Endophytic fungi from Passiflora incarnata: an antioxidant compound source.

Endophytes are considered one of the most important microbial resources for obtaining biomolecules of therapeutic use. Passiflora incarnata, widely employed by the pharmaceutical industry, shows therapeutic effects on anxiety, nervousness, constipation, dyspepsia and insomnia based on their antioxidant compounds. In this study, from 315 endophytic fungi isolated from P. incarnata leaves, 60 were selected to determinate presence of chemical constituents related with antioxidant activity, based on their production of soluble pigments. The promising fungi were evaluated specifically on their potential to produce phenolic compounds, flavonoids and for antioxidant activity. Five isolates significantly produced flavonoids and phenolic compounds in the ethyl acetate and n-Butanol extracts, also saponins and high antioxidant activity against the DPPH (2.2-diphenyl-1-picrylhydrazyl) free radical. A strain of Aspergillus nidulans var. dentatus (former Emericella dentata) was able to produce tannins as well; its butanolic extract was very similar than the BHT (butylated hydroxytoluene) (94.3% × 94.32%) and Rutin (95.8%) reference substances in the DPPH radical scavenging. Similarly, a Chaetomium strain exhibited 93.6% and 94.7% of antioxidant activity in their ethyl acetate and butanolic fractions, respectively. The chromatographic analysis of the ethyl acetate fraction from the Aspergillus strain revealed the production of orcinol (3.19%). Four-methoxymethylphenol (4.79%), sorbicillin (33.59%) and ergosterol (23.08%) was produced by Trichoderma longibrachiatum and isopropenyl-1,4-dimethyl-1,2,3,3a,4,5,6,7-octahydroazulene were found in two Fusarium oxysporum strains. The phytochemical screening showed that all analyzed fungi were able to produce a kind of secondary metabolite (phenols, flavonoids, tannins and/or saponins). The study shows a great underexplored potential for industrial application of P. incarnata endophytes.

Morada Nova sheep breed: Resistant or resilient to Haemonchus contortus infection?

Morada Nova is a Brazilian hair sheep breed that is well adapted to the country's mainly tropical climate and has good potential for meat and leather production. This breed is reported to be resistant to Haemonchus contortus infection, a highly desired characteristic due to the large impact of this parasite on sheep farming. Therefore, the present study aimed to characterize 287 recently weaned Morada Nova lambs and 123 ewes in relation to their resistance against H. contortus. The animals were dewormed and 15 days later artificially infected with 4000 H. contortus L3 (D0). They were individually monitored by periodic assessment of fecal egg count (FEC), packed cell volume (PCV), and live weight (LW). On D42, the sheep were again dewormed and submitted to a new parasitic challenge, following the same scheme. The animals of each category (lambs and ewes) were ranked according to individual mean FEC values, and classified as resistant (R, 20%), intermediate (I, 60%), or susceptible (S, 20%) to H. contortus infection. At weaning, high FEC were observed in all three phenotypes (P>0.05). After the artificial infections, there was a significant difference (P<0.05) among the three lamb phenotypes for the mean FEC (RI > S), and LW (R=I > S). The infection levels (FEC) were negatively correlated with PCV (r = -0.66; P<0.001), and LW (r = -0.30; P<0.001). Despite this, the lambs were resilient, since more than 88% of these animals maintained the PCV above 24%, even when heavily infected. The importance of selective parasite control before weaning to reduce the negative impact on slaughter weight was evidenced, taking into account the high positive correlation between LW at weaning and final LW (r=0.73; P<0.001). The ewes, in turn, were strongly resistant to the parasite. Despite highly significant differences (P<0.001) for mean FEC between phenotypes (R0.05). With the phenotypic characterization performed here, it is possible to introduce procedures for parasite control in Morada Nova flocks, facilitating the target-selective treatment approach. The results of this study can also support improvement of meat production by the Morada Nova breed.

Morada Nova sheep breed: Resistant or resilient to Haemonchus contortus infection?

Morada Nova is a Brazilian hair sheep breed that is well adapted to the country's mainly tropical climate and has good potential for meat and leather production. This breed is reported to be resistant to Haemonchus contortus infection, a highly desired characteristic due to the large impact of this parasite on sheep farming. Therefore, the present study aimed to characterize 287 recently weaned Morada Nova lambs and 123 ewes in relation to their resistance against H. contortus. The animals were dewormed and 15 days later artificially infected with 4000 H. contortus L3 (D0). They were individually monitored by periodic assessment of fecal egg count (FEC), packed cell volume (PCV), and live weight (LW). On D42, the sheep were again dewormed and submitted to a new parasitic challenge, following the same scheme. The animals of each category (lambs and ewes) were ranked according to individual mean FEC values, and classified as resistant (R, 20%), intermediate (I, 60%), or susceptible (S, 20%) to H. contortus infection. At weaning, high FEC were observed in all three phenotypes (P > 0.05). After the artificial infections, there was a significant difference (P < 0.05) among the three lamb phenotypes for the mean FEC (R < I < S), PCV (R > I > S), and LW (R = I > S). The infection levels (FEC) were negatively correlated with PCV (r = -0.66; P < 0.001), and LW (r = -0.30; P < 0.001). Despite this, the lambs were resilient, since more than 88% of these animals maintained the PCV above 24%, even when heavily infected. The importance of selective parasite control before weaning to reduce the negative impact on slaughter weight was evidenced, taking into account the high positive correlation between LW at weaning and final LW (r = 0.73; P < 0.001). The ewes, in turn, were strongly resistant to the parasite. Despite highly significant differences (P < 0.001) for mean FEC between phenotypes (R < I < S), 98% of the ewes maintained FEC below 4000 EPG. Their health was not affected, since PCV and LW did not differ between phenotypes, and these parameters were not significantly correlated with FEC (P > 0.05). With the phenotypic characterization performed here, it is possible to introduce procedures for parasite control in Morada Nova flocks, facilitating the target-selective treatment approach. The results of this study can also support improvement of meat production by the Morada Nova breed.

Identification of appropriate reference genes for local immune-related studies in Morada Nova sheep infected with Haemonchus contortus.

Due to the great economic impact of Haemonchus contortus on sheep farming, there is an increasing number of studies addressing host resistance against this nematode, including identification of directly related immune mechanisms. In this context, relative gene expression by RT-qPCR have been largely used, due to its rapidity, high sensitivity, specificity, and reproducibility. Although, appropriate reference gene selection is crucial for accurate interpretation of results. In this study, five reference genes (GAPDH, G6PDH, YWHAZ, ACTB, and B2M) were tested for expression stability in abomasum (fundic and pyloric regions) and abomasal lymph nodes of Morada Nova sheep classified as resistant (n = 5) or susceptible (n = 5) to H. contortus infection in a flock of 151 animals. GAPDH combined with YWHAZ were selected as reference genes for abomasal fundic region and abomasal lymph nodes, whereas YWHAZ was the most stable gene for abomasal pyloric region. These genes presented the lowest intra- and inter-group variations and, consequently, highest stability. In contrast, expression of G6PDH was the least stable in all tissues. The impact of reference gene selection was demonstrated by relative quantification of a pro-inflammatory cytokine (TNFα) in abomasal fundic region. Significant differences in TNFα expression levels between resistant and susceptible groups were only observed when the most stable genes (GAPDH combined with YWHAZ) or GAPDH were used as reference genes, whereas no significant differences were observed when other tested reference genes were used. It was demonstrated that normalization of expression data using inappropriate reference genes may significantly influence interpretation results.