Colonic drug delivery: Formulating the next generation of colon-targeted therapeutics

Colonic drug delivery can facilitate access to unique therapeutic targets and has the potential to enhance drug bioavailability whilst reducing off-target effects. Delivering drugs to the colon requires considered formulation development, as both oral and rectal dosage forms can encounter challenges if the colon's distinct physiological environment is not appreciated. As the therapeutic opportunities surrounding colonic drug delivery multiply, the success of novel pharmaceuticals lies in their design. This review provides a modern insight into the key parameters determining the effective design and development of colon-targeted medicines. Influential physiological features governing the release, dissolution, stability, and absorption of drugs in the colon are first discussed, followed by an overview of the most reliable colon-targeted formulation strategies. Finally, the most appropriate in vitro, in vivo, and in silico preclinical investigations are presented, with the goal of inspiring strategic development of new colon-targeted therapeutics

Expression of two Sclerotinia sclerotiorum endo-PG genes correlates with endo-polygalacturonase activity during Glycine max colonization

Quantitative expression of Sclerotinia sclerotiorum genes encoding two endo-polygalacturonase (endo-PG) isoforms (PGa and PGb), malate dehydrogenase (MDH, a key enzyme in fungal biosynthetic pathway of oxalic acid), and plant polygalacturonase-inhibiting protein (PGIP) were monitored by real-time reverse transcription-polymerase chain reaction (qRT-PCR) during the early stages (0-48 h) of soybean seedling infection. The activity of the two endo-PGs was also investigated during plant infection. PGa and PGb activity reflected very closely the pattern of their transcript accumulation as determined by qRT-PCR. In particular, the PGb encoding gene (Sspgb) was induced at 8 h after inoculation and reached a maximum at 16 h; expression of the PGa encoding gene (Sspga) was comparatively lower, reaching its maximum level later and its rate of increase paralleled that of the S. sclerotiorum b-tubulin gene; the expression of the MDH encoding gene (Ssmdh) was maximal 16 h after infection; soybean pgip transcript began to accumulate 8 h after inoculation reaching a maximum after 24 h. Expression patterns of reported genes are discussed in relation to the ability of S. sclerotiorum to induce disease by regulating endo-PGs and oxalate accumulation to elude the effect of plant PGIP

Characterization of Fusarium graminearum pectic enzymes secreted in liquid culture and during wheat infection

Fusarium graminearum (teleomorph Giberella zeae) causes important diseases in cereals, like wheat, barley and maize. During the infection process this fungus produces mycotoxins and secretes several cell wall degrading enzymes (CWDEs) which could have a role in host colonization. Among CWDEs, we analyzed pectic enzymes produced in liquid culture and during wheat infection. In culture, activity of endo-polygalacturonase (endo-PG) resulted much greater than that of pectin lyase (PNL). Two endo-PGs are secreted and they exhibit different pH range and optimum: one of them, named PG1, has an optimum pH of 5.0 and is inactive at pH 8.0; the second one, named PG2, has an optimum pH of 7.0 and is still active at pH 8.0. Gene expression analysis performed by real time RT-PCR (qRT-PCR) and enzyme activity data showed that, in liquid culture, PG1 was more expressed than PG2. The expression of pg1 and pg2 genes during the infection of wheat spikes was compared to that of pnl gene, encoding a pectin lyase, and xylA gene, encoding an endo-xylanase. This latter gene was later expressed than pg and pnl genes, but its expression resulted higher. To clarify the importance of F. graminearum endo-PGs in the infection process we performed transformation-mediated gene disruptions. A phenotypic characterization of these mutants will be presented

Characterization and expression of Fusarium graminearum endo-polygalacturonases in vitro and during wheat infection

This study investigated the expression and characterization of two polygalacturonases (PG1 and PG2) of Fusarium graminearum during infection of wheat spikelets; after purification, these were demonstrated to be products of two unique endo - pg genes annotated in the genome database of F. graminearum . Both genes (Fgpg1 and Fgpg2) were expressed in vitro and during spike infection. PG1 had a greater specific activity, with a maximum at pH 5\u20137, was largely secreted in liquid culture and clearly detectable in the infected ovary tissue. PG2 was more active at pH 7\u20137.8, was poorly secreted in liquid culture and faintly detectable in infected ovaries. Both PG-encoding genes were maximally expressed 24 h after wheat spikelet infection, paralleling the expression of a pectin lyase (Fgpnl1) gene; they anticipated the expression of a xylanase gene (FgxylA) that was induced only 48 h after infection with a maximum at 96 h. These data strongly indicate F. graminearum -secreted PG activity at an early stage of wheat infection

Do probiotic interventions improve female unexplained infertility? A critical commentary

Disruption of the women's gut and cervicovaginal microbiota has been associated with multiple gynaecologic diseases such as endometriosis, polycystic ovary syndrome (PCOS), noncyclic pelvic pain, and infertility. Female infertility affects 12.6% of women worldwide; its aetiology is complex and multifactorial and can be underpinned by uterine pathologies, systemic diseases, and age. In addition, a new perspective has emerged on the role of the gut and vaginal microbiomes in reproductive health. Research shows that the administration of precisely selected probiotics, often in combination with prior antibiotic treatment, may facilitate the restoration of symbiotic microbiota to increase successful conception and assisted reproductive technology outcomes. However, full research clarity is currently hampered by a lack of consistency and harmonisation in clinical studies: various lactobacilli and bifidobacteria species have been delivered through both the oral and vaginal routes, in different dosages, for different treatments’ durations. This commentary explores the intricate relationship between the microbiota in the cervicovaginal and gut of women, exploring their potential contribution to infertility. It highlights ongoing research on the use of probiotic formulation in improving pregnancy outcomes, critically examining the divergent findings in these studies, which complicate a conclusive assessment of the efficacy of these interventions

Gene disruption approach to investigate the role of Fusarium graminearum and Fusarium verticillioides polygalacturonases during plant infection

Fusarium graminearum and Fusarium verticillioides are two important pathogens of cereal species, causing yield and quality losses. These fungi are known to produce polygalacturonase (PG) activity during liquid culture, but the role played by these enzymes during plant infection has not been ascertained yet. In particular, F. graminearum secretes two endo-PG isoforms, encoded by the two putative endo-pg genes contained in its genome, and F. verticillioides secretes an isoform which has been previously characterized together with its encoding gene. In order to establish the role of these PGs in pathogenesis, we have obtained by targeted homologous recombination the transformation-mediated disruption of their pg encoding genes, and the virulence of each knock-out mutant has been therefore evaluated by infecting host plants. Two different strains of F. graminearum have been transformed: preliminary infection experiments of wheat plants seem to indicate that both pg knock-out mutants maintain the capability to infect wheat, although colonization of spikes appears delayed compared to the wild-type strain. Infection experiments with the F. verticillioides pg knock-out mutant have been performed on maize seedlings and corn husks: the mutant maintains the capability to infect both tissues, but it shows a clearly evident delay in the progression of symptoms. The demonstration of the importance of F. graminearum and F. verticillioides PGs in pathogenesis might contribute to develop strategies aimed to increase the resistance of host plants to infection by these pathogens