Antiarthritic potential of Ocimum gratissimum L. in collagen induced arthritic Sprague-Dawley rats

A review on the traditional uses, phytochemistry, and pharmacological activities of clove basil (Ocimum gratissimum L.)

In traditional medicine, Ocimum gratissimum (clove basil) is used in the treatment of various diseases such as diabetes, cancer, inflammation, anaemia, diarrhoea, pains, and fungal and bacterial infections. The present study reviewed the phytochemicals, essential oils, and pharmacological activities of O. gratissimum. The bioactive compounds extracted from O. gratissimum include phytochemicals (oleanolic acid, caffeic acid, ellagic acid, epicatechin, sinapic acid, rosmarinic acid, chlorogenic acid, luteolin, apigenin, nepetoidin, xanthomicrol, nevadensin, salvigenin, gallic acid, catechin, quercetin, rutin, and kaempfero) and essential oils (camphene, β-caryophyllene, α- and β-pinene, α-humulene, sabinene, β-myrcene, limonene, 1,8-cineole, trans-β-ocimene, linalool, α- and δ-terpineol, eugenol, α-copaene, β-elemene, p-cymene, thymol, and carvacrol). Various in vivo and in vitro studies have shown that O. gratissimum and its bioactive constituents possess pharmacological properties such as antioxidant, anti-inflammatory, anticancer, hepatoprotective, antidiabetic, antihypertensive, antidiarrhoeal, and antimicrobial properties. This review demonstrated that O. gratissimum has a strong preventive and therapeutic effect against several diseases. The effectiveness of O. gratissimum to ameliorate various diseases may be attributed to its antimicrobial and antioxidant properties as well as its capacity to improve the antioxidant systems. However, despite the widespread pharmacological activities of O. gratissimum, further experiments in human clinical trial studies are needed to establish effective and safe doses for the treatment of various diseases.

Bioguided identification of pentacyclic triterpenoids as anti-inflammatory bioactive constituents of Ocimum gratissimum extract

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.

Ocimum gratissimum Linn. Leaf extract inhibits free radical generation and suppressed inflammation in carrageenan-induced inflammation models in rats

BACKGROUND

Ocimum gratissimum leaf is used in managing rheumatism and other inflammatory conditions. In this study, we investigated the antioxidant and anti-inflammatory effects of phenolic extract obtained by sequential methanol extraction of O. gratissimum leaves (MEOg).

METHODS

The methanol extract (MEOg) was obtained after sequential maceration (n-hexane, chloroform and methanol) of dried O. gratissimum leaves. The fingerprint of the extract was obtained using a high-performance liquid chromatrographic method. In vitro effects were tested by 1,1-Diphenyl-2-picryl-hydrazyl (DPPH), nitric oxide (NO) free radical scavenging, lipoxygenase, and xanthine oxidase inhibitory assays. MEOg was studied for anti-inflammatory activity in carrageenan-induced paw edema and air pouch inflammation in rats.

RESULTS

HPLC fingerprint of the extract shows the presence of caffeic acid, rutin, ferulic acid, apigenin, and quercetin. Antioxidant activity of MEOg revealed an IC50 value in DPPH (31.5±0.03 μg/mL) and NO assay (201.6±0.01 μg/mL), respectively. The extract demonstrated strong xanthine oxidase inhibitory and weak antilipoxygenase activities. MEOg (100 mg/kg) significantly inhibited carrageenan-induced paw edema by 43.2%. Furthermore, MEOg (50 and 100 mg/kg) significantly reduced exudate volume, leucocyte count, neutrophil infiltration, TNF-α, nitrites, myeloperoxidase, and malondialdehyde in carrageenan-induced air pouch inflammation. MEOg also elevated the glutathione levels in the inflammatory exudates.

CONCLUSIONS

MEOg shows potential therapeutic benefits in slowing down inflammation and oxidative stress in chronic diseases, such as arthritis.