In addition, chlorophyllin significantly reduces mortality related to IBD, weight loss, diarrhea and hidden blood in the stool, intestinal epithelial damage and infiltration of inflammatory cells.
The findings are published ahead of print in the American Journal of Physiology-Gastrointestinal and Liver Physiology, and the study has been chosen as an APS select article for August.
While the exact cause of IBD isn’t fully understood, some contributing factors include stress and environmental, lifestyle, and dietary choices, such as high consumption of meat or fish.
Chronic inflammation, abnormality in autophagy—the body’s process of cleaning out damaged cells to make room for newer, healthier cells—and lysosomal stress (an abnormality in an organelle leading to inflammation) are also linked to the condition.
Current therapeutics for IBD include medications that suppress the immune system (immunosuppressants) and surgery. However, long-term use of immunosuppressive treatments could result in severe adverse effects, including opportunistic infections and even organ failure.
Also, consumption of green vegetables and chlorophyllin may be helpful for IBD recovery, in part through alleviation of inflammation and autolysosomal flux (a process that uses lysosome to degrade and remove toxic molecules and organelles).
Green pigment found in these foods and supplements can initiate a feeding signaling to modulate autophagy in the cells, which suppresses IBD symptoms.
Researchers believe these findings could be a pathway to a less intrusive treatment for IBD.
“Consuming green-colored vegetables or green pigment supplement such as chlorophyllin might help people with inflammatory bowel disease,” said Xiaofeng Zheng, Ph.D., of Sichuan University and a co-author of the study.
Inflammatory bowel diseases (IBDs) are chronic and relapsing gastrointestinal disorders, featured as ulcerative colitis (UC) and Crohn’s disease (CD) (1). Although the etiology of IBD remains poorly understood, accumulating evidence suggests that dietary, environmental, genetic, epigenetic, and immunological factors may promote initiation and progression of the disease (2–5).
Two forms of IBD syndromes share certain common mechanisms but are distinct in their pathophysiological characteristics. In Crohn’s disease (CD), inflammation is typically segmental, asymmetrical, and transmural. CD impacts the whole gastrointestinal tract and pathological findings are mostly found in the terminal ileum and colon (6). Conversely, UC exhibits a continuous pattern of illness, involving superficial mucosal and submucosal, and is limited to the colon (7).
However, these treatments have shortcomings such as serious side effects and surgical risk. Moreover, many patients do not respond well to these treatments. Therefore, alternative therapeutic approaches and even diets or dietary supplements should be explored.
Imbalanced diet composition is well known for the pathogenesis of IBD. Diets rich in high sugar and high fat are closely related to the incidence of IBD (12, 13), whereas fruit and vegetable diets are negatively correlated (12, 14). Consistent with this notion, incidences of IBD are high in Western Europe and North America in association with diet and lifestyle.
Conversely, low incidences of IBD in Asia and other regions are related to a diet rich in green vegetables. Various vitamins and fiber in green vegetables are beneficial for human health and can prevent many illnesses including IBD. However, the green pigment in green vegetables, namely chlorophyll, has yet to be examined for improvement of IBD.
Chlorophyllin (CHL, C34H31CuN4Na3O6) is a water-soluble and semisynthetic food-grade derivative of chlorophyll, which is widely used in food industry (15). Numerous studies have demonstrated the roles of CHL in antigenotoxicity, antioxidation, and anticarcinogenesis (16–20), however, the potential therapeutical effects of CHL on IBD have yet to be investigated.
On the other hand, autophagy in physiological dynamics is essential for maintaining intestinal homeostasis. Autophagy is a basic biological process for all eukaryotes and it is vital for environmental response and adaptation machinery for nutrient and calorie availability (21).
A major function of autophagy is turnover of long-lived or misfolded proteins and damaged organelles for metabolic recycling (22). Autophagic flux is concerted with lysosomal digestion and plays an important role in maintaining metabolic homeostasis in programmed cell death, cell differentiation, intracellular pathogen clearance, and immunomodulation (23, 24).
Previous studies showed that genetic variation of autophagy genes, including autophagy-related 16-like 1 (ATG16L1), immunity-related GTPase family M (IRGM), and Unc-51-like kinase 1 (ULK1), is associated with IBD susceptibility (25–27). Mice with Atg16l1 deletion are susceptible to dextran sulfate sodium (DSS)-induced colitis partly due to Paneth cell abnormalities or enhanced IL-1β production (28, 29).
Conversely, abnormal activation of intestinal autophagy can aggravate IBD progression (30–32). Given the fundamental roles of nutrients in regulation of mTOR and autophagy, it is thus interesting to know if chlorophyllin, a dietary green pigment, can regulate intestinal autophagy in the context of IBD.
In this study, we found persistent activation of autophagy in experimental colitis. Furthermore, we uncovered that CHL could alleviate experimental colitis partly due to activation of Akt/mTOR pathway, leading to suppression of autophagic flux in the IBD model. Thus, this study indicates a potential beneficial role of CHL and green vegetables in mitigation of IBD syndromes.
https://journals.physiology.org/doi/full/10.1152/ajpgi.00291.2021
Original Research: Open access.
“Liver-on-a-chip devices: the pros and cons of complexity” by Philip Dalsbecker et al. American Journal of Physiology-Gastrointestinal and Liver Physiology
