Cisplatin (cis-diamminedichloroplatinum (II) or CDDP), used in the treatment of many solid-tissue cancers, has its chief side-effect in nephrotoxicity. Hence, this study sought to investigate and compare the protective effect of gallic acid (GA) and tannic acid (TA) against cisplatin induced nephrotoxicity in rats. The rats were given a prophylactic treatment of GA and TA orally at a dose of 20 and 40 mg/kg body weight for 7 consecutive days before the administration of a single intraperitoneal (i.p.) injection of cisplatin (CP) at 7.5 mg/kg bwt. The protective effects of both GA and TA on CP induced nephrotoxicity were investigated by assaying renal function, oxidative stress biomarkers, and histopathological examination of kidney architecture. A single dose of cisplatin (7.5 mg/kg bwt) injected i.p. caused a significant increase in some biomarkers of renal function (creatinine, uric acid, and urea levels), with a marked elevation in malondialdehyde (MDA) content accompanied by a significant (P<0.05) decrease in reduced glutathione (GSH) content (103.27%) of kidney tissue as compared to control group. Furthermore, a significant (P<0.05) reduction in kidney antioxidant enzymes (SOD, catalase, GPx, and GST) activity was observed. However, pretreatment with oral administration of tannic acid and gallic acid at a dose of 20 and 40 mg/kg body weight, respectively, for 7 days prior to cisplatin administration reduced histological renal damage and suppressed the generation of ROS, lipid peroxidation, and oxidative stress in kidney tissues. These results indicate that both gallic and tannic acids could serve as a preventive strategy against cisplatin induced nephrotoxicity.

This study evaluated the effect of dietary inclusions of Garcinia kola (GK) seed on geotactic behavior and some oxidative stress markers in wildߚtype fruit flies (Drosophila melanogaster). Flies were raised on diet supplement with GK seed for 5 days. The negative geotactic behavior of flies which was used to evaluate their locomotor performance was thereafter evaluated. The flies were subsequently homogenized and the reactive oxygen species (ROS) level, acetylcholinesterase (AChE), catalase and glutathioneߚSߚtransferase (GST) activities, as well as nitric oxide (NO) and total thiol contents were assayed. The phytochemical constituents of GK seed were also determined. It was observed that higher dietary inclusions of GK seed reduced the survival rate of D. melanogaster more significantly compared to control flies. Also, higher dietary inclusions of GK seed significantly reduced locomotor performance and AChE activity, while the ROS level was increased compared to the control. Activities of GST and catalase were significantly increased in flies fed diet supplemented with higher GK seed inclusions but their NO content was significantly reduced compared to control. Phytochemical analysis of GK seed revealed abundance of saponin > glycosides > alkaloids > phenols > flavonoids. These results have shown that dietary inclusion of GK seed at higher concentrations reduced survival rate of D. melanogaster and impaired cholinergic system, with elevated activities of some antioxidant enzymes under acute exposure. These observations could be associated with bioactivities of predominant phytochemicals in GK seed such as saponin and glycosides which have been reportedly toxic at high concentration. Therefore, this study suggests that high consumption of GK seed could induce some toxicological effects and moderate consumption is hence recommended.

This study reports the phenolic composition, antioxidant activity, and capacity of Physalis angulata and Newbouldia laevis leaves to inhibit enzymes (phosphodiesterase-5′ [PDE-5′], arginase, acetylcholinesterase [AChE], and angiotensin-I converting enzyme [ACE]) linked to erectile dysfunction. High-performance liquid chromatography–diode array detector analysis of the aqueous extracts revealed the presence of phenolic acids (caffeic, ellagic, chlorogenic, and gallic acids) and flavonoids (quercetin, rutin, isoquercitrin, kaempferol, and quercitrin). N. laevis exhibited significantly higher inhibitory effects on PDE-5′, arginase, and ACE activities compared to P. angulata. There was no significant (P < 0.05) difference in the AChE inhibitory activities of both extracts. Furthermore, P. angulata exhibited lower radical scavenging and chelating abilities compared to N. laevis. These findings revealed that P. angulata and N. laevis leaves are good candidates for the development of functional foods with potentials to improve erectile function.