Abstract
In two recent phytochemical studies [1,2], the flavonoides of
Pongamia pinnata
fruits were studied. Because of the broad structural and biological variation of
Pongamia
extracts [3–6], our study aimed at the isolation of flavonoids in the 70% aqueous methanol extract (AME) of
Pongamia pinnata
leaves and evaluation of its hypoglycaemic, anti-inflammatory, hepatoprotective and antioxidant activities. Successive column chromatographic separation has led to isolation of two new isoflavonoids, genistein 4'-
O
-methyl ether 7-
O
-β-D-rutinoside and 2',5'-dimethoxy-genistein 7-
O-
β-D-apiofuranosyl-(1'''→6“)-
O-
β-D-glucopyranoside and a new rotenoid, 12a-hydroxy-α-toxicarol, together with seven metabolites, vicenin-2, kaempferol 3-
O
-β-D-rutinoside, rutin, vitexin, isoquercitrin, kaempferol 3-
O-
β-D-glucopyranoside, 11,12a-dihydroxy-munduserone, kaempferol, and quercetin. The structures were established by UV, ESI-MS, 1D and 2D NMR [1–3,5,7]. As a conclusion for the biological studies on male Swiss Albino mice (18–20g) infected with Egyptian
Schistosoma mansoni
100±10
cercariae
/mouse [8] and rats (100–150g), it was found that the AME is non-toxic to mice (LD
50
up to 4g.Kg
-1
b.wt, the maximum soluble dose). At the two dose levels (100 and 200mg Kg
-1
b. wt.), it improved significantly the liver functions i.e reduced the elevated ALT and GGT serum levels in comparison with praziquantel and reduced the MDA and GSH levels in liver homogenate, in comparison with silymarin. Also, it showed significant hypoglycemic and anti-inflammatory activities at the dose levels of 50 and 200mg Kg
-1
b.wt, respectively. Moreover, a significant reduction of granuloma diameter and esenophilic counts was recorded through a histopathological investigation on treatment with AME (200mg Kg
-1
b. wt.), in comparison with mofebutazone.
References:
[1] Ahmed, G. et al. (2004). Phytochemistry 65: 921. [2] Yadav, P. P. et al. (2004). Phytochemistry 65: 439. [3] Sekine, T. et al. (1999). Phytochemistry 52: 87. [4] Ito, C. et al. (2004). Planta Med. 70: 585. [5] Laupattararakasem, P. et al. (2004). Planta Med. 70: 496.. [6] Ito, C. et al. (2004). J Ethnopharmacol. 105: 39. [7] Agrawal, P. K. (1989) Studies in organic chemistry 39,
13
C NMR of flavonoids. Elsevier science, New York, pp. 283–364. [8] Liang, Y.S. et al. (1987) Proceeding of the first Sino-American Symposium, 1: 34.