Evaluation of anti-inflammatory properties of herbal drugs: how useful could be ATR-FTIR spectroscopy?

Abstract

Inflammation is a hallmark of some of today's most life-threatening diseases such as arteriosclerosis, cancer, diabetes and Alzheimer's disease. Herbal medicines (HMs) are re-emerging resources in the fight against these conditions and for many of them, anti-inflammatory activity has been demonstrated. However, several aspects of HMs such as their multi-component character, natural variability and pharmacodynamic interactions (e.g. synergism) hamper identification of their bioactive constituents and thus the development of appropriate quality control (QC) workflows. In this study, we investigated the potential use of Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy as a tool to rapidly and non-destructively assess different anti-inflammatory properties of ethanolic extracts from various species of the Genus Lonicera (Caprifoliaceae). Reference measurements for multivariate calibration comprised in vitro bioactivity of crude extracts towards four key players of inflammation: Nitric oxide (NO), interleukin 8 (IL-8), peroxisome proliferator-activated receptor β/δ (PPAR β/δ), and nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB). Multivariate analysis of variance (MANOVA) revealed a statistically significant, quantitative pattern-activity relationship between the extracts' ATR-FTIR spectra and their ability to modulate these targets in the corresponding cell models. Ensemble orthogonal partial least squares (OPLS) discriminant models were established for the identification of extracts exhibiting high and low activity with respect to their potential to suppress NO and IL-8 production. Predictions made on an independent test set revealed good generalizability of the models with overall sensitivity and specificity of 80% and 100%, respectively. Partial least squares (PLS) regression models were successfully established to predict the extracts' ability to suppress NO production and NF-κB activity with root mean squared errors of cross-validation (RMSECV) of 8.7% and 0.05-fold activity, respectively.

Conclusions

Taken together the present work has demonstrated the potential use of ATR-FTIR spectroscopy for the quantitative assessment of in vitro anti-inflammatory activity of Lonicera. In particular, our data i) revealed a significant quantitative pattern-activity relationship between the here investigated extracts IR spectra and their in vitro bioactivities, ii) yielded chemometric models tailored to predict bioactivity towards NO, IL-8 and NF-κB with reasonable accuracy, and iii) allowed reliable assessment of bioactivity of extracts prepared from accessions from different origins (i.e. China, Austria), species (i.e. L. japonica, L. macrantha) and even plant organs (i.e. flower buds, leaves). The latter point underpins that the here presented approach was capable of capturing the pharmacological activity-related spectral patterns in a wide array of biologically diverse samples which goes beyond previous studies where metabolomic fingerprint data has been exploited for the prediction of bioactivity of samples from a single species only [40]. Finally, we want to point out that although correlation between spectral patterns and bioactivity does not necessarily imply a direct, causal relationship they possibly provide valuable information that might help guiding discovery of the underlying active principle(s). In light of the here presented results we conclude that ATR-FTIR in combination with pharmacological assays holds promise for the assessment of HMs beyond mere authentication and quantification of marker compounds.


Full text access
(the full text can also be obtained directly from the authors)

R. Nikzad-Langerodi, S. Ortmann, E.M. Pferschy-Wenzig, V. Bochkov, Y.M. Zhao, J.H. Miao, J. Saukel, A. Ladurner, E.H. Heiss, V.M. Dirsch, R. Bauer, A.G. Atanasov, Assessment of anti-inflammatory properties of extracts from Honeysuckle (Lonicera sp. L., Caprifoliaceae) by ATR-FTIR spectroscopy, Talanta, Available online 18 July 2017, ISSN 0039-9140 doi.org/10.1016/j.talanta.2017.07.045
Link from Elsevier for a free access to the publication (valid for 50 days, until September 09, 2017): https://authors.elsevier.com/a/1VP-m_w5I5HBE


Keywords relevant for this post: natural products, medicinal plants, scientific studies, research, biochemistry, herbal medicine, botanicals, phytotherapy, natural product, phytochemistry, pharmacognosy, phytochemicals, bioactivity, ATR-FTIR spectroscopy, traditional Chinese medicine, anti-inflammatory activity, plant quality control, chemometrics, cell-based assays, Lonicera, ATR-FTIR fingerprint, herbal medicines.