In Vivo Hepatoprotective and Nephroprotective Activity of Acylated Iridoid Glycosides from Scrophularia hepericifolia

Abstract

Phytochemical investigation of the chloroform fraction obtained from Scrophularia hypericifolia aerial parts led to the isolation of nine acylated iridoid glycosides. The new compounds were identified as 6-O-α-L(2″-acetyl, 3″,4″-di-O-trans-cinnamoyl) rhamnopyranosyl-6'-acetyl catalpol (6'-acetyl hypericifolin A) (1), 6-O-α-L(2″, 4″-diacetyl, 3″-O-trans-cinnamoyl) rhamnopyranosyl-6'-acetyl catalpol (6'-acetyl hypericifolin B) (2), 6-O-α-L(2″-acetyl, 3″,4″-di-O-trans-cinnamoyl) rhamnopyranosyl catalpol (hypericifolin A) (3) and 6-O-α-L(2″, 4″-diacetyl, 3″-O-trans-cinnamoyl) rhamnopyranosyl catalpol (hypericifolin B) (4). Previously reported compounds were identified as laterioside (5), 8-O-acetylharpagide (6), 6-O-α-L(4'-O-trans-cinnamoyl) rhamnopyranosyl catalpol (7), lagotisoside D (8) and harpagoside (9). Identification achieved via analyses of physical and spectral data including 1D, 2D NMR and High Resolution Electrospray Ionization Mass spectroscopy (HRESIMS). Compounds 2-4 and 6 were subjected to biological evaluation against paracetamol-induced toxicity. The biochemical parameters aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and gamma glutamyl transpeptidase (GGT) as well as total bilirubin were used to access the liver condition. Measurement of serum levels of urea, creatinine, sodium and potassium cations were indicators for kidney condition. Liver and kidney samples were subjected to histopathological study. The best protection was found in the group treated with 3 followed by 4 and 6, while 2 was almost inactive.

Keywords: Scrophularia hypericifolia; acylate iridoid glycoside; hepatoprotective; nephroprotective.

Figure 1

Structures of the isolated compounds (1–9).

Figure 2

Effect of compounds 2–4, 6 on liver serum biochemical parameters AST, ALT, GGT, APL and bilirubin (% reduction).

Figure 3

Effect of compounds 2–4, 6 on liver (A) and kidney (B) TP.

Figure 4

Effect of compounds 2–4, 6 on liver and kidney NP-SH.

Figure 5

Light microscope pictures of liver tissues: (A) Liver cells of normal control group showing central vein, normal sinusoids and cells. (B) Liver cells of Pa-treated group showing hydropic swelling, rosette formation, portal dilated congested vessels, focal necrosis, lymphocytic infiltrate and lymphocytic exudate. (C) Liver cells of Pa- and Sil-treated group showing mostly normal cells with mild congestion in the central venules. (D) Liver cells of group treated with 3 showing almost normal lobules and portal tract with the absence of degeneration and vein congestion. (E) Liver cells of group treated with 4 showing mild focal necrosis and portal tract congestion. (F) Liver cells of group treated with 6 showing moderate to high degree of degeneration, portal congestion and inflammatory cell infiltration.

Figure 6

Effect of compounds 2–4, 6 on kidney serum biochemical parameters (% reduction).

Figure 7

Light microscope pictures of kidney cells: (A) Normal cells. (B) Kidney cells of Pa-treated group showing abnormal cellular structures with degenerated corpuscle, reduced size of glomeruli, shrinkage of Bowman capsule, cloudy swelling in tubules and inflammatory infiltrate. (C) Kidney cells of rats treated with Pa and Sil showing no marked changes, nearly normal glomeruli and mild cloudy swelling in tubules. (D) Kidney cells of group treated with 3 showing moderate cortical atrophy and reduced size of glomeruli. (E) Kidney cells of group treated with 4 showing kidney cortical congestion, abnormal glomeruli (reduced in size) and cloudy swelling in tubules. (F) Kidney cells of group treated with 6 showing inflammatory cell infiltration at corticomedullary junction, kidney cortical infiltration, almost complete absence of Bowman space, degenerated and convoluted necrotic tubules.