Induction of Biologically Active Flavonoids in Cell Cultures of Morus nigra and Testing their Hypoglycemic Efficacy.

The antidiabetic activity of both leaves and MJ-treated cell cultures of Morus nigra was evaluated after their oral administration to streptozotocin-induced diabetic rats. The antidiabetic activity of extracts from leaves given to streptozotocin (STZ)-diabetic rats for 10 days increased with increasing doses of leaves extract up to 500 mg/kg/day. The administration of 500 mg/kg/day of leaves extract reduced the concentration of glucose from 370 ± 7.31 mg/dl (control) to 154 ± 6.27 mg/dl, and a significant increase in the insulin level from 11.3 ± 0.31 µU/ml (control) to 14.6 ± 0.43 µU/ml was recorded. Cell suspension cultures were established from the young leaves of Morus nigra cultivated on modified MS medium supplemented with 2.0 mg/l 1-naphthaleneacetic acid (NAA), 0.2 mg/l 6-(furfurylamino)purine (kinetin). The changes in cell weight and flavonoid content were monitored between day zero and 12. The linear increase in fresh weight was found to be parallel to flavonoids production. Cell cultures treated with 100 µM methyl jasmonate for 24 hours showed a noticeable increase in level of flavonoids and significant and more effective hypoglycemic activity than that for extract from leaves. The major flavonoids were isolated by TLC and HPLC and identified as rutin, quercetin, Morusin and cyclomorusin by co-chromatography and mass spectrometry in comparison to samples of authentic reference compounds.

Effects of Gum acacia aqueous extract on the histology of the intestine and enzymes of both the intestine and the pancreas of albino rats treated with Meloxicam.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) cause gastrointestinal damage both in the upper and lower gastrointestinal tract, in addition to their undesirable side effects on the pancreas. Meloxicam like all NSAIDs has damaging effects on the gastrointestinal tract including perforations, ulcers and bleeding. OBJECTIVE: The present work describes the effects of Gum acacia aqueous extract on the histology of intestine and enzymes of both intestine and Pancreas of albino rats treated with Meloxicam. MATERIALS AND METHODS: This study was performed on four groups of equally weighed male rats, each group included ten animals; the first group was received a diet containing 0.2 mg/kg bw meloxicam per day; the second was given 1gm Gum acacia per day in its diet; the third was given meloxicam followed by gum in the same doses per day; while the fourth group (control rats) was placed on a normal diet and water. All rats were received their diet for a period of 21 days. RESULTS: A considerable protective effect of Gum acacia aqueous extract on the histology of intestine of albino rats treated with meloxicam was recorded. In addition, the study displayed a significant increase (P < 0.001) in the intestinal enzymes; lipase, amylase, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in the 1(st) and 3(rd) groups animals while these enzymes were significantly decreased (P < 0.001) in the 2(nd) group when compared with the 4(th) control group. CONCLUSION: This study concluded that Gum acacia provides a protection and defense against the harmful effects of meloxicam therapy used as one of the novel anti-Cox-1 and Cox-2 NSAIDs.

Cardiac glycosides from shoot cultures of Cryptostegia grandiflora.

Cardiac glycosides in shoot cultures of Cryptostegia grandiflora were identified when grown in modified MS medium. The change in shoot segments and cardiac glycosides content was followed between day zero and day 12 at 2-day intervals. The content of cardiac glycosides in leaves and shoot cultures of Cryptostegia grandiflora was monitored by HPLC. Two major compounds were detected and isolated from shoot cultures extract, named oleandrigenin 3-O-ß - glucopyranosyl-(1→4) - ß-cymaropyranosyl-(1→4)-ß-digitoxopyranoside (cryptostigmin I) and oleandrigenin 3-O-ß - glucopyranosyl-(1→4)-α-rhamnopyranoside (cryptostigmin II). The structures of the isolated compounds were verified by means of MS and NMR spectral analysis, as well as by comparison with authentic samples. The leaves and shoot cultures were analyzed for their cardiac glycosides content. The shoot cultures inoculated into MS-based culture media supplemented with 0.1 mg L(-1) BA, 30 g L(-1) sucrose, 0.1 g L(-1)myo-inositol and 0.1 g L(-1) ascorbic acid were found to contain a quantity of cardiac glycosides that was about four fold the cardiac glycosides content of leaves extract.

Benzoic acid biosynthesis in cell cultures of Hypericum androsaemum.

Biosynthesis of benzoic acid from cinnamic acid has been studied in cell cultures of Hypericum androsaemum L. The mechanism underlying side-chain shortening is CoA-dependent and non-beta-oxidative. The enzymes involved are cinnamate:CoA ligase, cinnamoyl-CoA hydratase/lyase and benzaldehyde dehydrogenase. Cinnamate:CoA ligase was separated from benzoate:CoA ligase and 4-coumarate:CoA ligase, which belong to xanthone biosynthesis and general phenylpropanoid metabolism, respectively. Cinnamoyl-CoA hydratase/lyase catalyzes hydration and cleavage of cinnamoyl-CoA to benzaldehyde and acetyl-CoA. Benzaldehyde dehydrogenase finally supplies benzoic acid. In cell cultures of H. androsaemum, benzoic acid is a precursor of xanthones, which accumulate during cell culture growth and after methyl jasmonate treatment. Both the constitutive and the induced accumulations of xanthones were preceded by increases in the activities of all benzoic acid biosynthetic enzymes. Similar changes in activity were observed for phenylalanine ammonia-lyase and the xanthone biosynthetic enzymes benzoate:CoA ligase and benzophenone synthase.