Cyclohexenonic long-chain fatty alcohol has therapeutic effects on diabetes-induced angiopathy in the rat aorta

In vitro α-amylase and α-glucosidase Inhibition, Antioxidant, Anti- Inflammatory Activity and GC-MS Profiling of Avicennia alba Blume

BACKGROUND

Avicennia alba Blume, is a well-known mangrove plant used in traditional medicinal practices for several human ailments.

OBJECTIVE

The study aimed at the evaluation of antidiabetic, antioxidant, anti-inflammatory and cytotoxic activities of A. alba ethanolic leaf (AAL) and bark (AAB) extract along with phytochemical investigation.

METHODS

In vitro antidiabetic study was done by α-amylase, α-glucosidase enzyme inhibition assay; antioxidant study by DPPH, ABTS, superoxide, and metal chelating assays, antiinflammatory study by protein denaturation assay. The cytotoxicity study was done on TC1 murine cell line. Further, GC-MS analysis was carried out for AAL extracts.

RESULTS

AAL exhibited better antidiabetic activities with IC50 values of 1.18 and 0.87 mg/ml against α-amylase and α-glucosidase enzymes respectively. The AAL exhibited better ABTS, superoxide scavenging and metal chelating potential with IC50 values of 0.095, 0.127 and 0.444 mg/ml. However, AAB showed higher DPPH scavenging potential with IC50 value of 0.163 mg/ml. The AAL also exhibited higher protein denaturation potential with IC50 value of 0.370 mg/ml. The bark extract exhibited better cytotoxic activity as compared to leaf extracts on the TC1 murine cell line. The phytochemical study revealed higher total phenol (25.64 mg GAE/g), flavonoid (205.09 mg QE/g), and tannin content (251.17 mg GAE/g) in AAL. The GC-MS analysis revealed the presence of several compounds in AAL extract.

CONCLUSION

The result of the present study highlights the antidiabetic, antioxidant and cytotoxic activities of mangrove plant Avicennia alba.

Long-chain fatty alcohols from evening primrose oil inhibit the inflammatory response in murine peritoneal macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Evening primrose (Oenothera biennis L., Onagraceae) is a wild medicinal plant of Central American origin that is now one of the most widely used herbal medicines in different parts of the world. Oil extracted from it seeds is traditionally used in the treatment of eczema, asthma, rheumatoid arthritis, breast problem, premenstrual and menopausal syndrome, all they have an inflammatory component. The present study demonstrates the in vitro anti-inflammatory effect of long-chain fatty alcohols, minor compounds isolated from Evening primrose oil (EPO).

MATERIAL AND METHODS

A mixture of long chain fatty alcohols (LCFAs) was isolated from the non-triacylglycerol fraction of the EPO. Hexacosanol (C26OH: 38.65%), tetracosanol (C24OH: 31.59%), docosanol (C22OH: 11.36%) and octocosanol (C28OH: 7.64%), were the major constituents, identified and quantified by GC and GC-MS. LCFA was tested with LPS stimulated murine peritoneal macrophage. This fraction, significantly and dose-dependently decreased nitric oxide production induced by LPS (P<0.001) and the inhibitory effect seems to be consequence of an action at the level of the inducible nitric-oxide synthethase (iNOS) gene enzyme expression rather than to a direct inhibitory action on enzyme activity. The release of PLA2 and TXB2 also was significantly inhibited by LCFAs (P<0.001) although LCFAs did not affect to PGE2 generation, however the western blot assay showed that LCFAs reduced cyclooxygenase-2 enzyme gene expression at all doses assayed. In the same way, the secretion of inflammatory cytokines interleukin 1β (IL-1β) and tumour necrosis factor α (TNF-α) from LPS-stimulated murine macrophage, were also significantly reduced (P<0.001).

CONCLUSION

These results demonstrates the anti-inflammatory activity of LCFAs, providing an additional value about the role of bioactive minor compounds in the beneficial effect of EPO and supports its traditional uses in inflammatory processes management.

Fasudil improves the endothelial dysfunction in the aorta of spontaneously hypertensive rats

We investigated the effects of fasudil, a Rho kinase inhibitor, in the endothelial dysfunction of aortas from spontaneously hypertensive rats (SHRs). SHRs were divided in three groups; intraperitoneally (i.p.) vehicle-treated SHRs (SHR), SHRs treated with fasudil 3 mg/kg i.p. (Fas3), and SHRs treated with fasudil 10 mg/kg i.p. (Fas10). Vehicle-treated Wistar rats were used as normo-tensive control group. After a six-week-treatment, blood pressure and heart rate were measured by the tail cuff method. Afterwards animals were sacrificed and aortas were examined in vitro by organ bath studies to evaluate the contraction and relaxation ability. Rho kinase activity, myosin light chain (MLC), phosphorylated MLC (phospho-MLC), eNOS, phospho-eNOS protein expression and eNOS mRNA levels were evaluated. SHR demonstrated a significant hypercontractility and impaired relaxation compared to the control. Fasudil 10mg/kg significantly corrected the hypercontractility, restored the relaxation, and significantly decreased the mean arterial blood pressure, while no change observed in the systolic blood pressure. Rho kinase activity was significantly higher in the SHR, and was significantly inhibited by the high dose of fasudil. There was a slight up-regulation in the MLC, and phospho-MLC protein levels in the SHR. eNOS and phospho-eNOS protein levels were significantly lower in the SHR, and this abnormality was significantly normalized by fasudil treatment. No significant difference was observed in the eNOS gene expression. This study suggests that fasudil by inhibiting the Rho kinase activity normalizes the eNOS expression and phosphorylation and ameliorates the endothelial dysfunction induced by hypertension in the SHR model.

Edaravone ameliorates diabetes-induced dysfunction of NO-induced relaxation in corpus cavernosum smooth muscle in the rat

INTRODUCTION

Diabetes mellitus (DM) represents a major risk factor for erectile dysfunction (ED). Although the etiology of diabetes-induced ED is multifactorial and still unknown, reactive oxygen species are thought to be one of the key factors.

AIM

The aim of this article is to investigate whether administration of edaravone, a free radical scavenger, could prevent type 1 diabetes-induced dysfunction of nitric oxide (NO)-induced relaxation in corpus cavernosum smooth muscle in the rat.

METHODS

Six-week-old male Wistar rats were randomly divided into three groups. One group was treated with citrate-phosphate buffer plus normal saline (group Cont), whereas in the other two groups, diabetes was induced by streptozotocin (50 mg/kg intraperitoneally [i.p.]). Subsequently, the diabetic rats were treated for 4 weeks either with edaravone (10 mg/kg/day, i.p.; group DM + E) or with normal saline (group DM).

MAIN OUTCOME MEASURES

Serum glucose and malondialdehyde levels as well as penile cyclic guanosine monophosphate (cGMP) concentrations were determined, and penile function was estimated by organ bath studies with norepinephrine-mediated contractions and acetylcholine-mediated relaxations. The participation mRNA levels of muscarinic M(3) receptors, neuronal nitrous oxide synthase (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS), and participation protein levels of nNOS, eNOS, phosphorylated nNOS, and phosphorylated eNOS were investigated by quantitative real-time polymerase chain reaction (PCR) and immunoblot analysis, respectively.

RESULTS

Treatment with edaravone prevented partially but significantly the decreased body and penile weight induced by diabetes. Treatment with edaravone significantly improved the increased diabetes-induced malondialdehyde levels, the decreased penile cGMP concentrations, the increased diabetes-induced norepinephrine-mediated contractions, and the decreased acetylcholine-mediated relaxation. Although there were no significant differences in expression levels of mRNAs in nNOS, diabetes-induced upregulation of muscarinic M(3) receptor and iNOS mRNAs as well as diabetes-induced downregulations of eNOS, phosphorylated nNOS, and phosphorylated eNOS were significantly prevented by edaravone.

CONCLUSIONS

Edaravone decreases the oxidative insult in the penile corpus cavernosum by ameliorating the NO-NOS system and thus preventing partially the developing ED in DM in the rat.

Effects of cyclohexenonic long-chain fatty alcohol in type 2 diabetic rat nephropathy

We attempted to clarify the effects of cyclohexenonic long-chain fatty alcohol (CHLFA) on the alterations of type 2 diabetes-induced nephropathy. Forty-week-old male Goto-Kakizaki (GK) and Wistar rats were divided into four groups of 6 to 8 animals. Group A consisted of eight Wistar rats and served as an age-matched control group. Group B (7 GK rats) received no treatment and served as a diabetic group. Group C (6 GK rats) was treated daily with low-dose CHLFA (2 mg/ kg/body weight, subcutaneously) for 30 weeks, and Group D (6 GK rats) with high-dose CHLFA (8 mg/kg/body weight) for 30 weeks. At the end of the treatment period, urinary protein excretion, blood chemistry, renal histological, and immunohistological analyses were conducted. Although CHLFA administration did not influence serum glucose or insulin levels, it reversed diabetes-induced increases in urinary protein excretion and serum creatinine. Light microscopically, CHLFA treatment ameliorated the otherwise elevated glomerular sclerotic scores in the diabetic group.Immunohistochemically, increased expression of desmin and decreased expression of rat endothelial cell antigen-1 in the group with untreated diabetes both showed a reversal to control levels in the high-dose CHLFA treatment group. In conclusion, CHLFA may ameliorate type 2 diabetes-induced nephropathy.

Reactive oxygen-derived free radicals are key to the endothelial dysfunction of diabetes

Vascular complications are an important pathological issue in diabetes that lead to the further functional deterioration of several organs. The balance between endothelium-dependent relaxing factors and endothelium-dependent contracting factors (EDCFs) is crucial in controlling local vascular tone and function under normal conditions. Diabetic endothelial dysfunction is characterized by reduced endothelium-dependent relaxations and/or enhanced endothelium-dependent contractions. Elevated levels of oxygen-derived free radicals are the initial source of endothelial dysfunction in diabetes. Oxygen-derived free radicals not only reduce nitric oxide bioavailability, but also facilitate the production and/or action of EDCFs. Thus, the endothelial balance tips towards vasoconstrictor responses over the course of diabetes.