Some physical properties of tabletted seed of Garcinia kola (HECKEL).
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The formulation of Garcinia kola seeds into tablet dosage form and evaluation of some physical properties of the tablets are presented. A chemical assay was conducted on the dry, powdered seeds as well as the crude aqueous extract of the seeds. The dry powdered seeds contain 0.003% of flavonoids while the crude extract contained 0.007% of flavonoids based on rutin used as the standard. The powdered material (50 mg) and crude extract (10 mg) were formulated into tablets using the wet granulation method. Named binders were evaluated in these formulations. The various tablet parameters were evaluated, namely: weight variation, thickness and diameter, hardness, friability, disintegration time, dissolution profile and content uniformity. The results indicated that the tablets had good disintegration time, dissolution and hardness/friability profiles. Tablets formulated with starch had the best disintegration properties but were consequently very friable. Tablets formulated from 10 mg of the crude extract needed a larger proportion of diluents, which affected the tablet properties. (+info)
Complete NMR assignments of the antibacterial biflavonoid GB1 from Garcinia kola.
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From the antibacterial fraction of the roots of Garcinia kola, 3'',4',4''',5,5'',7,7''-heptahydroxy-3,8''-biflavanone (GB1) was isolated as the major constituent, whose interesting conformations were studied on the basis of its 1D and 2D NMR spectra obtained at different temperatures and in different solvents. GB1 showed antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) with MIC of 32 and 128 microg/ml, respectively. (+info)
Endothelium-independent vasodilation induced by kolaviron, a biflavonoid complex from Garcinia kola seeds, in rat superior mesenteric arteries.
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Previous studies have established the hepatoprotective, gastroprotective, hypolipidemic and hypoglycemic effects of kolaviron (KV), a biflavonoid complex from Garcinia kola seeds. In this study, we investigated the mechanisms involved in the vasorelaxant effects of KV in isolated superior mesenteric arteries from normotensive rats. KV (1, 10, 30, 100, 300, 500 and 1,000 microg/ml) concentration-dependently inhibited the contractions induced by phenylephrine (PHE) (10 microM) and KCl (80 mM) in both endothelium-intact (E(max) = 58.3 +/- 1.7% and 51.4 +/- 1.3%, respectively) and -denuded rings (E(max) = 59.3 +/- 5.5% and 64.3 +/- 2.4%, respectively). Furthermore, KV reduced CaCl(2)-induced contraction in Ca(2+)-free medium containing KCl 60 mM, thus acting as a Ca(2+)-antagonist. In addition, KV inhibited the transient contraction by PHE in Ca(2+)-free medium containing EGTA, suggesting a possible action on the release of intracellular Ca(2+) via the inositol-1,4,5-triphosphate (IP(3)) pathway. KV is not a specific alpha-adrenoceptor blocker, since it also caused a concentration-dependent inhibition of contractile responses to KCl, suggesting that KV also blocks the L-type Ca(2+)-channel. As a Ca(2+) antagonist, KV (100 microg/ml) potentiates the relaxant effects of nifedipine in denuded rings (E(max) = 97.6 +/- 1.2%; control = 75.1 +/- 3.0%, P<0.05). Also, the vasorelaxation induced by KV was significantly inhibited after pre-treatment of the denuded rings with 4-aminopyridine (4-AP) 1 mM, a selective blocker of voltage-dependent K(+) (K(v)) channels and, tetraethylammonium (TEA) 1 mM or charybdotoxin (ChTX) 0.1 microM, non-selective blockers of large and intermediate conductance Ca(2+)-activated K(+) (BK(Ca)) channels. In contrast, neither glibenclamide (10 microM), BaCl2 (1 mM) nor apamin (0.1 microM), blockers of K(ATP), K(IR) and SK(Ca) channels, respectively affected the KV-induced vasorelaxation. In conclusion, our results provide functional evidence that the vasorelaxant effects by KV involve extracellular Ca(2+) influx blockade, inhibition of intracellular Ca(2+) release and the opening of K(+) channels sensitive to 4-AP and ChTX with a resultant membrane hyperpolarization/ repolarization. (+info)
Biocidal activity of partially purified fractions from methanolic extract of Garcinia kola (Heckel) seeds on bacterial isolates.
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Protective effect of kolaviron, a biflavonoid from Garcinia kola seeds, in brain of Wistar albino rats exposed to gamma-radiation.
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This study was designed to evaluate the protective effect of kolaviron (KV), a biflavonoid from Garcinia kola seeds, against gamma-radiation (5 Gy)-induced oxidative stress in brain of Wistar rats. Vitamin C (VC) served as standard antioxidant. Forty-four rats were divided into 4 groups of 11 animals each. One group was un-irradiated (normal), two groups were treated with KV and VC (250 mg/kg) for 6 weeks prior to and 8 weeks after irradiation, and fourth group was only irradiated. Rats were sacrificed 1 and 8 weeks after irradiation. Cellular alterations were monitored using changes in the levels of malondialdehyde (MDA)-an index of lipid peroxidation, superoxide dismutase (SOD), glutathione-S-transferase (GST), reduced glutathione (GSH), catalase (CAT), alanine and aspartate aminotransferases (ALT and AST), urea and creatinine. MDA levels increased significantly (p<0.05) by 90% and 151% after 1 and 8 weeks of irradiation. Furthermore, levels of GSH and antioxidant enzymes were significantly (p<0.05) decreased in gamma-irradiated animals. GSH and GST decreased by 61% and 43% after 1 week, and by 75% and 74%, after 8 weeks of exposure, respectively. gamma-Irradiation decreased SOD and CAT levels by 53% and 68%, respectively, and caused significant (p<0.05) increases in serum ALT, AST and urea after 8 weeks of exposure. Treatment with KV and VC significantly decreased the levels of MDA, ALT, AST and urea. The antioxidant indices were significantly ameliorated in KV-treated animals. These data suggest that kolaviron may protect against gamma-radiation-induced oxidative stress in brain of exposed rats. (+info)
Identification and antibacterial evaluation of bioactive compounds from Garcinia kola (Heckel) seeds.
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Antidiabetic effect of kolaviron, a biflavonoid complex isolated from Garcinia kola seeds, in Wistar rats.
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BACKGROUND: Hypoglycaemic effect of kolaviron (KV), (biflavonoid from Garcinia kola) in streptozotocin (STZ)-diabetic rats has been established. OBJECTIVES: To evaluate the possible protective effects of KV on cardiac, renal and hepatic tissues of STZ-diabetic rats. METHODS: This study consists of four groups of 6 rats each. Groups one and two contained non-diabetic and untreated-diabetic rats, respectively. Groups three and four were made up of KV- and glibenclamide (GB) - treated diabetic rats, respectively. RESULTS: STZ-intoxication caused a significant (p<0.05) increase in the relative weight of liver in diabetic rats. STZ-diabetic rats had significant increase (p<0.05) in the levels of fasting blood glucose (FBG), a-amylase and HbA1c. A marked and significant (p<0.05) increase in the levels of cardiac, renal and liver marker indices such as serum creatine kinase, lactate dehydrogenase, creatinine, urea and alanine aminotransferase were observed in untreated diabetic rats. Also, untreated diabetic rats had significantly (p<0.05) elevated urinary glucose and protein and, lowered creatinine clearance. In KV- and GB- treated groups, the levels of FBG, a-amylase and HbA1c were significantly (p<0.05) reduced, while treatment with KV significantly (p<0.05) attenuated the cardiac, renal and liver marker indices. CONCLUSION: KV offered significant antidiabetic and tissues protective effects in the rats. (+info)