Antioxidant, carbonic anhydrase inhibition and diuretic activity of Leptadenia pyrotechnica Forssk. Decne

BACKGROUND: Leptadenia pyrotechnica Forssk. Decne is a member of family Apocynaceae and locally known as 'Khipp'. It is found in dry, sandy habitat of Pakistan and in several other regions around the world including Asia, Tropical Africa, Western Gulf and Mediterranean countries. It has nutritional value, containing 4 % lipids, 23 % proteins, 28 % carbohydrates, 4 % fibers, vitamin E and several minerals. Traditionally, this plant has been used by several communities for pain, different inflammatory and kidney disorders. Ethno-botanical studies have reported the use of L. pyrotechnica in nephrolithiasis, kidney disorders and induction of diuresis, which requires a detailed pharmacological study to validate the folkloric use of L. pyrotechnica as diuretic.

METHODS: The 70 % methanolic L. pyrotechnica (Lp.Cr) extract was prepared and qualitatively checked for the presence of various phytochemicals. Phenolic, flavonoid, tannin and saponin contents were quantified. GC-MS analysis of Lp.Cr was also performed. Antioxidant potential of Lp.Cr was evaluated by DPPH, ABTS and nitrite radical scavenging assays. CUPRAC and FRAP assay described the reducing potential of Lp.Cr. Diuretic activity was performed in both acute and prolonged models at different doses followed by the estimation of electrolytes, urea and creatinine levels. The mechanism of diuresis was described by pre-treatment with atropine, l-NAME, indomethacin and carbonic anhydrase inhibition.

RESULTS: Lp.Cr. indicated high phenolic and flavonoid contents which correlated with good antioxidant activity. GC-MS analysis showed the presence of 104 compounds from different phytochemical classes. Diuretic activity was performed at 10-300 mg/kg concentrations where the dose of 100 and 300 mg/kg showed good diuretic and saluretic activity comparable to furosemide. Lp.Cr exhibited diuresis both in acute and prolonged study protocols which can be attributed to carbonic anhydrase inhibition, effect on prostaglandins and cholinergic pathways.

CONCLUSION: L. pyrotechnica contained several phytochemicals and exhibited good antioxidant activity. It induced diuresis and saluretic activity which was comparable to furosemide at higher doses. Diuretic activity can be attributed to carbonic anhydrase inhibition, prostaglandin synthesis and cholinergic pathways.