Antinociceptive activity of the fractionated extracts of Muntingia calabura

Non-steroidal Anti-inflammatory Drugs (NSAIDs) have been shown to be effective in inflammatory and pain management. However, this group of drugs can also cause various undesirable side effects such as dyspepsia, upper gastrointestinal and renal effects. Thus, it is necessary to continue searching for new sources of anti-inflammatory and pain-relieving agents from natural sources, which exert lesser or, possibly, no side effects. Muntingia calabura L. is known locally as Kerukup siam [1]. This plant has been claimed by the Peruvian folklore to possess medicinal values which include soothing gastric ulcers, relieving headache and cold, reducing swelling of the prostate gland and antiseptic [1]. This study focuses on understanding the antinociceptive effects of the extracts using Sprague Dawley (S.D.) rats. In the present study, activity-guided studies of the methanolic extract of Muntingia calabura collected in Shah Alam, Selangor, Malaysia were conducted for their antinociceptive property using formalin test [2]. Seven fractions of petroleum ether extract labelled A-G were separately administered (orally) with distilled water or 10% DMSO as negative controls and morphine and aspirin as a positive control. Fraction D showed the most significant antinociceptive activity when compare to other fractions (Table 1). At the dose of 300mg/kg, fraction D exhibited 66.2% and 81.4% antinociception in first (analgesic) and second phase (inflammation) respectively. Fraction D showed no significant different (p<0.5) when compared to aspirin (100mg/kg) as a positive control. In further experiment, active compounds from fraction D will be identified and their antinociceptive and anti-inflammation properties will be investigated.

Table 1: Antinociceptive activity for petroleum ether fraction of Mutingia calabura

Fraction (mg/kg)	First phase	Percentage %	Second phase	Percentage %
A (300)	79.667±1.585	2.6	145.667±2.246	0.45
B (300)	74.833±1.922	8.6	137.833±2.056	5.8
C (300)	57.167±2.056	30.1	86.167±1.851	41.1
D (300)	27.667±2.418	66.2	27.167±1.778	81.4
E (300)	42.167±3.381	48.5	77.833±1.537	46.8
F (300)	81.82±3.26	0.01	86.667±1.819	40.8
G (300)	74.333±1.429	9.2	143.833±2.428	1.7

Acknowledgement: This study was supported by the National Science Fellowship (NSF) scholarship from Ministry of Science Technology and Innovation Malaysia (MOSTI).

References: [1]. Morton JF (1987) Jamaica cherry in fruit of warm climates. Miami. pp: 65–69.

[2]. Rosland JH, Tjolsen A, Maehle B & Hole K (1990). Pain 42: 235–242.