Bergenin determination in different extracts by high-performance thin-layer chromatographic densitometry

Bergenin is an active secondary metabolite, found in Bergenia ligulata, family Saxifragaceae, which is an important medicinal plant used in the traditional system of medicine. It is distributed throughout the South and East Asia and some European countries, usually growing on high altitude in the Himalayan region and known as Pashanbhed (meaning "to break the stone"). The rhizome of B. ligulata has been used since long time in different traditional formulations of kidney and liver disorders. Due to its exhaustive use in the traditional system, it is commonly adulterated with the rhizome of other plants which do not contain its chemical marker bergenin. Hence, we developed high-performance thin-layer chromatographic (HPTLC) method for quantification of bergenin in B. ligulata which can be used for its quality control.

A sensitive HPTLC method has been developed for the estimation of bergenin in different extracts of B. ligulata and its traditional formulations. Precoated HPTLC silica gel plates were used as stationary phase, and chloroform: methanol: acetic acid (8:1:1, v/v/v) was used as mobile phase.

The Rf value of bergenin was found to be 0.28 ± 0.03. Detection and quantification were performed by densitometry at 276 nm. The calibration plot was linear in the range of 200-5000 ng of bergenin with the correlation coefficient of (r (2)) 0.999, which confirms good linearity. The content of bergenin in methanolic and acetone extracts was found to be 5.51 ± 0.14 and 5.76 ± 0.16, respectively.

The method can be applied for quality control and standardization of B. ligulata and its traditional formulations as well as for checking the presence of adulterants.