Nutraceutical potential of olive pomace: insights from cell-based and clinical studies.

Olive oil production yields a substantial volume of by-products, constituting up to 80% of the processed fruits. The olive pomace by-product represents a residue of significant interest due to the diverse bioactive compounds identified in it. However, a thorough characterization and elucidation of the biological activities of olive pomace are imperative to redirect its application for functional food, nutraceutical, and pharmaceutical purposes both for animals and humans. In this review, we examine data from experimental models, including immortalized human vascular endothelial cells, human corneal and conjunctival epithelial cells, human colorectal adenocarcinoma cells, non-tumorigenic human hepatoma cells, and murine macrophages alongside clinical trials. These studies aim to validate the safety, nutritional value, and pharmacological effects of olive pomace. In vitro studies suggest that biophenols extracted from olive pomace possess antioxidant, anti-inflammatory, and antiproliferative properties that could be beneficial in mitigating cardiovascular disorders, particularly atherosclerosis, hepatosteatosis, and dry-eye disease. Protective effects against dry-eye disease were confirmed in a mouse model assay. Olive pomace used in the feed for fish and poultry has demonstrated the ability to enhance animals' immunity and improve nutritional quality of meat and eggs. Human clinical trials are scarce and have revealed minimal biological changes following the consumption of olive pomace-enriched foods. However, alterations in certain biomarkers tentatively suggest cardioprotective properties. The review underscores the value of olive pomace while addressing potential drawbacks and future perspectives, with a specific focus on the need for further investigation into the animal feed and human nutritional properties of olive pomace. © 2024 Society of Chemical Industry.

Protocatechuic acid modulates hepatic oxidative stress and inflammation linked to DMN exposure in rat.

Dimethyl nitrosamine (DMN), a potent hepatotoxin, exerts carcinogenic effects and induces hepatic necrosis in experimental animals via CYP2E1 metabolic activation, and generation of reactive oxygen species (ROS). Protocatechuic acid (PCA), a plant-based simple phenolic compound and potent antioxidant, has been shown to affect the development of neoplasia in the rat liver and inhibit the initiation or progression phases of most cancers. In this study, the modulatory effects of PCA on DMN-induced hepatotoxicity, oxidative stress, inflammation, and selected phase I xenobiotic metabolizing enzymes were investigated in male Wistar rats. This study assessed biomarkers of hepatic injury (alanine transaminase, aspartate aminotransferase, alkaline phosphatase, and gamma- glutamyl transferase); oxidative stress (hydrogen peroxide concentration, lipid peroxidation, and reduced glutathione levels); measured activities of antioxidant enzymes (catalase, sodium dismutase, glutathione peroxidase, glutathione S-transferase); and inflammation (Tumor necrosis factor (TNF)-α, interleukin-1-Beta (IL-1ß) and iNOS). The results of our investigation demonstrated that pretreatment with PCA at 50 and 100 mg/kg body weight p.o. reduced DMN (20 mg/kg bw) i.p. mediated hepatic injury, oxidative stress, and inflammation in a dose-dependent manner. In addition, the activities of phase I metabolizing enzymes were significantly induced except for aminopyrine-N-demethylase in the DMN-treated rats when compared with the DMN alone control group. This induction was also reversed by pre-treatment with PCA. The result of this study suggests that PCA is hepatoprotective against DMN-induced hepatic damage by its ability to suppress oxidative stress, inflammation, and modulate the activities of the selected phase I drug metabolizing enzymes. Thus, PCA may prove useful in combating DMN-induced hepatic damage.

6- shogaol suppresses AOM/DSS-mediated colorectal adenoma through its antioxidant and anti-inflammatory effects in mice.

Colorectal adenoma appears as benign lesions and is a precursor of colorectal adenocarcinoma. The effect of 6-Shogaol (6-[S]), a bioactive agent from ginger, in early colonic adenoma growth is unknown. As a result, this study examines the effect of 6-[S] in a mouse colorectal adenoma model induced by Azoxymethane (AOM) and dextran sulfate sodium (DSS). Adult male mice served as control in Group 1. Group 2 was treated orally with 6-[S] extract (20 mg/kg BW). Group 3 was exposed to AOM (25 mg/kg BW, ip) and one cycle of DSS (2.5%) in drinking water alone while Group 4 was co-treated with 6-[S] for twenty-one (21) days. The body weight gain, organ weight and length, oxidative stress indices, inflammatory markers and histological examination were estimated. Our findings show that 6-[S] co-treatment reversed AOM/DSS-induced elevation in colon weight, colon length, nitric oxide (NO), myeloperoxidase (MPO), hydrogen peroxidase (H2 O2 ), and tumor necrosis factor-alpha (TNF-α). However, the antioxidant enzyme activities measured namely catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), and glutathione-S-transferase were significantly increased in 6-[S] treated mice. Taken together, the protective effect of 6-[S] on oxidative burden, inflammation, and histological aberration observed in the colon of the AOM/DSS model of adenoma growth in mice is mediated primarily owing to its anti-inflammatory and anti-oxidative properties. Thus, this study reveals 6-[S] as a useful agent in the possible clinical intervention of colorectal adenoma. PRACTICAL APPLICATIONS: Certain spices have been reported to have numerous phytochemicals with numerous medicinal purposes. However, no studies have been conducted to investigate the role of 6-[S], a phytochemical found in ginger, in the treatment of colorectal adenoma. The study's findings show that 6-[S] is protective in early colonic cancer development, as it manages colorectal adenoma cancer models of AOM/DSS. As a result, 6-[S]'s ability to reduce oxidative stress and inflammation in the colon may be a potential nutritional therapeutic adjuvant for colorectal adenoma.

6-Gingerol, an active constituent of ginger, attenuates lipopolysaccharide-induced oxidation, inflammation, cognitive deficits, neuroplasticity, and amyloidogenesis in rat.

This study examined the protective effect of 6-Gingerol (6G) against lipopolysaccharide (LPS)-induced cognitive impairments, oxidative stress, neuroplasticity, amyloidogenesis, and inflammation. Male rats were allocated into six groups in this manner; Group I placed on normal saline only. Group II was treated for 7 days with LPS alone intraperitoneally at 250 µg/kg body weight (bw). Group III received 6G alone at 50 mg/kg bw orally for 14 days. Groups IV and V received 6G at 20 and 50 mg/kg bw for 7 days, respectively, and LPS for another 7 days to induce neurotoxicity. Group VI received 5 mg/kg bw of donepezil for 7 days and LPS for 7 days. Pretreatment with 20 and 50 mg/kg bw of 6G protected against LPS-mediated learning and memory function, and also locomotor and motor deficits. Besides, 20 and 50 mg/kg bw 6G mitigated LPS-induced alteration in markers of oxidative stress. Furthermore, induction of amyloidogenesis associated with disruption of histoarchitecture and high expression of interleukin 1ß, inducible nitric oxide synthase, amyloid precursor protein (APP), ß-secretase 1, and brain-derived neurotrophic factor by LPS was mitigated by the two doses of 6G in the rat hippocampus and cerebral cortex region of the brain. 6G pretreatment at the two doses mitigated LPS-mediated histopathological changes in the hippocampus and cerebral cortex of rats. Overall, our results demonstrate that the protective effect of 6G is mediated through the reversal of neurobehavioral deficit, oxidative stress, inflammation, and amyloidogenesis, thus making 6G a possible chemoprophylactic agent against brain injury as a result of LPS exposure. PRACTICAL APPLICATIONS: In the search for a holistic prevention of inflammation-associated neurodegeneration, nutraceuticals are becoming prominent. Hence, this study presents 6G, an active constituent of ginger, as a chemoprotective, antioxidant, and anti-inflammatory agent, which is able to ameliorate cognitive impairments, oxidative stress, neuroplasticity, amyloidogenesis, and inflammation in LPS-induced rat model of neuroinflammation.

Kolaviron suppresses dysfunctional reproductive axis associated with multi-walled carbon nanotubes exposure in male rats.

Reproductive toxicity associated with excessive exposure to multi-walled carbon nanotubes (MWCNTs), which are commonly used in medicine as valuable drug delivery systems, is well documented. Kolaviron, a bioflavonoid isolated from Garcinia kola seeds, elicits numerous health beneficial effects related to its anti-inflammatory, anti-genotoxic activities, anti-apoptotic, and antioxidant properties. However, information on the role of kolaviron in MWCNTs-induced reproductive toxicity is not available in the literature. Herein, we assessed the protective effects of kolaviron on MWCNTs-induced dysfunctional reproductive axis in rats following exposure to MWCNTs (1 mg/kg) and concurrent treatment with kolaviron (50 or 100 mg/kg body weight) for 15 successive days. Results showed that MWCNTs-induced dysfunctional reproductive axis as evidenced by deficits in pituitary and testicular hormones, marker enzymes of testicular function, and sperm functional characteristics were abrogated in rats co-administered with kolaviron. Moreover, co-administration of kolaviron-abated MWCNTs-induced inhibition of antioxidant enzyme activities increases in oxidative stress and inflammatory indices. This is evidenced by diminished levels of tumor necrosis factor-alpha, nitric oxide, lipid peroxidation, reactive oxygen, and nitrogen species as well as reduced activity of myeloperoxidase in testes, epididymis, and hypothalamus of the rats. Biochemical data on the chemoprotection of MWCNTs-induced reproductive toxicity were corroborated by histological findings. Taken together, kolaviron suppressed dysfunctional reproductive axis associated with MWCNTs exposure via abrogation of oxidative stress and inflammation in male rats.

Pterocarpus mildbraedii (Harms) extract resolves propanil-induced hepatic injury via repression of inflammatory stress responses in Wistar rats.

Pterocarpus mildbraedii (PME) is a green leafy vegetable from the Papilionaceae family. This study evaluated the anti-inflammatory activity of PME in Wistar rats exposed to experimental hepatotoxicity using propanil (PRP), a post-emergent herbicide. Animals were grouped as control, PRP, PME, and PME + PRP. After 7 days, the levels of stress-activated protein kinases/c-Jun N-terminal kinase (SAPK/JNK), p38 mitogen-activated protein kinase (p38 MAPK), and signal transducer and activator of transcription (STAT-3) were measured in rat liver. Furthermore, myeloperoxidase (MPO) and nitric oxide (NO) levels, as well as protein expressions of nuclear factor-κB (NF-κB p65), inducible nitric oxide synthase (iNOS), and cyclo-oxygenase-2 (COX-2) were determined. Compared with PRP-treated rats, PME significantly reduced the hepatic MPO and NO levels. PME also diminished NFκB, iNOS, and COX-2 protein expressions in PRP-treated rats. This study showed that Pterocarpus mildbraedii leaves produce active principles with relevant anti-inflammatory potential. PRACTICAL APPLICATIONS: Previous studies have shown that bioactive principles contained in medicinal plants can offer protection against chemically induced inflammation. Pterocarpus mildbraedii leaves, with rich content of polyphenols, flavonoids, and essential fatty acids, could be exploited as a therapeutic agent against pesticide-induced oxidative stress and inflammation. This current study has also shown that the potential of PME as a functional food is boosted by the presence of α-linolenic acid, an omega-3-fatty acid known to possess anti-inflammatory activity. Here, we elucidated the cellular mechanisms of the anti-inflammatory action of PME.

D-Penicillamine prolongs survival and lessens copper-induced toxicity in Drosophila melanogaster.

D-penicillamine (DPA) is an amino-thiol that has been established as a copper chelating agent for the treatment of Wilson's disease. DPA reacts with metals to form complexes and/or chelates. Here, we investigated the survival rate extension capacity and modulatory role of DPA on Cu2+-induced toxicity in Drosophila melanogaster. Adult Wild type (Harwich strain) flies were exposed to Cu2+ (1 mM) and/or DPA (50 µM) in the diet for 7 days. Additionally, flies were exposed to acute Cu2+ (10 mM) for 24 h, followed by DPA (50 µM) treatment for 4 days. Thereafter, the antioxidant status [total thiol (T-SH) and glutathione (GSH) levels and glutathione S-transferase and catalase activities] as well as hydrogen peroxide (H2O2) level and acetylcholinesterase activity were evaluated. The results showed that DPA treatment prolongs the survival rate of D. melanogaster by protecting against Cu2+-induced lethality. Further, DPA restored Cu2+-induced depletion of T-SH level compared to the control (P < 0.05). DPA also protected against Cu2+ (1 mM)-induced inhibition of catalase activity. In addition, DPA ameliorated Cu2+-induced elevation of acetylcholinesterase activity in the flies. The study may therefore have health implications in neurodegenerative diseases involving oxidative stress such as Alzheimer's disease.

Improvement of 2-Vessel Occlusion Cerebral Ischaemia/Reperfusion-Induced Corticostriatal Electrolyte and Redox Imbalance, Lactic Acidosis and Modified Acetylcholinesterase Activity by Kolaviron Correlates with Reduction in Neurobehavioural Deficits.

BACKGROUND: Disruption of electrolyte, redox and neurochemical homeostasis alongside cellular energy crisis is a hallmark of cerebral ischaemia and reperfusion injury. PURPOSE: This study investigated the effect of kolaviron (KV) on cortical and striatal cation imbalance, oxidative stress and neurochemical disturbances as well as neurobehavioural deficits in animals subjected to bilateral common carotid artery occlusion (BCCAO)-induced ischaemia/reperfusion injury. METHODS: KV was administered at a dose of 100 or 200 mg/kg to male Wistar rats 1 h before a 30 min BCCAO/4 h reperfusion (I/R). This was followed by neurobehavioral assessment and biochemical evaluations of cation levels, oxidative stress indicators, lactate dehydrogenase activity and acetylcholinesterase (AChE) activity in the brain of animals. CONCLUSION: KV significantly restored altered cortical and striatal Ca2+, Na+, K+ and Mg2+ levels, ameliorated redox imbalance, lactic acidosis and modified AChE activity caused by I/R injury. The favourable neurobehavioural effects of KV correlated with biochemical outcomes. The pharmacological potential of KV in the treatment and management of ischemic stroke and allied pathological conditions via multiple targets (neurotransmitter metabolism, bioenergetic failure and ionic homeostasis) is highlighted by the study.

Garcinia kola seed biflavonoid fraction (Kolaviron), increases longevity and attenuates rotenone-induced toxicity in Drosophila melanogaster.

Rotenone, a naturally occurring and commonly used pesticide, has been established as a model for inducing Parkinson's Disease (PD) in rodents. Kolaviron is a biflavonoid complex from Garcinia kola seeds with anti-oxidative and anti-inflammatory properties. Here, we evaluated the ameliorative role of Kolaviron on rotenone-induced toxicity in Drosophila melanogaster. Flies for longevity study were exposed to Kolaviron (100-500mg/kg diet) throughout the lifespan. For biochemical study, Groups A, B and C flies were treated with ethanol (2.0%, control, vehicle), Kolaviron (200mg/kg diet) and rotenone (250µM) respectively. Flies in Group D were co-treated with both rotenone (250µM) and Kolaviron (200mg/kg diet) for 7days. Subsequently, selected markers of antioxidant status, inflammatory and neurotoxicity were evaluated in the flies. The results from longevity experiment showed that Kolaviron (200, 100, 300 and 400mg/kg) extended lifespan of flies by 38.2%, 20.6%, 11.8% and 2.9% respectively. Also, Kolaviron attenuated rotenone-induced inhibition of catalase, glutathione-S-transferase and acetylcholinesterase activities and depletion of total thiols content in flies. Moreover, Kolaviron prevented rotenone-induced increases in hydrogen peroxide and nitric oxide (nitrite and nitrate) levels and improved rotenone-induced decrease in locomotor performance of flies (p<0.05). Overall, this study evidenced for the first time, the lifespan extension property of Kolaviron and its chemoprotective role on rotenone-induced toxicity in D. melanogaster via anti-oxidative and anti-inflammatory mechanisms.

Kolaviron and Garcinia kola Seed Extract Protect Against Ischaemia/Reperfusion Injury on Isolated Rat Heart.

BACKGROUND: The incidence of cardiovascular diseases and its associated complications have increased greatly in the past three decades. The purpose of this study was to evaluate the acute cardioprotective effects of Garcinia kola (GK) seed extract and Kolaviron (KV) and determine mechanisms of action involving RISK signalling pathways. METHODS: Male Wistar rats were used in this study. Hearts were excised and mounted on the Langendorff perfusion system. The control, group 1 was perfused with dimethyl sulfoxide (DMSO), group II with KV and group III with GK respectively. Western blot analyses were performed on frozen heart tissues. RESULTS: Isolated rat hearts perfused with KV and GK attenuated apoptotic pathways with significant reduction in p38 MAPK protein phosphorylation, as well as reduction in total caspase 3, cleaved caspase 3 (Asp 175) and PARP cleavage. KV and GK also down-regulated p-JNK1 (Tyr 185) and p-JNK 2 (Thr 183) protein expression at the 10 min reperfusion time ponit. Cardioprotection was achieved in part, by enhancement of the reperfusion injury signalling kinase (RISK) pathway; as evidenced by significant increases in protein expresion of Akt/PKB and p-Akt/PKB (Ser 473) in KV and GK respectively. CONCLUSIONS: KV and GK supplementation led to significant increases in the expressions of survival proteins. It is noteworthy that both KV and GK supplementation offered cardioprotection in ischaemic/reperfusion injury rat heart model. In all, GK showed better cardioprotective effect that KV.

Neuroprotective role of 6-Gingerol-rich fraction of Zingiber officinale (Ginger) against acrylonitrile-induced neurotoxicity in male Wistar rats.

Background Acrylonitrile (AN) is a neurotoxin that is widely used to manufacture synthetic fibres, plastics and beverage containers. Recently, we reported the ameliorative role of 6-gingerol-rich fraction from Zingiber officinale (Ginger, GRF) on the chlorpyrifos-induced toxicity in rats. Here, we investigated the protective role of GRF on AN-induced brain damage in male rats. Methods Male rats were orally treated with corn oil (2 mL/kg, control), AN (50 mg/kg, Group B), GRF (200 mg/kg, Group C), AN [50 mg/kg+GRF (100 mg/kg) Group D], AN [(50 mg/kg)+GRF (200 mg/kg) Group E] and AN [(50 mg/kg)+N-acetylcysteine (AC, 50 mg/kg) Group F] for 14 days. Then, we assessed the selected markers of oxidative damage, antioxidant status and inflammation in the brain of rats. Results The results indicated that GRF restored the AN-induced elevations of brain malondialdehyde (MDA), interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and Nitric Oxide (NO) levels. GRF also prevented the AN-induced depletion of brain glutathione (GSH) level and the activities of Glutathione S-transferase (GST), glutathione peroxidase (GPx) and superoxide dismutase (SOD) in rats (p<0.05). Furthermore, GRF prevented the AN-induced cerebral cortex lesion and increased brain immunohistochemical expressions of Caspases-9 and -3. Conclusions Our data suggest that GRF may be a potential therapeutic agent in the treatment of AN-induced model of brain damage.

Kolaviron and Garcinia kola attenuate doxorubicin-induced cardiotoxicity in Wistar rats.

Background The Garcinia kola seeds have been reported for its antibacterial, antioxidant, antidiabetic and also for its chemoprevention property. The use of doxorubicin as an anticancer drug has been accompanied with avalanche of side effects including cardiotoxicity. The aim of this study was to investigate the cardioprotective effect of Kolaviron and Garcinia kola and their mechanisms of action. Methods Sixty male rats (Wistar strain) were used in this study. They were divided into 6 groups (A-F) each containing 10 animals. Group A was the control. Rats in Groups B, C, D, E and F were treated with doxorubicin at the dosage of 15 mg/kg body weight i.p. Prior to this treatment, rats in groups C, D, E and F were pre-treated orally with Kolaviron at the dosage of 100 mg/kg and 200 mg/kg, and Garcinia kola 100 mg/kg and 200 mg/kg for 7 days, respectively. Results The results show that doxorubicin caused a significant increase in heart rate and prolonged QT, reduced antioxidant status, increased oxidative stress, inflammation and markers of cardiac damage which were reversed by pre-treatment with Kolaviron and Garcinia kola. Conclusions Overall, pre-treatment with Kolaviron or Garcinia kola caused reversal of cardiac damage, ECG alteration and oxidative stress by increasing the activity of antioxidant enzymes and reducing the markers of inflammation on doxorubicin-induced cardiotoxicity.

Hesperidin, a citrus bioflavonoid, alleviates trichloroethylene-induced oxidative stress in Drosophila melanogaster.

Trichloroethylene (TCE) is a chlorinated organic pollutant of groundwater with diverse toxic effects in animals and humans. Here, we investigated the ameliorative role of hesperidin, a citrus bioflavonoid on TCE-induced toxicity in Drosophila melanogaster. Four groups of D. melanogaster (50 flies/vial, with 5 vials/group) were exposed to ethanol (2.5%, control), HSP (400mg/10g diet), TCE (10µM/10g diet) and TCE (10µM/10g diet)+HSP (400mg/10g diet) respectively in the diet for 5days. Then, selected oxidative stress and antioxidant markers were evaluated. The results showed that TCE significantly increased the level of reactive oxygen species (ROS) and inhibited catalase, glutathione S-transferase and acetylcholinesterase (AChE) activities with concurrent depletion of total thiol level. However, co-administration of TCE and hesperidin mitigated TCE-induced depletion of antioxidants, and restored ROS level and AChE activity in the flies (p<0.05). Overall, hesperidin offered protective potency on TCE-induced oxidative stress in the flies via anti-oxidative mechanism.

Kolaviron, a biflavonoid of Garcinia kola seed mitigates ischemic/reperfusion injury by modulation of pro-survival and apoptotic signaling pathways.

OBJECTIVE: The study was designed to investigate the ameliorative effect of Kolaviron (KV) on ischemic/reperfusion injury in experimental animal models. MATERIALS AND METHODS: Male Wistar rats were randomly divided into two groups: Group 1 received corn oil as a vehicle and rats in Group 2 were administered KV at 200 mg/kg for 4 weeks. The rats were fed with rat standard chow pellet and water administered ad libitum. After 4 weeks of KV administration, hearts were excised and mounted on the working heart perfusion system. Western blot analysis for protein expression was carried out on frozen heart samples. RESULTS: There was significant (P < 0.05) reduction in the activity of catalase, superoxide dismutase, and glutathione peroxidase with concomitant reduction in oxygen radical absorbance capacity in ischemic rat heart of control compared to group pre-treated with KV, respectively. Similarly, intracellular reactive oxygen species and malondialdehyde were significantly elevated in control compared to KV pre-treated rats. KV significantly increased total Akt/protein kinase B (PKB), phosphorylated Akt/PKB at serine 473 and also caused a significant reduction in p38 mitogen-activated protein kinase, Caspase 3, and cleaved poly adenosine diphosphate ribose polymerase. CONCLUSION: Taken together, KV offered significant cardioprotection via free radical scavenging activity and upregulation of pro-survival pathway.

Hepatic and renal toxicological evaluations of an industrial ovotoxic chemical, 4-vinylcyclohexene diepoxide, in both sexes of Wistar rats.

4-Vinylcyclohexene diepoxide (VCD) is an industrial occupational health hazard chemical because it induces ovotoxicity in rodents. The current study investigated the impacts of VCD on selected hepatic and renal markers of oxidative stress and inflammation in both sexes of Wistar rats. Thus, male and female rats were randomly distributed into four groups of ten rats per group, and dosed orally with VCD for 28days. The control male and female groups of rats received corn oil only, while each of the three remaining groups of both sexes of rats received VCD (100, 250 and 500mg/kg BW) respectively. Thereafter, biomarkers of hepatic and renal oxidative damage, inflammation and immunohistochemical expressions of iNOS, COX-2, caspase-9 and caspase-3 were evaluated. The results revealed that VCD increased markers of liver and kidney functions, oxidative damage and inflammation, and disrupted the antioxidant homeostasis of the rats (p<0.05). Lastly, VCD enhanced the immunohistochemical expressions of iNOS, COX-2, caspase-9 and caspase-3 in the liver of the rats. Thus, our data imply that VCD induced toxicity in the liver and kidney of rats via the combined impacts of oxidative damage and inflammation.

Transient effect of single dose exposure of Nigerian Bonny-light crude oil on testicular steroidogenesis in Wistar rats is accompanied by oxidative stress.

The folkloric use of Nigerian Bonny-light crude oil (BLCO) in Niger Delta area of Nigeria is a common practice. There is increasing experimental evidence portending the adverse effects of BLCO an environmental toxicant on testicular function. We investigated the effects of single dose of BLCO (800 mg/kg body weight) on the activities of steroidogenic and antioxidant enzymes such as serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone, 3 ß-hydroxy-steroid dehydrogenase (3 ß-HSD), 17 ß-hydroxy-steroid dehydrogenase (17 ß-HSD), superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione peroxidase (GSH-Px), levels of lipid peroxidation (LPO), glutathione reduced (GSH) and steroidogenic acute regulatory (StAR) protein, in testes of rats. There was a sequential reduction in the concentration of steroid hormones and activities of steroidogenic enzymes with a concomitant decrease in levels of StAR protein, followed by a parallel increase in antioxidant enzyme activities and levels of LPO. These findings revealed inhibitory effects of BLCO on testicular steroidogenesis and the possible role of oxidative stress in testicular dysfunction observed in this study.

Effect of tenofovir, an antiretroviral drug, on hepatic and renal functional indices of Wistar rats: protective role of vitamin E.

BACKGROUND: Tenofovir (TFR) is a nucleotide reverse transcriptase inhibitor with activity against human immunodeficiency virus. We studied the effect of TFR administered to Wistar rats on hepatic and renal function markers and the possible modulatory role of vitamin E (Vit E). METHODS: The study consists of four groups of six rats each. The first group served as control, the second group received TFR at 50 mg/kg/day for 4 weeks, third group received TFR and Vit E, and the last group received Vit E alone. RESULTS: TFR administration caused a significant (p<0.05) increase in the levels of serum urea, creatinine, urinary glucose, and protein by 65%, 51%, 88%, and 79%, respectively, relative to controls. This was followed by a significant (p<0.05) reduction in creatinine clearance of TFR-treated rats. There were no significant differences (p>0.05) in the activities of serum aminotransferases, γ-glutamyltransferase, and alkaline phosphatase in TRF-treated rats relative to controls. TFR administration caused a marked elevation of malondialdehyde (MDA; index of lipid peroxidation) in the animals. Specifically, serum, hepatic, and renal MDA levels increased by 75%, 90%, and 102%, respectively. TRF-treated rats had significantly (p<0.05) reduced activities of renal catalase, glutathione-S-transferase, and superoxide dismutase. Supplementation of Vit E ameliorated TFR-induced effects by decreasing the levels of MDA and enhancing the activities of renal antioxidative enzymes. The biochemical data were supported by histopathological findings from the slides. CONCLUSIONS: TFR increased oxidative stress and altered kidney function markers in the rats, whereas supplementation of Vit E attenuated these effects.

Extract of Xylopia aethiopica (Annonaceae) protects against gamma-radiation induced testicular damage in Wistar rats.

Ionizing radiation is an important environmental risk factor and, a major therapeutic agent for cancer treatment. This study was designed to evaluate the protective effect of extract of Xylopia aethiopica (XA) on gamma-radiation-induced testicular damage in rats. Vitamin C (VC) served as the reference antioxidant during the study. The study consists of 4 groups of 11 rats each. Group I received corn oil (vehicle), groups II and IV were pretreated with XA (250 mg/kg) and VC (250mg/kg) for 6 weeks before and 8 weeks after exposure to gamma-radiation; group III was exposed to a single dose of gamma-radiation (5 Gy). Biochemical analysis revealed that gamma-irradiation caused a significant increase (p < .05) in serum and testicular lipid peroxidation (LPO) levels by 217% and 221%, respectively. Irradiated rats had markedly decreased testicular catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), and reduced glutathione (GSH) levels. Irradiation resulted in 59% and 40% decreases in spermatozoa motility and live/dead sperm count, respectively, and a 161% increase in total sperm abnormalities. Histologically, testes of the irradiated rats showed extensive degenerative changes in the seminiferous tubules and defoliation of spermatocytes. Supplementation of XA and VC reversed the adverse effects of gamma-radiation on biochemical and histological indices of the rats. These findings demonstrated that Xylopia aethiopica has a protective effect by inhibiting oxidative damage in testes of irradiated rats.

Curcumin and kolaviron ameliorate di-n-butylphthalate-induced testicular damage in rats.

The present study was carried out to evaluate the ameliorative effects of kolaviron (a biflavonoid from the seeds of Garcinia kola) and curcumin (from the rhizome, Curcuma longa L.) on the di-n-butylphthalate (DBP)-induced testicular damage in rats. Administration of DBP to rats at a dose of 2 g/kg for 9 days significantly decreased the relative testicular weights compared to the controls, while the weights of other organs remained unaffected. Curcumin or kolaviron did not affect all the organ weights of the animals. While only DBP treatment significantly increased the testicular malondialdehyde level and gamma-glutamyl transferase activity (gamma-GT), it markedly decreased glutathione level, the testicular catalase, glucose-6-phosphate dehydrogenase, superoxide dismutase, sperm gamma-GT activities and serum testosterone level compared to the control group. Data on cauda epididymal sperm count and live/dead ratio were not significantly affected in the DBP-treated rats. Alone, DBP treatment resulted in a 66% decrease in spermatozoa motility and a 77% increase in abnormal spermatozoa in comparison to control. DBP-treated rats showed marked degeneration of the seminiferous tubules with necrosis and defoliation of spermatocytes. The DBP-induced injuries in biochemical, spermatological parameters and histological structure of testis were recovered by treatment with kolaviron or curcumin. The pattern in the behaviour of these compounds might be correlated with their structural variations. Our results indicate that kolaviron and curcumin protect against testicular oxidative damage induced by DBP. The chemoprotective effects of these compounds may be due to their intrinsic antioxidant properties and as such may prove useful in combating phthalate-induced reproductive toxicity.

Heme oxygenase-1 as a potential therapeutic target for hepatoprotection.

Heme oxygenase (HO), the rate limiting enzyme in the breakdown of heme into carbon monoxide (CO), iron and bilirubin, has recently received overwhelming research attention. To date three mammalian HO isozymes have been identified, and the only inducible form is HO-1 while HO-2 and HO-3 are constitutively expressed. Advances in unveiling signal transduction network indicate that a battery of redox-sensitive transcription factors, such as activator protein-1 (AP-1), nuclear factor-kappa B (NF-kappaB) and nuclear factor E2-related factor-2 (Nrf2), and their upstream kinases including mitogen-activated protein kinases play an important regulatory role in HO-1 gene induction. The products of the HO-catalyzed reaction, particularly CO and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression contributes to protection against liver damage induced by several chemical compounds such as acetaminophen, carbon tetrachloride and heavy metals, suggesting HO-1 induction as an important cellular endeavor for hepatoprotection. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect against chemically-induced liver injury as well as hepatocarcinogenesis.