Inhibitory effect of tannic acid and its derivative (gallic acid) against cisplatin–induced thiobarbituric acid reactive substances (TBARS) production in rat kidney – in vitro

Increasing amounts of evidence suggests tannic acid (TA) and its derivative, gallic acid (GA) has beneficial effects against nephrotoxicity. The aim of this study was to investigate the effect of TA and GA (two structurally related phenolic acids) against cisplatin-induced thiobarbituric acid reactive substances (TBARS) production in rat kidney in vitro. The effect of both phenolic acids on kidney TBARS level in the presence of cisplatin, an antineoplastic drug used in the treatment of many solid-tissue cancers which has its chief side effect in nephrotoxicity, was assessed. Thereafter, the antioxidant properties were also determined. Incubation of the kidney tissue homogenate in the presence of cisplatin (1 mM) caused a significant (P<0.05) increase in the TBARS level. However, both phenolic acids caused a significant (P<0.05) decrease in the TBARS content of the kidney in a dose dependent manner (0 – 12.5 µM). Nevertheless, TA had a significantly higher (P<0.05) inhibitory effect on TBARS production than gallic acid judging by their IC50 value. Furthermore, TA possesses stronger antioxidant properties than GA as revealed by their scavenging, chelating and reducing ability. The inhibition of cisplatin–induced thiobarbituric acid reactive substances (TBARS) production in rat kidney by both TA and GA could be due to their antioxidant properties and this provide further insight into the mechanism of action for their nephroprotective properties from previous reported experimental studies. However, the study revealed that hydrolysis of TA reduces its potenc

Proliferaton index in pituitary adenomas from a black African population

Background: The WHO has recognized a variant of pituitary adenomas with potential aggressive behaviour which have been termed atypical pituitary adenomas. This group of tumours are recognized by their mitotic rate of more than &gt;3%, p53 expression and invasion of surrounding structures. There has however been no study of the occurrence of these tumours in a black African population. This study is a preliminary attempt to examine this group of tumours in blacks.Methods: This study retrospectively reviewed fifty-seven histologically diagnosed and immunohistochemically characterized pituitary adenomas received in our department over a twenty-one year period. Specimens were stained with ki67, a nuclear marker of cell proliferation which has been identified as the single best predictor of atypical pituitary adenoma.Results: Twelve of the tumours showed atypical features with eight (67%) of these tumours being prolactinomas. Two of the tumours were gonadotrophs and two were null cell adenomas. There was no correlation with age or gender. Two of the tumours required neurosurgical re-exploration with one of these showing a higher mitotic index in the second biopsy.Conclusion: The study suggests similarity in the rate of occurrence of pituitary adenomas with atypical features in a black African population with what is seen in Caucasians. Prolactinomas constitute a significant percentage of the tumours with this feature.Keywords: Pituitary adenoma, Immunohistochemistry, Atypical, Ki6

Coffee, caffeine, chlorogenic acid, and the purinergic system

Coffee is a drink prepared from roasted coffee beans and is lauded for its aroma and flavour. It is the third most popular beverage in the world. This beverage is known by its stimulant effect associated with the presence of methylxanthines. Caffeine, a purine-like molecule (1,3,7 trymetylxantine), is the most important bioactive compound in coffee, among others such as chlorogenic acid (CGA), diterpenes, and trigonelline. CGA is a phenolic acid with biological properties as antioxidant, anti-inflammatory, neuroprotector, hypolipidemic, and hypoglicemic. Purinergic system plays a key role inneuromodulation and homeostasis. Extracellular ATP, other nucleotides and adenosine are signalling molecules that act through their specific receptors, namely purinoceptors, P1 for nucleosides and P2 for nucleotides. They regulate many pathological processes, since adenosine, for instance, can limit the damage caused by ATP in the excitotoxicity from the neuronal cells. The primary purpose of this review is to discuss the effects of coffee, caffeine, and CGA on the purinergic system. This review focuses on the relationship/interplay between coffee, caffeine, CGA, and adenosine, and their effects on ectonucleotidases activities as well as on the modulation of P1 and P2 receptors from central nervous system and also in peripheral tissue

Inhibitory effect of tannic acid and its derivative (gallic acid) against cisplatin–induced thiobarbituric acid reactive substances(TBARS)production in rat kidney –in vitro

Increasing amounts of evidence suggests tannic acid (TA) and its derivative, gallic acid (GA) has beneficial effects against nephrotoxicity. The aim of this study was to investigate the effectof TA and GA (two structurally related phenolic acids)against cisplatin-induced thiobarbituric acid reactive substances(TBARS) production in rat kidney in vitro. The effect of both phenolic acids on kidney TBARS level in the presence of cisplatin, an anti-neoplastic drug used in the treatment of many solid-tissue cancers which has its chief side effect in nephrotoxicity, was assessed. Thereafter, the antioxidant properties were also determined. Incubation of the kidney tissue homogenate in the presence of cisplatin (1 mM) caused a significant (P<0.05) increase in the TBARS level. However, both phenolic acids caused a significant (P<0.05) decrease in the TBARS content of the kidney in a dose dependent manner (0 –12.5 μM). Nevertheless, TA had a significantly higher (P<0.05) inhibitory effect on TBARS production than gallic acid judging by their IC50value.Furthermore, TA possesses stronger antioxidant properties than GA as revealed by their scavenging, chelating and reducing ability.The inhibition of cisplatin–induced thiobarbituric acid reactive substances(TBARS)production in rat kidney by both TA and GA could be due to their antioxidant properties and this provide further insight into the mechanism of action for their nephroprotective properties from previous reported experimental studies.However, the study revealed that hydrolysis of TA reduces its potenc

Cyperus esculentus L. and Tetracarpidium conophorum Müll. Arg. Supplemented Diet Improved Testosterone Levels, Modulated Ectonucleotidases and Adenosine Deaminase Activities in Platelets from L-NAME-Stressed Rats

In hypertensive individuals, platelet morphology and function have been discovered to be altered, and this has been linked to the development of vascular disease, including erectile dysfunction (ED). The impact of nutritional supplementation with Cyperus esculentus (tiger nut, TN) and Tetracarpidium conophorum (walnut, WN) on androgen levels, ectonucleotidases, and adenosine deaminase (ADA) activities in platelets from L-NAME (Nω-nitro-L-arginine methyl ester hydrochloride) challenged rats were investigated. We hypothesized that these nuts may show a protective effect on platelets aggregation and possibly enhance the sex hormones, thereby reverting vasoconstriction. Wistar rats (male; 250–300 g; n = 10) were grouped into seven groups as follows: basal diet control group (I); basal diet/L-NAME/Viagra (5 mg/kg/day) as positive control group (II); ED-induced group (basal diet/L-NAME) (III); diet supplemented processed TN (20%)/L-NAME (IV); diet supplemented raw TN (20%)/L-NAME (V); diet supplemented processed WN (20%)/L-NAME (VI); and diet supplemented raw WN (20%)/L-NAME (VII). The rats were given their regular diet for 2 weeks prior to actually receiving L-NAME (40 mg/kg/day) for ten days to induce hypertension. Platelet androgen levels, ectonucleotidases, and ADA were all measured. L-NAME considerably lowers testosterone levels (54.5 ± 2.2; p &lt; 0.05). Supplementing the TN and WN diets revealed improved testosterone levels as compared to the control (306.7 ± 5.7), but luteinizing hormone levels remained unchanged. Compared to control groups, the L-NAME-treated group showed a rise in ATP (127.5%) hydrolysis and ADA (116.7%) activity, and also a decrease in ADP (76%) and AMP (45%) hydrolysis. Both TN and WN supplemented diets resulted in substantial (p &lt; 0.05) reversal effects. Enhanced testosterone levels and modulation of the purinergic system in platelets by TN and WN could be one of the mechanisms by which they aid in vasoconstriction control

Inhibitory effect of aqueous extract of different parts of Gossypium herbaceum on key enzymes linked with type 2 diabetes and oxidative stress in rat pancreas in vitro

This study sought to determine the inhibitory effect of aqueous extract of different parts (bark, leaf, and flower) of cotton plant (Gossypium herbaceum) on key enzymes linked with type 2 diabetes and oxidative stress in rat pancreas in vitro. The aqueous extract (1:10 w/v) of Gossypium herbaceum was prepared and the ability of the extract to inhibit the activity of α-amylase and α-glucosidase as well as activities of pro-oxidant Fe2+-induced lipid peroxidation was determined spectrophotometrically. The results revealed that the three varieties were able to inhibit the activity of α-amylase and α-glucosidase in rat's pancreas in a dose dependent manner (0–88.8 mg/ml). Also, the incubation of pancreas tissue homogenate in the presence of Fe2+ caused a significant increase (233.3%) in the malondialdehyde (MDA) content of pancreas homogenate, nevertheless, the introduction of the aqueous extract inhibited MDA production dose dependently (0–33.33 mg/ml) and also exhibited further antioxidant properties as represented by their high radical scavenging and Fe2+ chelating abilities. Inhibition of α-amylase and α-glucosidase activities has been the primary treatment for the management/prevention of type 2 diabetes. Therefore, the α-amylase and α-glucosidase inhibitory activities of aqueous extracts of different parts of Gossypium herbaceum in rat pancreas and prevention of lipid peroxidation in the tissue may be attributed to the presence of polyphenol content of the plant