WHO prescribed shelf life assessment of Syzygium cumini extract through chromatographic and biological activity analyses

Background: Regulatory guidelines recommend shelf life of herbal products to be established throughsystematic stability studies.Objective: The study was designed to establish shelf life of Syzygium cumini extract through acceleratedand long-term stability testing as per WHO guidelines.Material and methods: The extract was stored under accelerated (40_x005F_x005F_x0001_C/75 %RH) and long-term (25_x005F_x005F_x0001_C/60%RH) stability conditions for 6 and 30 months, respectively. Samples were withdrawn at periodic intervals and analysed through two validated HPLC-UV methods (I and II) for fingerprint and quantitativeanalysis of markers. Antidiabetic activity of control and stability samples was evaluated by a-glucosidaseinhibitory model.Results: Method I generated a well resolved fingerprint of the control sample that was found to containgallic acid (GA, 1.45 % w/w) and ellagic acid (EA, 3.97 % w/w). The content of GA did not change underboth the stability conditions, but that of EA varied insignificantly (3.97e4.77 % w/w) under long-termconditions up to 24 months and subsequently decrease to 3.15 % w/w after 30 months. There was novisible change in LC-UV fingerprint of any stability sample with respect to control. a-Glucosidaseinhibitory activity of all stability samples also remained unaltered as compared to control sample (IC501.48 mg/mL). GA and EA did not elicit any activity at the concentrations present in the extract.Conclusion: Phytochemical composition and antidiabetic efficacy of S. cumini extract remain unchangedduring its storage under both accelerated and long-term stability conditions, which suggest its shelf lifeto be 30 months. Also, GA and EA are not appropriate anti-diabetic markers