Quality assessment of ardisia elliptica fruit and analysis of embelin content by thin layer chromatographic techniques

Abstract

Ardisia elliptica Thunb. dried fruits has been traditionally used as crude drug in Thai remedies such as Apaisali, Plookfietad and Prabchomphuthaveeb. This study aimed to report the current information on the pharmacognostic specification of A. elliptica dried fruits and analysed the chemical constituent, embelin by thin layer chromatography-densitometry and thin layer chromatography image analysis. The fruits were collected from 15 habitats located at various regions throughout Thailand. The whole plant of A. elliptica was illustrated in detail. The crude drug was prepared by cleaning, and drying in a hot air oven. The macroscopic characters were dried fruits with calyx, variable in sizes, dark brown and brown seeds. The anatomical and histological characteristics were sclereids or stone cell, recticulated vessels, endosperm, epidermis of seed. The total ash, acid insoluble ash, loss on drying, ethanol–soluble extractive, water–soluble extractive and water content of 5.57 ± 0.15, 0.34 ± 0.06, 10.54 ± 0.08, 4.92 ± 0.45, 9.42 ± 0.91 and 10.61 ± 0.69 % dry weight respectively. Thin-layer chromatographic fingerprints of ethanolic extracts of A. elliptica dried fruits were studied using chloroform, ethyl acetate and formic acid (5:4:1) as mobile phase. Detection under ultraviolet light (254 nm and 365 nm) as well as spraying with phosphomolypdic acid reagent showed the dominant band at Rf = 0.35. Thin layer chromatography for quantitative analysis was studied using n-butabol, n-propanol, 4N ammonia (1:7:2) as mobile phase. Linearity range of embelin by TLC-densitometry was 0.60 - 3.00 µg with correlation coefficient (r2) of 0.992, LOD and LOQ were 21.04 and 63.76 ng respectively. The precision was evaluated by the % RSD of repeatability and intermediate precision, was between 8.83 – 12.45 % RSD and 8.55 – 18.74 %RSD respectively. The average recoveries were 82.88 – 103.00 % recoveries. Linearity range of embelin by TLC-image analysis was 0.60 - 3.00 µg with correlation coefficient (r2) of 0.994, LOD and LOQ were 8.05 and 24.40 ng respectively. The precision was evaluated by the % RSD of repeatability and intermediate precision, was between 5.27 – 8.12 % RSD and 1.92 – 9.29 %RSD respectively. The average recoveries were between 103.83 – 123.50 % recoveries. The quantitative results showed that embelin content in A. elliptica fruits by TLC-densitometry were between 0.20 – 4.53 g/100 g of dried fruit whereas by TLC image analysis was found at 0.23 – 4.43 g/100 g of dried fruit. The comparison of embelin content between TLC densitometry and TLC image analysis were statistically tested using Wilcoxon Signed Ranks Test. It was found that the embelin contents by two methods were not significantly different (Z = -1.761, P = 0.078). This study provides scientific information for the quality control of A. elliptica dried fruits including embelin content in Thailand that leads to safe use of this crude drug.