Abstract
INTRODUCTION: Herbal medicines have gained increasing popularity in the last few decades, and this global resurgence of herbal medicines increases their commercial value. However, this increasing demand has resulted in a decline in their quality, primarily due to a lack of adequate regulations pertaining to herbal medicines. AIM: To develop an optimized methodology for the standardization of herbal raw materials. MATERIALS AND METHODS: The present study has been designed to examine each of the five herbal anti-diabetic drugs, Gymnema sylvester R. Br., Pterocarpus marsupium Roxburgh., Enicostema littorale Blume., Syzygium cumini (L.) Skeels. and Emblica officinalis Gaertn. The in-house extracts and marketed extracts were evaluated using physicochemical parameters, preliminary phytochemical screening, quantification of polyphenols (Folin-Ciocalteu colorimetric method) and high performance thin layer chromatography (HPTLC) fingerprint profiling with reference to marker compounds in plant extracts. RESULTS: All the plants mainly contain polyphenolic compounds and are quantified in the range of 3.6-21.72% w/w. E. officinalis contain the highest and E. littorale contain the lowest content of polyphenol among plant extracts analyzed. HPTLC fingerprinting showed that the in-house extracts were of better quality than marketed extracts. CONCLUSION: The results obtained from the study could be utilized for setting limits for the reference phytoconstituents (biomarker) for the quality control and quality assurance of these anti-diabetic drugs.