Quantitative Estimation of Rosmarinic Acid in Ocimum sanctum Extracts and Polyherbal Formulation by HPTLC

 

 

Bincy Raj1*, Salma Khanam2, Soosamma John3 and Madhavi T3 Ayesha Siddique1

Dayananda Sagar College of Pharmacy, Kumaraswamy Layout, Bangalore- 560 078

2Al-Ameen College of Pharmacy, Bangalore-560027.

3East Point College of Pharmacy, Bangalore- 560049.

 

 

ABSTRACT:

Rosmarinic acid is an important bioactive content having analgesic and inflammatory activity. The content of Rosmarinic acid in Ocimum sanctum and three polyherbal formulations was estimated by HPTLC.

 

KEYWORDS:

 

INTRODUCTION:

Ocimum sactum is ranked among few wonder herbs for having enormous curative effect. Due to this the plant is considered as highly sacred, worth worshipping and hence was given the name of sacred, Tulsi or holy basil in India1. Different part of the plant has been reported to exhibit several medicinal properties2-4 like analgesic5, anti-oxident6,7, antibacterial and anthelmentic activity.

 

The chemical constituents of Ocimum sanctum indicate volatile oil and triterpine. Rosmarinic acid have been isolated and characterized from the leaves of Ocimum sanctum. This compound can be used as marker compound to evaluate and standardize extracts and formulations containing Tulsi. Literature survey reveals that very few validated HPTLC8-10 methods for estimation of Rosmarinic acid in extract and formulation.

 

MATERIAL AND METHODS:

Whole plant of Ocimum sanctum was collected from Natural Remedies and authenticated by RRI Bangalore. Formulation F-1 (marketed), each 10ml contains 100mg of Ocimum sanctum, formulation F-2 (marketed), each 5ml contains 100mg of Ocimum sanctum and formulation F-3 (marketed), each capsule contain 250mg of Ocimum sanctum.

 

The powdered drug (100g) was refluxed with 70% methanol, filtered and then concentrated under reduced pressure. 1g of extract was dissolved in 100ml methanol and filtered through whatman No 1 filter paper. The same procedure was applied for the extract as well as for the polyherbal formulations.

 

The apparatus used was: Camag HPTLC system, consisting of Linomat V spotting device and Scanner III with winCat 4 software; TLC aluminium sheets silica gel F254 precoated layer (10X10 cm). Toluene, ethyl acetate and formic acid in the ratio of 9:1:0.2 was used as mobile phase. The chromatogram was developed up to 80mm and scanned at 254 and 366. Spectrum analysis was done in the range of 200 – 700nm using D2 lamp and tungsten lamp. The spectrum showing λ max is given in the fig 1. The λ max for rosmarinic acid was found to be 320nm with Rf value 0.62.

 

Methanolic solution of Rosmarinic acid (50ng/µl) was used for the application on TLC plate. The five standard levels (2-6µl) of standard Rosmarinic acid were applied in triplicate on TLC plate.

 


 

The chromatogram was scanned at 320nm and average peak areas of three samples were calculated. The HPTLC chromatogram of extract along with standard Rosmarinic acid is shown in the fig 3. The HPTLC method was validated according to ICH guidelines. The recovery of analyte from the sample was confirmed by analysis of sample of known content. The solutions were spiked with three different known concentrations and analysis of each sample was repeated six times. The %RSD and % recovery was calculated. The repeatability was studied by analysing each sample for six times under the same analytical procedure and intermediate precision was studied by analysing each sample for six times on different days. The %RSD / CV was obtained.

 

RESULTS AND DISCUSSION:

The Rf value of standard Rosmarinic acid was found to be 0.62 and the peak area of the drug was reproducible as indicated by low coefficient of variation 1.65-1.81. A good linear relationship(r=0.996) was observed between the range 100 -400ng. Linearity curve of Rosmarinic acid is shown in the fig 2. The recovery of the method by this method was found to be more than 99.6-101%, which indicate high accuracy of proposed HPTLC method. The low percentage RSD (2.1-2.3) indicates that the proposed HPTLC method is highly precise. More over the limit of quantification was found to be 100ng. The content of Rosmarinic acid in dried extract and formulations F-1(marketed), F-2(marketed) and F-3(marketed) was found to be 1.44, 0.1, 0.05 and 0.15%w/w respectively. The highest amount of Rosmarinic acid was found to be in the dried plant extract. The result of all parameter was within limit. The method was found to be simple, sensitive and accurate. The good recovery of Rosmarinic acid showed the reliability and suitability of the method.

 

REFERENCE:

1.     Prakash P., Neelu Gupta. 2005; Therapeutic uses of Ocimum sanctum linn ( tulsi) with a note on eugenol and its pharmacological actions. A short review. Indian J Pharmacol 49 (2); p 125-131.

2.     Indian Herbal Pharmacopoeia. 1999: A joint publication of Regional Research institute (Jammu Tawi) and Indian drug manufactures association.11: p77-84.

3.     Elizabeth M Williamson. 2002; Major herbs of ayurveda. Churchill Livingston. 201-204

4.     Philip M. P., Damodaran  N. P. 1985; Chemotypes of Ocimum sanctum L Indian perfumers .29 (1-2): p  49-56.

5.     Surrender Singh, Majumdar D K. 1995; Analgesic activity of Ocimum sanctum and its possible mechanism of action. Internarional journal of pharmacognosy. 33 (3): p 188-192.

6.     Troncoso, Sierra H, Carvajal L, Delpiano P, Gunther G. 2005;Fast high performance liquid chromatography and ultra violet-visible quantification of principle phenolic antioxidants in fresh rosemary. Journal of chromatography A 1100: p 20-25.

7.     Tram Ngoc Ly, Makoto Shimoyamada, Ryo Yamauchi. 2006; Isolation and characterization of rosmarinic acid oligomers in celastrus hindsii benth leaves and their antioxidative activity.  J. Agric. Food Chem., 54: p 3786 –3793.

8.     Jerome Bouligand, Thomas Storme, Isabelle Laville, Lionel Mercier, Odile Oberlin, Gilles Vassal , Philippe Bourget, Angelo Paci. 2005; Quality control and stability study using HPTLC: application to cyclophosphamide in various pharmaceutical products. J of pharmaceutical and biomedical analysis.38:p180-185

9.     Edmond Ali Reza Fakhari, Afshin Rajabi Khorrami, Mojtaba Shamsipur.2005;  fluorescence detection combined with either HPLC or HPTLC for pharmaceutical quality control in a hospital chemotherapy production unit. Application to camptothecin derivatives. . J of pharmaceutical and biomedical analysis.39: p 581-586.

10.   Kuldeep M Patil, Subhash L, Bodhankar.2005; High performance thin-layer chromatographic determination of lamotrigine in serum. J of chromatography B. 823 : p 152-157

 

Received on 08.11.2009

Accepted on 31.12.2009   

© A&V Publication all right reserved

Research Journal of Pharmacognosy  and Phytochemistry. 2(1): Jan.-Feb. 2010, 46-48