HEPATOPROTECTIVE EFFECT OF ALCHORNEA CORDIFOLIA LEAF ON LIVER DAMAGE IN ALBINO RATS

Ethnopharmacological relevance: The dry leaf of Alchornea cordifolia (AC) is used, in traditional medicine in the S Nigeria, for the preparation of blood tonic, remedies for urinary, respiratory, liver and gas intestinal disorders. Aim of the study: This study investigated the protective property of AC leaf against liver damage in animals with a view to exploring its use for the treatment of hepatotoxicity in humans. Material and methods: Ethanol extract of A. cordifolia was used to study the hepatoprotective activity in acetaminophen-induced Albino rats (150-200g). Animals in Group 1 served as vehicle control, Group 2 served as hepatotoxin (Acetaminophen 2g/kg treated) group, Groups 3 and 4 served as positive control (Vitamin E and Curcumin 100 mg/kg bw respectively) groups, and Groups 5-8 served as (200-500mg/kg bw) AC leaf extract treated groups while Group 9 served as normal group (AC extract only 300 mg/kg bw). Results: The hepatotoxic group showed hepatocytic necrosis, cellular infiltration and inflammation in the liver. The treatment group restored the liver cells to their normal lobular architecture in a dose dependent manner. The protection offered by the plant extract compared well with the standard antioxidant agents (Curcumin and Vitamin E). Tannins, flavonoids, alkaloids and saponins were detected in the phytochemical screening. Conclusion: Our findings suggest Alchornea cordifolia ethanol leaf extract as promising herpatoprotective herb and give credence to the folkloric use of this plant for the treatment of liver problem

HPLC quantification of phenolic content and assessment of methanolic extract of Antiaris africana for toxicological study

The study was aimed at evaluating the toxicological and antioxidant activities of Antiaris africana Engl. (family Moraceae), that is used in Nigeria and other West Africa countries as a panacea for the treatment of several ailments. The methanolic extract of A. africana (MEA) obtained was analysed for antioxidant activities in vitro and screened for various phytochemicals present. Phenolic and flavonoid contents were determined followed with high performance liquid chromatography -diode-array detection (HPLC-DAD) fingerprinting of phenolic content. Furthermore, the sub-acute toxicity of MEA was determined via oral administration of varying doses for 14 consecutive days (0, 50, 100, 200 and 400 mg/kg) in rats. After oral administration for 14 consecutive days in male rats, the toxicity effect was assayed by determining aspartate aminotransferase (AST) and alanine aminotransferase (ALT) for hepatic function; urea and creatinine for renal function; creatinine kinase (CK) for cardiac function; and lipid profile. HPLC results showed that the major phenolics present are quercetin, rutin, caffeic acid, garlic acid and quercetin. MEA was able to scavenge diphenyl picryl hydrazyl, hydroxyl and nitric oxide radicals and prevent lipid peroxidation induced by ferrous sulphate at all concentration tested. The toxicology investigation showed that at low doses, A. africana is non-toxic, while at high doses; it is moderately toxic to the animals. In conclusion, A. Africana is generally non-toxic; however, care must be taken in administration at higher doses.Keywords: Toxicology, HPLC, phytochemicals, Antiaris african

Neurological Complications in COVID-19: Implications on International Health Security and Possible Interventions of Phytochemicals

Global health security or international health security (IHS) includes any natural or man-made phenomenon that challenged human health and well-being including emerging infectious diseases such as the current global pandemic: COVID-19. Since the sudden outburst of COVID-19 pandemic in 2019, many COVID-19 patients have exhibited neurological symptoms and signs. Till now, there is no known effective established drug against the highly contagious COVID-19 infection despite the frightening associated mortality rate. This chapter aims to present the mechanism of action of coronavirus-2 (SARS-CoV-2), the clinical neurological manifestations displayed by COVID-19 patients, impact on the global health system and present phytochemicals with neuroprotective ability that can offer beneficial effects against COVID-19 mediated neuropathology. Reports from COVID-19 clinical studies, case reports, and other related literature were evaluated. Neurological complications of COVID-19 include anosmia, acute cerebrovascular disease, acute disseminated post-infectious encephalomyelitis, encephalitis, etc. Also, SARS-CoV-2 соuld be a neurotropic vіruѕ due to its iѕоlаtіоn from сеrеbrоѕріnаl fluіd. Multірlе nеurоlоgісаl dаmаgе displayed by COVID-19 patients might be due to hyperinflammation associated with SARS-CoV-2 infections. Kolaviron, resveratrol, vernodalin, vernodalol, and apigenin are natural phytochemicals with proven anti-inflammatory and therapeutic properties that could extenuate the adverse effects of COVID-19. The phytochemicals have been documented to suppress JNK and MAPK pathways which are essential in the pathogenesis of COVID-19. They also showed significant inhibitory activities against SARS-CoV-2 main protease. Taken together, these phytochemicals may offer neuroprotective benefits against COVID-19 mediated neuropathology and suppress the burden of the pandemic on IHS

Reactive Oxygen Species in Neurodegenerative Diseases: Implications in Pathogenesis and Treatment Strategies

Neurodegenerative diseases are debilitating disorders which compromise motor or cognitive functions and are rapidly becoming a global communal disorder with over 46.8 million people suffering dementia worldwide. Aetiological studies have showed that people who are exposed to agricultural, occupational and environmental toxic chemicals that can interfere and degenerate dopaminergic neurons are prone to developing neurodegenerative diseases such as Parkinson Disease. The complex pathogenesis of the neurodegenerative diseases remains largely unknown; however, mounting evidence suggests that oxidative stress, neuroinflammation, protein misfolding, and apoptosis are the hallmarks of the diseases. Reactive oxygen species (ROS) are chemically reactive molecules that have been implicated in the pathogenesis of neurodegenerative diseases. ROS play a critical role as high levels of oxidative stress are commonly observed in the brain of patients with neurodegenerative disorders. This chapter focus on the sources of ROS in the brain, its involvement in the pathogenesis of neurodegenerative diseases and possible ways to mitigate its damaging effects in the affected brain

Antioxidant and antiulcer potential of aqueous leaf extract of Kigelia africana against ethanol-induced ulcer in rats

Ethnobotanical claims regarding Kigelia africana reported antiulcer properties as part of its medicinal application. In this work, aqueous leaf extract from K. africana was investigated for its phytochemical constituents and antiulcer potential against ethanol-induced ulcer in rats. The participation of oxidative stress on ethanol-induced ulcer and the potential protective antioxidant activity of K. africana extracts were investigated by determining vitamin C and thiobarbituric acid reactive species (TBARS) contents in the gastric mucosa of rats. The HPLC analysis showed the presence of gallic acid, chlorogenic acid, caffeic acid and also the flavonoids rutin, quercetin and kaempferol in the aqueous plant extract. Oral treatment with K. africana extract (1.75; 3.5; 7 and 14mg/kg) one hour after ulcer induction with ethanol decreased in a dose dependent manner the ulcer index. Ethanol increased significantly stomachal TBARS levels and decreased vitamin C content when compared to the control animals. K. africana blunted the ethanol-induced oxidative stress and restored vitamin C content to the control levels. The present results indicate that the aqueous leaf extract from K. africana possesses antiulcer potential. The presence of flavonoids in plant extract suggests that its antiulcerogenic potential is associated with antioxidant activity. Of particular therapeutic potential, K. africana was effective against ethanol even after the induction of ulcer, indicating that it can have protective and curative effects against gastric lesion

Cross-Reactivity of Two SARS-CoV-2 Serological Assays in a Setting Where Malaria Is Endemic

Background: Accurate SARS-CoV-2 serological assays are critical for COVID-19 serosurveillance. However, previous studies have indicated possible cross-reactivity of these assays, including in malaria-endemic areas.Methods: We tested 213 well-characterized pre-pandemic samples from Nigeria using two SARS-CoV-2 serological assays: Abbott Architect IgG and Euroimmun NCP IgG assay, both targeting SARS-CoV-2 nucleocapsid protein. To assess antibody binding strength, an avidity assay was performed on these samples and on plasma from SARS-CoV-2 PCR-positive persons.Results: Thirteen (6.1%) of 212 samples run on the Abbott assay and 38 (17.8%) of 213 run on the Euroimmun assay were positive. Anti-Plasmodium IgG levels were significantly higher among false-positives for both Abbott and Euroimmun; no association was found with active P. falciparum infection. An avidity assay using various concentratIons of urea wash in the Euroimmun assay reduced loosely-bound IgG: of 37 positive/borderline pre-pandemic samples, 46%, 86%, 89%, and 97% became negative using 2M, 4M, 5M, and 8M urea washes, respectively. The wash slightly reduced avidity of antibodies from SARS-CoV-2 patients within 28 days of PCR confirmation; thereafter avidity increased for all urea concentrations except 8M.Conclusions: This validation found moderate to substantial cross-reactivity on two SARS-CoV-2 serological assays using samples from a malaria-endemic setting. A simple urea wash appeared to alleviate issues of cross-reactivity

Innate Immune Response to Rift Valley Fever Virus in Goats

Rift Valley fever (RVF), a re-emerging mosquito-borne disease of ruminants and man, was endemic in Africa but spread to Saudi Arabia and Yemen, meaning it could spread even further. Little is known about innate and cell-mediated immunity to RVF virus (RVFV) in ruminants, which is knowledge required for adequate vaccine trials. We therefore studied these aspects in experimentally infected goats. We also compared RVFV grown in an insect cell-line and that grown in a mammalian cell-line for differences in the course of infection. Goats developed viremia one day post infection (DPI), which lasted three to four days and some goats had transient fever coinciding with peak viremia. Up to 4% of peripheral blood mononuclear cells (PBMCs) were positive for RVFV. Monocytes and dendritic cells in PBMCs declined possibly from being directly infected with virus as suggested by in vitro exposure. Infected goats produced serum IFN-γ, IL-12 and other proinflammatory cytokines but not IFN-α. Despite the lack of IFN-α, innate immunity via the IL-12 to IFN-γ circuit possibly contributed to early protection against RVFV since neutralising antibodies were detected after viremia had cleared. The course of infection with insect cell-derived RVFV (IN-RVFV) appeared to be different from mammalian cell-derived RVFV (MAM-RVFV), with the former attaining peak viremia faster, inducing fever and profoundly affecting specific immune cell subpopulations. This indicated possible differences in infections of ruminants acquired from mosquito bites relative to those due to contact with infectious material from other animals. These differences need to be considered when testing RVF vaccines in laboratory settings

Validation of xMAP SARS-CoV-2 Multi-Antigen IgG assay in Nigeria

Objective: There is a need for reliable serological assays to determine accurate estimates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence. Most single target antigen assays have shown some limitations in Africa. To assess the performance of a multi-antigen assay, we evaluated a commercially available SARS-CoV-2 Multi-Antigen IgG assay for human coronavirus disease 2019 (COVID-19) in Nigeria. / Methods: Validation of the xMAP SARS-CoV-2 Multi-Antigen IgG assay was carried out using well-characterized SARS-CoV-2 reverse transcription polymerase chain reactive positive (97) and pre-COVID-19 pandemic (86) plasma panels. Cross-reactivity was assessed using pre-COVID-19 pandemic plasma specimens (213) from the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). / Results: The overall sensitivity of the xMAP SARS-CoV-2 Multi-Antigen IgG assay was 75.3% [95% CI: 65.8%– 82.8%] and specificity was 99.0% [95% CI: 96.8%– 99.7%]. The sensitivity estimate increased to 83.3% [95% CI: 70.4%– 91.3%] for specimens >14 days post-confirmation of diagnosis. However, using the NAIIS pre-pandemic specimens, the false positivity rate was 1.4% (3/213). / Conclusions: Our results showed overall lower sensitivity and a comparable specificity with the manufacturer’s validation. There appears to be less cross-reactivity with NAIIS pre-pandemic COVID-19 specimens using the xMAP SARS-CoV-2 Multi-Antigen IgG assay. In-country SARS-CoV-2 serology assay validation can help guide the best choice of assays in Africa