Region‐specific effects of the cysteine protease papain on gastric motility

Abstract

Background: Papaya is a traditional remedy for gastrointestinal complaints in the folk medicine. On this basis, papain, a cysteine protease of the fruit, is sold as a nutritional supplement, although scientific data on its effects in the gastrointestinal tract are lacking. We aimed to explore the effect of papain on gastric motility in vitro.Methods: Guinea pig antrum and corpus strips were mounted in organ bath. Key results:Papain reversibly increased the amplitude of ongoing phasic contractions in both circular and longitudinal antrum strips without having an effect on the frequency or on the muscle tone. All three tested doses of papain (end cc.: 12.5 mg L −1 , 50 mg L −1 , 100 mg L −1 ) were similarly effective. Contrarily, in the corpus circular and longitudinal muscle strips, papain caused a dose-dependent relaxation, which was preceded by a transient contraction in most tissues. The effect was resistant to tetrodotoxin (1 µM), but diminished by the cysteine protease inhibitor E64 (4.5 µM) in both regions. In the corpus, L-NAME (100 µM) and the protease-activated receptor (PAR)-1 antagonist SCH79797 (5 µM) or the PAR-2 antagonist GB 83 (3 µM) did not change the effect of papain significantly. This demonstrates that the effects of papain are not neurally mediated and nitrergic pathways are not involved in the mechanism. The effects are linked to the enzymatic activity, but not executed via PAR-1 or 2. Conclusions and inferences:Papain alters gastric motility in a region-specific manner, which could at least partly explain its claimed beneficial effects in functional gastrointestinal disorders.

Effectiveness of Nutritional Ingredients on Upper Gastrointestinal Conditions and Symptoms: A Narrative Review

“…Animal and in vitro studies suggest that papaya has an ability to scavenge ROS and inhibit gastric secretion through histamine reduction [ 69 , 70 , 71 ] and that it also acts directly upon gastric smooth muscle to impact its motility [ 72 ].…”

Enteric neuroanatomy and smooth muscle activity in the western diamondback rattlesnake (Crotalus atrox)

“…The stomach was cut up longitudinally, rinsed in Krebs solution, and fixed mucosal side up with metal pins in Sylgard-coated Petri dishes. With the mucosa still on, muscle strips (0.5 cm wide and 1 cm long in the stomach and 1 cm 2 in the colon) were cut along the circular muscle axis of the proximal and distal stomach and the colon under an Olympus SZ51 stereomicroscope (Olympus, Hamburg, Germany), and mounted in a four-chamber, 25 mL automatic organ bath (Panlab, Barcelona, Spain), The method was similar to our previous studies with guinea pig tissue with a few adaptations to the snake [ 57 , 58 ].…”

Assessing the Prevalence of Age-related Enzyme Deficiency in Indian Population and the Efficacy of Supplementing with a Combination of Alpha- Amylase and Papain Enzyme in this Population

“…It reduced symptoms including heartburn, nausea, vomiting, burping and bloating as compared to the placebo. 28 A recent study by Annaházi et al (2021) examined the effects of papain on guinea pig corpus and antrum strips. Papain increased the antrum's ongoing phasic contractions, but the muscle tone and frequency stayed the same.…”

“…Hence, it is hypothesized that papainlike cysteine proteases may also have a direct impact on the GI muscles, potentially alleviating IBS symptoms. 29 Postprandial digestive symptoms as diarrhea, abdominal distension, flatulence, bloating and a fullness sensation are frequent complaints with frequently unidentified etiology and pathophysiology. Numerous studies, including a number of randomized placebo-controlled trials, have documented the beneficial effects of products containing various combinations of digestive enzymes.…”