Anti-inflammatory and associated analgesic activities of HPLC standardized alcoholic extract of known ayurvedic plant Schleichera oleosa

Abstract

Ethnopharmacological relevance

Schleichera oleosa (Lour.) Oken. commonly known as ‘Koshamra’ in Ayurveda is a tropical tree readily found in Asia and is used to treat pain and rheumatism, as traditional medicine in different parts of India. However, scientific evidences to justify these claims are lacking. Considering the traditional use of S.oleosa and the lack of information about its pharmacological properties, we investigated the anti-inflammatory and analgesic effect of the alcoholic extract of S.oleosa (SE) against different animal models in rodents.

Materials and methods

The anti-inflammatory activity was evaluated against carrageenan induced paw edema and TPA (12-O-tetradecanoylphorbol-13-acetate) induced ear edema. To assess the mechanism of anti-inflammatory action the extract was tested against different phlogistic agents like histamine, serotonin, bradykinin and, prostaglandin E2. The analgesic activity was assessed against formalin induced pain.

Results

The ethanolic extract of S. oleosa bark, did not exhibited any signs of toxicity up to a dose of 2000 mg/kg. The extract significantly inhibited increase in paw edema and ear edema. A percent reduction of 60.84% was found against carrageenan induced paw edema by 400 mg/kg dose of SE. The extract was effective against edema induced by serotonin, histamine and PGE₂. In formalin test the extract inhibited both the neurogenic 1st and mainly the inflammatory 2nd phase. Significant reduction in tissue levels of inflammatory mediators was also observed (p<0.05 for NO and p<0.01 for MDA). The extract showed presence of potent analgesic and anti-inflammatory compounds lupeol, lupeol acetate, betulin and betulinic acid on HPLC analysis which can be held responsible for its studied biological activity.

Conclusions

The results suggest that SE is effective in inflammatory processes and targets multiple mediators of inflammation. Its action is markedly influenced by the inhibition of neutrophil migration, anti-oxidant action and reduction in inflamed tissue.

Introduction

Inflammation is a protective response of mammalian tissues against diverse stimuli, giving rise to a series of complex events which are facilitated by a number of inflammatory mediators like the prostaglandins, prostacyclin and leukoterines which persuade, uphold and exaggerate many associated disorders (Ricciotti and Fitzgerald, 2011). Non-steroidal anti-inflammatory drugs (NSAIDs) are the front line drugs used to reduce the noxious events associated with inflammation. However, these drugs exhibit devastating adverse events ranging from gastric irritation and ulcers to hepato-toxicity and renal failure on chronic administration (Kunanusorn et al., 2009). These drawbacks of the NSAIDs can be by-passed or minimized by substituting them with relatively safer and efficient plant drugs (Khan et al., 2011). Moreover, the shortcomings of the drugs available for treatment of chronic inflammatory conditions like arthritis, has driven the discovery of new medicinal agents in from plant sources (Khan et al., 2013). To determine the potential of herbal medicines and to promote their use it is essential to intensify the study of medicinal plants that find a place in folklore.

Schleichera oleosa (Lour.) Oken. is commonly known as “Kusum” in Hindi and belongs to family Sapindaceae. It is a tropical tree readily available in the Asian sub-continent including India, Thailand and other tropical parts of the globe and is being used as traditional therapy for many ailments in different parts of India (Mikolajczak et al., 1971). Traditional healers use the bark and seed of this plant to treat various pathological states in human beings like rheumatic pain, topical itching, acne, burns, other skin troubles, hair dressing and for promoting hair growth (Thind et al., 2010; Ghalme et al., 2010; Jain, 2011). It is known to be a fast spreading tree in Ayurveda and is believed to be effective in skin diseases and ulcers (Sangu et al., 2012, Mishra, 2004). As per the Ayurvedic texts the bark of Schleichera oleosa is used for treatment of kushtha and tvak rogas i.e. skin disorders and is also indicated in ‘shotha’ i.e. inflammatory conditions (Dash and Kashyap, 2000). Some of the scientific studies have reported the antioxidant, anticancer and antiulcer activities of the plant (Thind et al., 2011). The plant has shown the presence of triterpenes and flavonoids in different phytochemical studies and the role of triterpenes of this plant against cancer has been well established (Kantamreddi et al., 2010, Pushker et al., 2011). However, the potential of this readily available plant against inflammation still remains to be explored scientifically so as to validate its traditional claim.

The present work explores the possibility of Schleichera oleosa to counteract inflammatory response in rodents.