Extracellular vesicles and angiotensin-converting enzyme 2 in COVID-19 disease

Extracellular vesicles(EVs)are membranous vesicular structures released from almost all eukaryotic cell types under different physiological or pathological conditions.Growing evidence demonstrates that EVs can serve as mediators of intercellular communication between donor and recipient cells or microorganism-infected and noninfected cells.Coronavirus disease 2019(COVID-19)disease is caused by infection of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)of host cells in the respiratory system and various extra-pulmonary tissue/organs,resulting in complications of multiple organ systems.As the cell surface receptor,angiotensin-converting enzyme 2(ACE2)mediates cellular entry of SARS-CoV-2 into the host cells in patients with COVID-19.Recent studies have found that ACE2 can be released with EVs,which have been shown to interfere with the entry of the virus into host cells and thus may be involved in COVID-19 pathophysiology.In addition,ACE2,neprilysin(NEP),and thimet oligopeptidase(TOP)are the key enzymes that regulate angiotensin metabolism by converting angiotensin II or angiotensin I to angiotensin 1-7,the latter of which has protective effects in counterbalancing the harmful effects of angiotensin II in COVID-19 disease.This review summarizes the recent research progress regarding EV-associated ACE2,NEP,and TOP and the perspectives of their potential involvement in the pathophysiology of COVID-19 disease.

Extracellular Enzyme Activity of Sclerotia-forming and Non-Sclerotia-forming Morchella Strains

The extracellular enzyme activities of sclerotia-forming and nonsclerotia- forming single spore strains of Morchella conica and M. crasspies were determined and compared. The non sclerotia-forming strains of M. conica exhibited higher aver- age activities of protease, catalase and xylanase but lower laccase activity than those of sclerotia-forming strains. However, the differences did not reach significance level. The soluble amylases activity of M. crasspies was significantly higher than that of M. conica, while the mean activity of other enzymes had differences between them, but the differences did not reach significance level.

Inhibition Effects of Different Trace and Secondary Elements on Scab of Cucurbits(Cladosporium cucumerinum) and Their Effects on Enzyme Activities of Cucumber Plants

The paper was to explore the effect of trace and secondary elements on scab of cucurbits （ Cladosporium cucumerinum） and their effects on enzyme activities of cucumber plants. [ Method ] Indoor antifungd experiment and pot test was carried out to study the control effect of different trace and secondary dements on scab of cucu.rbits; after trace and secondary element compounds were sprayed for 7 d, the content of soluble protein and malondialdehyde （MDA） and the activities of peroxidase （POD） and superoxide dismutase （SOD） of cucumber leaves during seedling stage were simultaneously detected. [ Result] The inhibi- tion effects on scab of cucurbits were found in the three trace and secondary dements, especially for the CaC12 （66.9%）, and about 54.6% and 24.1% for ZnSO4 and H3 BO3 , respectively. When cucumber plants were infected by scab of cuea.rbits, the contents of MDA for all treatments were significantly decreased in cucum- ber leaves after spraying the three trace and secondary elements compared with control. The contents of soluble protein in cucumber seedling were increased by Zn- SO4 and H3 BO3 application, while the contents of POD and SOD were increased on ZnSO4 and CaCI2 treatments. The defense system of cucumber was induced and strengthened by application of the three trace and secondary elements. [ Conclusion ] The results provided the theoretical basis for practical application and research on resistance mechanism of using trace and secondary dements to control scab of eueurbits.

Role of renin-angiotensin system/angiotensin converting enzyme-2 mechanism and enhanced COVID-19 susceptibility in type 2 diabetes mellitus

Coronavirus disease 2019(COVID-19)is a disease that caused a global pandemic and is caused by infection of severe acute respiratory syndrome coronavirus 2 virus.It has affected over 768 million people worldwide,resulting in approx-imately 6900000 deaths.High-risk groups,identified by the Centers for Disease Control and Prevention,include individuals with conditions like type 2 diabetes mellitus(T2DM),obesity,chronic lung disease,serious heart conditions,and chronic kidney disease.Research indicates that those with T2DM face a hei-ghtened susceptibility to COVID-19 and increased mortality compared to non-diabetic individuals.Examining the renin-angiotensin system(RAS),a vital regulator of blood pressure and pulmonary stability,reveals the significance of the angiotensin-converting enzyme(ACE)and ACE2 enzymes.ACE converts angiotensin-I to the vasoconstrictor angiotensin-II,while ACE2 counters this by converting angiotensin-II to angiotensin 1-7,a vasodilator.Reduced ACE2 exp-ression,common in diabetes,intensifies RAS activity,contributing to conditions like inflammation and fibrosis.Although ACE inhibitors and angiotensin receptor blockers can be therapeutically beneficial by increasing ACE2 levels,concerns arise regarding the potential elevation of ACE2 receptors on cell membranes,potentially facilitating COVID-19 entry.This review explored the role of the RAS/ACE2 mechanism in amplifying severe acute respiratory syndrome cor-onavirus 2 infection and associated complications in T2DM.Potential treatment strategies,including recombinant human ACE2 therapy,broad-spectrum antiviral drugs,and epigenetic signature detection,are discussed as promising avenues in the battle against this pandemic.

Angiotensin-converting enzyme 2 alleviates liver fibrosis through the renin-angiotensin system

The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.

Pancreatic enzyme replacement therapy for pancreatic exocrine insufficiency in the 21^(st) century

Restitution of normal fat absorption in exocrine pancreatic insufficiency remains an elusive goal. Although many patients achieve satisfactory clinical results with enzyme therapy, few experience normalization of fat absorption, and many, if not most, will require individualized therapy. Increasing the quantity of lipase administered rarely eliminates steatorrhea but increases the cost of therapy. Enteric coated enzyme microbead formulations tend to separate from nutrients in the stomach precluding coordinated emptying of enzymes and nutrients. Unprotected enzymes mix well and empty with nutrients but are inactivated at pH 4 or below. We describe approaches for improving the results of enzyme therapy including changing to, or adding, a different product, adding non-enteric coated enzymes,(e.g., giving unprotected enzymes at the start of the mealand acid-protected formulations later), use of antisecretory drugs and/or antacids, and changing the timing of enzyme administration. Because considerable lipid is emptied in the first postprandial hour, it is prudent to start therapy with enteric coated microbead prior to the meal so that some enzymes are available during that first hour. Patients with hyperacidity may benefit from adjuvant antisecretory therapy to reduce the duodenal acid load and possibly also sodium bicarbonate to prevent duodenal acidity. Comparative studies of clinical effectiveness of different formulations as well as the characteristics of dispersion, emptying, and dissolution of enteric-coated microspheres of different diameter and density are needed; many such studies have been completed but not yet made public. We discuss the history of pancreatic enzyme therapy and describe current use of modern preparations, approaches to overcoming unsatisfactory clinical responses, as well as studies needed to be able to provide reliably effective therapy.

Hepatic angiotensin-converting enzyme 2 expression in metabolic dysfunction-associated steatotic liver disease and in patients with fatal COVID-19

BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD),characterised by hepatic lipid accumulation,causes inflammation and oxidative stress accompanied by cell damage and fibrosis.Liver injury(LI)is also frequently reported in patients hospitalised with coronavirus disease 2019(COVID-19),while preexisting MASLD increases the risk of LI and the development of COVID-19-associated cholangiopathy.Mechanisms of injury at the cellular level remain unclear,but it may be significant that severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)which causes COVID-19,uses angiotensin-converting expression enzyme 2(ACE2),a key regulator of the‘anti-inflammatory’arm of the renin-angiotensin system,for viral attachment and host cell invasion.AIM To determine if hepatic ACE2 levels are altered during progression of MASLD and in patients who died with severe COVID-19.METHODS ACE2 protein levels and localisation,and histological fibrosis and lipid droplet accumulation as markers of MASLD were determined in formalin-fixed liver tissue sections across the MASLD pathological spectrum(isolated hepatocellular steatosis,metabolic dysfunction-associated steatohepatitis(MASH)+/-fibrosis,end-stage cirrhosis)and in post-mortem tissues from patients who had died with severe COVID-19,using ACE2 immunohistochemistry and haematoxylin and eosin and picrosirius red staining of total collagen and lipid droplet areas,followed by quantification using machine learning-based image pixel classifiers.RESULTS ACE2 staining is primarily intracellular and concentrated in the cytoplasm of centrilobular hepatocytes and apical membranes of bile duct cholangiocytes.Strikingly,ACE2 protein levels are elevated in non-fibrotic MASH compared to healthy controls but not in the progression to MASH with fibrosis and in cirrhosis.ACE2 protein levels and histological fibrosis are not associated,but ACE2 and liver lipid droplet content are significantly correlated across the MASLD spectrum.Hepatic ACE2 levels are also increased in COVID-19 patients,especially those showing evidence of LI,but are not correlated with the presence of SARS-CoV-2 virus in the liver.However,there is a clear association between the hepatic lipid droplet content and the presence of the virus,suggesting a possible functional link.CONCLUSION Hepatic ACE2 levels were elevated in nonfibrotic MASH and COVID-19 patients with LI,while lipid accumulation may promote intra-hepatic SARS-CoV-2 replication,accelerating MASLD progression and COVID-19-mediated liver damage.

Timosaponin AⅢ induces drug-metabolizing enzymes by activating constitutive androstane receptor (CAR) via dephosphorylation of the EGFR signaling pathway

The current study aimed to assess the effect of timosaponin AⅢ(T-AⅢ)on drug-metabolizing enzymes during anticancer therapy.The in vivo experiments were conducted on nude and ICR mice.Following a 24-day administration of T-AⅢ,the nude mice exhibited an induction of CYP2B10,MDR1,and CYP3A11 expression in the liver tissues.In the ICR mice,the expression levels of CYP2B10 and MDR1 increased after a three-day T-AⅢ administration.The in vitro assessments with HepG2 cells revealed that T-AⅢ induced the expression of CYP2B6,MDR1,and CYP3A4,along with constitutive androstane receptor(CAR)activation.Treatment with CAR siRNA reversed the T-AⅢ-induced increases in CYP2B6 and CYP3A4 expression.Furthermore,other CAR target genes also showed a significant increase in the expression.The up-regulation of murine CAR was observed in the liver tissues of both nude and ICR mice.Subsequent findings demonstrated that T-AⅢ activated CAR by inhibiting ERK1/2 phosphorylation,with this effect being partially reversed by the ERK activator t-BHQ.Inhibition of the ERK1/2 signaling pathway was also observed in vivo.Additionally,T-AⅢ inhibited the phosphorylation of EGFR at Tyr1173 and Tyr845,and suppressed EGF-induced phosphorylation of EGFR,ERK,and CAR.In the nude mice,T-AⅢ also inhibited EGFR phosphorylation.These results collectively indicate that T-AⅢ is a novel CAR activator through inhibition of the EGFR pathway.

Soil Microbial Community and Enzyme Activity Responses to Herbaceous Plant Expansion in the Changbai Mountains Tundra, China

As one of the most sensitive regions to global climate change, alpine tundra in many places around the world has been undergoing dramatic changes in vegetation communities over the past few decades.Herbaceous plant species in the Changbai Mountains area have significantly expanded into tundra shrub communities over the past 30 yr.Soil microbial communities, enzyme activities, and soil nutrients are intertwined with this expansion process.In order to understand the responses of the soil microbial communities to such an expansion, we analyzed soil microbial community structures and enzyme activities in shrub tundra as well as areas with three different levels of herbaceous plant expansion.Our investigation was based on phospholipid fatty acid(PLFA) analysis and 96-well microtiter plates.The results showed that herbs have expanded greatly in the tundra, and they have become the dominant species in herbaceous plant expansion areas.There were differences for community composition and appearance among the shrub tundra and the mild expansion, moderate expansion, and severe expansion areas.Except for soil organic matter, soil nutrients were increased in herbaceous plant expansion areas, and the total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were greatest in moderate expansion areas(MOE), while soil organic matter levels were highest in the non-expanded areas(CK).The total soil PLFAs in the three levels of herbaceous plant expansion areas were significantly higher than those in the non-expanded areas, and total soil PLFAs were highest in the moderately expanded area and lowest in the severely expanded area(SEE).Bacteria increased significantly more than fungi and actinomycetes with herbaceous plant expansion.Soil hydrolase activities(β-1,4-glucosidase(βG) activity, β-1, 4-N-acetylglucosaminidase(NAG) activity, and acid phosphatase(aP) activity) were highest in MOE and lowest in the CK treatment.Soil oxidase activities(polyphenol oxidase(PPO) activities and peroxidase(PER) activities) were also highest in MOE, but they were lowest in the SEE treatment.The variations in total soil PLFAs with herbaceous plant expansion were mostly correlated with soil organic matter and available phosphorus concentrations, while soil enzyme activities were mostly correlated with the total soil nitrogen concentration.Our results suggest that herbaceous plant expansion increase the total soil PLFAs and soil enzyme activities and improved soil nutrients.However, soil microorganisms, enzyme activity, and nutrients responded differently to levels of herbaceous plant expansion.The soil conditions in mild and moderate expansion areas are more favorable than those in severe expansion areas.

Angiotensin I converting enzyme(ACE)inhibitory activity and antihypertensive effects of rice peptides

In this paper,the antihypertension effect of rice peptide(RP)was studied.With spontaneously hypertensive rats(SHR)and Wistar Kyoto(WKY)as the research objects,RP disposable gastric and long-term gastric irrigation experiments were carried out and systolic blood pressure(SBP)was measured.At the end of the long-term gastric irrigation experiment,the content of nitric oxide(NO),angiotensin-converting enzyme(ACE),angiotensin II(Ang II)and renin in the plasma and the activity of ACE were determined.The results showed that RP could reduce systolic pressure of SHR and had time-dose dependence while high-dose RP signifi cantly reduced systolic pressure by 24.6 and 17.2 mm Hg,respectively after a single and long-term gastric irrigation test.RP also could inhibit the activity of ACE and increase the release of NO.These results suggested that the decompression mechanism of RP is likely to be related to the regulation of the renin-angiotensin system(RAS)and NO.

Soil Enzyme Activities with Greenhouse Subsurface Irrigation

Various environmental conditions determine soil enzyme activities, which are important indicators for changes of soil microbial activity, soil fertility, and land quality. The effect of subsurface irrigation scheduling on activities of three soil enzymes (phosphatase, urease, and catalase) was studied at five depths (0-10, 10-20, 20-30, 30-40, and 40-60 cm) of a tomato greenhouse soil. Irrigation was scheduled when soil water condition reached the maximum allowable depletion (MAD) designed for different treatments (-10, -16,-25,-40, and-63 kPa). Results showed that soil enzyme activities had significant responses to the irrigation scheduling during the period of subsurface irrigation. The neutral phosphatase activity and the catalase activity were found to generally increase with more frequent irrigation (MAD of -10 and -16 kPa). This suggested that a higher level of water content favored an increase in activity of these two enzymes. In contrast, the urease activity decreased under irrigation, with less effect for MAD of -40 and -63 kPa. This implied that relatively wet soil conditions were conducive to retention of urea N, but relatively dry soil conditions could result in increasing loss of urea N. Further, this study revealed that soil enzyme activities could be alternative natural bio-sensors for the effect of irrigation on soil biochemical reactions and could help optimize irrigation management of greenhouse crop production.

The effect of enzymes on release of trace elements in feedstuffs based on in vitro digestion model for monogastric livestock

Background: This experiment was conducted to study the effect of different feed enzymes(phytase,xylanase,β-glucanase) on release rate of trace elements(Fe,Cu,Mn and Zn) in 6 commonly used feedstuffs(corn,wheat,barley,soybean meal,wheat bran,wheat middlings) by using an in vitro model,simulating the digestive processes in stomach for 2 h and then in small intestine for 6 h at 39 °C.Results: Phytase raised(P < 0.05) the release rate of Cu and Zn in corn,Cu,Zn and Mn in wheat,Cu in barley,Cu,Zn and Mn in soybean meal,Zn,Fe in wheat bran and Zn,Fe,Mn in wheat middlings.The release rate of various trace elements in feedstuffs was increased after xylanase addition.Compared with the control group,the release rate of soluble Cu in corn,wheat,barley and soybean meal,soluble Zn in corn,wheat and wheat middlings and soluble of Mn in corn,wheat,barley and wheat bran increased(P < 0.05) after xylanase treatment.After the treatment of β-glucanase,the release rate of soluble Cu in corn,wheat and wheat bran,soluble Fe in barley,soybean meal and wheat bran and soluble Mn in corn and wheat bran all increased(P < 0.05) compared with the control group.In each feedstuff,after corresponding enzyme treatment,the contents of phytic acid,xylan and β-glucan were significantly lower than those of the control group(P < 0.05).Conclusions: Results showed that bound trace elements in feedstuffs can be released by feed enzymes.It may be necessary to take the trace elements in feedstuffs into account in the actual feed preparation including feed enzymes.

Effects of soybean meal replacement with fermented alfalfa meal on the growth performance,serum antioxidant functions,digestive enzyme activities,and cecal microflora of geese

Fermented forages are important feedstuffs. Bacillus subtilis inoculants are often used to improve the value of forage legume fermentation. The present work was conducted to study the effects of replacing soybean meal with solid-state fermented alfalfa meal（FAM） with B. subtilis ACCC 01746 on growth performance, serum antioxidant and digestive enzyme activities, and cecal microflora in goose. 300 healthy geese with similar body weights were randomly assigned to six treatment groups with five replicates of 10 geese（five males and five females） each. Geese were fed ad libitum for 35 days. Results showed that the geese fed with 4 and 8% FAM exhibited no significant effects on their final body weights（FBW） and average day gain（ADG）（P〉0.05）, whereas 12% or higher FAM caused poor growth of the geese compared with control diet（linear（L）： P〈0.05）. The average daily feed intake（ADFI）（quadratic（Q）： P〈0.05） and feed conversion ratio（FCR）（L： P〈0.05） with 8% or higher supplementation level were higher than those of the control group. The activities of antioxidant enzyme in serum increased, and the level of malondialdehyde（MDA） significantly decreased with increasing dietary FAM level（L： P〈0.05）. However, no significant differences were observed at 8% or lower supplementation level for glutathione peroxidase（GSH-Px） and superoxide dismutase（SOD）（P〉0.05） and at 4% for catalase（CAT） supplementation level compared with the control group. All diets containing FAM increased digestive enzyme activities in geese. However, geese fed diets with 12% FAM supplementation showed the highest trypsin activities in pancreas（Q： P〈0.05）. Supplementation with 12% or higher FAM significantly increased amylase activities in pancreas（L： P〈0.05） and duodenum（L： P〈0.05） compared with the control group. Significant differences were not observed in total anaerobic bacteria between geese fed with FAM and control diets on day 35（P〉0.05）. The numbers of Bifidobacterium and Lactobacillus in the cecum of geese fed with FAM significantly increased（L： P〈0.05）, but no significant effects were found with 4 and 8% FAM supplementation levels compared with the control（P〉0.05）. By contrast, the coliform counts of cecum decreased with increasing inclusion of FAM, but these counts were significantly reduced in geese fed diets with 12% or higher FAM supplementation level（L： P〈0.05）. Collectively, our results indicated that supplementation of the basal geese diet with 8% FAM had no apparent adverse effects on growth performance, serum antioxidant enzyme activities, and digestive parameters and beneficial microbiota.

Contribution of pancreatic enzyme replacement therapy to survival and quality of life in patients with pancreatic exocrine insufficiency

The objective of this study was to analyze the current evidence for the use of pancreatic enzyme replacement therapy (PERT) in affecting survival and quality of life in patients with pancreatic exocrine insufficiency (PEI). Systematic searches of the literature were performed using the PubMed database. Articles were selected for inclusion if they reported findings from trials assessing the effects of PERT on quality of life, survival, malabsorption, growth parameters (such as height, body weight and body mass index), or gastrointestinal symptoms (such as abdominal pain, stool consistency and flatulence). PERT improved PEI-related malabsorption and weight maintenance in patients with cystic fibrosis, chronic pancreatitis, pancreatic cancer, and post-surgical states. In patients with chronic pancreatitis, PERT improved PEI-related symptoms and quality of life measures. Several small retrospective studies have also suggested that PERT may have a positive impact on survival, but long-term studies assessing this effect were not identified. PERT is effective for treating malnutrition and supporting weight maintenance, and it is associated with improved quality of life and possibly with enhanced survival in patients with PEI. However, there is evidence that not all patients with PEI receive adequate PERT. Future work should aim to assess the long-term effects of PERT on the survival of patients with PEI.

Engineering high amylose and resistant starch in maize by CRISPR/Cas9-mediated editing of starch branching enzymes

To improve the amylose content(AC)and resistant starch content(RSC)of maize kernel starch,we employed the CRISPR/Cas9 system to create mutants of starch branching enzyme I(SBEI)and starch branching enzyme IIb(SBEIIb).A frameshift mutation in SBEI(E1,a nucleotide insertion in exon 6)led to plants with higher RSC(1.07%),lower hundred-kernel weight(HKW,24.71±0.14 g),and lower plant height(PH,218.50±9.42 cm)compared to the wild type(WT).Like the WT,E1 kernel starch had irregular,polygonal shapes with sharp edges.A frameshift mutation in SBEIIb(E2,a four-nucleotide deletion in exon 8)led to higher AC(53.48%)and higher RSC(26.93%)than that for the WT.E2 kernel starch was significantly different from the WT regarding granule morphology,chain length distribution pattern,X-ray diffraction pattern,and thermal characteristics;the starch granules were more irregular in shape and comprised typical B-type crystals.Mutating SBEI and SBEIIb(E12)had a synergistic effect on RSC,HKW,PH,starch properties,and starch biosynthesis-associated gene expression.SBEIIa,SS1,SSIIa,SSIIIa,and SSIIIb were upregulated in E12 endosperm compared to WT endosperm.This study lays the foundation for rapidly improving the starch properties of elite maize lines.

In vitro and comparative study on the extracellular enzyme activity of molds isolated from keratomycosis and soil

AIMTo isolate and identify the molds involved in mycotic keratitis; to isolate corresponding species from soil samples; to compare the extracellular enzyme activity indices of the molds isolated from keratitis cases and the corresponding soil isolates.

Optimization of angiotensin I-converting enzyme (ACE) inhibition by rice dregs hydrolysates using response surface methodology

Angiotensin I-converting enzyme (ACE) inhibitory peptides have been shown to have antihypertensive effects and have been utilized for physiologically functional foods and pharmaceuticals. The ACE inhibitory ability of a hydrolysate is de- termined by its peptide composition. However, the peptide composition of a hydrolysate depends on proteolytic enzyme and the hydrolysis conditions. In this study, the effect of process conditions on the ACE inhibitory activity of rice dregs hydrolyzed with a trypsin was investigated systematically using response surface methodology. It was shown that the ACE inhibitory activity of rice dregs hydrolysates could be controlled by regulation of five process conditions. Hydrolysis conditions for optimal ACE inhibition were defined using the response surface model of fractional factorial design (FFD), steepest ascent design, and central composite design (CCD).

Effects on antioxidant enzyme activities and osmolytes in Halocnemum strobilaceum under salt stress

The seedlings of Halocnermum strobilaceum were cultivated in 0.5% hoagland nutrient solution containing 0.0%, 0.9%, 2.7% and 5.4% of NaC1 as well as composite salt （Na^＋, Ca^2＋, K^＋, Si^4＋） for 20 days; all the contents are in weight ratio. Succulent level, inorganic ions （Na^＋, K^＋）, organics such as betaine, proline, malondialdehyde, and antioxidant enzyme activities including superoxide dismutase （SOD）, catalase （CAT）, peroxidase （POD）, betaine aldehyde dehydrogenase （BADH） were measured to reveal its salt tolerance mechanism. When the composite salt concentration reaches 5.4%, SOD activity level, and MDA content is five times the control group; when it reaches 2.7%, the succulent level of seedlings, and the content ofK＋ in roots is nearly two times the NaCl treatment; the dry weight is more than three times the control group; with the NaCl treatment, MDA is three times the contrast; when the salt concentration is 2.7%, POD reaches the maximum. Results indicate that Si^4＋, K^＋, and Ca^20 from composite salt in the roots of H. strobilaceum improved the water-holding capacity. The activities of antioxidant enzyme were raised by the accumulation ofproline and betaine, which increased the salt tolerance. The absorption of K^＋ promoted the high ratio of K^＋/Na^＋ and alleviated the damage of cell membranes of H. strobilaceum, which is associated with osmotic contents such as betaine and proline.

Interactions of Marsh Orchid(Dactylorhiza spp.)and Soil Microorganisms in Relation to Extracellular Enzyme Activities in a Peat Soil

The nature of the interactions between microbes and roots of plants in a peaty soil were studied in a laboratory- based experiment by measuring activities ofβ-glucosidase,phosphatase,N-acetylglucosaminidase,and arylsulphatase.The experiment was based on control(autoclaved),bacteria-inoculated,and plant(transplanted with Dactylorhiza)treatments, and samples were collected over 4 sampling intervals.Higher enzyme activities were associated with the bacteria-inoculated treatment,suggesting that soil enzyme activities are mainly of microbial origin.For example,β-glucosidase activity varied between 25-30μmol g^(-1)min^(-1)in the bacteria-inoculated samples whilst the activity of the control ranged between 4-12μmol g^(-1)min^(-1)A similar pattern was found for all other enzymes. At the end of the incubation,the microcosms were destructively sampled and the enzyme activities determined in bulk soil,rhizospheric soil,and on the root surface.Detailed measurement in different fractions of the peat indicated that higher activities were found in rhizosphere.However,the higher activities ofβ-glucosidase,N-acetylglucosaminidase,and arylsulphatase appeared to be associated with bacterial proliferation on the root surface,whilst a larger proportion of phosphatase appeared to be released from root surface.

Processing Effects on Selected Antioxidant Activities and Metabolizing Enzyme Inhibition of M. Koneigii (Curry Leaves) Extracts

Curry leaves, scientifically termed Murraya koenigii, are renowned in South Asian cuisine for their flavor enhancement and potential health benefits, including antioxidative, anti-inflammatory, and antidiabetic properties. This study aimed to evaluate the impact of thermal processing methods on curry leaves by analysing Total Phenolic Content (TPC), Total Flavonoid Content (TFC), antioxidant activity, and metabolizing enzyme inhibition. Fresh curry leaves were subjected to thermal treatments: Oven-dried at 60˚C and Air-dried at 25˚C for 2 weeks. Extracts were prepared using Ethanol and water solvents. Results indicated that Air-dried leaves exhibited significantly higher TPC (5132.65 mg GAE/100 g) and TFC (243.13 mg CE/100 g) compared to Fresh and Oven-dried leaves. Antioxidant assays show that oven-dried curry leaves at 60˚C displayed higher results in NORS, FRAP, and TEAC assays compared to Fresh and Air-dried leaves. Ethanol extracts showed better extraction of bioactive compounds than aqueous extracts. Moreover, Lipase inhibition activity was notably high, indicating potential health benefits. This study provides valuable insights into the effects of processing methods on curry leaf extracts, emphasizing the importance of solvent selection for optimal extraction of bioactive compounds.