Bioguided identification of pentacyclic triterpenoids as anti-inflammatory bioactive constituents of Ocimum gratissimum extract. (25th March 2021)

• Record Type: Journal Article
• Authors: Dzoyem, Jean Paul; Nganteng, Dieu Ne Dort; Melong, Raduis; Wafo, Pascal; Ngadjui, Bonaventure; Allémann, Eric; Delie, Florence
• Is Part Of: Journal of ethnopharmacology. Volume 268(2021)
• Publication Date: 2021-03-25
• Subjects: Ocimum gratissimum -- Bioguided fractionation -- Pentacyclic triterpenes -- Inflammation -- Nitric oxide -- Cytokines -- Cyclooxygenase -- Apoptosis; Ethnopharmacology -- Periodicals; Pharmacognosy -- Periodicals; Herbs -- Periodicals; Herbs -- Periodicals; Pharmacognosy -- Periodicals; Pharmacognosie -- Périodiques; Herbes -- Périodiques; 615.1
• DOI: 10.1016/j.jep.2020.113637
• Languages: English
• ISSNs: 0378-8741

Abstract

Abstract: Ethnopharmacological relevance: Ocimum gratissimum is a plant spice widely used in African traditional medicine to treat pain-related conditions. However, the anti-inflammatory mechanisms underlying this activity and the main active ingredients in O. gratissimum have not yet been fully characterized. Aim of the study: To isolate and identify the main anti-inflammatory active constituents of Ocimum gratissimum extract and their underlying mechanisms in murine macrophages. Material and methods: Chromatographic techniques and spectroscopic data were used for compounds isolation and identification. Inflammatory conditions were produced in cultured RAW 264.7 macrophage cells by the application of lipopolysaccharide (LPS). The WST-1 assay was used to evaluate the cell viability, and the nitric oxide production was quantified by the Griess reagent method. The fluorometric cyclooxygenase (COX) activity assay kit was used to assess the activity of COX-1 and COX-2 enzymes. The levels of IFN-γ, TNF-α, IL-2, IL-4, IL-6, and IL-10 cytokines and the apoptosis-inducing effect were measured by flow cytometer using the cytometric Bead Array (CBA) Human Th1/Th2 Cytokine Kit II and FITC Annexin V Apoptosis Detection kit, respectively. Results: The results showed that the extract and fractions of Ocimum gratissimum inhibit nitric oxide production and the proliferation of Raw 264.7 macrophage cells. The bioguided fractionation led to the identification of pentacyclic triterpenes as anti-inflammatory bioactive compounds. Pomolic and tormentic acids being the most active, inhibiting the secretion of IFN-γ cytokine, COX enzyme, and inducing apoptosis in activated Raw 264.7 macrophage cells. Conclusions: This study revealed that pomolic and tormentic acids are the main active principles responsible at least in part for the anti-inflammatory effect of the extract of Ocimum gratissimum . Besides of providing more evidence for the traditional use of Ocimum gratissimum against inflammatory disorders, this study reveals the multitarget potential of pomolic and tormentic acids as promising future drugs against inflammatory diseases. Graphical abstract: Image 1 Highlights: Pentacyclic triterpenoids were identified as the anti-inflammatory constituents of Ocimum gratissimum . Pomolic and tormentic acids being the most actives. The inhibition of IFN-γ cytokine, COX enzyme activity arise as their underlying mechanisms of action. Pomolic and tormentic acids appear as multitarget potential drugs against inflammatory diseases. This study provides more evidence for the traditional use of Ocimum gratissimum against anti-inflammatory diseases.