACKGROUND

Profound apprehension towards safety of irradiated food has remained a major cause behind tardy acceptance of this technology although it has immense socio-economic potential. Generation of in-depth scientific evidence will help to refute these apprehensions. With this prospective, the present study was undertaken where safety of various irradiated (D_min up to 25 kGy) foods was evaluated through long-term exposure studies in models including human lymphoblast TK6 cell line (100 generations) and Escherichia coli MG1655 cells (exclusive sub-culturing in irradiated food medium for 3000 generations). Additionally, the Ames test, micronucleus test, comet assay, DNA sequencing and restriction profiling of phagemid DNA from E. coli cells sub-cultured in irradiated food medium were also performed.

RESULTS

No induced mutagenesis was observed in these cells during long-term sub-culturing in various irradiated food medium. Also no change was observed in profiles of comet, micronucleus, restriction digestion, random amplification of polymorphic DNA as well as DNA sequences. The latter also ruled out the possibility of any silent mutation.

CONCLUSION

Findings of the current study thus provided credible molecular evidence supporting the safety of irradiated foods. This would be helpful in confidence building among consumers, entrepreneurs, and strengthening the overall food irradiation program to achieve 'food safety' and 'security'. © 2017 Society of Chemical Industry.

Lack of induced mutagenesis in E. coli or human lymphoblast cell line upon long-term sub-culturing in medium from irradiated meat

PURPOSE

Current study was aimed to enhance the confidence of consumers as well as entrepreneurs towards food irradiation program.

MATERIALS AND METHODS

In this work, safety of high dose (25 kGy) irradiated meat samples (HDIMS) was ascertained by scoring mutation frequency through a long-term sub-culturing study in Escherichia coli MG1655 cells (ATCC 700926) up to 1500 generations (at 1%), 250 generations (at 5% and 10%) and human lymphoblast thymidine kinase heterozygote (TK6) cell line (ATCC CRL-8015) [at two gene loci, tk^-/+ (thymidine kinase) and hprt⁺ (Hypoxanthine Phosphoribosyltransferase)] up to 156 generations using goat meat sample. Also these samples were assayed at further radiation doses of 10, 45 and 70 kGy at 2% concentration (in cell line), and 1% (in E. coli). Study was also performed with other meat samples such as chicken, fishes (pomfret and rohu) and shrimps by carrying out limited long-term sub-culturing trials in human lymphoblast cell line. Mutation analysis was also carried out using a novel DPAR (Differential loss of Plasmid Antibiotic Resistance) assay followed by sequencing of tc^R (tetracycline resistance) gene of pBR322 plasmid isolated from E. coli cells grown for 1500 generations on HDIMS medium and RAPD (Random Amplified Polymorphic DNA) analysis of the genome.

RESULTS AND CONCLUSION

None of the assays exhibited any induced mutation when analyzed at regular time intervals. RAPD analysis also did not indicate any change in its nucleotide sequence, ruling out the occurrence of any silent mutation. Thus, the present findings report absence of mutagenic effect of high dose irradiated meat samples.

Natural Predominance of Abscisic Acid in Pongammia pinnata ("Karanj") Honey Contributed to its Strong Antimutagenicity

Various samples of raw (unprocessed) floral honey collected from different geographical locations of India were assayed for its antimutagenicity against ethyl methanesulfonate in E. coli MG1655 cells through rifampicin resistance assay. A monofloral honey ("Pongammia pinnata", local name "Karanj") displayed maximum antimutagenicity (78.0 ± 1.7; P ≤ 0.05). Solid phase extraction (using Amberlite XAD-2 resin) followed by HPLC resulted into different peaks displaying varying antimutagenicity. Peak at retention time (R_t) 27.9 min (henceforth called P₂₈) displayed maximum antimutagenicity and was further characterized to be abscisic acid (ABA) using ESI-MS and NMR. Its antimutagenicity was reconfirmed through human lymphoblast cell line (TK6) mutation assay using thymidine kinase (tk^+/-) cell line. Although ABA from this honey displayed strong antimutagenicity, it lacked any in vitro antioxidant capacity indicating noninvolvement of any radical scavenging in the observed antimutagenicity.

Purification and Characterization of the Principal Antimutagenic Bioactive as Ethoxy-Substituted Phylloquinone from Spinach (Spinacea oleracea L.) Based on Evaluation in Models Including Human Lymphoblast TK+/- Cells

During in vitro analysis, spinach (Spinacea oleracea L.) leaf extracts displayed varying antimutagenicity when analyzed in models including human lymphoblast (TK^+/-) cell line (thymidine kinase gene mutation assay) and Escherichia coli MG1655 (rifampicin resistance assay) against chemically (ethyl methanesulfonate and 5-azacytidine) induced mutagenicity. Highest antimutagenicity was displayed by the quinone extract. The principal bioactive compound exhibited fluorescence in TLC at 366 nm (termed C4) resolved at R_f 0.32 and t_R 15.2 min in TLC and HPLC, respectively. On the TLC plate, three spots (C1-C3), observed at 254 nm, displayed comparatively lesser antimutagenicity. Furthermore, biochemical and spectroscopic analyses using MALDI-TOF MS and NMR indicated the nature of the potent compound (C4) as an ethoxy-substituted phylloquinone derivative [2-ethoxy-3-((E)-3,7,11,15-tetramethylhexadec-2-enyl)naphthalene-1,4-dione]. The C4 compound did not display any cytotoxicity and hence possesses significant nutraceutical-based intervention possibility to combat the onset of mutation-associated disease(s).