From Selye's and Szabo's Cysteamine-Duodenal Ulcer in Rats to Dopamine in the Stomach: Therapy Significance and Possibilities

We reviewed gastric ulcer healing by dopamine considering several distinctive duodenal key points. Selye and Szabo describe the cysteamine-induced duodenal ulcer in rats as a duodenal stress ulcer in patients. Szabo's cysteamine duodenal ulcer as the dopamine duodenal healing and cysteamine as a dopamine antagonist signifies the dopamine agonists anti-ulcer effect and dopamine antagonists ulcerogenic effect. From these viewpoints, we focused on dopamine and gastric ulcer healing. We mentioned antecedent studies on the dopamine presence in the stomach and gastric juice. Then we reviewed, in the timeline, therapy significance arising from the anti-ulcer potency of the various dopamine agonists, which is highly prevailing over the quite persistent beneficial evidence arising from the various dopamine antagonists. Meanwhile, the beneficial effects of several peptides (i.e., amylin, cholecystokinin, leptin, and stable gastric pentadecapeptide BPC 157, suggested as an acting mediator of the dopamine brain-gut axis) were included in the dopamine gastric ulcer story. We attempt to resolve dopamine agonists/antagonists issue with the dopamine significance in the stress (cysteamine as a prototype of the duodenal stress ulcer), and cytoprotection (cysteamine in small dose as a prototype of the cytoprotective agents; cysteamine duodenal ulcer in gastrectomized rats). Thereby, along with dopamine agonists' beneficial effects, in special circumstances, dopamine antagonists having their own ulcerogenic effect may act as "mild stress (or)" or "small irritant" counteracting subsequent strong alcohol or stress procedure-induced severe lesions in this particular tissue. Finally, in the conclusion, as a new improvement in further therapy, we emphasized the advantages of the dopamine agents' application in lower gastrointestinal tract therapy.

Stable Gastric Pentadecapeptide BPC 157-Possible Novel Therapy of Glaucoma and Other Ocular Conditions

Recently, stable gastric pentadecapeptide BPC 157 therapy by activation of collateral pathways counteracted various occlusion/occlusion-like syndromes, vascular, and multiorgan failure, and blood pressure disturbances in rats with permanent major vessel occlusion and similar procedures disabling endothelium function. Thereby, we revealed BPC 157 cytoprotective therapy with strong vascular rescuing capabilities in glaucoma therapy. With these capabilities, BPC 157 therapy can recover glaucomatous rats, normalize intraocular pressure, maintain retinal integrity, recover pupil function, recover retinal ischemia, and corneal injuries (i.e., maintained transparency after complete corneal abrasion, corneal ulceration, and counteracted dry eye after lacrimal gland removal or corneal insensitivity). The most important point is that in glaucomatous rats (three of four episcleral veins cauterized) with high intraocular pressure, all BPC 157 regimens immediately normalized intraocular pressure. BPC 157-treated rats exhibited normal pupil diameter, microscopically well-preserved ganglion cells and optic nerve presentation, normal fundus presentation, nor- mal retinal and choroidal blood vessel presentation, and normal optic nerve presentation. The one episcleral vein rapidly upgraded to accomplish all functions in glaucomatous rats may correspond with occlusion/occlusion-like syndromes of the activated rescuing collateral pathway (azygos vein direct blood flow delivery). Normalized intraocular pressure in glaucomatous rats corresponded to the counteracted intra-cranial (superior sagittal sinus), portal, and caval hypertension, and aortal hypotension in occlusion/occlusion-like syndromes, were all attenuated/eliminated by BPC 157 therapy. Furthermore, given in other eye disturbances (i.e., retinal ischemia), BPC 157 instantly breaks a noxious chain of events, both at an early stage and an already advanced stage. Thus, we further advocate BPC 157 as a therapeutic agent in ocular disease.

Pentadecapeptide BPC 157 and the central nervous system

We reviewed the pleiotropic beneficial effects of the stable gastric pentadecapeptide BPC 157, three very recent demonstrations that may be essential in the gut-brain and brain-gut axis operation, and therapy application in the central nervous system disorders, in particular. Firstly, given in the reperfusion, BPC 157 counteracted bilateral clamping of the common carotid arteries-induced stroke, sustained brain neuronal damages were resolved in rats as well as disturbed memory, locomotion, and coordination. This therapy effect supports particular gene expression in hippocampal tissues that appeared in BPC 157-treated rats. Secondly, there are L-NG-nitro arginine methyl ester (L-NAME)- and haloperidol-induced catalepsy as well as the rat acute and chronic models of 'positive-like' schizophrenia symptoms, that BPC 157 counteracted, and resolved the complex relationship of the nitric oxide-system with amphetamine and apomorphine (dopamine agents application), MK-801 (non-competitive antagonist of the N-methyl-D-aspartate receptor) and chronic methamphetamine administration (to induce sensitivity). Thirdly, after rat spinal cord compression, there were advanced healing and functional recovery (counteracted tail paralysis). Likewise, in BPC 157 therapy, there is specific support for each of these topics: counteracted encephalopathies; alleviated vascular occlusion disturbances (stroke); counteracted dopamine disturbances (dopamine receptors blockade, receptors super sensitivity development, or receptor activation, over-release, nigrostriatal damage, vesicles depletion), and nitric oxide-system disturbances ("L-NAME non-responsive, L-arginine responsive," and "L-NAME responsive, L-arginine responsive") (schizophrenia therapy); inflammation reduction, nerve recovery in addition to alleviated hemostasis and vessels function after compression (spinal cord injury therapy). Thus, these disturbances may be all resolved within the same agent's beneficial activity, i.e., the stable gastric pentadecapeptide BPC 157.

BPC 157 as Potential Treatment for COVID-19

The emergence of coronavirus disease (COVID-19) in China at the end of 2019 has caused a large global outbreak. COVID-19 is largely seen as a thrombotic and vascular disease targeting endothelial cells (ECs) throughout the body that can provoke the breakdown of central vascular functions. This explains the complications and multi-organ failure seen in COVID-19 patients including acute respiratory distress syndrome, cardiovascular complications, liver damage, and neurological damage. Acknowledging the comorbidities and potential organ injuries throughout the course of COVID-19 is therefore crucial in the clinical management of patients. Here we discuss BPC 157, based primarily on animal model data, as a novel agent that can improve the clinical management of COVID-19. BPC 157 is a peptide that has demonstrated anti-inflammatory, cytoprotective, and endothelial-protective effects in different organ systems in different species. BPC 157 activated endothelial nitric oxide synthase (eNOS) is associated with nitric oxide (NO) release, tissue repair and angiomodulatory properties which can lead to improved vascular integrity and immune response, reduced proinflammatory profile, and reduced critical levels of the disease. As a result, discussion of its use as a potential prophylactic and complementary treatment is critical. All examined treatments, although potentiality effective against COVID-19, need either appropriate drug development or clinical trials in humans to be suitable for clinical use.

Robert's Intragastric Alcohol-Induced Gastric Lesion Model as an Escalated General Peripheral and Central Syndrome, Counteracted by the Stable Gastric Pentadecapeptide BPC 157

We redefined Robert’s prototypical cytoprotection model, namely the intragastric administration of 96% alcohol in order to generate a general peripheral and central syndrome similar to that which occurs when major central or peripheral veins are occluded in animal models. With this redefinition, we used Robert’s model to examine the cytoprotective effects of the stable gastric pentadecapeptide BPC 157. The intragastric administration of alcohol induced gastric lesions, intracranial (superior sagittal sinus) hypertension, severe brain swelling and lesions, portal and vena caval hypertension, aortal hypotension, severe thrombosis, inferior vena cava and superior mesenteric vein congestion, azygos vein failure (as a failed collateral pathway), electrocardiogram disturbances, and heart, lung, liver and kidney lesions. The use of BPC 157 therapy (10 µg/kg or 10 ng/kg given intraperitoneally 1 min after alcohol) counteracted these deficits rapidly. Specifically, BPC 157 reversed brain swelling and superior mesenteric vein and inferior vena caval congestion, and helped the azygos vein to recover, which improved the collateral blood flow pathway. Microscopically, BPC 157 counteracted brain (i.e., intracerebral hemorrhage with degenerative changes of cerebral and cerebellar neurons), heart (acute subendocardial infarct), lung (parenchymal hemorrhage), liver (congestion), kidney (congestion) and gastrointestinal (epithelium loss, hemorrhagic gastritis) lesions. In addition, this may have taken place along with the activation of specific molecular pathways. In conclusion, these findings clarify and extend the theory of cytoprotection, offer an approach to its practical application, and establish BPC 157 as a prospective cytoprotective treatment.

Complex Syndrome of the Complete Occlusion of the End of the Superior Mesenteric Vein, Opposed with the Stable Gastric Pentadecapeptide BPC 157 in Rats

Background. Gastric pentadecapeptide BPC 157 therapy in rats compensated irremovable occlusion of various vessels and counteracted the consequent multiorgan dysfunction syndromes by activation of the corresponding collateral bypassing loops. Thus, we used BPC 157 therapy against the irremovable occlusion of the end of the superior mesenteric vein. Methods. Assessments, for 30 min (gross recording, venography, ECG, pressure, microscopy, biochemistry, and oxidative stress) include the portal and caval hypertension, aortal hypotension, and centrally, the superior sagittal sinus hypertension, systemic arterial and venous thrombosis, ECG disturbances, MDA-tissue increase, and heart, lung, liver, kidney and gastrointestinal tract, in particular, and brain (cortex (cerebral, cerebellar), hypothalamus/thalamus, hippocampus) lesions. Rats received BPC 157 medication (10 µg/kg, 10 ng/kg) intraperitoneally at 1 or 15 min ligation time. Results. BPC 157 rapidly activated the superior mesenteric vein-inferior anterior pancreati-coduodenal vein-superior anterior pancreaticoduodenal vein-pyloric vein-portal vein pathway, reestablished superior mesenteric vein and portal vein connection and reestablished blood flow. Simultaneously, toward inferior caval vein, an additional pathway appears via the inferior mesenteric vein united with the middle colic vein, throughout its left colic branch to ascertain alternative bypassing blood flow. Consequently, BPC 157 acts peripherally and centrally, and counteracted the intracranial (superior sagittal sinus), portal and caval hypertension, aortal hypotension, ECG disturbances attenuated, abolished progressing venous and arterial thrombosis. Additionally, BPC 157 counteracted multiorgan dysfunction syndrome, heart, lung, liver, kidney and gastrointestinal tract, and brain lesions, and oxidative stress in tissues. Conclusion. BPC 157 therapy may be specific management also for the superior mesenteric vein injuries.

Therapy with the Stable Gastric Pentadecapeptide BPC 157

Background. We investigated the occluded essential vessel tributaries, both arterial and venous, occluded superior mesenteric vein and artery in rats, consequent noxious syndrome, peripherally and centrally. As therapy, we hypothesized the rapidly activated alternative bypassing pathways, arterial and venous, and the stable gastric pentadecapeptide BPC 157 since it rapidly alleviated venous occlusion syndromes. Methods. Assessments were performed for 30 min (gross recording, venography, ECG, pressure, microscopy, biochemistry, and oxidative stress), including portal hypertension, caval hypertension, aortal hypotension, and centrally, the superior sagittal sinus hypertension; systemic arterial and venous thrombosis, ECG disturbances, MDA-tissue increase, the multiple organs lesions, heart, lung, liver, kidney and gastrointestinal tract, including brain (swelling, and cortex (cerebral, cerebellar), hypothalamus/thalamus, hippocampus lesions). Rats received BPC 157 medication (10 µg/kg, 10 ng/kg) intraperitoneally at 1 min ligation-time. Results. BPC 157 rapidly activated collateral pathways. These collateral loops were the superior mesenteric vein-inferior anterior pancreaticoduodenal vein-superior anterior pancreaticoduodenal vein-pyloric vein-portal vein pathway, an alternative pathway toward inferior caval vein via the united middle colic vein and inferior mesenteric vein through the left colic vein, and the inferior anterior pancreaticoduodenal artery and inferior mesenteric artery. Consequently, BPC 157 counteracted the superior sagittal sinus, portal and caval hypertension, aortal hypotension, progressing venous and arterial thrombosis peripherally and centrally, ECG disturbances attenuated. Markedly, the multiple organs lesions, heart, lung, liver, kidney, and gastrointestinal tract, in particular, as well as brain lesions, and oxidative stress in tissues were attenuated. Conclusions. BPC 157 therapy rapidly recovered rats, which have complete occlusion of the superior mesenteric vein and artery.

BPC 157 Therapy and the Permanent Occlusion of the Superior Sagittal Sinus in Rat: Vascular Recruitment

We show the complex syndrome of the occluded superior sagittal sinus, brain swelling and lesions and multiple peripheral organs lesions in rat. Recovery goes centrally and peripherally, with the stable gastric pentadecapeptide BPC 157, which alleviated peripheral vascular occlusion disturbances, rapidly activating alternative bypassing pathways. Assessments were gross recording, venography, ECG, pressure, microscopy, biochemistry. The increased pressure in the superior sagittal sinus, portal and caval hypertension, aortal hypotension, arterial and venous thrombosis, severe brain swelling and lesions (cortex (cerebral, cerebellar), hypothalamus/thalamus, hippocampus), particular veins (azygos, superior mesenteric, inferior caval) dysfunction, heart dysfunction, lung congestion as acute respiratory distress syndrome, kidney disturbances, liver failure, and hemorrhagic lesions in gastrointestinal tract were all assessed. Rats received BPC 157 medication (10 µg/kg, 10 ng/kg) intraperitoneally, intragastrically, or topically to the swollen brain at 1 min ligation-time, or at 15 min, 24 h and 48 h ligation-time. BPC 157 therapy rapidly attenuates the brain swelling, rapidly eliminates the increased pressure in the ligated superior sagittal sinus and the severe portal and caval hypertension and aortal hypotension, and rapidly recruits collateral vessels, centrally ((para)sagittal venous collateral circulation) and peripherally (left superior caval vein azygos vein-inferior caval vein). In conclusion, as shown by all assessments, BPC 157 acts against the permanent occlusion of the superior sagittal sinus and syndrome (i.e., brain, heart, lung, liver, kidney, gastrointestinal lesions, thrombosis), given at 1 min, 15 min, 24 h or 48 h ligation-time. BPC 157 therapy rapidly overwhelms the permanent occlusion of the superior sagittal sinus in rat.

BPC 157 as a Therapy for Retinal Ischemia Induced by Retrobulbar Application of L-NAME in Rats

Providing NO-system importance, we suggest that one single application of the NOS-blocker L-NAME may induce retinal ischemia in rats, and that the stable pentadecapeptide BPC 157 may be the therapy, since it may interact with the NO-system and may counteract various adverse effects of L-NAME application. A rat retinal ischemia study was conducted throughout 4 weeks, including fundoscopy, behavior presentation, tonometry, and histology assessment. Retrobulbar L-NAME application (5 mg/kg; 0.5 mg/0.1 ml saline/each eye) in rats immediately produced moderate generalized irregularity in the diameter of blood vessels with moderate atrophy of the optic disc and faint presentation of the choroidal blood vessels, and these lesions rapidly progressed to the severe stage. The specific L-NAME-induced vascular failure points to normal intraocular pressure (except to very transitory increase upon drug retrobulbar administration). When BPC 157 (10 μg; 10 ng/kg, as retrobulbar application, 1 μg; 1 ng/0.1 ml saline/each eye) is given at either 20 min after L-NAME or, lately, at 48 h after L-NAME, the regular retrobulbar L-NAME injection findings disappear. Instead, fundoscopy demonstrated only discrete generalized vessel caliber irregularity with mild atrophy of the optic disc, and then, quite rapidly, normal eye background and choroidal blood vessels, which remain in all of the subsequent periods. Also, histology assessment at 1, 2, and 4 weeks shows that BPC 157 counteracted the damaged inner plexiform layer and inner nuclear layer, and revealed normal retinal thickness. The poor behavioral presentation was also rescued. Thus, while further studies will be done, BPC 157 counteracted L-NAME-induced rat retinal ischemia.

Occlusion of the Superior Mesenteric Artery in Rats Reversed by Collateral Pathways Activation: Gastric Pentadecapeptide BPC 157 Therapy Counteracts Multiple Organ Dysfunction Syndrome; Intracranial, Portal, and Caval Hypertension; and Aortal Hypotension

Gastric pentadecapeptide BPC 157 therapy counteracts multiple organ dysfunction syndrome in rats, which have permanent occlusion of the superior mesenteric artery close to the abdominal aorta. Previously, when confronted with major vessel occlusion, its effect would rapidly activate collateral vessel pathways and resolve major venous occlusion syndromes (Pringle maneuver ischemia, reperfusion, Budd-Chiari syndrome) in rats. This would overwhelm superior mesenteric artery permanent occlusion, and result in local, peripheral, and central disturbances. Methods: Assessments, for 30 min (gross recording, angiography, ECG, pressure, microscopy, biochemistry, and oxidative stress), included the portal hypertension, caval hypertension, and aortal hypotension, and centrally, the superior sagittal sinus hypertension; systemic arterial and venous thrombosis; ECG disturbances; MDA-tissue increase; and multiple organ lesions and disturbances, including the heart, lung, liver, kidney, and gastrointestinal tract, in particular, as well as brain (cortex (cerebral, cerebellar), hypothalamus/thalamus, hippocampus). BPC 157 therapy (/kg, abdominal bath) (10 µg, 10 ng) was given for a 1-min ligation time. Results: BPC 157 rapidly recruits collateral vessels (inferior anterior pancreaticoduodenal artery and inferior mesenteric artery) that circumvent occlusion and ascertains blood flow distant from the occlusion in the superior mesenteric artery. Portal and caval hypertension, aortal hypotension, and, centrally, superior sagittal sinus hypertension were attenuated or eliminated, and ECG disturbances markedly mitigated. BPC 157 therapy almost annihilated venous and arterial thrombosis. Multiple organ lesions and disturbances (i.e., heart, lung, liver, and gastrointestinal tract, in particular, as well as brain) were largely attenuated. Conclusions: Rats with superior mesenteric artery occlusion may additionally undergo BPC 157 therapy as full counteraction of vascular occlusion-induced multiple organ dysfunction syndrome.

BPC 157 Rescued NSAID-cytotoxicity Via Stabilizing Intestinal Permeability and Enhancing Cytoprotection

The stable gastric pentadecapeptide BPC 157 protects stomach cells, maintains gastric integrity against various noxious agents such as alcohol, nonsteroidal anti-inflammatory drugs (NSAIDs), and exerts cytoprotection/ adaptive cytoprotection/organoprotection in other epithelia, that is, skin, liver, pancreas, heart, and brain. Especially BPC 157 counteracts gastric endothelial injury that precedes and induces damage to the gastric epithelium and generalizes "gastric endothelial protection" to protection of the endothelium of other vessels including thrombosis, prolonged bleeding, and thrombocytopenia. In this background, we put the importance of BPC 157 as a possible way of securing GI safety against NSAIDs-induced gastroenteropathy since still unmet medical needs to mitigate NSAIDs-induced cytotoxicity are urgent. Furthermore, gastrointestinal irritants such as physical or mental stress, NSAIDs administration, surfactants destroyer such as bile acids, alcohol can lead to leaky gut syndrome through increasing epithelial permeability. In this review article, we described the potential rescuing actions of BPC 157 against leaky gut syndrome after NSAIDs administration for the first time.

Clopidogrel-Induced Gastric Injury in Rats is Attenuated by Stable Gastric Pentadecapeptide BPC 157

Aim

Although Clopidogrel is safe in healthy volunteers, it can induce recurrence of gastric ulcers in high-risk patients. Here, we investigated the protective effect of the natural product, stable gastric pentadecapeptide 157 (BPC 157) on Clopidogrel-induced gastric injury.

Methods

We used acetic acid to induce gastric ulcer in Sprague Dawley rats. Clopidogrel alone or in combination with BPC 157 or L-NAME (nitric oxide system blockade) were administered after healing of acetic acid-induced ulcer. One percent methylcellulose solution was used as control. Ulcer recurrence rate and the ulcer index were compared between these groups. Gastric mucosal apoptosis rate, microscopic inflammation activity and angiogenesis markers vascular endothelial growth factor A (VEGF-A) and CD34 were examined by TUNEL, histological evaluations (HE) and immunohistochemistry (IHC). Pathways involved, expressions of endoplasmic reticulum (ER) stress apoptosis marker CHOP, angiogenic markers VEGF-A and its receptor VEGFR1, and endothelial NO synthase (eNOS) were all analyzed by Western blot.

Results

This study indicated that Clopidogrel significantly induced the gastric ulcers recurrence, severe inflammation and ER stress related apoptosis of the gastric mucosa, suppressed the synthesis of angiogenic markers and eNOS. Furthermore, Clopidrogel intervention resulted in the activation of protein kinase B (AKT) and p38 mitogen-activated protein kinase (p38/MAPK). BPC 157 attenuated the gastric mucosal damage caused by Clopidogrel and reversed these molecular effects. However, NO blockade L-NAME weakened the protective effect and thus the molecular effects of BPC 157 on gastric mucosa.

Conclusion

In conclusion, these results suggest that BPC 157 inhibited Clopidogrel-induced gastric mucosa injury partially by inhibition of gastric mucosa cell ER stress-mediated apoptosis and inflammation, and promoting gastric mucosa angiogenesis via VEGF-A/VEGFR1 mediated-AKT/p38/MAPK signaling pathways.

Bowel adhesion and therapy with the stable gastric pentadecapeptide BPC 157, L-NAME and L-arginine in rats

BACKGROUND

After parietal peritoneum excision with an underlying superficial layer of muscle tissue in rats, there is failed vasculature, and finally, increased adhesion formation. We hypothesized that unlike nitric oxide (NO)-agents, L-NAME and/or L-arginine, the application of the stable gastric pentadecapeptide BPC 157 with its most recent vascular effects (“vascular recruitment”) means attenuated bowel adhesion formation and NO- and malondialdehyde (MDA)-tissue values.

AIM

To focused on the bowel adhesion and the therapy with the BPC 157, its most and application of NO-agents.

METHODS

Along with defect creation, medication was (1) during surgery, once, at 1 min after defect creation as an abdominal bath (1 mL/rat), BPC 157 (10 µg/kg, 10 ng/kg, 1 mL/rat), an equivolume of saline, L-NAME (5 mg/kg), L-arginine (200 mg/kg) alone and/or combined. Alternatively, medication was (2) intraperitoneally once daily, first application at 30 min after surgery, last application 24 h before assessment at d 7 or d 14. As a postponed therapy to pre-existing adhesion (3), BPC 157 (10 µg/kg, 10 ng/kg intraperitoneally, 1 mL/rat) was given once daily since d 7.

RESULTS

The recovery effect of the BPC 157 regimens goes with the presence of abundant vascular vessels in and near the defect, which occurs rapidly. Lastly, also applied as post-treatment, BPC 157 creates attenuated adhesions, minimal or no adhesion. Contrarily, NO-agents have diverse initial and final effects: The initial weakening of blood vessel disappearance and finally, severe worsening of adhesions (L-NAME) vs the initial weakening of blood vessel disappearance and finally, attenuation of adhesions formation (L-arginine), which counteract each other response given together. Importantly, BPC 157 maintains its beneficial effect also when given with NO-agents (L-NAME + BC 157; L-arginine + BPC 157; L-NAME + L-arginine + BPC 157). Finally, with respect to the increased NO- and MDA- values-adhesion tissue formation relation, unlike diverse effect of the NO-agents, the BPC 157 application effect regularly combines decrease on the increased NO- and MDA- values and the beneficial outcome (less adhesion formation).

CONCLUSION

BPC 157 therapy can be suited for the realization of the peritoneal defect healing with minimal or no adhesion formation.

BPC 157, L-NAME, L-arginine, NO-relation, in the suited rat acute and chronic models resembling 'positive-like' symptoms of schizophrenia

In the suited rat-models, we focused on the stable pentadecapeptide BPC 157, L-NAME, NOS-inhibitor, and L-arginine, NOS-substrate, relation, the effect on schizophrenia-like symptoms. Medication (mg/kg intraperitoneally) was L-NAME (5), L-arginine (100), BPC 157 (0.01), given alone and/or together, at 5 min before the challenge for the acutely disturbed motor activity (dopamine-indirect/direct agonists (amphetamine (3.0), apomorphine (2.5)), NMDA-receptor non-competitive antagonist (MK-801 (0.2)), or catalepsy, (dopamine-receptor antagonist haloperidol (2.0)). Alternatively, BPC 157 10 μg/kg was given immediately after L-NAME 40 mg/kg intraperitoneally. To induce or prevent sensitization, we used chronic methamphetamine administration, alternating 3 days during the first 3 weeks, and challenge after next 4 weeks, and described medication (L-NAME, L-arginine, BPC 157) at 5 min before the methamphetamine at the second and third week. Given alone, BPC 157 or L-arginine counteracted the amphetamine-, apomorphine-, and MK-801-induced effect, haloperidol-induced catalepsy and chronic methamphetamine-induced sensitization. L-NAME did not affect the apomorphine-, and MK-801-induced effects, haloperidol-induced catalepsy and chronic methamphetamine-induced sensitization, but counteracted the acute amphetamine-induced effect. In combinations (L-NAME + L-arginine), as NO-specific counteraction, L-NAME counteracts L-arginine-induced counteractions in the apomorphine-, MK-801-, haloperidol- and methamphetamine-rats, but not in amphetamine-rats. Unlike L-arginine, BPC 157 maintains its counteracting effect in the presence of the NOS-blockade (L-NAME + BPC 157) or NO-system-over-stimulation (L-arginine + BPC 157). Illustrating the BPC 157-L-arginine relationships, BPC 157 restored the antagonization (L-NAME + L-arginine + BPC 157) when it had been abolished by the co-administration of L-NAME with L-arginine (L-NAME + L-arginine). Finally, BPC 157 directly inhibits the L-NAME high dose-induced catalepsy. Further studies would determine precise BPC 157/dopamine/glutamate/NO-system relationships and clinical application.

Pentadecapeptide BPC 157 shortens duration of tetracaine- and oxybuprocaine-induced corneal anesthesia in rats

We focused on the relationship of 0.5% tetracaine- and 0.4% oxybuprocaine-induced corneal anesthesia in rats, and pentadecapeptide BPC 157 (0.4 µg/eye), along with nitric oxide synthase (NOS) inhibitor N(gamma)-nitro-L-arginine methyl ester (L-NAME) (0.1 mg/eye) and/or NOS substrate L-arginine (2 mg/eye), applied in the form of eye drops. We assessed corneal sensitivity recovery (Cochet-Bonnet esthesiometer), corneal lesion elimination (staining with 10% fluorescein) and decrease in tear volume (Schirmer test). BPC 157 administration had a full counteracting effect. Recovery also occurred in the presence of NOS blockade and NOS substrate application. L-arginine eventually shortened duration of corneal insensitivity and exerted corneal lesion counteraction (and counteraction of tetracaine-induced decrease of tear volume) only in earlier but not in later period. L-NAME application led to longer duration of corneal insensitivity, increase in corneal lesions and decrease in tear volume. When L-NAME and L-arginine were applied together, they antagonized each other’s effect. These distinctions may indicate particular NOS involvement (corneal insensitivity vs. corneal lesion along with tear production), distinctively affected by the administration of NO agents. However, additional BPC 157 co-administration would re-establish counteraction over topical ophthalmic anesthetic-induced effect, be it in its early or late course. We suggest BPC 157 as an antidote to topical ophthalmic anesthetics.

The effect of pentadecapeptide BPC 157 on hippocampal ischemia/reperfusion injuries in rats

BACKGROUND AND PURPOSE

We focused on the, yet undescribed, therapy effect of the stable gastric pentadecapeptide BPC 157 in hippocampal ischemia/reperfusion injuries, after bilateral clamping of the common carotid arteries in rats. The background is the proven therapy effect of BPC 157 in ischemia/reperfusion injuries in different tissues. Furthermore, there is the subsequent oxidative stress counteraction, particularly when given during reperfusion. The recovering effect it has on occluded vessels, results with activation of the alternative pathways, bypassing the occlusion in deep vein thrombosis. Finally, the BPC 157 therapy benefits with its proposed role as a novel mediator of Roberts' cytoprotection and bidirectional effects in the gut-brain axis.

MATERIALS AND METHODS

Male Wistar rats underwent bilateral clamping of the common carotid arteries for a 20-min period. At 30 s thereafter, we applied medication (BPC 157 10 µg/kg; or saline) as a 1 ml bath directly to the operated area, that is, trigonum caroticum. We documented, in reperfusion, the resolution of the neuronal damages sustained in the brain, resolution of the damages reflected in memory, locomotion, and coordination disturbances, with the presentation of the particular genes expression in hippocampal tissues.

RESULTS

In the operated rats, at 24 and 72 hr of the reperfusion, the therapy counteracted both early and delayed neural hippocampal damage, achieving full functional recovery (Morris water maze test, inclined beam-walking test, lateral push test). mRNA expression studies at 1 and 24 hr, provided strongly elevated (Egr1, Akt1, Kras, Src, Foxo, Srf, Vegfr2, Nos3, and Nos1) and decreased (Nos2, Nfkb) gene expression (Mapk1 not activated), as a way how BPC 157 may act.

CONCLUSION

Together, these findings suggest that these beneficial BPC 157 effects may provide a novel therapeutic solution for stroke.

Pentadecapeptide BPC 157 resolves Pringle maneuver in rats, both ischemia and reperfusion

BACKGROUND

The Pringle maneuver [portal triad obstruction(PTO)] provides huge disturbances during ischemia and even more thereafter in reperfusion. Contrarily, a possible solution may be stable gastric pentadecapeptide BPC 157, with already documented beneficial effects in ischemia/reperfusion conditions. Recently, BPC 157, as a cytoprotective agent, successfully resolved vessel occlusions in rats (ischemic colitis; deep vein thrombosis, superior anterior pancreaticoduodenal vein; bile duct cirrhosis) through rapid collateral vessel recruitment to circumvent vessel occlusion. Thereby, medication BPC 157 regimens were administered as a single challenge before and during ischemia or, alternatively, at various time points during reperfusion.

AIM

To introduce BPC 157 therapy against pringle maneuver-damage.

METHODS

In deeply anesthetised rats, the portal triad was clamped up for 30 min. Rats then underwent reperfusion for either 15 min or 24 h. Medication [(10 µg, 10 ng/kg) regimens, administered as a single challenge] picked (a) ischemia, PTO period [at 5 min before (ip) or at 5 or 30 min of ligation time (as a bath to PTO)] or (b) reperfusion, post-PTO period [at 1 or 15 min (bath during surgery) or 24 h (ip) reperfusion-time]. We provided gross, microscopy, malondialdehyde, serum enzymes, electrocardiogram, portal, caval, and aortal pressure, thrombosis and venography assessments.

RESULTS

BPC 157 counteracts electrocardiogram disturbances (increased P wave amplitude, S1Q3T3 QRS pattern and tachycardia). Rapidly presented vascular pathway (portal vein-superior mesenteric vein-inferior mesenteric vein-rectal veins-left ileal vein-inferior caval vein) as the adequate shunting immediately affected disturbed haemodynamics. Portal hypertension and severe aortal hypotension during PTO, as well as portal and caval hypertension and mild aortal hypotension in reperfusion and refractory ascites formation were markedly attenuated (during PTO) or completely abrogated (reperfusion); thrombosis in portal vein tributaries and inferior caval vein or hepatic artery was counteracted during portal triad obstruction PTO. Also, counteraction included the whole vicious injurious circle [i.e., lung pathology (severe capillary congestion), liver (dilated central veins and terminal portal venules), intestine (substantial capillary congestion, submucosal oedema, loss of villous architecture), splenomegaly, right heart (picked P wave values)] regularly perpetuated in ischemia and progressed by reperfusion in Pringle rats.

CONCLUSION

BPC 157 resolves pringle maneuver-damage in rats, both for ischemia and reperfusion.

Pentadecapeptide BPC 157 resolves suprahepatic occlusion of the inferior caval vein, Budd-Chiari syndrome model in rats

BACKGROUND

Recently, as a possible therapy resolving solution, pentadecapeptide BPC 157 therapy, has been used in alleviating various vascular occlusion disturbances. BPC 157 was previously reviewed as novel mediator of Robert cytoprotection and endothelium protection in the stomach, and gut-brain axis, beneficial therapy in gastrointestinal tract, with particular reference to vascular recruitment, ulcerative colitis and tumor cachexia, and other tissues healing. Here we raised new hypothesis about BPC 157 therapy in the Budd-Chiari syndrome in rats, rapid bypassing of the suprahepatic inferior caval vein occlusion, and rats recovery with the active and effective pharmacotherapy treatment.

AIM

To investigate Budd-Chiari syndrome model (inferior caval vein suprahepatic occlusion) resolution, since BPC 157 resolves various rat vascular occlusion.

METHODS

We assessed the activated bypassing pathways between the inferior and superior caval veins and portocaval shunt, counteracted caval/portal hypertension, aortal hypotension, venous/arterial thrombosis, electrocardiogram disturbances, liver and gastrointestinal lesions (i.e., stomach and duodenum hemorrhages, in particular, congestion). Rats with suprahepatic occlusion of the inferior vena cava by ligation were medicated at 1 min, 15 min, 24 h, or 48 h post-ligation. Medication consisted of 10 µg/kg BPC 157, 10 ng BPC 157 or 5 mL/kg saline, administered once as an abdominal bath or intragastric application. Gross and microscopic observations were made, in addition to assessments of electrical activity of the heart (electrocardiogram), portal and caval hypertension, aortal hypotension, thrombosis, hepatomegaly, splenomegaly and venography. Furthermore, levels of nitric oxide, malondialdehyde in the liver and serum enzymes were determined.

RESULTS

BPC 157 counteracted increased P wave amplitude, tachycardia and ST-elevation, i.e., right heart failure from acute thrombotic coronary occlusion. The bypassing pathway of the inferior vena cava-azygos (hemiazygos) vein-superior vena cava and portocaval shunt occurred rapidly. Even with severe caval ˃ portal hypertension, BPC 157 antagonized portal and caval hypertension and aortal hypotension, and also reduced refractory ascites. Thrombosis of portal vein tributaries, inferior vena cava, and hepatic and coronary arteries was attenuated. In addition, there was reduced pathology of the lungs (severe capillary congestion) and liver (dilated central veins and terminal portal venules), decreased intestine hemorrhagic lesions (substantial capillary congestion, submucosal edema and architecture loss), and increased liver and spleen weight. During the period of ligation, nitric oxide- and malondialdehyde-levels in the liver remained within normal healthy values, and increases in serum enzymes were markedly reduced.

CONCLUSION

BPC 157 counteracts Budd Chiari syndrome in rats.

Stable gastric pentadecapeptide BPC 157, L-arginine, L-NAME

We focused on the cyclophosphamide-induced hemorrhagic cystitis (100 mg/kg/day intraperitoneally throughout three days) as a particular NO-system disturbance, and therapy possibilities. We demonstrated that it may be attenuated by subsequent administration of the NOS substrate L-arginine (100 mg/kg/day intraperitoneally), aggravated by NOS-blocker L-NAME (5 mg/kg/day intraperitoneally), all influenced by the stable gastric pentadecapeptide BPC 157 (10 μg/kg/day, 10 ng/kg/day, intraperitoneally or perorally, in drinking water). Regularly, cyclophosphamide dose- and time-dependently induced severe hemorrhagic cystitis lesions, gross lesions, and corresponding urothelial necrosis, vesical edema, erosion, hemorrhage, inflammation, and ulceration, microscopically. The bladder wet weight dramatically increased. Functionally, already after first cyclophosphamide administration, there is an increased leak point pressure. Until the second cyclophosphamide administration, L-arginine consistently attenuated regular cyclophosphamide-induced severe hemorrhagic cystitis lesions, grossly and microscopically, but not functionally. L-NAME aggravated these lesions and eradicated beneficial effect of L-arginine when combined. BPC 157 administration after cyclophosphamide, given in either dose or in either regimen markedly attenuated all cyclophosphamide lesions, grossly, microscopically. The increase of the bladder wet weight was consistently attenuated. Functionally, increased leak point pressure was reversed to the values noted in normal rats. The similar findings were noted in rats that received BPC 157 together with L-NAME or L-arginine, given alone or combined. Thus, the lesions are NO-related based on the administration of L-NAME as well as administration of L-arginine, and their mutual interaction, and counteraction by BPC 157 application. Likewise, we reveal new therapeutic possibilities, emphasizing stable gastric pentadecapeptide BPC 157 and L-arginine, versus L-NAME in rats underwent cyclophosphamide-induced cystitis.

Stable gastric pentadecapeptide BPC 157 can improve the healing course of spinal cord injury and lead to functional recovery in rats

BACKGROUND

We focused on the therapeutic effects of the stable gastric pentadecapeptide BPC 157 in spinal cord injury using a rat model. BPC 157, of which the LD1 has not been achieved, has been implemented as an anti-ulcer peptide in inflammatory bowel disease trials and recently in a multiple sclerosis trial. In animals, BPC 157 has an anti-inflammatory effect and therapeutic effects in functional recovery and the rescue of somatosensory neurons in the sciatic nerve after transection, upon brain injury after concussive trauma, and in severe encephalopathies. Additionally, BPC 157 affects various molecular pathways.

METHODS

Therefore, BPC 157 therapy was administered by a one-time intraperitoneal injection (BPC 157 (200 or 2 μg/kg) or 0.9% NaCl (5 ml/kg)) 10 min after injury. The injury procedure involved laminectomy (level L2-L3) and a 60-s compression (neurosurgical piston (60-66 g) of the exposed dural sac of the sacrocaudal spinal cord). Assessments were performed at 1, 4, 7, 15, 30, 90, 180, and 360 days after injury.

RESULTS

All of the injured rats that received BPC 157 exhibited consistent clinical improvement, increasingly better motor function of the tail, no autotomy, and resolved spasticity by day 15. BPC 157 application largely counteracted changes at the microscopic level, including the formation of vacuoles and the loss of axons in the white matter, the formation of edema and the loss of motoneurons in the gray matter, and a decreased number of large myelinated axons in the rat caudal nerve from day 7. EMG recordings showed a markedly lower motor unit potential in the tail muscle.

CONCLUSION

Axonal and neuronal necrosis, demyelination, and cyst formation were counteracted. The functional rescue provided by BPC 157 after spinal cord injury implies that BPC 157 therapy can impact all stages of the secondary injury phase.

Gastric pentadecapeptide body protection compound BPC 157 and its role in accelerating musculoskeletal soft tissue healing

There is a current need for a therapy that can alleviate the social and economic burden that presents itself with debilitating and recurring musculoskeletal soft tissue injuries and disorders. Currently, several therapies are emerging and undergoing trials in animal models; these focus on the manipulation and administration of several growth factors implicated with healing. However, limitations include in vivo instability, reliance on biocompatible and robust carriers and restricted application procedures (local and direct). The aim of this paper is therefore to critically review the current literature surrounding the use of BPC 157, as a feasible therapy for healing and functional restoration of soft tissue damage, with a focus on tendon, ligament and skeletal muscle healing. Currently, all studies investigating BPC 157 have demonstrated consistently positive and prompt healing effects for various injury types, both traumatic and systemic and for a plethora of soft tissues. However, to date, the majority of studies have been performed on small rodent models and the efficacy of BPC 157 is yet to be confirmed in humans. Further, over the past two decades, only a handful of research groups have performed in-depth studies regarding this peptide. Despite this, it is apparent that BPC 157 has huge potential and following further development has promise as a therapy to conservatively treat or aid recovery in hypovascular and hypocellular soft tissues such as tendon and ligaments. Moreover, skeletal muscle injury models have suggested a beneficial effect not only for disturbances that occur as a result of direct trauma but also for systemic insults including hyperkalamia and hypermagnesia. Promisingly, there are few studies reporting any adverse reactions to the administration of BPC 157, although there is still a need to understand the precise healing mechanisms for this therapy to achieve clinical realisation.

Stable gastric pentadecapeptide BPC 157 in the therapy of the rats with bile duct ligation. Eur J Pharmacol. 2019;847:130-142. [PMID: 30690000 DOI: 10.1016/j.ejphar.2019.01.030]

Recently, stable gastric pentadecapeptide BPC 157 reversed the high MDA- and NO-tissue values to the healthy levels. Thereby, BPC 157 therapy cured rats with bile duct ligation (BDL) (sacrifice at 2, 4, 6, 8 week). BPC 157-medication (10 μg/kg, 10 ng/kg) was continuously in drinking water (0.16 μg/ml, 0.16 ng/ml, 12 ml/rat/day) since awakening from surgery, or since week 4. Intraperitoneal administration was first at 30 min post-ligation, last at 24 h before sacrifice. Local bath BPC 157 (10 µg/kg) with assessed immediate normalization of portal hypertension was given immediately after establishing portal hypertension values at 4, 6, 8 week. BPC 157 therapy markedly abated jaundice, snout, ears, paws, and yellow abdominal tegmentum in controls since 4th week, ascites, nodular, steatotic liver with large dilatation of main bile duct, increased liver and/or cyst weight, decreased body weight. BPC 157 counteracts the piecemeal necrosis, focal lytic necrosis, apoptosis and focal inflammation, disturbed cell proliferation (Ki-67-staining), cytoskeletal structure in the hepatic stellate cell (α-SMA staining), collagen presentation (Mallory staining). Likewise, counteraction includes increased AST, ALT, GGT, ALP, total bilirubin, direct and indirect and decreased albumin serum levels. As the end-result appear normalized MDA- and NO-tissue values, next to Western blot of NOS2 and NOS3 in the liver tissue, and decreased IL-6, TNF-α, IL-1β levels in liver tissue. Finally, although portal hypertension is sustained in BDL-rats, with BPC 157 therapy, portal hypertension in BDL-rats is either not even developed or rapidly abated, depending on the given BPC 157's regimen. Thus, BPC 157 may counteract liver fibrosis and portal hypertension.

Counteraction of perforated cecum lesions in rats: Effects of pentadecapeptide BPC 157, L-NAME and L-arginine

AIM

To study the counteraction of perforated cecum lesion using BPC 157 and nitric oxide (NO) system agents.

METHODS

Alongside with the agents’ application (after 1 min, medication (/kg, 10 mL/2 min bath/rat) includes: BPC 157 (10 μg), L-NAME (5 mg), L-arginine (100mg) alone or combined, and saline baths (controls)) on the rat perforate cecum injury, we continuously assessed the gross reappearance of the vessels (USB microcamera) quickly propagating toward the defect at the cecum surface, defect contraction, bleeding attenuation, MDA- and NO-levels in cecum tissue at 15 min, and severity of cecum lesions and adhesions at 1 and 7 d.

RESULTS

Post-injury, during/after a saline bath, the number of vessels was significantly reduced, the defect was slightly narrowed, bleeding was significant and MDA-levels increased and NO-levels decreased. BPC 157 bath: the vessel presentation was markedly increased, the defect was noticeably narrowed, the bleeding time was shortened and MDA- and NO-levels remained normal. L-NAME: reduced vessel presentation but not more than the control, did not change defect and shortened bleeding. L-arginine: exhibited less vessel reduction, did not change the defect and prolonged bleeding. In combination, mutual counteraction occurred (L-NAME + L-arginine) or the presentation was similar to that of BPC 157 rats (BPC 157 + L-NAME; BPC 157 + L-arginine; BPC 157 + L-NAME + L-arginine), except the defect did not change. Thereby at day 1 and 7, saline, L-NAME, L-arginine and L-NAME + L-arginine failed (defect was still open and large adhesions present).

CONCLUSION

The therapeutic effect was achieved with BPC 157 alone or in combination with L-NAME and L-arginine as it was able to consolidate the stimulating and inhibiting effects of the NO-system towards more effective healing recruiting vessels.

Bypassing major venous occlusion and duodenal lesions in rats, and therapy with the stable gastric pentadecapeptide BPC 157, L-NAME and L-arginine

AIM

To investigate whether duodenal lesions induced by major venous occlusions can be attenuated by BPC 157 regardless nitric oxide (NO) system involvement.

METHODS

Male Wistar rats underwent superior anterior pancreaticoduodenal vein (SAPDV)-ligation and were treated with a bath at the ligated SAPDV site (BPC 157 10 μg, 10 ng/kg per 1 mL bath/rat; L-NAME 5 mg/kg per 1 mL bath/rat; L-arginine 100 mg/kg per 1 mL bath/rat, alone and/or together; or BPC 157 10 μg/kg instilled into the rat stomach, at 1 min ligation-time). We recorded the vessel presentation (filled/appearance or emptied/disappearance) between the 5 arcade vessels arising from the SAPDV on the ventral duodenum side, the inferior anterior pancreaticoduodenal vein (IAPDV) and superior mesenteric vein (SMV) as bypassing vascular pathway to document the duodenal lesions presentation; increased NO- and oxidative stress [malondialdehyde (MDA)]-levels in duodenum.

RESULTS

Unlike the severe course in the SAPDV-ligated controls, after BPC 157 application, the rats exhibited strong attenuation of the mucosal lesions and serosal congestion, improved vessel presentation, increased interconnections, increased branching by more than 60% from the initial value, the IAPDV and SMV were not congested. Interestingly, after 5 min and 30 min of L-NAME and L-arginine treatment alone, decreased mucosal and serosal duodenal lesions were observed; their effect was worsened at 24 h, and no effect on the collateral vessels and branching was seen. Together, L-NAME+L-arginine antagonized each other’s response, and thus, there was an NO-related effect. With BPC 157, all SAPDV-ligated rats receiving L-NAME and/or L-arginine appeared similar to the rats treated with BPC 157 alone. Also, BPC 157 in SAPDV-ligated rats normalized levels of NO and MDA, two oxidative stress markers, in duodenal tissues.

CONCLUSION

BPC 157, rapidly bypassing occlusion, rescued the original duodenal flow through IAPDV to SMV flow, an effect related to the NO system and reduction of free radical formation.

Stable gastric pentadecapeptide BPC 157 in the treatment of colitis and ischemia and reperfusion in rats: New insights

AIM

To provide new insights in treatment of colitis and ischemia and reperfusion in rats using stable gastric pentadecapeptide BPC 157.

METHODS

Medication [BPC 157, L-NAME, L-arginine (alone/combined), saline] was bath at the blood deprived colon segment. During reperfusion, medication was BPC 157 or saline. We recorded (USB microscope camera) vessel presentation through next 15 min of ischemic colitis (IC-rats) or reperfusion (removed ligations) (IC + RL-rats); oxidative stress as MDA (increased (IC- and IC + RL-rats)) and NO levels (decreased (IC-rats); increased (IC + RL-rats)) in colon tissue. IC + OB-rats [IC-rats had additional colon obstruction (OB)] for 3 d (IC + OB-rats), then received BPC 157 bath.

RESULTS

Commonly, in colon segment (25 mm, 2 ligations on left colic artery and vein, 3 arcade vessels within ligated segment), in IC-, IC + RL-, IC + OB-rats, BPC 157 (10 μg/kg) bath (1 mL/rat) increased vessel presentation, inside/outside arcade interconnections quickly reappeared, mucosal folds were preserved and the pale areas were small and markedly reduced. BPC 157 counteracted worsening effects induced by L-NAME (5 mg) and L-arginine (100 mg). MDA- and NO-levels were normal in BPC 157 treated IC-rats and IC + RL-rats. In addition, on day 10, BPC 157-treated IC + OB-rats presented almost completely spared mucosa with very small pale areas and no gross mucosal defects; the treated colon segment was of normal diameter, and only small adhesions were present.

CONCLUSION

BPC 157 is a fundamental treatment that quickly restores blood supply to the ischemically injured area and rapidly activates collaterals. This effect involves the NO system.

BPC 157 counteracts QTc prolongation induced by haloperidol, fluphenazine, clozapine, olanzapine, quetiapine, sulpiride, and metoclopramide in rats

AIM

Commonly, neuroleptics and prokinetics induce a prolonged QTc interval. In this study, stable gastric pentadecapeptide BPC 157 counteracts the prolongation of the QTc interval in Wistar rats that underwent daily administration of dopamine neuroleptics or prokinetics. Previously, in rats and mice, BPC 157 counteracted neuroleptic-induced catalepsy and gastric ulcers.

MAIN METHODS

To counteract neuroleptic- or prokinetic-induced prolongation of the QTc interval, rats were given a BPC 157 regimen once daily over seven days (10μg, 10ng/kg ip) immediately after each administrations of haloperidol (0.625, 6.25, 12.5, and 25.0mg/kg ip), fluphenazine (0.5, 5.0mg/kg ip), clozapine (1.0, 10.0mg/kg ip), quetiapine (1.0, 10.0mg/kg ip), sulpiride (1.6, 16.0mg/kg ip), metoclopramide (2.5, 25.0mg/kg ip) or (1.0, 10.0mg/kg ip). Controls simultaneously received saline (5ml/kg ip). To assess the ECG presentation before and after neuroleptic/prokinetic medication, the assessment was at 1, 2, 3, 4, 5, 10, 15, 20 and 30min (first administration) as well as at 30min, 60min and 24h (first administration and subsequent administrations) and the ECG recording started prior to drug administration.

KEY FINDINGS

Since very early, a prolonged QTc interval has been continually noted with haloperidol, fluphenazine, clozapine, olanzapine, quetiapine, sulpiride, and metoclopramide in rats as a central common effect not seen with domperidone. Consistent counteraction appears with the stable gastric pentadecapeptide BPC 157. Thus, BPC 157 rapidly and permanently counteracts the QTc prolongation induced by neuroleptics and prokinetics.

SIGNIFICANCE

Pentadecapeptide BPC 157 is suited for counteracting a prolonged QT interval.

Celecoxib-induced gastrointestinal, liver and brain lesions in rats, counteraction by BPC 157 or L-arginine, aggravation by L-NAME

AIM

To counteract/reveal celecoxib-induced toxicity and NO system involvement.

METHODS

Celecoxib (1 g/kg b.w. ip) was combined with therapy with stable gastric pentadecapeptide BPC 157 (known to inhibit these lesions, 10 μg/kg, 10 ng/kg, or 1 ng/kg ip) and L-arginine (100 mg/kg ip), as well as NOS blockade [N(G)-nitro-L-arginine methyl ester (L-NAME)] (5 mg/kg ip) given alone and/or combined immediately after celecoxib. Gastrointestinal, liver, and brain lesions and liver enzyme serum values in rats were assessed at 24 h and 48 h thereafter.

RESULTS

This high-dose celecoxib administration, as a result of NO system dysfunction, led to gastric, liver, and brain lesions and increased liver enzyme serum values. The L-NAME-induced aggravation of the lesions was notable for gastric lesions, while in liver and brain lesions the beneficial effect of L-arginine was blunted. L-arginine counteracted gastric, liver and brain lesions. These findings support the NO system mechanism(s), both NO system agonization (L-arginine) and NO system antagonization (L-NAME), that on the whole are behind all of these COX phenomena. An even more complete antagonization was identified with BPC 157 (at both 24 h and 48 h). A beneficial effect was evident on all the increasingly negative effects of celecoxib and L-NAME application and in all the BPC 157 groups (L-arginine + BPC 157; L-NAME + BPC 157; L-NAME + L-arginine + BPC 157). Thus, these findings demonstrated that BPC 157 may equally counteract both COX-2 inhibition (counteracting the noxious effects of celecoxib on all lesions) and additional NOS blockade (equally counteracting the noxious effects of celecoxib + L-NAME).

CONCLUSION

BPC 157 and L-arginine alleviate gastrointestinal, liver and brain lesions, redressing NSAIDs’ post-surgery application and NO system involvement.

Class side effects: decreased pressure in the lower oesophageal and the pyloric sphincters after the administration of dopamine antagonists, neuroleptics, anti-emetics, L-NAME, pentadecapeptide BPC 157 and L-arginine

The ulcerogenic potential of dopamine antagonists and L-NAME in rats provides unresolved issues of anti-emetic neuroleptic application in both patients and experimental studies. Therefore, in a 1-week study, we examined the pressures within the lower oesophageal and the pyloric sphincters in rats [assessed manometrically (cm H2O)] after dopamine neuroleptics/prokinetics, L-NAME, L-arginine and stable gastric pentadecapeptide BPC 157 were administered alone and/or in combination. Medication (/kg) was given once daily intraperitoneally throughout the 7 days, with the last dose at 24 h before pressure assessment. Given as individual agents to healthy rats, all dopamine antagonists (central [haloperidol (6.25 mg, 16 mg, 25 mg), fluphenazine (5 mg), levomepromazine (50 mg), chlorpromazine (10 mg), quetiapine (10 mg), olanzapine (5 mg), clozapine (100 mg), sulpiride (160 mg), metoclopramide (25 mg)) and peripheral(domperidone (10 mg)], L-NAME (5 mg) and L-arginine (100 mg) decreased the pressure within both sphincters. As a common effect, this decreased pressure was rescued, dose-dependently, by BPC 157 (10 µg, 10 ng) (also note that L-arginine and L-NAME given together antagonized each other's responses). With haloperidol, L-NAME worsened both the lower oesophageal and the pyloric sphincter pressure, while L-arginine ameliorated lower oesophageal sphincter but not pyloric sphincter pressure, and antagonized L-NAME effect. With domperidone, L-arginine originally had no effect, while L-NAME worsened pyloric sphincter pressure. This effect was opposed by L-arginine. All these effects were further reversed towards a stronger beneficial effect, close to normal pressure values, by the addition of BPC 157. In addition, NO level was determined in plasma, sphincters and brain tissue. Thiobarbituric acid reactive substances (TBARS) were also assessed. Haloperidol increased NO levels (in both sphincters, the plasma and brain), consistently producing increased TBARS levels in the plasma, sphincters and brain tissues. These effects were all counteracted by BPC 157 administration. In conclusion, we revealed that BPC 157 counteracts the anti-emetic neuroleptic class side effect of decreased pressure in sphincters and the dopamine/NO-system/BPC 157 relationship.

Cyclophosphamide induced stomach and duodenal lesions as a NO-system disturbance in rats: L-NAME, L-arginine, stable gastric pentadecapeptide BPC 157. Inflammopharmacology. 2017;25:255-264. [PMID: 28255738 DOI: 10.1007/s10787-017-0330-7]

We revealed a new point with cyclophosphamide (150 mg/kg/day intraperitoneally for 7 days): we counteracted both rat stomach and duodenal ulcers and increased NO- and MDA-levels in these tissues. As a NO-system effect, BPC 157 therapy (10 µg/kg, 10 ng/kg, intraperitoneally once a day or in drinking water, till the sacrifice) attenuated the increased NO- and MDA-levels and nullified, in rats, severe cyclophosphamide-ulcers and even stronger stomach and duodenal lesions after cyclophosphamide + L-NAME (5 mg/kg intraperitoneally once a day). L-arginine (100 mg/kg intraperitoneally once a day not effective alone) led L-NAME-values only to the control values (cyclophosphamide + L-NAME + L-arginine-rats). Briefly, rats were sacrificed at 24 h after last administration on days 1, 2, 3, or 7, and assessment included sum of longest lesions diameters (mm) in the stomach and duodenum, oxidative stress by quantifying thiobarbituric acid reactivity as malondialdehyde equivalents (MDA), NO in stomach and duodenal tissue samples using the Griess reaction. All these parameters were highly exaggerated in rats who underwent cyclophosphamide treatment. We identified high MDA-tissue values, high NO-tissue values, ulcerogenic and beneficial potential in cyclophosphamide-L-NAME-L-arginine-BPC 157 relationships. This suggests that in cyclophosphamide damaged rats, NO excessive release generated by the inducible isozyme, damages the vascular wall and other tissue cells, especially in combination with reactive oxygen intermediates, while failing endothelial production and resulting in further aggravation by L-NAME which was inhibited by L-arginine. Finally, BPC 157, due to its special relations with NO-system, may both lessen increased MDA- and NO-tissues values and counteract effects of both cyclophosphamide and L-NAME on stomach and duodenal lesions.

Hypermagnesemia disturbances in rats, NO-related: pentadecapeptide BPC 157 abrogates, L-NAME and L-arginine worsen

AIM

Stable gastric pentadecapeptide BPC 157, administered before a high-dose magnesium injection in rats, might be a useful peptide therapy against magnesium toxicity and the magnesium-induced effect on cell depolarization. Moreover, this might be an NO-system-related effect. Previously, BPC 157 counteracts paralysis, arrhythmias and hyperkalaemia, extreme muscle weakness; parasympathetic and neuromuscular blockade; injured muscle healing and interacts with the NOS-blocker and NOS-substrate effects.

MAIN METHODS

Assessment included magnesium sulfate (560 mg/kg intraperitoneally)-induced muscle weakness, muscle and brain lesions, hypermagnesemia, hyperkalaemia, increased serum enzyme values assessed in rats during and at the end of a 30-min period and medication (given intraperitoneally/kg at 15 min before magnesium) [BPC 157 (10 µg, 10 ng), L-NAME (5 mg), L-arginine (100 mg), alone and/or together]. In HEK293 cells, the increasing magnesium concentration from 1 to 5 mM could depolarize the cells at 1.75 ± 0.44 mV.

KEY FINDINGS

L-NAME + magnesium-rats and L-arginine + magnesium-rats exhibited worsened severe muscle weakness and lesions, brain lesions, hypermagnesemia and serum enzymes values, with emerging hyperkalaemia. However, L-NAME + L-arginine + magnesium-rats exhibited all control values and normokalaemia. BPC 157 abrogated hypermagnesemia and counteracted all of the magnesium-induced disturbances (including those aggravated by L-NAME or L-arginine). Thus, cell depolarization due to increasing magnesium concentration was inhibited in the presence of BPC 157 (1 µM) in vitro.

SIGNIFICANCE

BPC 157 likely counteracts the initial event leading to hypermagnesemia and the life-threatening actions after a magnesium overdose. In contrast, a worsened clinical course, higher hypermagnesemia, and emerging hyperkalaemia might cause both L-NAME and L-arginine to affect the same events adversely. These events were also opposed by BPC 157.

Stable gastric pentadecapeptide BPC 157 and bupivacaine

Bupivacaine toxicity following accidental overdose still lacks therapeutic solution. However, there are major arguments for testing BPC 157 against bupivacaine toxicity in vivo in rats, in particular, and then finally, in vitro. These are: the lack of any known BPC 157 toxicity, a lifesaving effect via the mitigation of arrhythmias in rats underwent hyperkalemia or digitalis toxicity, the elimination of hyperkalemia and arrhythmias in rats underwent succinylcholine toxicity and finally, the reduction of potassium-induced depolarization in vitro (in HEK293 cells) in severe hyperkalemia. Most importantly, BPC 157 successfully prevents and counteracts bupivacaine cardiotoxicity; BPC 157 is effective even against the worst outcomes such as a severely prolonged QRS complex. Here, rats injected with bupivacaine (100mg/kg IP) exhibited bradycardia, AV-block, ventricular ectopies, ventricular tachycardia, T-wave elevation and asystole. All of the fatalities had developed T-wave elevation, high-degree AV-block, respiratory arrest and asystole. These were largely counteracted by BPC 157 administration (50µg/kg, 10µg/kg, 10ng/kg, or 10pg/kg IP) given 30min before or 1min after the bupivacaine injection. When BPC 157 was given 6min after bupivacaine administration, and after the development of prolonged QRS intervals (20ms), the fatal outcome was markedly postponed. Additionally, the effect of bupivacaine on cell membrane depolarization was explored by measuring membrane voltages (Vm) in HEK293 cells. Bupivacaine (1mM) alone caused depolarization of the cells, while in combination with BPC 157 (1µm), the bupivacaine-induced depolarization was inhibited. Together, these findings suggest that the stable gastric pentadecapeptide BPC 157 should be a potential antidote for bupivacaine cardiotoxicity.

Therapeutic potential of pro-angiogenic BPC157 is associated with VEGFR2 activation and up-regulation

BPC 157, a pentadecapeptide with extensive healing effects, has recently been suggested to contribute to angiogenesis. However, the underlying mechanism is not yet clear. The present study aimed to explore the potential therapeutic effect and pro-angiogenic mechanism of BPC 157. As demonstrated by the chick chorioallantoic membrane (CAM) assay and endothelial tube formation assay, BPC 157 could increase the vessel density both in vivo and in vitro, respectively. BPC 157 could also accelerate the recovery of blood flow in the ischemic muscle of the rat hind limb as detected by laser Doppler scanning, indicating the promotion of angiogenesis. Histological analysis of the hind limb muscle confirmed the increased number of vessels and the enhanced vascular expression of vascular endothelial growth factor receptor 2 (VEGFR2) in rat with BPC 157 treatment. In vitro study using human vascular endothelial cells further confirmed the increased mRNA and protein expressions of VEGFR2 but not VEGF-A by BPC 157. In addition, BPC 157 could promote VEGFR2 internalization in vascular endothelial cells which was blocked in the presence of dynasore, an inhibitor of endocytosis. BPC 157 time dependently activated the VEGFR2-Akt-eNOS signaling pathway which could also be suppressed by dynasore. The increase of endothelial tube formation induced by BPC 157 was also inhibited by dynasore. This study demonstrates the pro-angiogenic effects of BPC 157 that is associated with the increased expression, internalization of VEGFR2, and the activation of VEGFR2-Akt-eNOS signaling pathway. BPC 157 promotes angiogenesis in CAM assay and tube formation assay. BPC 157 accelerates the blood flow recovery and vessel number in rats with hind limb ischemia. BPC 157 up-regulates VEGFR2 expression in rats with hind limb ischemia and endothelial cell culture. BPC 157 promotes VEGFR2 internalization in association with VEGFR2-Akt-eNOS activation.

KEY MESSAGE

BPC 157 promotes angiogenesis in CAM assay and tube formation assay. BPC 157 accelerates the blood flow recovery and vessel number in rats with hind limb ischemia. BPC 157 up-regulates VEGFR2 expression in rats with hind limb ischemia and endothelial cell culture. BPC 157 promotes VEGFR2 internalization in association with VEGFR2-Akt-eNOS activation.

Esophagogastric anastomosis in rats: Improved healing by BPC 157 and L-arginine, aggravated by L-NAME

AIM

To cure typically life-threatening esophagogastric anastomosis in rats, lacking anastomosis healing and sphincter function rescue, in particular.

METHODS

Because we assume esophagogastric fistulas represent a particular NO-system disability, we attempt to identify the benefits of anti-ulcer stable gastric pentadecapeptide BPC 157, which was in trials for ulcerative colitis and currently for multiple sclerosis, in rats with esophagocutaneous fistulas. Previously, BPC 157 therapies have promoted the healing of intestinal anastomosis and fistulas, and esophagitis and gastric lesions, along with rescued sphincter function. Additionally, BPC 157 particularly interacts with the NO-system. In the 4 d after esophagogastric anastomosis creation, rats received medication (/kg intraperitoneally once daily: BPC 157 (10 μg, 10 ng), L-NAME (5 mg), or L-arginine (100 mg) alone and/or combined or BPC 157 (10 μg, 10 ng) in drinking water). For rats underwent esophagogastric anastomosis, daily assessment included progressive stomach damage (sum of the longest diameters, mm), esophagitis (scored 0-5), weak anastomosis (mL H₂O before leak), low pressure in esophagus at anastomosis and in the pyloric sphincter (cm H₂O), progressive weight loss (g) and mortality. Immediate effect assessed blood vessels disappearance (scored 0-5) at the stomach surface immediately after anastomosis creation.

RESULTS

BPC 157 (all regimens) fully counteracted the perilous disease course from the very beginning (i.e., with the BPC 157 bath, blood vessels remained present at the gastric surface after anastomosis creation) and eliminated mortality. Additionally, BPC 157 treatment in combination with L-NAME nullified any effect of L-NAME that otherwise intensified the regular course. Consistently, with worsening (with L-NAME administration) and amelioration (with L-arginine), either L-arginine amelioration prevails (attenuated esophageal and gastric lesions) or they counteract each other (L-NAME + L-arginine); with the addition of BPC 157 (L-NAME + L-arginine + BPC 157), there was a marked beneficial effect. BPC 157 treatment for esophagogastric anastomosis, along with NOS-blocker L-NAME and/or NOS substrate L-arginine, demonstrated an innate NO-system disability (as observed with L-arginine effectiveness). BPC 157 distinctively affected corresponding events: worsening (obtained with L-NAME administration that was counteracted); or amelioration (L-arginine + BPC 157-rats correspond to BPC 157-rats).

CONCLUSION

Innate NO-system disability for esophagogastric anastomoses, including L-NAME-worsening, suggests that these effects could be corrected by L-arginine and almost completely eliminated by BPC 157 therapy.

BPC 157: The counteraction of succinylcholine, hyperkalemia, and arrhythmias

After the demonstration of its life-saving effect in severe hyperkalemia and the recovery of skeletal muscle after injury, pentadecapeptide BPC 157 has been shown to attenuate the local paralytic effect induced by succinylcholine, in addition to systemic muscle disability (and consequent muscle damage). Hyperkalemia, arrhythmias and a rise in serum enzyme values, were counteracted in rats. Assessments were made at 3 and 30min and 1, 3, 5, and 7 days after succinylcholine administration (1.0mg/kg into the right anterior tibial muscle). BPC 157 (10µg/kg, 10ng/kg) (given intraperitoneally 30min before or immediately after succinylcholine or per-orally in drinking water through 24h until succinylcholine administration) mitigated both local and systemic disturbances. BPC 157 completely eliminated hyperkalemia and arrhythmias, markedly attenuated or erradicated behavioral agitation, muscle twitches, motionless resting and completely eliminated post-succinylcholine hyperalgesia. BPC 157 immediately eliminated leg contractures and counteracted both edema and the decrease in muscle fibers in the diaphragm and injected/non-injected anterior tibial muscles. Therefore, the depolarizing neuromuscular blocker effects of succinylcholine were successfully antagonized.

Stable gastric pentadecapeptide BPC 157 heals rat colovesical fistula

To establish the effects of BPC 157 on the healing of rat colovesical fistulas, Wistar Albino male rats were randomly assigned to different groups. BPC 157, a stable gastric pentadecapeptide, has been used in clinical applications-specifically, in ulcerative colitis-and was successful in treating both external and internal fistulas. BPC 157 was provided daily, perorally, in drinking water (10µg/kg, 12ml/rat/day) until sacrifice or, alternatively, 10µg/kg or 10ng/kg intraperitoneally, with the first application at 30min after surgery and the last at 24h before sacrifice. Controls simultaneously received an equivolume of saline (5.0ml/kg ip) or water only (12ml/rat/day). Assessment (i.e., colon and vesical defects, fistula leaking, fecaluria and defecation through the fistula, adhesions and intestinal obstruction as healing processes) took place on days 7, 14 and 28. Control colovesical fistulas regularly exhibited poor healing, with both of the defects persisting; continuous fistula leakage; fecaluria and defecation through the fistula; advanced adhesion formation; and intestinal obstruction. By contrast, BPC 157 given perorally or intraperitoneally and in µg- and ng-regimens rapidly improved the whole presentation, with both colon and vesical defects simultaneously ameliorated and eventually healed. The maximal instilled volume was continuously raised until it reached the values of healthy rats, there were no signs of fecaluria and no defecation through the fistula, there was counteraction of advanced adhesion formation or there was an intestinal obstruction. In conclusion, BPC 157 effects appear to be suited to inducing full healing of colocutaneous fistulas in rats.

Stable gastric pentadecapeptide BPC 157 heals rectovaginal fistula in rats. Life Sci. 2016;148:63-70. [PMID: 26872976 DOI: 10.1016/j.lfs.2016.02.029]

AIM

Rectovaginal fistula is a devastating condition providing more than 99% of patients for surgical treatment. We hypothesized that rectovaginal fistula may be healed by therapy with stable gastric pentadecapeptide BPC 157, in consistence with its initial clinical application and effect on external fistulas.

MAIN METHODS

BPC 157 (10μg/kg or 10ng/kg) was given perorally, in drinking water (0.16μg/ml or 0.16ng/ml, 12ml/rat/day) till sacrifice, or alternatively, intraperitoneally, first application at 30min after surgery, last at 24h before sacrifice. Controls simultaneously received an equivolume of saline (5.0ml/kg ip) or water only (12ml/rat/day). The assessment (i.e., rectal and vaginal defect, fistula leakage, defecation through the fistula, adhesions and intestinal obstruction as healing processes) was at day 1, 3, 5, 7, 10, 14 and 21.

KEY FINDINGS

Regularly, rectovaginal fistulas exhibited poor healing, with both of the defects persisting, continuous fistula leakage, defecation through the fistula, advanced adhesion formation and intestinal obstruction. By contrast, BPC 157 given perorally or intraperitoneally, in μg- and ng-regimens rapidly improved the whole presentation, with both rectal and vaginal defects simultaneously ameliorated and eventually healed. The maximal instilled volume was continuously raised till the values of healthy rats were achieved, there were no signs of defecation through the fistula. A counteraction of advanced adhesion formation and intestinal obstruction was achieved. Microscopic improvement was along with macroscopic findings.

SIGNIFICANCE

BPC 157 effects appear to be suited to induce a full healing of rectovaginal fistulas in rats.

NO system dependence of atropine-induced mydriasis and L-NAME- and L-arginine-induced miosis: Reversal by the pentadecapeptide BPC 157 in rats and guinea pigs

We revealed an immediate and hours-lasting particular NO-specific parallel miotic effect of L-NAME and L-arginine in rats and guinea pigs and a stable gastric pentadecapeptide BPC 157 157-particular effect vs. that of atropine-induced mydriasis while examining the NO system role in the normal pupils responses and pupils with atropine-induced mydriasis. We also assessed the responses to BPC 157 and its possible modulation of the changes caused by L-NAME/L-arginine and atropine. We administered locally (two drops/eye) or systemically (intraperitoneally/kg) [BPC 157 (0.4µg/eye; 10µg, 10ng, 10pg/kg), L-NAME (0.1mg/eye; 5mg/kg), and L-arginine (2mg/eye; 100mg/kg) alone and combined] at 3min prior to assessment (normal pupils) or alternatively at maximal 1% atropine-induced mydriasis (30min after two drops were administered to each eye). L-NAME/L-arginine. Normal pupil. L-NAME-miosis and L-arginine-miosis shortened and attenuated each other's responses when combined (L-NAME+L-arginine) (except with guinea pigs treated locally) and were thereby NO-specific. Atropine-pupil. Both L-NAME and L-arginine counteracted atropine-induced mydriasis. With few exceptions, the atropine+L-NAME+L-arginine-animals showed a consistent shift toward the left. BPC 157. Normal pupil. Always, BPC 157 alone (both species; locally; systemically; all regimens) did not affect normal pupils. Despite specific exceptions, BPC 157 distinctively affects L-arginine-miosis (prolongation) and L-NAME-miosis (shortening). When L-arginine and L-NAME were combined (L-NAME+L-arginine+BPC 157), the effect was less pronounced. Atropine-pupil. BPC 157 alone counteracted atropine-induced mydriasis. With few exceptions (when administered with L-NAME or L-arginine or L-NAME+L-arginine), BPC 157 augments their counteracting effects. Thus, along with its l-NAME/L-arginine effects, BPC 157 participates in ocular control, potentially via NO-mediated and cholinergic mechanisms.

BPC 157 antagonized the general anaesthetic potency of thiopental and reduced prolongation of anaesthesia induced by L-NAME/thiopental combination

AIM

We hypothesized that certain effects of the general anaesthetic thiopental are dependent on NO-related mechanisms, which were consequently counteracted by stable gastric pentadecapeptide BPC 157.

MAIN METHODS

(1) All rats intraperitoneally received thiopental (20, 30, 40, and 50 mg/kg) while medication BPC 157 (10 μg/kg, 10 ng/kg, and 10 pg/kg) was given intraperitoneally at 5 min before thiopental. (2) To determine NO-related mechanisms, all rats received intraperitoneally thiopental 40 mg/kg while BPC 157 (10 μg/kg), L-NAME (10 mg/kg) and L-arginine (30 mg/kg) were applied alone and/or combined. BPC 157 was given at 25 min before thiopental while L-NAME, L-arginine, alone and/or combined, were applied at 20 min before thiopental.

KEY FINDINGS

(1) BPC 157 own effect on thiopental anaesthesia: BPC 157 (10 ng/kg and 10 μg/kg) caused a significant antagonism of general anaesthesia produced by thiopental with a parallel shift of the dose-response curve to the right. (2) L-NAME-L-arginine-BPC 157 interrelations: L-NAME: Thiopental-induced anaesthesia duration was tripled. L-arginine: Usual thiopental anaesthesia time was not influenced. Active only when given with L-NAME or BPC 157: potentiating effects of L-NAME were lessened, not abolished; shortening effect of BPC 157: abolished. BPC 157 and L-NAME: Potentiating effects of L-NAME were abolished. BPC 157 and L-NAME and L-arginine: BPC 157 +L-NAME +L-arginine rats exhibited values close to those in BPC 157 rats.

SIGNIFICANCE

Thiopental general anaesthesia is simultaneously manipulated in both ways with NO system activity modulation, L-NAME (prolongation) and BPC 157 (shortening/counteraction) and L-arginine (interference with L-NAME and BPC 157).

Perforating corneal injury in rat and pentadecapeptide BPC 157

Based on its healing effects in various tissues, we hypothesized that the stable gastric pentadecapeptide BPC 157 heals corneal ulcerations in rats and effects corneal transparency. We made a penetrant linear 2-mm incision in the paralimbal region of the left cornea at the 5 o'clock position with a 20-gauge MVR incision knife at 45° under an operating microscope. Medication was BPC 157 (2 pg/mL, 2 ng/mL, and 2 μg/mL distilled water, two eye drops/left rat eye) immediately after injury induction and then every 8 h up to 120 h; controls received an equal volume of distilled water. In contrast to the poor healing response in controls, BPC 157 significantly accelerated the healing process in 2 μg and 2 ng BPC 157-treated eyes, starting 24 h after the injury, and the fluorescein and Seidel tests became negative. The epithelial defects were completely healed at 72 h (2 μg BPC 157-treated group) and at 96 h (2 ng BPC 157-treated group) after injury. Aqueous cells were absent at 96 h and 120 h after injury in the 2 μg and 2 ng BPC 157-treated groups, respectively. In conclusion, BPC 157 effects the rapid regaining of corneal transparency. Whereas controls developed new vessels that grew from the limbus to the penetrated area, BPC 157-treated rats generally had no new vessels, and those that did form in the limbus did not make contact with the penetrated area. Thus, BPC 157 eye drops successfully close perforating corneal incisions in rats.