Screening of six Ayurvedic medicinal plants for anti-obesity potential: An investigation on bioactive constituents from Oroxylum indicum (L.) Kurz bark

Abstract

Ethnopharmacological relevanceAs an effort to identify newer anti-obesity lead(s) we have selected 13 plant materials from the six plant species which have been reported in Indian Ayurvedic medicine as remedy against complications affecting glucose and lipid homeostasis. Aim of the studyIn vitro screening of six Indian Ayurvedic medicinal plants on anti-adipogenic and pancreatic lipase (PL) inhibition potential followed by bioactivity guided isolation from most active plant material. Materials and methodsIn vitro anti-adipogenic assay using 3T3-L1 preadipocytes and pancreatic lipase (PL) inhibition assay were performed for hexanes, dichloromethane, ethyl acetate and methanolic extracts of all the plant materials. Bioactivity guided isolation approach was used to identify active constituent for anti-adipogenesis and PL inhibition assay. Inhibition of lipid accumulation and adipogenic transcription factor was measured by oil Red ‘O’ staining and quantitative real-time PCR method respectively. ResultsEthyl acetate extract of Oroxylum indicum bark was found to be most active in screening of anti-adipogenesis (59.12±1.66% lipid accumulation as compared to control at 50μg/mL dose) and PL inhibition (89.12±6.87% PL inhibition at 250μg/mL dose) assays. Further, three bioactive flavonoids were isolated and identified as oroxylin A, chrysin and baicalein from O. indicum bark. Oroxylin A, chrysin, and baicalein were inhibited lipid accumulation in 3T3-L1 preadipocytes (75.00±5.76%, 70.21±4.23% and 77.21±5.49% lipid accumulation respectively in comparison to control at 50μM dose) and PL enzyme (69.86±2.96%, 52.08±2.14% and 45.06±2.42% PL inhibition respectively at 250μg/mL dose). In addition, oroxylin A and chrysin also inhibited PPARγ and C/EBPα, major adipogenic transcription factors, in 3T3L-1 preadipocytes during adipogenesis process at 50μM dose. ConclusionThe present study augurs the anti-obesity potential of well practiced Ayurvedic herb O. indicum and its flavonoids.