Sap Activity Research Articles

Genome-wide association study identified BnaPAP17 genes involved in exogenous ATP utilization and regulating phosphorous content in Brassica napus.

BnaPAP17s associated with root-secreted APases activity were identified by genome-wide association study, and those were induced by Pi-deficiency. BnaPAP17s were involved in improving exogenous organophosphorus utilization as secreted APases. Deficiency of available phosphorus (P) in soil has become an important limiting factor for yield and quality in oilseed rape (Brassica napus). In many soils, organic P (Po) is the main component of the soil P pool. Po must be hydrolyzed to inorganic P (Pi) through acid Phosphatase (APases), and then taken up by plants. However, root-secreted APases (SAP) activity, as a quantitative trait, plays an important role in soil Po utilization; those genetic loci are not clear in B. napus. In this study, we performed a genome-wide association study for SAP activity under Pi-deficiency using a panel of 350 accessions of B. napus and more than 4.5 million polymorphic single nucleotide polymorphisms (SNPs). Thirty-five significant SNPs associated with SAP activity were identified. BnaA01.PAP17 (BnaA01g27810D) was a candidate gene underlying lead SNP (ChrA01_19576615). We experimentally verified that both BnaA01.PAP17 and its three homologous genes had similar expression pattern in response to Pi-deficiency. The dynamic changes in BnaPAP17s expression level were opposite to those of Pi concentration in both roots and leaves, suggesting their potential utility as Pi marker genes in B. napus. Transient expression of BnaPAP17s in tobacco leaves proved that BnaPAP17s were located in the apoplast as secreted APases. The overexpression of BnaPAP17s enhanced SAP activity in response to Pi-deficiency and resulting in increased P content in plants when ATP was supplied as the sole P resource. Taken together, these results suggest that BnaPAP17s contributed to SAP activity, thus having a function in extracellular Po utilization in B. napus.

Analysis of data on phytophotodermatitis caused by contact with the sap of plants of the genus Hogweed (<i>Heracleum</i> L.)

The rapid spread of overgrowth of plants of the genus Hogweed, associated with their use as an agricultural fodder crop, is currently a serious problem for the Russian Federation. This process has a negative impact on the biodiversity of the vegetation cover, destroying natural ecosystems and causing significant economic damage. However, the active spread of hogweeds on the territory of the Russian Federation would not be so catastrophic if it were not for their aggressive properties: in contact with the skin, plant sap causes phytophotodermitis, which is a burn similar to thermal burns of I, II and III degrees. The article considers qualitative and quantitative composition of the main biologically active substances of hogweeds sap and shows that the biologically active substances causing phytophotodermatitis are furanocoumarins. It has been established that the pronounced photosensitizing activity of furanocoumarins is determined by the presence of a furan ring at positions 6,7 and 7,8 of coumarin. Such compounds include psoralen and its main derivatives: xanthotoxin, bergapten, bergamotin, imperatorin, isopimpinellin and angelicin (isopsoralen) and its main derivatives: sfondin, pimpinellin, isobergapten. Substitution of furan ring condensed with coumarin ring as well as change of its position leads to loss of photosensitizing activity. It was determined that the activity of plant sap of the genus Hogweed is in direct dependence on such factors as qualitative and quantitative content of furanocoumarins in the plant sap, the amount of sap and the area of the skin lesion zone, the time of contact of the affected skin areas with the plant sap, the intensity of ultraviolet irradiation and the time of its effect on the affected areas, as well as the peculiarities of each person (e.g., age, skin phototype). The methods of standard therapy of three clinical forms of phytophotodermatitis were analyzed. It was found that currently no specific clinical recommendations for the diagnostics and treatment of phytophotodermatitis resulting from contact with the sap of hogweeds. At the end of the article, the conclusion is formulated that one of current and promising tasks of pharmaceutical technology may be the development of drugs used in the treatment of burns caused by the sap of plants of the genus Hogweed, taking into account the mechanism of action of furanocoumarins.

Antimicrobial Activity of Jatropha Curcas Sap on Selected Microorganisms

Jatropha curcas sap is used for medicinal purposes.It has played a major role in the treatment of various diseases including bacterial and fungal infections.This study evaluated the antimicrobial activity of Jatropha curcas sap against selected microorganisms (Shigella spp, Staphylococcus aureus, Salmonella spp,Candida albicans and Trichophyton spp) using standard procedures.The qualitative phytochemical screening of the sap reveals the presence of saponins, alkaloids, flavonoids,tannins, carbohydrate, glycosides while Steroids was absent. It was observed that the test organisms were more susceptible at high concentration which is 100. The highest zone of inhibition for bacteria was observed on Staphylococcus aureus and the lowest zone of inhibition was on Salmonella sp. For fungi the highest zone of inhibition was on Candida albicans and the lowest zone of inhibition was on Trichophyton sp. There was no zone of inhibition for water which serves as negative control. But there was zone of inhibition for the positive controls which were Ciprofloxacin and Ketoconazole. Jatropha curcas sap is a potential antimicrobial substance, active against Gram negative and Gram-positive bacteria and some fungi. It is therefore a potential antimicrobial agent.

Comparison of the Therapeutic Efficacy of Diminazene Aceturate and ‎Isometamidium Chloride in Local Dogs Experimentally Infected ‎with Trypanosoma brucei

The chemotherapeutic efficacy of diminazene aceturate (DA) and isometamidium chloride (IMC) were compared in dogs experimentally infected with Trypanosoma brucei. Twenty Nigerian local breeds of dogs were used for the study. They were divided into four groups of five dogs each. Dogs in group I served as uninfected untreated control, group II was infected untreated, while groups III and IV were the infected treated with DA and IMC respectively. Administration of DA and IMC effectively cleared the parasites from the blood stream of the treated dogs. However, the infection subsequently relapsed at days 28 and 49 post treatment (pt) in DA and IMC treated groups, respectively. The red cell parameters (PCV, HB, and RBC) decreased significantly (P<0.05) following infection. They were significantly (P < 0.05) higher in IMC treated group than the DA treated group comparable with the control. The infected groups had elevated total white blood cell counts. However, the DA treated, and IMC treated groups did not show any significant (P> 0.05) difference when compared together with the control. The mean activities of SAP, AST, and ALT increased significantly (P<0.05) in the infected groups compared with the control. The mean blood urea nitrogen (BUN) increased significantly (P<0.05) on days 21 and 28 post infection (pi) in the infected untreated group and IMC treated groups. The mean creatinine(CRT) was significantly (P<0.05) higher in all the infected groups on day 14 pi compared to the control. From day 35 pi the mean BUN and CRT levels returned to normal values. It was thus concluded from this study that IMC exhibited more chemotherapeutic therapeutic activity over DA, as evidenced from the result of relapsed infections post treatment and haematological changes. However, the serum biochemical parameters were significantly altered in both DA and IMC treated groups compared to the control.

Haematopoietic and Immunomodulatory Activity of Sap of Borassus flabellifer against Cyclophosphamide Mediated Haematotoxicity and Immunosuppression in Wistar Rats

Recent scientific evidence recommends that many of the adverse effects of chemotherapy can be prevented by remedying treatment with antioxidants, minerals, carbohydrates, proteins, and organic acids. The current research was performed to assess haematopoietic and immunomodulatory effects using sap of traditional tree, Borassus flabellifer, in cyclophosphamide induced haematotoxicity and immunosuppression in wistar rats. For eleven consecutive days, the animals were orally pre-treated with Borassus flabellifer sap (3.6 mL/kg). These animals were intra-peritoneally injected on the sixth day with cyclophosphamide (150 mg/kg) and sacrificed five days later. On the final day of the trial, blood samples were obtained from each rat and carried out evaluation of haematological (red blood cells, haemoglobin, mean corpuscular haemoglobin concentration, reticulocytes & serum iron content) and immunomodulatory (total leucocyte count, cellular immune response & tumor necrosis factor-α) parameters. To determine their index values, each rat's thymus and spleen were separated. By elevating red blood cells, haemoglobin, mean corpuscular haemoglobin concentration, reticulocytes & serum iron content, sap of Borassus flabellifer demonstrated an important protective role in cyclophosphamide mediated haematotoxicity. It has also shown substantial resistance against immunosuppression caused by cyclophosphamide by increasing the immunity boosting white blood cells and decreasing the hypersensitivity reaction and tumor necrosis factor-α level at the 3.6 mL/kg dose. The current research shows that therapy with traditional Borassus flabellifer sap has a major protective effect against oxidative stress, haematotoxicity and immunosuppression against cyclophosphamide induced haematotoxicity and immunosuppression.

Quick Decline and Stem Pitting Citrus tristeza virus Isolates Induce a Distinct Metabolomic Profile and Antioxidant Enzyme Activity in the Phloem Sap of Two Citrus Species

Susceptibility to the severe Citrus tristeza virus (CTV), T36, is higher for Citrus macrophylla (CM) than for C. aurantium (CA). How host-virus interactions are reflected in host physiology is largely unknown. In this study, the profile of metabolites and the antioxidant activity in the phloem sap of healthy and infected CA and CM plants were evaluated. The phloem sap of quick decline (T36) and stem pitting (T318A) infected citrus, and control plants was collected by centrifugation, and the enzymes and metabolites analyzed. The activity of the antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), in infected plants increased significantly in CM and decreased in CA, compared to the healthy controls. Using LC-HRMS2 a metabolic profile rich in secondary metabolites was assigned to healthy CA, compared to healthy CM. CTV infection of CA caused a drastic reduction in secondary metabolites, but not in CM. In conclusion, CA and CM have a different response to severe CTV isolates and we propose that the low susceptibility of CA to T36 may be related to the interaction of the virus with the host's metabolism, which reduces significantly the synthesis of flavonoids and antioxidant enzyme activity.

Severe anemia and neutrophilic leukocytosis resembling Sweet’s syndrome in a dog

Sweet’s syndrome is a rare inflammatory condition characterized by the presence of neutrophilic infiltrate of the skin. We describe a case of severe anemia and neutrophilia with post-mortem findings resembling Sweet's syndrome in a five-years-old female Labrador Retriever with bilateral epistaxis, hematemesis, hyporexia, pale oral mucosa, and fever. Laboratory analysis evidenced severe unresponsive anemia, thrombocytopenia, and leukocytosis. Biochemistry showed hypoalbuminemia and increased ALT and SAP activities. The patient was transfused and received doxycycline and prednisone for one week without improvement. Two further blood transfusions were administered. Bone marrow analysis showed a mild erythroid hypoplasia, granulocytic hyperplasia, myeloid to erythroid ratio of 6.01:1 (reference: 0.9:1 – 1.76:1) without dysplasia, mild megakaryocytic hyperplasia, and increased iron stores. Macrophages were slightly increased in number with erythrophagocytosis, and immune-mediated anemia was considered. Immunosuppressive treatment was prescribed to reduce red blood cell destruction, but no improvement after one week was observed, and euthanasia was performed. Necroscopic findings resembled those described for the systemic form of Sweet's Syndrome. Bone marrow histopathology showed remarkably increased granulopoiesis and destruction of platelets and erythrocytes. Sweet's syndrome is frequently associated with hematologic malignancy or drug exposure. Leukemia was excluded after bone marrow analysis because no increase in blast population was seen as well as no signs of dysplasia. Previous treatment could be related to the development of Sweet's syndrome, which might be the primary event. Although rare, this syndrome should be considered in the differential diagnosis of dermatosis and leukocytosis when infectious agents are not identified.

Effects of Plant Growth Regulators and Nitrogen Management on Root Lodging Resistance and Grain Yield under High-Density Maize Crops

Lodging is one of the main factors causing yield loss of maize under high-density planting conditions. Root lodging as an important lodging type has received little attention. Plant growth regulators (PGRs) and nitrogen fertilizer can coordinate the relationship between root lodging and yield. This two-year field experiment was conducted with two nitrogen levels of N225 (225 kg ha−1) and N300 (300 kg ha−1) at a high planting density (90,000 plants ha−1) during the maize growth season from 2019 to 2020. Plant growth regulator (Yuhuangjin, the mixture of 3% DTA-6 and 27% ethephon) was sprayed at the V8 stage. The results showed that PGRs significantly decreased plant height, improved root distribution and dry weight, enhanced photosynthetic rate and activities of photosynthetic carboxylase in ear leaves, and improved root bleeding sap and root activities after the silking stage. N225 combined with PGRs reduced the occurrence of root lodging and was conducive to photosynthate accumulation and root nutrient supply; it coordinated root regulation and morphological and physiological shoot functions, and played a crucial role in reducing root lodging and improving maize yield.

2,4-Diacetylphloroglucinol Modulates Candida albicans Virulence.

The dimorphic fungus Candida albicans is one of the most important opportunistic pathogens for humankind. The use of fungicides against Candida could be associated with sub-inhibitory effects, which are referred to as fungal stress responses and are undesirable for the host. In this work, we investigated the antifungal action of 2,4-diacetylphloroglucinol (2,4-DAPG) against Candida albicans ATCC 10231 with a focus on their biofilm-forming ability. We found that 2,4-DAPG was able to reduce the ability of Candida cells to form biofilms, but complete inhibition and eradication effects were not achieved. Furthermore, C. albicans cells in the adherent state were characterized by reduced susceptibility to 2,4-DAPG compared to planktonic cells. The investigation of the mechanisms that could explain the antibiofilm action of 2,4-DAPG revealed a reduction in the cell`s surface hydrophobicity and the inhibition of the yeast-to-hyphae transition. The inhibition of the Candida cells filamentation was accompanied by an increase in the expression of the NRG1 gene, which is a negative regulator of hyphal development. In addition, we microscopically visualized the treated biofilms and revealed numerous channels that were decorated with particles and localized on the hyphae. We assumed that these hyphal structures could be associated with the secretion of aspartyl proteases (Sap). The performed assessments revealed an increase in the activity of Sap, which was accompanied by an increase in the expression of the sap2 and sap4 genes. The antifungal action of 2,4-DAPG is known to be associated with affecting the permeability of cellular structures, which leads to H+ATPase malfunction and the disruption of mitochondrial respiration. The subsequent cytosol acidification and generation of ROS trigger the inhibition of Candida filamentation and activation of Sap production. The introduction of antioxidant Trolox simultaneously with 2,4-DAPG leads to a reduction in Sap production. Collectively, the obtained data indicate new aspects of the interaction of fungal cells with 2,4-DAPG, an antimicrobial metabolite of Pseudomonas spp.

The outward shaker channel OsK5.2 improves plant salt tolerance by contributing to control of both leaf transpiration and K+ secretion into xylem sap.

Soil salinity constitutes a major environmental constraint to crop production worldwide. Leaf K+ /Na+ homoeostasis, which involves regulation of transpiration, and thus of the xylem sap flow, and control of the ionic composition of the ascending sap, is a key determinant of plant salt tolerance. Here, we show, using a reverse genetics approach, that the outwardly rectifying K+ -selective channel OsK5.2, which is involved in both K+ release from guard cells for stomatal closure in leaves and K+ secretion into the xylem sap in roots, is a strong determinant of rice salt tolerance (plant biomass production and shoot phenotype under saline constraint). OsK5.2 expression was upregulated in shoots from the onset of the saline treatment, and OsK5.2 activity in guard cells led to a fast decrease in transpirational water flow and, therefore, reduced Na+ translocation to shoots. In roots, upon saline treatment, OsK5.2 activity in xylem sap K+ loading was maintained, and even transiently increased, outperforming the negative effect on K+ translocation to shoots resulting from the reduction in xylem sap flow. Thus, the overall activity of OsK5.2 in shoots and roots, which both reduces Na+ translocation to shoots and benefits shoot K+ nutrition, strongly contributes to leaf K+ /Na+ homoeostasis.

UPAYA PENINGKATAN PRODUKTIVITAS GETAH PINUS (Pinus merkusii) MENGGUNAKAN STIMULANSIA EKSTRAK LENGKUAS (Alpinia galanga) DAN JAHE (Zingiber officinale)

With the increasing world demand for pine resin, one of the efforts that can be made to increase the production of pine resin is to use stimulants of sap / stimulants. So far, in the activity of tapping pine sap, inorganic stimulants are used, but the main components are sulfuric acid and nitric acid or a mixture of which is a strong oxidizing agent that can damage human skin, wood and the environment if used in the long term and excessively. Alternative use of stimulants from natural ingredients that are safe, relatively inexpensive, and easy to obtain, such as galangal (Alpinia galanga) and ginger (Zingiber officinale). This research was conducted to determine the effect of stimulant administration of galangal and ginger extracts on increasing the productivity of pine sap. The results of this study showed that the highest sap productivity was produced by pine trees using ginger organic stimulants with a 50% concentration of 11.15 g / koakan / day. The quality of pine sap that has the best quality is produced by the stimulant of ginger, while the use of the stimulant of galangal has second quality based on SNI 7837: 2016.

Biological activity of needle sap of some plants of the order of Pine (Pinales)

The article presents the results of a study of the biological activity of the sap of the needles of Norway spruce ( Picea abies L.), Scots pine ( Pinus sylvestris L.) and Japanese yew ( Taxus cuspidata Siebold et Zucc. Ex Endl.). The highest antimicrobial activity of the Japanese yew’s needle sap against human pathogens and phytopathogens was established: the values minimum inhibitory concentration, the minimum bactericidal concentration and the minimum fungicidal concentration were 0.0313 and 0.0078%, respectively. Expressed antioxidant properties and membrane-protective activity of Scots pine needles sap were revealed in comparison with Norway spruce both in winter and in summer. The Japanese yew needle sap had the most pronounced antioxidant properties. With a decrease in the concentration of Japanese yew needle sap, its ability to protect membranes from peroxide hemolysis increased. Its high cytotoxicity and lack of selectivity in relation to tumor cells have also been established.

Antibacterial Activity and Toxicity of the Sap and Aqueous Extract of the Leaves of <i>Jatropha multifida</i> Linn

Introduction: Jatropha multifida Lin was a plant of traditional Beninese medicine used as an antibiotic. This study aimed to evaluate the antibacterial activity and the toxicity of the sap and the aqueous extract of Jatropha multifida leaves. Methods: Phytochemical screening of Jatropha multifida leaves was carried out. The extract was obtained by maceration. The antimicrobial activity of sap and leaves was evaluated on the five strains of hospital germs. Acute oral toxicity by forced gavage in a single dose of 2000 mg/kg body weight was performed on female Wistar rats. Biochemical and hematological parameters were determined. Results: The presence of flavonoids, tannins, alkaloids, anthocyanins, mucilages, leuco-anthocyanins and saponosides was noted in the leaves of Jatropha multifida. The aqueous extracts of the leaves inhibited two strains of Staphylococcus aureus out of three, while the sap of Jatropha multifida was 100% bactericidal against the strains of Staphylococcus aureus and Streptococcus D. The sap and aqueous leaf extract were not bactericidal on strains of Escherichia coli, Klebsiella oxytoca and Pseudomonas aeruginosa. For the toxicity, there was no death of rats and the aqueous extract of the leaves did not significantly vary the weight of the rats, the creatinine, the ALAT transaminase, the hemoglobin level, the number of white blood cells and blood platelets. Conclusion: The sap of Jatropha multifida exerted a more effective antibacterial activity than the aqueous extract of its leaves. The leaves were not acutely toxic.

Analysis of pathogenic factors of Candida albicans and the effect of vaginal immunization on recurrent vulvovaginal candidiasis in mice.

The role of fungal pathogenic factors and the immune response of the vaginal epithelium in vulvovaginal candidiasis (VVC) and recurrent vulvovaginal candidiasis (RVVC) are still unclear. Our study wants to clarify whether there are differences in pathogenic factors between VVC and RVVC strains, confirm the roles of pathogenic factors in the pathogenesis of RVVC, and analyze the influence of pathogenic factors on vaginal host immunity. VVC- and RVVC-causing Candida albicans strains were genotyped with 25S rDNA. Drug susceptibility assays using a modified alamarBlue broth microdilution method were carried out. Milk culture medium and egg yolk culture medium were used to measure the secreted aspartate protease (Sap) and phospholipase (Plb) activity of the samples. We used C. albicans with different Sap activity levels to induce RVVC in mice and measured interleukin 4 (IL4), interleukin 8 (IL8), and interleukin 17 (IL17) in vaginal lavage fluid at different stages of RVVC infection. There were no significant differences between VVC and RVVC fungi except that the Sap activity was lower for RVVC-causing C. albicans than for VVC-causing C. albicans. C. albicans with both strong Sap and weak Sap induced RVVC in mice. C. albicans with strong Sap had a reduced RVVC infection rate. In addition, C. albicans with strong Sap stimulated the vaginal epithelium to secrete more IL4, IL8, and IL17. Compared with that of VVC-causing C. albicans, the Sap activity of RVVC-causing C. albicans was lower. C. albicans with strong Sap was less capable of causing repeated vaginal infections than that with weak Sap and stimulated the vaginal epithelium to produce more cytokines.

Candida species biotypes and polyclonality of potentially virulent Candida albicans isolated from oral cavity of patients with orofacial clefts.

This study evaluated the incidence of Candida species, and the genetic diversity and virulence of C. albicans of the oral cavity from patients with cleft lip and palate (CLP). Oral samples were investigated by microbiological and species-specific PCR methods. The genetic diversity of C. albicans was established using isoenzyme markers, Nei's statistics, and clustering analysis. Hydrolytic enzymes (SAPs and PLs) were analyzed in vitro. Oral colonization by Candida species was observed in 29 patients with CLP (65.9%), and C. albicans was highly prevalent. SAP and PL activities were observed in 100% and 51.9% of isolates, respectively. High genetic diversity and patterns of monoclonal and polyclonal oral colonization by C. albicans were observed among patients with CLP. Two major polymorphic taxa (A and B) and other minor polymorphic taxa (C to J) were identified. Only one of the 16 clusters (taxon A) harbored strains from patients with and without CLP, whereas other clusters harbored strains exclusively from CLP patients. The anatomical conditions of the oral cavity of patients with CLP contribute to the high incidence of Candida species (C. albicans, C. krusei, C. tropicalis, and/or Candida spp.). Data suggest high genetic diversity of potentially virulent C. albicans strains in the oral cavity of CLP patients. Microbiological niches in orofacial clefts can contribute to the emergence of a relative clinical genotypic identity of C. albicans. However, orofacial rehabilitation centers can contribute to the direct and indirect sources of transmission and propagation of Candida species.

The Terpenoid Activity of Ethanol extracted from Purple Yam Sap to Inhibit the Growth of R. oligosporus and S. cerevisiae

Plants that contain secondary metabolite components can be used as an anti-microbial. Terpenoids are part of secondary metabolic, which is naturally in the plants. This study aims to investigate the terpenoid activity of purple yam sap as an anti-microbe to prevent the growth of R. Oligosporus’mold and S.Cerevicea’s yeast. The terpenoid property within the purple yam sap was identified using the thin-layer chromatography (TLC) eluent toluene of Etil Asetat (3: 7). The anti-microbial activity was tested using the agar diffusion method, and the cell damage analysis was carried out using SEM. This study showed that the anti-microbial activities of the terpenoid to inhibit the growth of R. Oligosporus mold were as follow: the 96% ethanol extract had the inhibition zone of 8.5 mm, the 80% ethanol extract had the inhibition zone of 9.5 mm, and 65% ethanol extract had the inhibition zone of 10.03 mm, whereas the 50% ethanol extract had the highest inhibition zone by 10.93 mm. Meanwhile, 96% ethanol extract had the most robust ability to inhibit the growth of S.crevicea yeast by 11.07 mm, and 80% of the ethanol extract had the weakest ability to inhibit the growth of this yeast only 9.23 mm diameter of inhibition zone. The terpenoids substance with the minimum concentrate (0.01%). Extract causes the cell of the R.oligosporus fungus and cells the S. Cereviceae’s yeast to leak; thus, the cell ruptured and died. On the one hand, the S.cereviceae cell changes the shapes and experiences cell damage.

Serum amyloid P component is an essential element of resistance against Aspergillus fumigatus

Serum amyloid P component (SAP, also known as Pentraxin 2; APCS gene) is a component of the humoral arm of innate immunity involved in resistance to bacterial infection and regulation of tissue remodeling. Here we investigate the role of SAP in antifungal resistance. Apcs−/− mice show enhanced susceptibility to A. fumigatus infection. Murine and human SAP bound conidia, activate the complement cascade and enhance phagocytosis by neutrophils. Apcs−/− mice are defective in vivo in terms of recruitment of neutrophils and phagocytosis in the lungs. Opsonic activity of SAP is dependent on the classical pathway of complement activation. In immunosuppressed mice, SAP administration protects hosts against A. fumigatus infection and death. In the context of a study of hematopoietic stem-cell transplantation, genetic variation in the human APCS gene is associated with susceptibility to invasive pulmonary aspergillosis. Thus, SAP is a fluid phase pattern recognition molecule essential for resistance against A. fumigatus.

Virulence of “white-gray-opaque” tri-stable transformation in clinical Candida albicans in vitro and in vivo

The study aimed to induce the white-opaque-gray tri-stable transformation in clinical C. albicans and to explore their potential pathogenicity. Sixty-four clinical strains were used to induce the white, opaque and gray cells of C. albicans. Secreted aspartyl proteinases (Sap) activity of the three phenotypes was then measured, and a vulvovaginal candidiasis (VVC) animal model was constructed. Of the 64 clinical strains, only 3 strains successfully underwent white-gray-opaque tri-stable transformation, and the three strains all belonged to MTL homozygous strains. Pz values in white, opaque and gray phenotypes were 0.834 ± 0.012, 0.707 ± 0.036, and 0.628 ± 0.002, respectively, which indicated that the cells with gray phenotype had higher Sap activity. After inoculation of different fungal suspension, the fungal colony count in descending order was as follows: gray phenotype, opaque phenotype and white phenotype. After treated with fluconazole for 3 days or 10 days, the fungal colony counts were significantly decreased compared with that before treatment (P < 0.05). The Sap activity and pathogenicity of gray cells in C. albicans were the strongest, followed by opaque cells and white cells. Additionally, white, gray and opaque phenotypic cells were all susceptible to fluconazole.

The effect of arginine addition on chemical and antioxidant properties of coconut sap during heating

Arginine contains positive charged ends that are suitable to bind molecules with negative charge like carbonyl groups of reducing sugar in coconut sap. This research aimed to determine the effect of various arginine concentrations on chemical and antioxidant properties of coconut sap during the heating process. A 2.5 L of coconut sap was added with 0.4; 0.8 and 1.2 mM arginine and heated with an open process until the temperature of sap reached 118 °C. Fifty grams of sap samples were collected in the temperature of 80, 100 and 118 °C during heating treatment. The results showed that the variation of arginine concentration did not significantly affect water content, reducing sugar, total sugar, and sucrose of coconut sap samples. Coconut sap added with 0.4 mM showed the highest pH during heating. The highest of free amino acid content was shown on coconut sap added with 0.8 mM arginine at the end of heating temperature. The 0.8 mM of arginine concentration and the sap temperature of 100 °C were the optimum condition to obtain the highest DPPH radical scavenging activity i.e. 69.93%, while the chelating activity of coconut sap added with 0.4 mM was significantly higher than other treatments (34.42%).

Secreted aspartyl peptidases by the emerging, opportunistic and multidrug-resistant fungal pathogens comprising the Candida haemulonii complex

The opportunistic pathogens comprising the Candida haemulonii complex (C. haemulonii, C. duobushaemulonii and C. haemulonii var. vulnera) are notable for their intrinsic resistance to different antifungal classes. Little is known about the virulence attributes in this emerging fungal complex. However, it is well-recognized that enzymes play important roles in virulence/pathogenesis of candidiasis. Herein, we aimed to identify aspartyl-type peptidases in 12 clinical isolates belonging to the C. haemulonii complex. All isolates were able to grow in a chemically defined medium containing albumin as the sole nitrogen source, and a considerable consumption of this protein occurred after 72–96 h. C. haemulonii var. vulnera isolates showed the lowest albumin degradation capability and the poorest growth rate. The measurement of secreted aspartyl peptidase (Sap) activity, using the cathepsin D fluorogenic substrate, varied from 91.6 to 413.3 arbitrary units and the classic aspartyl peptidase inhibitor, pepstatin A, significantly blocked the Sap released by C. haemulonii complex. No differences were observed in the Sap activity among the three fungal species. Flow cytometry, using a polyclonal antibody against Sap1-3 of C. albicans, detected homologous proteins at the surface of C. haemulonii complex (anti-Sap1-3-labeled cells ranged from 24.6 to 79.1%). Additionally, the immunoblotting assay, conducted with the same Sap1-3 antibody, recognized a protein of ∼50 kDa in all fungal isolates. A glimpse in the genome of these fungi revealed several potential proteins containing Sap1-3-like conserved domain. Altogether, our results demonstrated the potential of C. haemulonii species complex to produce Saps, an important virulence factor of Candida spp.