Gossypin

Gossypin protects primary cultured rat cortical cells from oxidative stress- and beta-amyloid-induced toxicity.[Pubmed:15180313]

Arch Pharm Res. 2004 Apr;27(4):454-9.

The present study investigated the effects of Gossypin, 3,3',4',5,7,8-hexahydroxyflavone 8-glucoside, on the toxicity induced by oxidative stress or beta-amyloid (Abeta) in primary cultured rat cortical cells. The antioxidant properties of Gossypin were also evaluated by cell-free assays. Gossypin was found to inhibit the oxidative neuronal damage induced by xanthine/xanthine oxidase or by a glutathione depleting agent, D,L-buthionine (S,R)-sulfoximine. In addition, Gossypin significantly attenuated the neurotoxicity induced by Abeta(25-35). Furthermore, Gossypin dramatically inhibited lipid peroxidation initiated by Fe2+ and ascorbic acid in rat brain homogenates. It also exhibited potent radical scavenging activity generated from 1,1-diphenyl-2-picrylhydrazyl. These results indicate that Gossypin exerts neuroprotective effects in the cultured cortical cells by inhibiting oxidative stress- and Abeta-induced toxicity, and that the antioxidant properties of Gossypin may contribute to its neuroprotective actions.

Evaluation of anti-allergic activity of gossypin and suramin in mast cell-mediated allergy model.[Pubmed:20521621]

Indian J Biochem Biophys. 2010 Apr;47(2):90-5.

The mast cell-mediated allergic reactions are involved in many allergic diseases, such as asthma, allergic rhinitis and sinusitis. Stimulation of mast cells initiates the process of degranulation, resulting in the release of mediators such as histamine and an array of inflammatory cytokines. In this report, we investigated the effect of Gossypin (a biflavonoid) and suramin (a synthetic polysulphonated naphtylurea) on the mast cell-mediated allergy model, and studied the possible mechanism of their action. Both Gossypin and suramin inhibited (P<0.001) compound 48/80-induced systemic anaphylaxis reactions, antiprurities (P<0.001) and reduced the histamine release in rats. Further, both showed significant (P<0.001) protection against rat peritoneal mast cells activated by compound 48/80. Thus, our findings provide evidence that Gossypin and suramin inhibit mast cell-derived allergic reactions.

Gossypin, a pentahydroxy glucosyl flavone, inhibits the transforming growth factor beta-activated kinase-1-mediated NF-kappaB activation pathway, leading to potentiation of apoptosis, suppression of invasion, and abrogation of osteoclastogenesis.[Pubmed:17332240]

Blood. 2007 Jun 15;109(12):5112-21.

Gossypin, a flavone originally isolated from Hibiscus vitifolius, has been shown to suppress angiogenesis, inflammation, and carcinogenesis. The mechanisms of these activities, however, are unknown. Because nuclear factor-kappaB (NF-kappaB) is associated with inflammation, carcinogenesis, hyperproliferation, invasion, and angiogenesis, we hypothesized that Gossypin mediates its effects through modulation of NF-kappaB activation. In the present study, we demonstrate that Gossypin (and not gossypetin, an aglycone analog) inhibited NF-kappaB activation induced by inflammatory stimuli and carcinogens. Constitutive NF-kappaB activation in tumor cells was also inhibited by this flavone. Inhibition of I kappa B alpha kinase by Gossypin led to the suppression of I kappa B alpha phosphorylation and degradation, p65 nuclear translocation, and NF-kappaB-regulated gene expression. This, in turn, led to the down-regulation of gene products involved in cell survival (IAP2, XIAP, Bcl-2, Bcl-xL, survivin, and antiFas-associated death domain-like interleukin-1 beta-converting enzyme-inhibitory protein), proliferation (c-myc, cyclin D1, and cyclooxygenase-2), angiogenesis (vascular endothelial growth factor), and invasion (matrix metalloprotease-9). Suppression of these gene products by Gossypin enhanced apoptosis induced by tumor necrosis factor and chemotherapeutic agents, suppressed tumor necrosis factor-induced cellular invasion, abrogated receptor activator of NF-kappaB ligand-induced osteoclastogenesis, and vascular endothelial growth factor-induced migration of human umbilical vein endothelial cells. Overall, our results demonstrate that Gossypin inhibits the NF-kappaB activation pathway, which may explain its role in the suppression of inflammation, carcinogenesis, and angiogenesis.

Ameliorative effect of gossypin against gentamicin-induced nephrotoxicity in rats.[Pubmed:28302561]

Life Sci. 2017 May 1;176:75-81.

AIM: Gentamicin (GEN) is an aminoglycoside antibiotic employed in treatment of life-threatening gram-negative infections, but one of its major side effects is the induction of nephrotoxicity. Therefore, the aim of this work was to scrutinize the possible protective effect of Gossypin against GEN-induced nephrotoxicity. METHOD: Rats were randomly divided into four groups. First group served as a control, second group was injected with Gossypin (10mg/kg, orally) for 7days, third group was injected with GEN (80mg/kg, i.p.) and the fourth group was co-treated with GEN and Gossypin for 7days. KEY FINDING: GEN-treated group showed kidney dysfunction as proteinuria excretion rate, podocalyxin excretion rates, renal monocyte chemoattractant protein-1 (MCP-1), blood urea nitrogen (BUN) and plasma creatinine were significantly increased as well as tubular degeneration occur. The significant decrease in renal reduced glutathione (GSH) level, superoxide dismutase (SOD) and catalase (CAT) activities and an increase in thiobarbituric acid reactive substances (TBARs) level, indicated that GEN-induced nephrotoxicity through oxidative stress reactions. Also, GEN up-regulated both gene expression and renal levels of inflammatory cytokines TNF-alpha and IL-6. On the other hand, concurrent treatment of Gossypin plus GEN protected kidney tissues against nephrotoxic effects of GEN through elevated levels of renal GSH, SOD and CAT activities while decreased in renal TBARs level. In addition, Gossypin down-regulated gene expression and renal levels of inflammatory cytokines TNF-alpha and IL-6 induced by GEN. SIGNIFICANCE: This study revealed that Gossypin exerts protection against nephrotoxicity induced by gentamicin via its antioxidant activity.

Gossypin up-regulates LDL receptor through activation of ERK pathway: a signaling mechanism for the hypocholesterolemic effect.[Pubmed:19007237]

J Agric Food Chem. 2008 Dec 10;56(23):11526-32.

Hypercholesterolemia is one of the major risk factors for the development of cardiovascular disease. This study aims to elucidate the effect of Gossypin on cholesterol metabolism in HepG2 cells. Results indicated that Gossypin significantly reduced the total cholesterol concentration in a dose-dependent manner. There was a time- and dose-dependent increase in the expression of low-density lipoprotein receptor (LDLR) protein. However, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in cholesterol synthesis, was not affected by Gossypin. Moreover, Gossypin had no effect on nuclear sterol regulatory element binding proteins (SREBP)-2 abundance. The activity of Gossypin on LDLR expression was inhibited by the extracellular signal-regulated kinase (ERK) inhibitor PD98059. Western blotting analysis revealed that Gossypin treatment dose- and time-dependently increased ERK activation and preceded the up-regulation of LDLR expression. Collectively, these new findings identify Gossypin as a new hypocholesterolemic agent that up-regulates LDLR expression independent of SREBP-2 but is dependent on ERK activation.

Antidiabetic activity of gossypin, a pentahydroxyflavone glucoside, in streptozotocin-induced experimental diabetes in rats.[Pubmed:21722326]

J Diabetes. 2012 Mar;4(1):41-6.

BACKGROUND: Most of the currently available oral hypoglycemic drugs for the treatment of diabetes mellitus elicit detrimental side effects. Hence, the search for plant-derived products for the treatment of diabetes continues. Gossypin, a pentahydroxy flavone glucoside found in the flowers of Hibiscus vitifolius, has many biological properties, including as an antioxidant, anti-inflammatory and anticancer agent. The aim of the present study was to evaluate the effect of Gossypin in streptozotocin (STZ)-induced experimental diabetes in rats. METHODS: Diabetic rats were administered 20 mg/kg per day Gossypin orally for 30 days. On the 28th day, rats were subjected to an oral glucose tolerance test. In addition, blood glucose, plasma insulin, hemoglobin, and HbA1c levels were determined, as was the glycogen content of the liver and muscles. Plasma protein and blood urea were also estimated. RESULTS: Oral administration of Gossypin to diabetic rats resulted in improved glucose tolerance. Increased blood glucose and HbA1c levels and the reduced plasma insulin and hemoglobin levels in diabetic rats were significantly reversed to near normal after oral administration of Gossypin. Furthermore, the glycogen content of the liver and muscles was significantly improved after Gossypin treatment of diabetic rats, and plasma protein and blood urea levels were almost normalized. The data obtained in Gossypin-treated rats were comparable with those obtained following gliclazide treatment of rats, a standard reference drug for diabetes. CONCLUSIONS: The results of the present study indicate that Gossypin has potent antidiabetic activity in STZ-induced experimental diabetes in rats.

Antiinflammatory and antinociceptive activities of gossypin and procumbentin--cyclooxygenase-2 (COX-2) inhibition studies.[Pubmed:19107863]

Phytother Res. 2009 Jun;23(6):878-84.

In the present study the antiinflammatory and antinociceptive activities of a few selected flavonoids were investigated. Procumbentin, Gossypin, chrysin and methylhespiridin were studied for antiinflammatory and antinociceptive activities using in vitro enzymatic assays and in animal models utilizing acetic acid-induced writhing in mice and hind paw edema in rats. In vitro studies were performed using TMPD (NNN'N'-tetramethyl-p-phenylene diamine) and oxygraphic methods for COX-1 (cyclooxygenase-1), COX-2, 5-LOX (5-lipoxygenase) and 15-LOX. Gossypin and procumbentin showed COX-2 inhibitory activity and exhibited IC(50) (COX-2/COX-1) ratios of 0.14 and 0.11, respectively. None of the flavonoids tested in this study showed LOX inhibitory activity. Four groups were studied for each test compound following intraperitoneal (i.p.) administration of doses of 10, 30 and 100 mg/kg. Antiinflammatory activity was measured by the carrageenin-induced rat hind paw edema model and antinociceptive activity by acetic acid-induced writhing. Procumbentin and Gossypin showed antinociceptive activity at the 100 mg/kg dose. Gossypin showed antiinflammatory activity at doses of 10, 30, 100 mg/kg. Procumbentin and Gossypin exhibited COX-2 inhibitory activity when tested by in vitro methods. Procumbentin and Gossypin showed antinociceptive, and Gossypin showed antiinflammatory, activities.