Evaluation of anti-diabetic and anti-allergic activities of brownlowia tersa (L.) kosterm leaves extract and determination of its phenolic compounds by HPLC-DAD

Abstract

Brownlowia tersa (L.), family Malvaceae, a shrub from Sundarbans (the largest Mangrove Forest of the World) has been traditionally used by the surrounding peoples for different ailments like inflammation, pain, diarrhea, allergy, etc. In this study, we investigated the anti-diabetic and anti-allergic activities of ethanol leaves extract of this plant. Oral glucose tolerance test (OGTT) was used to screen the anti-hyperglycemic activity. Streptozotocin (STZ)-induced diabetic mice were used to investigate the anti-diabetic activity. Anti-allergic activity was checked by using Toluene 2,4-diisocyanate (TDI)-induced allergic mice model by assessing allergic symptoms and WBC counts. HPLC-DAD analysis was used to detect the selected phenolic compounds. In OGTT, the extract showed a significant anti-hyperglycemic activity at 300 and 500 mg/kg doses in glucose loaded mice. In STZ-induced diabetic mice, the extract at both doses significantly reduced the blood and urine glucose levels. In addition, biochemical parameters such as serum glutamic-pyruvic transaminase (SGPT), serum glutamic-oxaloacetic transaminase (SGOT), creatinine, bilirubin, urea, and triglycerides levels were also decreased. The extract at 300 and 500 mg/kg doses also significantly reduced the TDI induced allergic symptoms like sneezing (P < 0.05), scratching (P < 0.05) and nasal score (P < 0.05) and blood WBC counts. HPLC analysis revealed the presence of ten phenolic compounds which might be responsible for the reported activities in this study.