Antisecretory factor-inducing therapy improves the clinical outcome in patients with Ménière's disease

Antisecretory factor in breastmilk is associated with reduced incidence of sepsis in preterm infants

BACKGROUND

Antisecretory Factor (AF) is a protein present in breastmilk that regulates inflammatory processes. We aimed to investigate the level of AF in mothers' own milk (MOM) in relation to sepsis and other neonatal morbidities in preterm infants.

METHODS

Samples of breastmilk and infant plasma were collected at 1, 4, and 12 weeks after birth from 38 mothers and their 49 infants born before 30 weeks gestation. AF-compleasome in MOM was determined by a sandwich enzyme-linked immunosorbent assay (ELISA) and inflammatory markers in infant plasma by a panel of 92 inflammatory proteins. Neonatal treatments and outcomes were recorded.

RESULTS

The level of AF in MOM week 1 was lower for infants with later sepsis compared to no sepsis (p = 0.005). Corrected for nutritional intake of MOM, higher levels of AF decreased the risk for sepsis, OR 0.24. AF in MOM week 1 was negatively correlated to inflammatory proteins in infant plasma week 4, markedly IL-8, which was also associated with infant sepsis. Overall, higher AF levels in MOM was associated with fewer major morbidities of prematurity.

CONCLUSION

Mother's milk containing high levels of antisecretory factor is associated with reduced risk for sepsis and inflammation in preterm infants.

IMPACT

High level of antisecretory factor (AF) in mothers' own milk is associated with less risk for later sepsis in preterm infants. Receiving mothers' milk with low AF levels during the first week after birth is correlated with more inflammatory proteins in infant's plasma 2-4 weeks later. Human breastmilk has anti-inflammatory properties, and antisecretory factor in mothers' own milk is a component of potential importance for infants born preterm. The findings suggest that food supplementation with AF to mothers of preterm infants to increase AF-levels in breastmilk may be a means to decrease the risk of inflammatory morbidities of prematurity.

Lifestyle and dietary interventions for Ménière's disease

BACKGROUND

Ménière's disease is a condition that causes recurrent episodes of vertigo, associated with hearing loss and tinnitus. Lifestyle or dietary modifications (including reducing the amount of salt or caffeine in the diet) are sometimes suggested to be of benefit for this condition. The underlying cause of Ménière's disease is unknown, as is the way in which these interventions may work. The efficacy of these different interventions at preventing vertigo attacks, and their associated symptoms, is currently unclear.

OBJECTIVES

To evaluate the benefits and harms of lifestyle and dietary interventions versus placebo or no treatment in people with Ménière's disease.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 14 September 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in adults with Ménière's disease comparing any lifestyle or dietary intervention with either placebo or no treatment. We excluded studies with follow-up of less than three months, or with a cross-over design (unless data from the first phase of the study could be identified).  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were: 1) improvement in vertigo (assessed as a dichotomous outcome - improved or not improved), 2) change in vertigo (assessed as a continuous outcome, with a score on a numerical scale) and 3) serious adverse events. Our secondary outcomes were: 4) disease-specific health-related quality of life, 5) change in hearing, 6) change in tinnitus and 7) other adverse effects. We considered outcomes reported at three time points: 3 to < 6 months, 6 to ≤ 12 months and > 12 months. We used GRADE to assess the certainty of evidence for each outcome.  MAIN RESULTS: We included two RCTs, one related to diet, and the other related to fluid intake and sleep. In a Swedish study, 51 participants were randomised to receive 'specially processed cereals' or standard cereals. The specially processed cereals are thought to stimulate the production of anti-secretory factor - a protein that reduces inflammation and fluid secretion. Participants received the cereals for three months. The only outcome reported by this study was disease-specific health-related quality of life.  The second study was conducted in Japan. The participants (223) were randomised to receive abundant water intake (35 mL/kg/day), or to sleep in darkness (in an unlit room for six to seven hours per night), or to receive no intervention. The duration of follow-up was two years. The outcomes assessed were 'improvement in vertigo' and hearing.  As these studies considered different interventions we were unable to carry out any meta-analysis, and for almost all outcomes the certainty of the evidence was very low. We are unable to draw meaningful conclusions from the numerical results.

AUTHORS' CONCLUSIONS

The evidence for lifestyle or dietary interventions for Ménière's disease is very uncertain. We did not identify any placebo-controlled RCTs for interventions that are frequently recommended for those with Ménière's disease, such as salt restriction or caffeine restriction. We identified only two RCTs that compared a lifestyle or dietary intervention to placebo or no treatment, and the evidence that is currently available from these studies is of low or very low certainty. This means that we have very low confidence that the effects reported are accurate estimates of the true effect of these interventions. Consensus on the appropriate outcomes to measure in studies of Ménière's disease is needed (i.e. a core outcome set) in order to guide future studies in this area and enable meta-analyses of the results. This must include appropriate consideration of the potential harms of treatment, as well as the benefits.

Antisecretory factor is safe to use as add-on treatment in newly diagnosed glioblastoma

PURPOSE

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Despite the best available treatment, prognosis remains poor. Current standard therapy consists of surgical removal of the tumor followed by radiotherapy and chemotherapy with the alkylating agent temozolomide (TMZ). Experimental studies suggest that antisecretory factor (AF), an endogenous protein with proposed antisecretory and anti-inflammatory properties, may potentiate the effect of TMZ and alleviate cerebral edema. Salovum is an egg yolk powder enriched for AF and is classified as a medical food in the European Union. In this pilot study, we evaluate the safety and feasibility of add-on Salovum in GBM patients.

METHODS

Eight patients with newly diagnosed, histologically confirmed GBM were prescribed Salovum during concomitant radiochemotherapy. Safety was determined by the number of treatment-related adverse events. Feasibility was determined by the number of patients who completed the full prescribed Salovum treatment.

RESULTS

No serious treatment-related adverse events were observed. Out of 8 included patients, 2 did not complete the full treatment. Only one of the dropouts was due to issues directly related to Salovum, which were nausea and loss of appetite. Median survival was 23 months.

CONCLUSIONS

We conclude that Salovum is safe to use as an add-on treatment for GBM. In terms of feasibility, adherence to the treatment regimen requires a determined and independent patient as the large doses prescribed may cause nausea and loss of appetite.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04116138. Registered on 04/10/2019.

Involvement of GABAA receptors containing α6 subtypes in antisecretory factor activity on rat cerebellar granule cells studied by two-photon uncaging

The antisecretory factor (AF) is an endogenous protein that counteracts intestinal hypersecretion and various inflammation conditions in vivo. It has been detected in many mammalian tissues and plasma, but its mechanisms of action are largely unknown. To study the pharmacological action of the AF on different GABA_A receptor populations in cerebellar granule cells, we took advantage of the two‐photon uncaging method as this technique allows to stimulate the cell locally in well‐identified plasma membrane parts. We compared the electrophysiological response evoked by releasing a caged GABA compound on the soma, the axon initial segment and neurites before and after administering AF‐16, a 16 amino acids long peptide obtained from the amino‐terminal end of the AF protein. After the treatment with AF‐16, we observed peak current increases of varying magnitude depending on the neuronal region. Thus, studying the effects of furosemide and AF‐16 on the electrophysiological behaviour of cerebellar granules, we suggest that GABA_A receptors, containing the α₆ subunit, may be specifically involved in the increase of the peak current by AF, and different receptor subtype distribution may be responsible for differences in this increase on the cell.

Upregulation of the endogenous peptide antisecretory factor enhances hippocampal long-term potentiation and promotes learning in wistar rats

Antisecretory Factor (AF) is an endogenous peptide known for its powerful antisecretory and anti-inflammatory properties. We have previously shown that AF also acts as a neuromodulator of GABAergic synaptic transmission in rat hippocampus in a way that results in disinhibition of CA1 pyramidal neurons. Disinhibition is expected to facilitate the induction of long-term potentiation (LTP), and LTP is known to play a crucial role in learning and memory acquisition. In the present study we investigated the effect of AF on LTP in CA3-CA1 synapses in rat hippocampus. In addition, endogenous AF plasma activity was upregulated by feeding the rats with specially processed cereals (SPC) and spatial learning and memory was studied in the Morris Water Maze (MWM). We found that LTP was significantly enhanced in the presence of AF, both when added exogenously in vitro as well as when upregulated endogenously by SPC-feeding. In the presence of the GABA_A-receptor antagonist picrotoxin (PTX) there was however no significant enhancement of LTP. Moreover, rats fed with SPC demonstrated enhanced spatial learning and short-term memory, compared with control animals. These results show that the disinhibition of GABAergic transmission in the hippocampus by the endogenous peptide AF enhances LTP as well as spatial learning and memory.

The relationship between nutrition and Ménière's disease

Ménière's disease is an inner ear disease with attacks characterized by ear fullness, tinnitus, fluctuant sensorineural hearing loss and vertigo. Although pathophysiology of the disease is not fully known, endolymphatic hydrops are believed to play a role. Although there is no certain treatment procedure for Ménière's disease, some treatments are applied to prevent attacks, to treat the symptoms that occur during the attacks, and to prevent the permanent effects of the symptoms on the hearing and balance system. Lifestyle changes, dietary modifications, diuretics, vasodilator corticosteroids, intratympanic steroids, surgical methods are some of these treatment methods. Dietary modification includes a low sodium diet, a reduction in daily alcohol and caffeine intake, a gluten-free diet, and a new dietary approach to specially processed grains, all of which are first-line treatments. The goal of this review article is to examine the relationship between MD and dietary intervention, which is frequently used in the prevention and treatment of MD attacks.

The role of endogenous Antisecretory Factor (AF) in the treatment of Ménière's Disease: A two-year follow-up study. Preliminary results

PURPOSE

To evaluate the effects of increased endogenous Antisecretory Factor (AF) synthesis using specially processed cereals (SPC) in a sample of patients with defined unilateral Meniere's disease (MD), compared to the results of a treatment protocol of intravenous glycerol and dexamethasone.

MATERIALS AND METHODS

Twenty-six patients with unilateral MD were divided in 2 groups and treated with SPC and with intravenous glycerol and dexamethasone for 24 months. Audio-vestibular evaluation was performed before (T0) and every six months. The number of vertigo spells were evaluated before and after therapy and the Efficacy Index (EI) was calculated. Questionnaires for hearing loss, tinnitus and quality of life were administered.

RESULTS

EI decreased in the SPC group after 18 (T18) (p = .0017) and 24 (T24) months of therapy (p = .0111). There was a significant reduction for tinnitus score in the SPC group at T24 (p = .0131). No significant differences were found between the two groups at T0 (p = .4723), while a significant difference was found at T24 (p = .0027). Quality of life showed a significant improvement in daily activities in the SPC group (p = .0033) compared to the infusion therapy group. No statistically significant changes in PTA thresholds were found in both groups between T0 and T24.

CONCLUSION

The preliminary results of our study show a significant reduction of vertigo spells and a positive effect on tinnitus severity and on quality of life in patients with unilateral MD treated with SPC and when compared to patients treated with intravenous glycerol and dexamethasone. No effects on hearing thresholds were noted in both groups.

Does the antisecretory peptide AF-16 reduce lung oedema in experimental ARDS?

Background: Acute respiratory distress syndrome (ARDS) is an acute inflammatory condition with pulmonary capillary leakage and lung oedema formation. There is currently no pharmacologic treatment for the condition. The antisecretory peptide AF-16 reduces oedema in experimental traumatic brain injury. In this study, we tested AF-16 in an experimental porcine model of ARDS.Methods: Under surgical anaesthesia 12 piglets were subjected to lung lavage followed by 2 hours of injurious ventilation. Every hour for 4 hours, measurements of extravascular lung water (EVLW), mechanics of the respiratory system, and hemodynamics were obtained.Results: There was a statistically significant (p = 0.006, two-way ANOVA) reduction of EVLW in the AF-16 group compared with controls. However, this was not mirrored in any improvement in the wet-to-dry ratio of lung tissue samples, histology, inflammatory markers, lung mechanics, or gas exchange.Conclusions: This pilot study suggests that AF-16 might improve oedema resolution as indicated by a reduction in EVLW in experimental ARDS.

Food-induced stimulation of the antisecretory factor to improve symptoms in Meniere's disease: our results

PURPOSE

Specially processed cereals (SPC) that increase endogenous antisecretory factor (AF) synthesis have been proposed to improve symptoms of Meniere's disease (MD) with controversial results. The aim of this study was to evaluate the effects of SPC in patients with definite unilateral MD and compare the results to a treatment protocol with intravenous glycerol and dexamethasone.

METHODS

Thirteen patients with unilateral MD were treated with SPC and 13 patients were treated with intravenous glycerol and dexamethasone for 12 months. Audio-vestibular evaluation was performed before (T0) and at the end of the treatments (T12). The number of vertigo spells were evaluated before and after therapy and the Efficacy Index (EI) was calculated. Questionnaires for hearing loss (HHIA), tinnitus (THI) and quality of life (TFL) were administered.

RESULTS

EI decreased in the SPC group in the second semester compared to the first although not significantly (p = 0.6323). There was a significant reduction for THI score in the SPC group at T12 (p = 0.0325). No significant differences were found between the two groups at T0 (p = 0.4723), while a significant difference was found at T12 (p = 0.0041). Quality of life showed an improvement in daily activities in the SPC group compared to infusion therapy group.

CONCLUSION

Our study shows a reduced number of vertigo attacks and a positive effect on the discomfort generated by tinnitus and quality of life in patients with unilateral MD treated with SPC and when compared to patients treated with intravenous glycerol and dexamethasone. No effects on hearing thresholds were noted in both groups.

Antisecretory Factor-Mediated Inhibition of Cell Volume Dynamics Produces Antitumor Activity in Glioblastoma

Interstitial fluid pressure (IFP) presents a barrier to drug uptake in solid tumors, including the aggressive primary brain tumor glioblastoma (GBM). It remains unclear how fluid dynamics impacts tumor progression and can be targeted therapeutically. To address this issue, a novel telemetry-based approach was developed to measure changes in IFP during progression of GBM xenografts. Antisecretory factor (AF) is an endogenous protein that displays antisecretory effects in animals and patients. Here, endogenous induction of AF protein or exogenous administration of AF peptide reduced IFP and increased drug uptake in GBM xenografts. AF inhibited cell volume regulation of GBM cells, an effect that was phenocopied in vitro by the sodium-potassium-chloride cotransporter 1 (SLC12A2/NKCC1) inhibitor bumetanide. As a result, AF induced apoptosis and increased survival in GBM models. In vitro, the ability of AF to reduce GBM cell proliferation was phenocopied by bumetanide and NKCC1 knockdown. Next, AF's ability to sensitize GBM cells to the alkylating agent temozolomide, standard of care in GBM patients, was evaluated. Importantly, combination of AF induction and temozolomide treatment blocked regrowth in GBM xenografts. Thus, AF-mediated inhibition of cell volume regulation represents a novel strategy to increase drug uptake and improve outcome in GBM. Mol Cancer Res; 16(5); 777-90. ©2018 AACR.

Nocebo Effect in Menière's Disease: A Meta-analysis of Placebo-controlled Randomized Controlled Trials

OBJECTIVE

To estimate the frequency and strength of nocebo effects in trials for Menière disease (MD).

DATA SOURCES

A literature search was conducted in PUBMED. The search terms we used were " Menière or Menière's," "treatment," and "placebo." Limitations included article type to be Clinical Trial or Randomized Controlled Trial, text availability to be Full text, Species to be Humans and Language to be English.

STUDY SELECTION

We included placebo-controlled pharmaceutical RCTs that referred specifically to MD and recruited at least 10 adults in each arm. We excluded those studies with JADAD score ≤3.

DATA EXTRACTION

Thirty-six articles were screened identifying 12 eligible studies. Studies were included after consensus of both authors.

DATA SYNTHESIS

The meta-analysis was conducted using the RevMan programme as suggested by the Cochrane Collaboration Group. Data were analyzed using a random effects model.

CONCLUSION

Nocebo is an important confounding factor of the reported AEs in RCTs for treatment of MD and subsequently in the clinical practice. The pooled estimate of the percentage of placebo-treated patients with at least one AE was 42.3% (95% CI 8.1% to 16.3%), in comparison to 53.8% (95% CI 48.0% to 59.5%) for active drug-treated patients. Reporting of RCTs in MD is suboptimal and we recommend authors to endorse the CONSORT checklist.

Antisecretory Factor Modulates GABAA Receptor Activity in Neurons

The antisecretory factor is an endogenous protein found in all mammalian tissues investigated so far. It acts by counteracting intestinal hypersecretion and various forms of inflammation, but the detailed mechanism of antisecretory factor (AF) action is unknown. We tested neuronal GABA_A receptors by means of AF-16, a potent AF peptide derived from amino acids 36-51 from the NH₂ part of AF. Cultured rat cerebellar granule cells were used, and the effects on the GABA-mediated chloride currents were determined by whole-cell patch clamp. Both the neurotransmitter GABA and AF-16 were added by perfusion of the experimental system. A 3-min AF-16 preincubation was more efficacious than 30 s in significantly elevating the rapidly desensitizing GABA-activated chloride current. No effect was found on the tonic, slowly desensitizing current. The GABA-activated current increase by AF-16 demonstrated a low k of 41 pM with a maximal increase of 37% persisting for some minutes after AF washout, independent from GABA concentration. This indicates an effect on the maximal stimulation (E%_Max) excluding an altered affinity between GABA and its receptor. An immunocytochemical fluorescence approach with anti γ2 subunit antibodies demonstrated an increased expression of GABA_A receptors. Thus, both the electrophysiological and the immunofluorescence approach indicate an increased appearance of GABA_A receptors on the neuronal membrane. The rationale of the experiments was to test the effect of AF on a defined neuronal population of GABA_A receptors. The implications of the results on the impact of AF on the enteric nervous system or on brain function are discussed.

Food-induced changes of lipids in rat neuronal tissue visualized by ToF-SIMS imaging

Time of flight secondary ion mass spectrometry (ToF-SIMS) was used to image the lipid localization in brain tissue sections from rats fed specially processed cereals (SPC). An IonTof 5 instrument equipped with a Bi cluster ion gun was used to analyze the tissue sections. Data from 15 brain samples from control and cereal-fed rats were recorded and exported to principal components analysis (PCA). The data clearly show changes of certain lipids in the brain following cereal feeding. PCA score plots show a good separation in lipid distribution between the control and the SPC-fed group. The loadings plot reveal that the groups separated mainly due to changes in cholesterol, vitamin E and c18:2, c16:0 fatty acid distribution as well as some short chain monocarboxylic fatty acid compositions. These insights relate to the working mechanism of SPC as a dietary supplement. SPC is thought to activate antisecretory factor (AF), an endogenous protein with regulatory function for inflammation and fluid secretion. These data provide insights into lipid content in brain following SPC feeding and suggest a relation to activating AF.

Mass spectrometric profiling of lipids in intestinal tissue from rats fed cereals processed for medical conditions

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used for lipid profiling of intestine tissue sections from rats fed specially processed cereals and rats fed ordinary feed as a control. This cereal is known to increase the activity of antisecretory factor in plasma and the exact mechanism for the activation process at the cellular level is unclear. ToF-SIMS has been used to track food induced changes in lipid content in intestinal tissue sections to gain insight into the possible mechanisms involved. Data from 20 intestine sections belonging to four different rats from each group of control and specially processed cereals-fed rats were obtained using the stage scan macroraster with a lateral resolution of 5 μm. Data were subsequently subjected to orthogonal partial least squares discriminant analysis. The data clearly show that changes of certain lipids are induced by the specially processed cereal feed. Scores plots show a well-defined separation between the two groups. The corresponding loading plots reveal that the groups separate mainly due to changes of vitamin E, phosphocholine, and phosphosphingolipid fragments, and that for the c18:2 fatty acid. The observed changes in lipids might give insight into the working mechanisms of antisecretory factor in the body, and this has been successfully used to understand the working mechanism of specially processed cereal-induced antisecretory factor activation in intestine.

Ménière's Syndrome or Disease: Time Trends in Management and Quality of Evidence Over the Last Two Decades

OBJECTIVE

To evaluate the evidence and trends in published literature on the treatment of Ménière's syndrome or disease (MS/D) by comparing studies published in the last two decades.

DATA SOURCES

A literature search was performed on AMED, EMBASE, HMIC, MEDLINE, PsycINFO, BNI, CINAHL, HEALTH BUSINESS ELITE, CENTRAL and Cochrane Ear, Nose and Throat disorders groups trials register using a combination of MeSH. The date of last search was October 2014.

STUDY SELECTION AND DATA EXTRACTION

Two hundred five studies (104 in decade I and 101 in decade II) were evaluated to report trends in the management of this condition, the differing levels of evidence published for each treatment modality, evaluate whether the guidelines published by the AAOHNS-Committee on Hearing and Equilibrium had been correctly employed, and whether the randomized controlled trials (RCTs) were compliant with the CONSORT guidelines.

RESULTS

The number of published RCTs almost tripled from decade I (1994-2003) to decade II (2004-2103). There was a significant decline in the use of surgical intervention (p = 0.013); however, the number of studies involving the use of intratympanic injection remained largely unchanged. There was a shift in the level of evidence in published studies; studies with level 1 evidence tripled from decade I to II (4.8 to 17.8%, respectively) (p = 0.03); however, compliance with the AAOHNS-CHE criteria for reporting treatment outcomes and the CONSORT checklist was still poor.

CONCLUSION

Although the evidence base on published literature on MS/D has improved over the last decade with an increase in emphasis on RCTs and quality of life (QoL) studies, a significant number of studies failed to follow AAOHNS-CHE criteria for reporting treatment outcome and the CONSORT criteria for reporting RCTs.

Antisecretory therapy with no improvement in functional level in Ménière's disease

Conclusion Antisecretory factor-inducing (AF) specially processed cereals (SPC) were not shown to significantly improve the functional level in patients with MD. Objectives The aim of this study was to evaluate the effect of AF-inducing SPC in patients suffering from Ménière's disease (MD). Methods A randomized double-blinded, placebo-controlled cross-over study was conducted. All patients had a 2 months intake of SPC and control cereal with a 2 months washout period in between. The severity of MD was classified according to the American Academy of Otolaryngology-Head and Neck Surgery (AOO-HNS) functional scale, and the frequency of attacks was registered. Results Thirty-two patients completed the study. No carryover effect was found. In both functional level and frequency of attacks no significant effect of SPC was found. Seventeen patients showed improvement in functional level when treated with SPC (mean improvement = 0.9 points) and 14 when treated with placebo (mean improvements = 0.7 points). No patients showed worsening in functional level during treatment with SPC, but three showed worsening when treated with placebo. Seventeen patients reported fewer attacks when treated with SPC, and 22 when treated with placebo. Three patients reported more frequent attacks when treated with SPC, and three when treated with placebo. A non-parametric comparison and a parametric analysis supported the findings.

Diet-induced antisecretory factor prevents intracranial hypertension in a dosage-dependent manner

Intake of specially processed cereal (SPC) stimulates endogenous antisecretory factor (AF) activity, and SPC intake has proven to be beneficial for a number of clinical conditions. The aim of the present study was to investigate the dosage relationship between SPC intake and plasma AF activity and to further correlate achieved AF levels to a biological effect. SPC was fed to rats in concentrations of 5, 10 or 15% for 2 weeks. A further group was fed 5% SPC for 4 weeks. AF activity and the complement factors C3c and factor H were analysed in plasma after the feeding period. Groups of rats fed the various SPC concentrations were subjected to a standardised freezing brain injury, known to induce increases in intracranial pressure (ICP). The AF activity in plasma increased after intake of SPC, in a dosage- and time-dependent manner. The complement factors C3c and factor H increased in a time-dependent manner. Measurements of ICP in animals fed with SPC prior to the brain injury showed that the ICP was significantly lower, compared with that of injured rats fed with a standard feed, and that the change was dose and time dependent. AF activity increases, in a dosage- and time-dependent manner, after intake of SPC. The inverse relationship between ICP after a head injury and the percentage of SPC in the feed indicate that the protective effect is, to a large extent, due to AF.

The peptide AF-16 and the AF protein counteract intracranial hypertension

Intracranial hypertension develops after, for example, trauma, stroke and brain inflammation, and contributes to increased morbidity, mortality, and persistent neuropsychiatric sequelae. Nonsurgical therapy offers limited relief. We investigated whether the peptide AF-16 and the endogenous protein Antisecretory Factor (AF) counteracted abnormal fluid transfer by cells, and lowered raised intracranial pressure (ICP). Adult rats, infected with an encephalitogenic Herpes simplex virus (HSV-1), developed after 5 days' sickness of increasing severity. AF-16 rescued all rats while vehicle treatment only saved 20%. AF-16 from day 4 reduced the ICP in HSV-1-infected rats from 30.7 to 14.6 mmHg and all survived without sequelae. A standardised closed head brain injury in rats raised the ICP. Continuous and intermittent AF-16 kept ICP at an almost normal level. A single dose of AF-16 maintained the raised ICP after a TBI lowered during 3-9 h. The AF protein, enriched in egg yolk, similarly lowered the post-traumatically raised ICP in rats. AF-16 also lowered the ICP in rabbits with diffuse brain injury. We conclude that the peptide AF-16 and the AF protein offer new approaches to treat raised ICP with no side effects.

The peptide AF-16 decreases high interstitial fluid pressure in solid tumors

BACKGROUND

The high interstitial fluid pressure (IFP) in solid tumors restricts the access to nutrients, oxygen and drugs.

MATERIAL AND METHODS

We investigated the ability of the peptide AF-16, involved in water and ion transfer through cell membranes, to lower the IFP in two different solid rat mammary tumors, one chemically induced, slowly growing, and the other transplantable, and rapidly progressing having high cellularity. AF-16 was administered either in the tumor capsule, intranasally or intravenously. The IFP was measured by a miniature fiber optic device.

RESULTS

AF-16 significantly lowered the IFP in both the slowly and the rapidly progressing tumors, whether administrated locally or systemically. The AF-16 induced IFP reduction was maximal after 90 min, lasted at least 3 h, and returned to pretreatment levels in less than 24 h. Topical AF-16 transiently reduced the IFP in the DMBA tumors from 17.7 ± 4.2 mmHg to 8.6 ± 2.1 mmHg.

CONCLUSION

We conclude that AF-16 transiently and reversibly lowered the high IFP in solid tumors during a few hours, which might translate into improved therapeutic efficacy.

Antisecretory factor as a potential health-promoting molecule in man and animals

Antisecretory factor (AF) is a protein secreted in plasma and other tissue fluids in mammals with proven antisecretory and anti-inflammatory activity; its immunohistological distribution suggests a role in the immune system. The expression level and the distribution of AF protein are altered during an immunological response. Exposure to bacterial toxins induces secretion of AF in plasma, probably reflecting a natural defence mechanism to agents causing diarrhoea, thereby contributing to a favourable clinical outcome and disease termination. An increase of AF levels in plasma by dietary means, such as specially processed cereals (SPC), has been demonstrated in human subjects and animals. Administration of SPC to patients affected by inflammatory bowel disease, gastroenteritis and Ménière's disease relieved symptoms and improved quality of life. A recent study showed the positive effect of SPC diet supplementation on prevention of the effects of exposure to low levels of blast overpressure in rats, reducing the extent of intracranial pressure increase and cognitive function impairment. AF-rich egg yolk powder improved health status in children suffering acute and chronic diarrhoea, reducing the frequency and increasing the consistency of stools. This kind of functional food could be used for prophylaxis in populations exposed to a high risk of morbidity and mortality caused by diarrhoea and as a complementary therapy in patients affected by chronic intestinal inflammatory disease to improve well-being. In pig husbandry AF-inducing diets, owing to their antisecretory activity and anti-inflammatory action, are a suitable option as an alternative to antibiotic growth promoters to counteract post-weaning diarrhoea.