Activity-Guided Fractionation to Characterize a Coffee Beverage that Effectively Down-Regulates Mechanisms of Gastric Acid Secretion as Compared to Regular Coffee

Abstract

In some individuals, the consumption of coffee beverages is related to symptoms of gastric irritation. Hot water steam-treatment of raw coffee beans is hypothesized to reduce the contents of stomach irritating compounds, and products to which this technology is applied are launched as stomach-friendly coffee. However, data on the effect of steam-treated coffee on gastric acid secretion are conflicting and it has not been proven yet as to which coffee components act as pro- or antisecretory stimulants. The work presented here aimed at the characterization of a coffee beverage that effectively down-regulates mechanisms of proton secretion in human gastric cells (HGT-1). At first, a regular coffee beverage was fractionated by using solvents of different polarity: water, ethylacetate, dichloromethane, and pentane. Functional assays on the proton secretory activity (PSA) of these solvent fractions revealed the least pronounced effect for the water fraction, for which quantitative analyses demonstrated the highest distribution of chlorogenic acid (95%), (beta)N-alkanoyl-5-hydroxytryptamides (55%), and N-methylpyridinium (N-MP, >99%) among all fractions. Following experiments demonstrated that HGT-1 cells treated with regular coffee fortified with N-MP at a concentration of about 20 mg/mL N-MP showed a significantly decreased PSA as compared to cells which were exposed to coffee beverages containing higher (32-34 mg/L) or lower (5 mg/L) N-MP concentrations. Results from cellular pathway analyses of transcription (ATF-1 and Akt1) and signaling (cAMP and EGFr) factors and kinases (ERK1/2), and experiments on the gene expression of pro (histamine-HRH2 and acetylcholine-CHRM3)- and anti (somatostatin-SSTR1)-secretory receptors and H(+),K(+)-ATPase verified this antisecretory activity of N-MP in coffee beverages.

Multi‐parametric approach to identify coffee components that regulate mechanisms of gastric acid secretion

“…N-MP also down-regulated the mRNA expression of the pro-secretory CHRM3. This finding is in accordance with the anti-secretory effect of N-MP after its addition to a lyophilized coffee beverage [9] and is also supported by an anti-ulcerogenic effect described in rats for 1-methylnicotinamide, a structure closely related to N-MP [18]. Thus, substituted pyridine structures may exhibit a stomach protective potential.…”

“…For the activation of the transcription factor ATF‐2, N‐MP, CAT and C5HT increased its phosphorylation status, whereas CAFF did not. In previous studies, it has already been shown that lyophilized coffee beverages with higher contents of N‐MP increase ERK1/2 activation compared with controls, whereas lyophilisates of coffee beverages with lower contents of N‐MP decreased the activity below control levels .…”

“…Using human parietal gastric tumor cells (HGT‐1) as a model system, we recently demonstrated a less pronounced proton secretory activity of reconstituted freeze‐dried coffee beverages prepared from commercial samples labeled stomach‐friendly or decaffeinated compared with lyophilizates from regular, neither steam‐treated nor decaffeinated, coffees . The results from the following studies revealed that the proton secretory activity of human stomach cells, induced by coffee beverages, is lowered by increasing concentrations of N‐MP in the coffee . However, the impact of other components such as CAFF, CA, or C5HT at a cellular level has not been extensively investigated, nor have interactions between individual coffee constituents in coffee representative biomimetic mixtures.…”

A dark brown roast coffee blend is less effective at stimulating gastric acid secretion in healthy volunteers compared to a medium roast market blend

“…Although these results do not provide conclusive evidence that the ratio of N‐MP to C5HTs and CGAs is predicative for the gastric acid stimulating potential of a coffee beverage, we further hypothesize that high concentrations of N‐MP in combinations with low concentrations of C5HTs and CGAs might be beneficial for subjects who react to coffee consumption with increased gastric acid secretion. From a mechanistic point of view, this hypothesis is supported by previous studies in which N‐MP was identified as an antisecretory constituent . Moreover, N ‐methylnicotinamide, another pyridine derivative, was shown to exhibit an anti‐ulcerogenic potential .…”

Impact of coffee components on inflammatory markers: A review

“…This shows that coffee may potentially have some benefit in the treatment of PD. Another study concluded that N-methylpyridinium infused coffee limited proton secretion in human gastric cells in a dose dependent fashion (Rubach et al, 2010). This research shows the power of coffee and Nmethylpyridinium to influence gene expression and downregulate gastric acid secretion.…”