Free radical scavenging activity from different extracts of leaves of Bauhinia vahlii Wight & Arn.

The objectives of this study were to determine phenolic content and antioxidant activities of chloroform, acetone, methanol and hot water extracts of Bauhinia vahlii leaves. The hot water extract afforded the highest yield (6.3%) while the lowest yield was obtained from the chloroform extract (2.1%). The methanol extract contains higher levels of total phenolics (48.7 ± 0.7 g GAE/100 g extract), tannins (21.7 ± 0.7 g GAE/100 g extract) and flavonoids (10.3 ± 0.2 RE/100 g extract). The extracts were subjected to assess their antioxidant potential using various in vitro systems such as DPPH, ABTS⁺, FRAP, OH, β-carotene linoleic acid bleaching system, phosphomolybdenum reduction and Fe²⁺ chelation. It is concluded that the methanolic extract of B. vahlii leaves have strong antioxidant potential. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidants.     

Phytochemical and antioxidant properties of unconventional leafy vegetables consumed in southern Africa

Indigenous leafy vegetables possess high horticultural potential based on their long utilisation history by local communities across Africa. Phytochemical and antioxidant properties of 50% aqueous methanol and water extracts of three indigenous as well as two commercial leafy vegetables commonly consumed in southern Africa were evaluated. The total extractable phenolic content was highest for Amarathus dubius (5.16 ± 0.12 mg GAE/g DW) followed by Cleome gynandra (3.94 ± 0.09 mg GAE/g DW). Total flavonoid concentration was highest for A. dubius (3.89 ± 0.28 mg CE/g DW) followed by C. gynandra (2.19 ± 0.11 mg CE/g DW) and Cucurbita maxima (1.55 ± 0.04 mg CE/g DW). No proanthocyanidins were detected in C. maxima and Brassica napus cv Covo whereas low concentrations were recorded in other vegetables. Total saponins were variable across the evaluated extracts, with the highest concentrations recorded for B. napus cv Covo (83.2 ± 16.58 mg DE/g DW). Total iridoid content was highest for C. gynandra (9.14 ± 0.20 mg HE/g DW). More potent DPPH radical scavenging activities were exhibited by 50% aqueous methanol extracts compared to water extracts. A similar trend was observed in the ferric-reducing antioxidant power assay. The antioxidant activity based on the rate of β-carotene bleaching was higher for water extracts compared to 50% aqueous methanol extracts. The indigenous vegetables evaluated in this study had higher levels of phytochemicals and also exhibited more potent antioxidant activity compared to the commercial varieties. These findings not only suggest the importance of the indigenous vegetables in a healthy diet, but also provide a motivation for exploring their horticultural potential.     

Total phenolics,flavonoids and antioxidant properties of three Ceropegia species from Western Ghats of India

The aim of present work was to assess the total phenolic content (TPC), total flavonoid content (TFC), phenolic compounds and antioxidant properties of various extracts of three Ceropegia spp.: Ceropegia spiralis, Ceropegia panchganiensis and Ceropegia evansii from Western Ghats of India. TPC of the samples varied from 0.3 ± 0.2 to 28.5 ± 0.3 mg TAE/g FW, whereas, TFC of the samples ranged between 0.1 ± 0.1 and 15.3 ± 0.3 mg RE/g FW. The major phenolic compounds identified were gallic acid, vanillin, cathechol and ferulic acid. All the extracts possess 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP) as well as metal chelating ability and this was also supported by significant correlation with TPC and TFC. To the best of our knowledge, this is the first paper presenting comprehensive data on TPC, TFC, phenolic profile and antioxidant properties of the Ceropegia spp.     

Antioxidative effect of Iranian Pulicaria gnaphalodes L. extracts in soybean oil

This study was aimed to evaluate antioxidative activities of the ethanol, methanol and water extracts of Pulicaria gnaphalodes in vegetable oil during the storage period. Different concentrations (0, 200, 400 and 800 ppm) of ethanol, methanol and water extracts and beta-hydroxy toluene (BHT; 100, 200 ppm) were added to soybean oil and incubated for 35 days at 65 °C. Peroxide values (PVs) and thiobarbituric acid-reactive substance (TBARS) levels were measured every week during the period of the study. Moreover, antioxidant capacities of the extracts were determined using DPPH and β-carotene–linoleic acid methods. Values were compared among groups in each incubation time points using ANOVA. Results showed that DPPH and β-carotene–linoleic acid assay findings on the P. gnaphalodes extracts were comparable to those found on BHT. Moreover, during incubation time, P. gnaphalodes extracts lowered PVs and TBARS levels when compared to the control (p < 0.001). In this respect, water extract was more potent than the ethanol and methanol extracts. It seems that water extract of P. gnaphalodes is a potent antioxidant which makes it as a potential antioxidant for oil and oily products during storage.     

Biological activities of two macroalgae from Adriatic coast of Montenegro

In the present investigation the acetone extracts of macroalgae Ulva lactuca and Enteromorpha intestinalis were tested for antioxidant, antimicrobial and cytotoxic potential. Antioxidant activity was evaluated by measuring the scavenging capacity of tested samples on DPPH and superoxide anion radicals, reducing the power of samples and determination of total phenolic and flavonoid compounds in extracts. As a result of the study, U. lactuca extract was found to have a better free radical scavenging activity (IC₅₀ = 623.58 μg/ml) than E. intestinalis extract (IC₅₀ = 732.12 μg/ml). Moreover, the tested extracts had effective ferric reducing power and superoxide anion radical scavenging. The total content of phenol in extracts of U. lactuca and E. intestinalis was 58.15 and 40.68 μg PE/mg, while concentrations of flavonoids were 39.58 and 21.74 μg RE/mg, respectively. Furthermore, among the tested species, extracts of U. lactuca showed a better antimicrobial activity with minimum inhibitory concentration values ranging from 0.156 to 5 mg/ml, but it was relatively weak in comparison with standard antibiotics. Bacillus mycoides and Bacillus subtilis were the most susceptible to the tested extracts. Contrary to this Aspergillus flavus, Aspergillus fumigatus and Penicillium purpurescens were the most resistant. Finally, cytotoxic activity of tested extracts was evaluated on four human cancer cell lines. Extract of E. intestinalis expressed the stronger cytotoxic activity towards all tested cell lines with IC₅₀ values ranging from 74.73 to 155.39 μg/ml.     

Antioxidative,antimicrobial and cytotoxic effects of the phenolics of Leea indica leaf extract

This study investigated the phytochemical, antioxidative, antimicrobial and cytotoxic effects of Leea indica leaf ethanol extract. Phytochemical values namely total phenolic and flavonoid contents, total antioxidant capacity, DPPH radical scavenging effect, FeCl₃ reducing power, DMSO superoxide scavenging effect and Iron chelating effects were studied by established methods. Antibacterial, antifungal and cytotoxic effects were screened by disk diffusion technique, food poison technique and brine shrimp bioassay, respectively. Results showed the total phenolic content 24.00 ± 0.81 g GAE/100 g, total flavonoid content 194.68 ± 2.43 g quercetin/100 g and total antioxidant capacity 106.61 ± 1.84 g AA/100 g dry extract. Significant (P < 0.05) IC₅₀ values compared to respective standards were recorded in DPPH radical scavenging (139.83 ± 1.40 μg/ml), FeCl₃ reduction (16.48 ± 0.64 μg/ml), DMSO superoxide scavenging (676.08 ± 5.80 μg/ml) and Iron chelating (519.33 ± 16.96 μg/ml) methods. In antibacterial screening, the extract showed significant (P < 0.05) zone of inhibitions compared to positive controls Ampicillin and Tetracycline against Gram positive Bacillus subtilis, Bacillus cereus, Bacillus megaterium, and Staphylococcus aureus and Gram negative Salmonella typhi, Salmonella paratyphi, Pseudomonas aeroginosa, Shigella dysenteriae, Vibrio cholerae, and Escherichia coli. Significant minimum inhibitory concentrations compared to tetracycline were obtained against the above organisms. In antifungal assay, the extract inhibited the growth of Aspergillus flavus, Candida albicans and Fusarium equisetii by 38.09 ± 0.59, 22.58 ± 2.22, and 22.58 ± 2.22%, respectively. The extract showed a significant LC₅₀ value compared to vincristine sulfate in cytotoxic assay. The results evidenced the potential antioxidative, antimicrobial and cytotoxic capacities of Leea inidica leaf extract to be processed for pharmaceutical use.     

GC/MS and LC/MS analysis,and antioxidant and antimicrobial activities of various solvent extracts from Mirabilis jalapa tubers

The antioxidant and antimicrobial activities of various solvent extracts from Mirabilis jalapa tubers (MJT) were investigated using various in vitro assays. The total phenolic and flavonoid contents varied from 21.45 to 364.6 mg gallic acid equivalent (GAE)/g dried extract and 5.2 to 71.6 mg quercetin/g dried extract, respectively. Water extract of MJT was the most potent antioxidant in all assays used, followed by methanol extract. The five solvent extracts were screened for antibacterial and antifungal activities. Water extract was the most effective with minimum inhibitory concentration <200 μg/ml against Staphylococcus aureus, Micrococcus luteus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus cereus and Enterococcus faecalis. Only water extract showed antifungal activity against Aspergillus niger, Fusarium solani, Fusarium oxysporium and Fusarium granularium. GC/MS analysis of MJT dichloromethane and methanol extracts showed that oleic acid and β-sitosterol were, respectively, the major compounds. LC/MS analysis of the aqueous extract showed a high content of flavanol and flavonol compounds. Phenolic acids such as ferulic and caffeic acid were also detected.To our knowledge, this is the first report on the chemical composition, and antioxidant and antimicrobial activities of phenolic extracts from M. jalapa tubers (MJT). The results of the present work indicate that MJT extracts could be used as natural antioxidant and antimicrobial agents in the food preservation and human health.     

In vitro anti-cancer activities of Job’s tears (Coix lachryma-jobi Linn.) extracts on human colon adenocarcinoma

The whole seed (W), endosperm (E) and hull (H) of five cultivars of Job’s tears (Coix lachryma-jobi Linn. var. ma-yuen Stapf) including Thai Black Phayao, Thai Black Loei, Laos Black Loei, Laos White Loei and Laos Black Luang Phra Bang were processed before solvent extraction by non-cooking, roasting, boiling and steaming Each part of the Job’s tears was extracted by the cold and hot process by refluxing with methanol and hexane. The total of 330 extracts included 150 methanol extracts and 180 hexane extracts were investigated for anti-proliferative activity on human colon adenocarcinoma cell line (HT-29) by the sulforhodamine B (SRB) assay. The extracts which gave high anti-proliferative activity were tested for apoptotic activity by acridine orange and ethidium bromide double staining and anti-oxidative activities including free radical scavenging and lipid peroxidation inhibition activities. The extract from the hull of Thai Black Loei roasted before extracting by hot methanol (M-HTBL-R2) showed the highest anti-proliferative activity on HT-29 with the IC₅₀ values of 11.61 ± 0.95 μg/ml, while the extract from the non-cooked hull of Thai Black Loei by cold methanol extraction (M-HTBL-N1) gave the highest apoptosis (8.17 ± 1.18%) with no necrosis. In addition, M-HTBL-R2 and M-HTBL-N1 indicated free radical scavenging activity at the SC₅₀ values of 0.48 ± 0.12 and 2.47 ± 1.15 mg/ml, respectively. This study has demonstrated the anti-colorectal cancer potential of the M-HTBL-R2 and M-HTBL-N1 extracts.     

Isolation of antioxidant constituents from Combretum apiculatum subsp. apiculatum

Species of the family Combretaceae are used extensively in traditional medicine against inflammation and infections, and although antibacterial activity has been reported in non-polar extracts, further rationale for the widespread use of the Combretaceae is expected to exist. Methanol extracts of leaves of ten different Combretum species were evaluated for antioxidant activity by spraying TLC chromatograms of each leaf extract with 2,2-diphenyl-1-picrylhydrazyl (DPPH). Compounds with antioxidant activity were detected by bleaching of the purple DPPH colour. Leaf extracts of Combretum apiculatum subsp. apiculatum had the most antioxidant compounds. This species was consequently selected for phytochemical investigation. A DPPH assay-directed fractionation of the leaf extracts of C. apiculatum led to the isolation of four antioxidant compounds from the ethyl acetate and butanol soluble fractions. The structures of the compounds were determined by spectroscopic analyses (¹H-NMR, ¹³C-NMR and MS) and identified as: cardamonin (1), pinocembrin (2), quercetrin (3) and kaempferol (4). In a quantitative antioxidant assay, the more polar fractions (ethyl acetate and butanol) obtained by solvent–solvent fractionation had the highest antioxidant activity among the solvent fractions obtained from C. apiculatum, with EC₅₀ values of 3.91 ± 0.02 and 2.44 ± 0.02 μg/ml respectively. Of the four isolated compounds, quercetrin (4) and kaempferol (3) had the strongest antioxidant activity, with EC₅₀ values of 11.81 ± 85 and 47.36 ± 0.03 μM respectively. Cardamonin (1) and pinocembrin (2) did not demonstrate strong activity. L-ascorbic acid was used as standard antioxidant agent (EC₅₀ = 13.37 ± 0.20 μM or 2.35 μg/ml). The cytotoxicity of cardamonin and pinocembrin was evaluated on Vero kidney cells using the MTT (3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide) assay with berberine as positive control. At concentrations higher than 50 μg/ml of cardamonin or pinocembrin, the cells were not viable. Cardamonin was more toxic (LC₅₀ = 1.97 μg/ml) than pinocembrin (LC₅₀ = 29.47 μg/ml) and even the positive control, berberine (LC₅₀ = 12.35 μg/ml).     

In vitro biological properties of Streptomyces cangkringensis isolated from the floral rhizosphere regions

This context was investigated to determine in vitro antimicrobial, antioxidative, and anticancer traits of crude ethyl acetate extract of Streptomyces cangkringensis strain TSAS 04 isolated from soil sample of rhizosphere regions. The antimicrobial activity of ethyl acetate extract of strain TSAS 04 was determined against indicator pathogens using disc diffusion assay which exhibited maximum zones of inhibition of 20.6 ± 0.3 and 16.3 ± 0.6 mm against Bacillus subtilis and Trichoderma viride, respectively. In vitro antioxidant properties of the crude ethyl acetate extract were performed using standard methodologies. The extract revealed maximum DPPḢ and ABTS⁺ radical scavenging activities of 51.1 ± 0.39 and 81.25 ± 0.33%, respectively. Likewise, maximum phosphomolybdenum reduction and Fe³⁺ reduction of the crude ethyl acetate extract of strain TSAS 04 were estimated 76.18 ± 0.10 and 89.01 ± 0.44%, respectively. In vitro anticancer trait of the extract was determined against HeLa cell line using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay which showed anticancer activities in a dose dependent manner with an IC₅₀ value of 410.5 µg/mL. Fourier transform infrared spectroscopy (FT-IR) and Gas chromatography–mass spectrometry (GC-MS) analyses indicated the presence of distinct functional groups and bioactive components in the extract, respectively. In conclusion, S. cangkringensis strain TSAS 04 showed its effectiveness as ideal bioactive agent by exhibiting substantial antimicrobial, antioxidant, and anticancer properties.     

Antimicrobial and cytotoxic activities of the crude extracts of Dietes bicolor leaves,flowers and rhizomes

The crude extracts of Dietes bicolor leaves, flowers and rhizomes were subjected to comparative antimicrobial screening against two Gram-positive, two Gram-negative bacteria and four fungal strains using the agar well diffusion method. The minimum inhibitory concentrations (MIC) of the tested extracts were also determined. Furthermore, the cytotoxic activity was evaluated. D. bicolor extracts generally demonstrated notable broad spectrum antimicrobial activities (MIC values ≤ 500 μg/mL) against all tested pathogens. D. bicolor leaf extract showed potent broad spectrum antimicrobial activity with MIC values ranging between 0.24 and 31.25 μg/mL against all tested pathogens. Moreover, the flowers extract exhibited promising antimicrobial activities, displaying MIC values ranging between 1.95 and 125 μg/mL against the tested bacteria and fungi. However, the rhizomes extract showed moderate antimicrobial activity with MIC values ranging between 31.25 and 500 μg/mL. Despite the potent antimicrobial activity of D. bicolor extracts, they were ineffective as cytotoxic agents against nine tested cancer cell lines, displaying 50% inhibitory concentration (IC₅₀) values above 100 μg/mL. The reported potent antimicrobial activity along with the lack of measurable cytotoxic activity indicated that the antimicrobial activity of D. bicolor crude extracts is mediated through a mechanism other than cytotoxicity. These results suggest that D. bicolor can act as a potential source for natural antibacterial and antifungal agents with a good safety profile at a preliminary level.     

Acaricidal activity of Aloe vera L. leaf extracts against Tetranychus cinnabarinus (Boisduval) (Acarina: Tetranychidae)

Four different extracts of Aloe vera L. leaves were evaluated for acaricidal activity against female adults of carmine spider mite, Tetranychus cinnabarinus (Boisduval), by slide-dip bioassay. At 72 h after treatment, the acetone extract showed the strongest acaricidal activity with LC₅₀ value of 90 ppm. The LC₅₀ values for ethyl acetate, water, and ethanol extracts were 113, 340, and 391 ppm, respectively. The acetone extract was fractionated using a silica gel column. Among the twenty-two fractions obtained the fifth, tenth, eleventh, twelfth, fifteenth, and seventeenth fractions showed strong acaricidal activity, causing 80.39 to 92.16% mortality at 72 h after treatment. The tenth and eleventh fractions had the strong activity, with LC₅₀ values of 44 ppm and 33 ppm, respectively. The results suggested that A. vera has a great potential for development as a botanical acaricide for T. cinnabarinus control.     

Production of novel halo-alkali-thermo-stable xylanase by a newly isolated moderately halophilic and alkali-tolerant Gracilibacillus sp. TSCPVG

An aerobic xylanolytic Gracilibacillus sp. TSCPVG growing at moderate to extreme salinity (1–30%) and neutral to alkaline pH (6.5–10.5) was isolated from the salt fields near Sambhar district of Rajasthan, India. β-xylanase (18.44 U/ml) and β-xylosidase (1.01 U/ml) were produced in 60 h in the GSL-2 mineral base medium with additions of (in g/l) Birchwood xylan (7.5), yeast extract (10.0), tryptone (8.0), proline (2.0), thiamine (2.0), Tween-40 (2.0) and NaCl (35) at pH 7.5, 30 °C and 180 rpm. The β-xylanase was active within a broad salinity range (0–30% NaCl), pH (5.0–10.5) and temperature (50–70 °C). It exhibited maximal activity with 3.5% NaCl, pH 7.5 at 60 °C. It was extremely halotolerant retaining more than 80% of activity at 0 and 30% NaCl and alkali-tolerant retaining 76% of activity at pH 10.5. The acetone precipitated xylanase was highly stable (100%) at variable salinities of 0–30% NaCl, pH of 5.0–10.5 and temperatures of 0–60 °C for 48 h. HPLC analysis showed xylose, arabinose and xylooligosaccharides as hydrolysis products of xylan. This is the first report on hemi-cellulose degrading halo-alkali-thermotolerant enzyme from a moderately halophilic Gram-positive Gracilibacillus species.     

Anti adipogenic activity of Aegle marmelos Correa

In continuation of evaluating the anti-obesity effect of Aegle marmelos, we have screened the n-hexane, dichloro methane (DCM), ethyl acetate (EtOAc) and methanol (MeOH) extracts of the leaves at the concentration of 25, 50, 75 and 100 μg/ml for adipogenesis inhibition in the adipocytes. Nile red staining with the help of fluorometry was used as indicator of the antiobesity activity. The most active DCM extract showed the 33.98 ± 3.55% lipid content at 100 μg/ml and was selected for the further isolation. 14 compounds were isolated from DCM extract of A. marmelos leaves. The compounds were screened for the adipogenesis inhibition at 50 and 100 μM concentrations. Out of the 14 compounds, halfordinol, ethyl ether aegeline and esculetin were showing 10.04 ± 0.52, 16.29 ± 0.85 and 25.09 ± 1.31% lipid content respectively at 100 μM. We hereby report the adipogenesis inhibition by A. marmelos as one of the pathway for its antiobesity effect.     

Antimicrobial activity of medicinal plants and induction of defense related compounds in banana fruits cv. Robusta against crown rot pathogens

A total of 72 plant extracts were tested in vitro for their ability to inhibit the mycelial growth of Lasiodiplodia theobromae and Colletotrichum musae the causal agents of crown rot disease of banana. The results showed that the leaf extract of Zimmu (an interspecific hybrid of Allium cepa L. × Allium sativum L.) and tuber extract of Zehneria scabra recorded maximum inhibition of mycelial growth and spore germination of both the test pathogens. The dipping of banana fruits in Zimmu leaf extract at 25% conc. exhibited 100% inhibition of crown rot disease in cold storage (14 °C) up to 35 days and increased the shelf life to 64 days. However, at room storage (28 ± 2 °C), the same treatment exhibited 86% inhibition of crown rot disease up to 12 days. It was found that the treatment of banana fruits with Zimmu leaf extract did not alter the organoleptic properties of banana. The biochemical analysis of banana fruits treated with Zimmu leaf extract showed significant increase in phenylalanine ammonia-lyase (PAL), chitinase and β-1,3-glucanase activities and enhanced accumulation of phenolic compounds compared to other treatments. These findings suggest that the effect of Zimmu leaf extract on crown rot disease may be associated with the direct fungi toxic property against the test pathogens and elicitation of defense related compounds in banana fruits.     

Feruloyl esterase production by Aspergillus terreus CECT 2808 and subsequent application to enzymatic hydrolysis

Ferulic acid esterases (FAE) were produced by Aspergillus terreus CECT 2808 from vine trimming shoots (VTS) and corn cob. Later, the fungal extracts thus obtained were used to enzymatically release ferulic acid (FA) from both substrates. Our findings showed a higher FAE activity in the enzymatic extracts produced on corn cob (0.070 ± 0.004 U/mL). Nevertheless, the enzymatic extracts produced on VTS demonstrated a better performance for FA release from both corn cob (2.05 ± 0.01 mg/g) and VTS (0.19 ± 0.003 mg/g). This result was probably because of the higher xylanase/FAE ratio determined in VTS extract. Therefore, an additional assay was carried out by supplementing corn cob extract with a commercial xylanase to test the influence of FAE/xylanase ratio in FA release. The results revealed the relevance of the FAE/xylanase ratio for an optimal FA release.     

Pancreatic lipase inhibitory and antioxidative constituents from the aerial parts of Paeonia lactiflora Pall. (Ranunculaceae)

To date, there have been reports mostly about research results of the peony root in comparison to the aerial parts. According to our study, the aerial parts of P.lactiflora showed superior anti-oxidative and pancreatic lipase inhibitory activities than its root. Especially, the water extract and the ethyl acetate fraction of the ethanol extract exhibited potent pancreatic lipase inhibitory activity by 53.11 ± 1.22% and 46.16 ± 1.55% at the same dose of orlistat (62.5 ± 1.27%). The ethanol extract exhibited the best anti-oxidative activity with IC₅₀ of 17.08 ± 0.9 μg/mL, and the ethyl acetate fraction 19.75 ± 0.02 μg/mL, respectively, comparing to the positive control rutin (IC₅₀, 22.66 ± 0.29 μg/mL). From the anti-oxidative and pancreatic lipase inhibitory active fractions three new compounds, monplacphloroside (1), monplachydroxyquinoside (2) and herbacetin-7-O-β-d-sophoroside (3) were isolated along with 19 (4-22) known ones.Compounds, PGG (14), 1-O-methyl-2,3,4,6-tetra-O-galloyl-β-d-glucopyranose (17) and ethylgallate (9) were found to be the strongest antioxidants and pancreatic lipase inhibitors. Monoterpenes, albiflorin R₂ (19) and albiflorin (20) were determined for the first time as strong pancreatic lipase inhibitors. The presence of the esterified galloyl moiety, with its increasing numbers or the β-lactone cycle within the molecular structure plays an essential role for the enhancement of the pancreatic lipase enzyme inhibitory activity.     

Isolation and properties of β-xylosidase from Aspergillus niger GS1 using corn pericarp upon solid state fermentation

There is growing interest in developing high-yield and low-cost production of xylanolytic enzymes for industrial applications using agroindustrial byproducts. A native strain of Aspergillus niger GS1 was used to produce β-xylosidase (EC 3.2.1.37) on solid state fermentation using corn pericarp (CP) with innovative alkaline electrolyzed water (AEW) pretreatment at room temperature. β-xylosidase was purified by ammonium sulfate fractionation followed by anion exchange and hydrophobic interaction chromatographies. β-Xylosidase showed a molecular weight of 111 kDa, isoelectric point of 5.35 and specific activity of 386.7 U (mg protein)^?1, using p-nitrophenyl-β-d-xylopyranoside as substrate, at pH 5 and 60 °C, and optimal activity at pH 4.5. Optimal temperature was 65 °C, showing full activity after 1 h at 60 °C. Activity was reduced by 1 mM β-mercaptoethanol (55.6 ± 0.1%), and enhanced by 1 mM SDS (11.0 ± 0.03%). K_m and V_max were 6.1 ± 0.9 mM and 1364 ± 105 U (mg protein)^?1, respectively, whereas k_cat was 5.1 s^?1. A predominant α-helix (41%) was determined from circular dichroism on β-xylosidase, while thermal transition profiles produced a T_m of 54.1 ± 5.8 °C, enthalpy change for unfolding of 67.4 ± 6.7 kJ/mol, and onset temperature of 37 °C. Pre-treatment of CP using AEW is an ecologically friendly alternative to chemical and heat treatments for the production of relatively high levels of β-xylosidase.     

Role of hyaluronidase inhibitors in the neutralization of toxicity of Egyptian horned viper Cerastes cerastes venom

Hyaluronidase “venom spreading factor” is a common component of snake venoms and indirectly potentiates venom toxicity. It may cause permanent local tissue destruction at the bite site/systemic collapse of the envenomated victim. The present study was performed to assess the benefits of inhibiting the hyaluronidase activity of Egyptian horned viper, Cerastes cerastes (Cc). The aqueous extracts of some medicinal plants were screened for their inhibitory effect on hyaluronidase activity of Cc venom. The results revealed that the Rosmarinus officinalis (Ro) extract is the most potent hyaluronidase inhibitor among the tested extracts. The Ro extract is more potent inhibitory effect on the hyaluronidase activity than the prepared rabbit monoclonal antiserum of previously purified hyaluronidase enzyme from Cc venom (anti-CcHaseII). In addition, the Ro extract is efficiently inhibited the activity of hemorrhagic toxin previously purified from Cc venom, and it also neutralized the edema inducing activity of the Cc venom in vivo. Furthermore, the Ro extract markedly increased the survival time of experimental mice injected with lethal dose of Cc venom up to 7 h in compared to mice injected with venom alone or with venom/anti-CcHaseII (15 ± 5, 75 ± 4 min), respectively. Our findings imply the significance of plant-derived hyaluronidase inhibitor in the neutralization of local effects of Cc venom and retardation of death time. Therefore, it may use as a therapeutic value in complementary snakebite therapy.     

Partial purification and kinetic characterization of mushroom stem polyphenoloxidase and determination of its storage stability in different lyophilized forms

Monophenolase (1011 ± 626 U/g AP) and diphenolase activities (5163 ± 3059 U/g AP) of PPO in acetone powders (APs) of different mushroom stems varied considerably. However, the limited variation of average dipenolase (L-DOPA) to monophenolase (L-tyrosine) activity ratio (5.4 ± 0.7) in crude extracts showed the homogeneity of PPO from different mushroom stems. The change in extraction material or partial purification method (ammonium sulfate or acetone precipitation) did not affect the temperature stability, temperature and pH dependency and K_m of monophenolase activity considerably. However, some changes were observed in pH stability and substrate specificity of PPO in different parties of mushroom stems. The most important aspects of mushroom stem PPO are its lower diphenolase to monophenolase activity ratio than mushroom cap PPO, low temperature dependency of activity between 25 and 40 °C (E_a = 30 kJ/mol), broad optimum pH between 6 and 8, but lack of activity pH ≤5, and ability to use phloridzin as substrate. The mushroom stem PPOs partially purified and lyophilized by using sucrose, dextran or alginate showed moderate to high stability at −18 °C for 6–6.5 months. Thus, the mushroom stems obtained as a waste material during mushroom processing may be used as a more homogenous source than whole mushrooms to obtain PPO used for different industrial, clinical or research purposes.