Oral administration of aqueous extract of Avicennia marina leaves (ALE) is known to reduce serum blood glucose level and improve organ functions in diabetic models of rats. The anti αamylase property of crude ALEagainst human salivary amylase (HSA) has been investigated in this work as it can be the possible reason behind the abovesaid hypoglycemic effect. TheALE was found to inhibit ~90% of HSA, comparable to standard blockers while the inhibition was only ~45% against fungal diastase (FD). Known α-amylase blocker quercetin, found in ALE through GCMS, inhibits HSA and FD 91% and 42% respectively. Blind molecular docking showed that quercetin binds to HSA in the same pocket as miglitol whereas it interacts differently with FD.