NIR and 1H qNMR methods coupled to chemometrics discriminate the chemotypes of the gastroprotective herb Egletes viscosa

UPLC-QTOF-MS/MS-based metabolomic approach and gastroprotective effect of two chemotypes of Egletes viscosa (L.) less. against ethanol-induced gastric ulcer in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Egletes viscosa (L.) (macela) is a native wild herb that can be found in different states of northeastern Brazil. The infusions of its flower buds are traditionally used for the treatment of gastrointestinal disorders. E. viscosa possesses two chemotypes (named A and B), distinguishable by the composition of the essential oil from the flower buds. Although there are previous studies of the gastroprotective effect of the isolated constituents of E. viscosa, its infusions have not been investigated yet.

AIM OF THE STUDY

The present study aimed to evaluate and compare the chemical composition and the gastroprotective effect of flower bud infusions of E. viscosa from chemotype A (EVCA) and chemotype B (EVCB).

MATERIALS AND METHODS

Sixteen infusions were brewed with flower buds according to the traditional preparation mode and were analyzed through a UPLC-QTOF-MS/MS based metabolomic approach for determination of their metabolic fingerprints and quantification of bioactive compounds. Afterward, these data were analyzed by chemometric methods (OPLS-DA) for discrimination of the two chemotypes. Additionally, infusions of EVCA and EVCB (50, 100 and 200 mg/kg, p.o.) were evaluated on gastric ulcers induced by absolute ethanol (96%, 0.2 mL, p.o.) in mice. To elucidate the gastroprotective mechanisms, the effect of EVCA and EVCB on gastric acid secretion and gastric wall mucus was determined and the role of TRPV1 channels, prostaglandins, nitric oxide and K_ATP channels were assessed. Moreover, the oxidative stress-related parameters and the histological aspects of the stomach tissue were analyzed.

RESULTS

The chemotypes can be discriminated from each other using UPLC-QTOF-MS/MS chemical fingerprints. Both chemotypes presented similar chemical compositions, consisting basically of caffeic acid derivatives, flavonoids and diterpenes. The quantification of bioactive compounds demonstrated that chemotype A possesses more ternatin, tanabalin and centipedic than chemotype B. EVCA and EVCB (50, 100 and 200 mg/kg, p.o.) significantly decreased the severity of ethanol-induced gastric lesions, as shown by a reduction in histological alterations and leucocyte infiltration in gastric tissue. The gastroprotective mechanism of both infusions involves an antioxidant effect, maintenance of gastric mucus and reduction gastric secretion. Stimulation of endogenous prostaglandins and nitric oxide release, activation of TRPV1 channels, and K_ATP channels are also involved in the gastroprotection of the infusions.

CONCLUSION

The gastroprotective effect of EVCA and EVCB was equivalent and mediated through antioxidant and antisecretory actions, including the activation of TRPV1 receptors, stimulation of endogenous prostaglandins and nitric oxide, and opening of K_ATP channels. The presence of caffeic acid derivatives, flavonoids and diterpenes in both infusions is involved in mediating this protective effect. Our findings support the traditional use of infusions of E. viscosa for gastric disorders regardless of the chemotype.

Chemometric-Guided Approaches for Profiling and Authenticating Botanical Materials

Botanical supplements with broad traditional and medicinal uses represent an area of growing importance for American health management; 25% of U.S. adults use dietary supplements daily and collectively spent over $9. 5 billion in 2019 in herbal and botanical supplements alone. To understand how natural products benefit human health and determine potential safety concerns, careful in vitro, in vivo, and clinical studies are required. However, botanicals are innately complex systems, with complicated compositions that defy many standard analytical approaches and fluctuate based upon a plethora of factors, including genetics, growth conditions, and harvesting/processing procedures. Robust studies rely upon accurate identification of the plant material, and botanicals' increasing economic and health importance demand reproducible sourcing, as well as assessment of contamination or adulteration. These quality control needs for botanical products remain a significant problem plaguing researchers in academia as well as the supplement industry, thus posing a risk to consumers and possibly rendering clinical data irreproducible and/or irrelevant. Chemometric approaches that analyze the small molecule composition of materials provide a reliable and high-throughput avenue for botanical authentication. This review emphasizes the need for consistent material and provides insight into the roles of various modern chemometric analyses in evaluating and authenticating botanicals, focusing on advanced methodologies, including targeted and untargeted metabolite analysis, as well as the role of multivariate statistical modeling and machine learning in phytochemical characterization. Furthermore, we will discuss how chemometric approaches can be integrated with orthogonal techniques to provide a more robust approach to authentication, and provide directions for future research.