The Phenolic Signature of Psidium cattleianum Fruits and Leaves Modulates TRPV1 and TRPA1 Transient Receptor Potential Channels: A Metabolomics, In Vitro, and In Silico Study

Abstract

Although Psidium cattleianum (strawberry guava, Myrtaceae) is known for its anti-inflammatory, antioxidant, antimicrobial, and antidiabetic properties, its phytochemical profile and associated bioactivities remain largely underexplored. This study employed UHPLC-QTOF-HRMS for untargeted phenolic profiling of leaf and fruit extracts from P. cattleianum, followed by semi-quantification of phenolic subclasses and multivariate data analysis. Four hundred sixty-nine metabolites, including various phenolic subclasses-predominantly flavonoids and phenolic acids were- identified and annotated. Using HEK-293 cells stably transfected with TRPA1 or TRPV1 cation channels, it was found that both leaf and fruit extracts activate and rapidly desensitize TRPA1 in a concentration-dependent manner (EC₅₀ 18 and 30 μg/mL; IC₅₀ 60 and 47 μg/mL, respectively). Additionally, molecular docking analysis provided deeper insights into the interactions between P. cattleianum phytochemicals and the TRPA1 cation channel, identifying theaflavin 3,3'-O-digallate as the phenolic compound with the highest affinity (S score of -9.27 Kcal/mol). Interestingly, except for theaflavin 3,3'-O-digallate, compounds enriched in the leaf extract exhibited weaker binding interactions and lower S scores (approximately -7 Kcal/mol) compared to those enriched in the fruit extract. Also, a 100 ns molecular dynamics study of theaflavin 3,3'-O-digallate with TRAP1 demonstrated high binding stability of the complex. Overall, this study offers valuable insights into the phytochemical characteristics of P. cattleianum extracts and reveals their mechanism of action through affinity for the TRPA1 cation channel-receptors.

Keywords: Psidium cattleianum; TRP channels; metabolomics; molecular docking; myrtaceae; phenolic profiling.

FIGURE 1

Schematic representation of untargeted metabolomic analysis of Psidium cattleianum extracts of leaves and fruits growing in Egypt.

FIGURE 2

The semi‐quantification profile of the different phenolic classes of the extracts from the fruit and leaves of P. cattleianum . Results are expressed as mg Equivalent (Eq.)/g considering the mean value of n = 3 experiments. LMW, lower‐molecular‐weight phenolics (i.e., tyrosol derivatives).

FIGURE 3

(A) Unsupervised hierarchical cluster analysis (HCA) built according to the fold‐change heatmap based on flavonoids and phenolics in fruit and leaf extracts of P. cattleianum. The cluster was built using Log 10 median normalized values (similarity: Squared Euclidean; linkage rule: Ward). The heat‐map color range in each column represents the maximum (red) and minimum (blue) fold‐change values. (B) Orthogonal Partial Least Square Data Analysis model. (C) Variable Importance on Projection plot, considering vector 1. (D) Pie chart of different phenolic classes of VIP markers obtained from OPLS‐DA model.

FIGURE 4

Effect of P. cattleianum leaf and fruit extracts on TRPA1 channels. Concentration‐response curves showing the activity of P. cattleianum leaves and fruits on TRPA1 channels calculated log(concentration) versus response—variable slope. AITC (100 μM) were used to calculate the % of P. cattleianum response or induced desensitization.

FIGURE 5

Effect of P. cattleianum leaf and fruit extracts on TRPV1 channels. Concentration‐response curves showing the activity of P. Cattle leaves and fruits on TRPV1 channels calculated log(concentration) versus response—variable slope. Ionomycin (4 μM) and Capsaicin (100 nM) were used to calculate the % of P. cattleianum response or induced desensitization.

FIGURE 6

Docking of Theaflavin 3,3'‐O‐digallate to TRPA1 ion channel (PDB ID: 6X2J) analyzed on Protein Ligand Interaction Profiler website and visualized on Pymol software.

FIGURE 7

Agonist co‐crystallized with TRPA1 (PDB ID: 6X2J). (A) interactions of the co‐crystalized ligand. (B) interactions of the re‐docked co‐crystallized ligand using MOE—v.2019.01.

FIGURE 8

Molecular dynamics results from a 100 ns simulation of TRAP1‐theaflavin 3,3'‐O‐digallate complex: (upper left panel) ligand RMSD; (upper right panel) H‐Bonds formation; and (lower panel) SASA.