GC-MS analysis of aqueous extract of Nymphaea lotus and ameliorative potential of its biosynthesized gold nanoparticles against cadmium-induced kidney damage in rats.

Plants possess compounds serving as reducing agents for green synthesis of gold nanoparticles (AuNPs), which is currently considered for biomedical application. Exposure to cadmium (Cd) can affect the functional integrity of the several organs such as kidney and liver. Nymphaea lotus (NL) is known for its several medicinal properties, including its protective role against tissue damages. This study investigated the bioactive compounds in NL using gas chromatography-mass spectroscopy (GC-MS) and ameliorative potential of its biosynthesized AuNPs (NL-AuNPs) against Cd-induced nephrotoxicity in rats. The presence of bioactive compounds in N. lotus was investigated by GC-MS in aqueous extract of NL. Gold nanoparticles were synthesized using aqueous extract of NL. Thirty rats were grouped into six (n = 5). Group 1 served as control, while group 2, 3, 4 and 5 received CdCl2 (10 mg/kg) orally for five days. Thereafter, groups 3, 4, and 5, respectively, received silymarin (75 mg/kg), 5 and 10 mg/kg NL-AuNPs, orally for 14 days, while group 6 received 10 mg/kg NL-AuNPs only. Rats were sacrificed after treatment, and biochemical parameters and kidney histopathology were evaluated. Bioactive compounds of pharmacological importance identified include pyrogallol, oxacyclohexadecan-2-one, 22-Desoxycarpesterol, 7,22-Ergostadienol, ß-sitosterol and Dihydro-ß-agarofuran. Cadmium caused nephrotoxicity in rats, as evidenced by significant (p < 0.05) increase in the levels of kidney function markers (serum urea and creatinine) and inflammatory markers (Interleukin-6 (IL-6) and Nuclear Factor-κB (NF-κB)) when compared with control. These changes were significantly (p < 0.05) ameliorated by the spherically-synthesized NL-AuNPs (25-30 nm) with the 5 mg/kg NL-AuNPs more potent against kidney damage induced by Cd in rats but high doses of NL-AuNPs (≥10 mg/kg) could be suggested toxic. NL possess phytochemicals capable of reducing gold salts to nanoparticle form, and doses up to 5 mg/kg could be considered safe for the treatment of renal damage occasioned by cadmium.

Synthesized gold nanoparticles mediated by Crassocephalum rubens extract down-regulate KIM-1/NGAL genes and inhibit oxidative stress in cadmium-induced kidney damage in rats.

Cadmium (Cd) exposure induces kidney damage by mediating oxidative stress and inflammation. In this study, the role of Crassocephalum rubens-gold nanoparticles (C. rubens-AuNPs) in down-regulating kidney injury molecules-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) genes and inhibiting oxidative stress in Cd-induced kidney damage in rats was investigated. Thirty male Wistar rats were distributed randomly into six groups (n = 5). Group I served as control, while groups II, III, IV, and V rats were administered with 20 mg/kg b.w. cadmium chloride (CdCl2) for five consecutive days. Groups III, IV, and V rats were treated, 24 h after the last dose of CdCl2, with silymarin, 5 mg/kg and 10 mg/kg C. rubens-AuNPs, respectively, for 14 days. Group VI rats received 10 mg/kg C. rubens-AuNPs only for 14 days. Animals were sacrificed 24 h after the last dose of the treatment. Biochemical parameters such as kidney function markers, biomarkers of nephrotoxicity, and oxidative stress markers were assayed. Results indicated that 20 mg/kg b.w. CdCl2 caused kidney damage, as evidenced by significant (p < 0.05) increase in the levels of serum urea and creatinine, malondialdehyde, reduced level of superoxide dismutase (SOD), and increased mRNA expression of the kidney injury biomarkers (KIM-1 and NGAL genes), when compared with the control. However, these changes were attenuated by both doses of C. rubens-AuNPs when compared with Cd-induced nephrotoxic rats. It can be suggested that C. rubens-AuNPs have the potential to ameliorate kidney damage induced by Cd via oxidative stress inhibition and down-regulation of KIM-1/NGAL genes.

Combination of donepezil and gallic acid improves antioxidant status and cholinesterases activity in aluminum chloride-induced neurotoxicity in Wistar rats.

The present study compared the effect of donepezil only and combination of donepezil and gallic acid on oxidative status and cholinesterase activity in the brain of Wistar rats administered AlCl3 for 60 days. Twenty-eight rats (180 - 200 g) were arbitrarily distributed into four groups of seven animals apiece. Group 1 served as normal control and received distilled water throughout the study. Group 2 animals received only AlCl3 throughout the study while animals in groups 3 and 4 were administered donepezil only (10 mg/kg) and combination of donepezil (10 mg/kg) and gallic acid (50 mg/kg), respectively, in addition to AlCl3. Treatments were administered orally by gavage. At the end of the study, animals were sacrificed and activities of acetylcholinesterase, butyrylcholinesterase, superoxide dismutase (SOD) and catalase as well as levels of malondialdehyde (MDA), total thiol and nitric oxide (NO) were evaluated in the brain. Histopathological study was conducted on the hippocampus of experimental animals. Results showed that AlCl3 significantly (p < 0.05) increased brain activities of cholinesterases and levels of MDA and NO with a concomitant decrease in total thiol level as well as activities of SOD and catalase. Donepezil only and combination of donepezil and gallic acid reversed these alterations. Also, combination of donepezil and gallic acid significantly (p < 0.05) improved antioxidant status better than donepezil only. It could be concluded that a synergy might exist between gallic acid and donepezil especially in ameliorating oxidative stress associated with AlCl3-induced neurotoxicity.

Biological synthesis of gold and silver nanoparticles using leaf extracts of Crassocephalum rubens and their comparative in vitro antioxidant activities.

The use of plant and plant products in the synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) is made possible because of the natural inherent phytochemicals responsible for the reduction of respective metallic salts to nanoparticle forms, and ensuring therapeutic applicability. In this study, synthesis of AgNPs and AuNPs was performed using two different aqueous extraction methods for Crassocephalum rubens: maceration using laboratory method of extraction (cold aqueous extract of Crassocephalum rubens (AECR)), and decoction using traditional healer's method of extraction (hot aqueous crude extract of Crassocephalum rubens (CECR)). The synthesized nanoparticles were characterized using various methods, and in vitro antioxidant potential were thereafter investigated. The characterization results indicated the formation of mostly spherical-shaped AgNPs and AuNPs with surface plasmon resonance (SPR) band of 470 nm and 540 nm, respectively. The nanoparticles possess high antioxidant potentials but AECR synthesized AuNPs exhibited the least phytochemical contents and antioxidant potential when compared to other nanoparticles. It can therefore be concluded that extraction method and nanoparticle type are important factors that could influence the antioxidant properties of the nanoparticles. Further studies using these nanoparticles as anticancer or anti-inflammatory agent in both in vitro and in vivo are underway.

Antidiabetic potential of methanolic and flavonoid-rich leaf extracts of Synsepalum dulcificum in type 2 diabetic rats.

BACKGROUND: Synsepalum dulcificum is a plant indigenous to West Africa. The fruit is used to modify taste of foods to sweetness. OBJECTIVES: This study aims to investigate the antidiabetic potentials of both methanolic and flavonoid-rich leaf extracts of S. dulcificum (MSD and FSD respectively) in type 2 diabetic Wistar albino rats. MATERIALS AND METHODS: Sixty three rats were randomly distributed into nine groups of seven animals each with group 1 serving as the normal control. Groups 2 to 7 were given 10% fructose in their drinking water for 14 days, after which 40 mg/kg of streptozotocin was administered. Group 2 animals served as the diabetic control, while groups 3, 4, 5, 6 and 7 were treated with 30 mg/kg MSD, 60 mg/kg MSD, 30 mg/kg FSD, 60 mg/kg FSD and 5 mg/kg glibenclamide respectively. Groups 8 and 9, contained healthy animals, and were treated with only 60 MSD, and 60 mg/kg FSD respectively. Biochemical parameters such as liver and kidney function tests, lipid profile, as well as lipid peroxidation and antioxidant enzymes were assessed in addition to histopathology. RESULTS: It was observed that daily oral administration of MSD and FSD for 21 days significantly (p < 0.05) improved the observed pathological changes as a result of type 2 diabetes. CONCLUSION: It could be deduced from results obtained in this study that methanolic and flavonoid-rich leaf extracts of S.dulcificum have antidiabetic potential in type 2 diabetic rats.

Evaluation of acute and subacute toxicity of aqueous extract of Crassocephalum rubens leaves in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Crassocephalum rubens is found throughout tropical Africa including the Indian Ocean islands. The leaves are commonly eaten in form of soups and sauces in South-Western Nigeria, also in other humid zones of Africa. Traditionally, it is used as an antidote against any form of poisoning; used to treat stomach and liver complaints; and externally to treat burns, sore eyes, earache, leprosy and breast cancer. In this study, acute and subacute toxicity of aqueous extract of C. rubens leaves was evaluated in rats in order to assess its safety profile. MATERIALS AND METHODS: In acute toxicity study, rats were given a single oral administration of aqueous extract of C. rubens leaves at graded doses (250-5000mg/kg). The animals were monitored for behavioural changes and possible mortality over a period of 24h and thereafter, for 14 days. In the subacute toxicity study, rats of both sexes were administered C. rubens orally at doses of 250mg/kg, 500mg/kg, 750mg/kg and 1000mg/kg body weight daily, for 28 days. Rats were observed weekly for any changes in general behaviour and body weights. In addition, other relevant parameters were assayed at the end of the main and reversibility study periods. RESULTS: There was no observed adverse effect; including mortality in the animals. The extract caused no significant difference in the body weights as well as organs weights of treated groups when compared with the control groups. Haematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological assessments were normal in liver and kidney. CONCLUSIONS: It can therefore be suggested based on the results from this study that aqueous extract of C. rubens leaves, at dosage levels up to 1000mg/kg, is non-toxic and could also offer protection on some body tissues. Aqueous extract of C. rubens could therefore, be considered safe. This study supports the application of Crassocephalum rubens in traditional medicine.

Antinociceptive and Antioxidant Activities of the Methanolic Extract of Telfairia occidentalis Seeds.

CONTEXT: The seeds of Telfairia occidentalis have been known to possess different biological properties and are used in traditional medicine in Africa and Asia to treat many ailments. The plant is particularly noted traditionally for its healing properties and is usually consumed in the form of herbal decoctions/concoctions as a blood tonic, to treat sudden attacks of convulsions, pain, malaria and anaemia. AIMS: In the present study, various phytochemical and pharmacological studies were done on the methanolic extract of the seeds of Telfairia occidentalis to evaluate its antioxidant and antinociceptive properties to substantiate its traditional use. METHODS: Phytochemical screening of the extract was done according to standard procedures. Antioxidant potential was ascertained using 2,2-diphenyl-1-picryl hydrazyl (DPPH) scavenging activity, total phenolic content and total flavonoid content assays. Analgesic activity was analyzed using formalin induced paw licking test in albino rats at 100, 200 and 400 mg extract per kg body weight. STATISTICAL ANALYSIS USED: All results extrapolated from the experiments were expressed as mean ± SEM. Data obtained was analyzed statistically using ANOVA (one-way) followed by Dennett's posthoc test. RESULTS: Phytochemicals present in the extract were alkaloids, flavonoids, saponins, terpenoids, steroid and anthraquinones. The extract significantly inhibited DPPH scavenging activity with percentage inhibition of 147.3%. The methanolic seed extract of T. occidentalis significantly reduced (P < 0.05) formalin induced paw licking in both neurogenic and inflammatory phases of formalin induced paw licking test, with 35.59 and 78.51% inhibition at 400 mg/kg, in albino rats in a dose dependent manner. CONCLUSIONS: The seed extract in this study significantly reduced formalin induced hind paw licking, and could be used as an analgesic for treatment of pain and also showed marked antioxidant potential.

Genetic Analysis and Molecular Identification of Virulence in Xanthomonas oryzae pv. oryzae Isolates.

Bacterial leaf blight (BLB) of rice is a very destructive disease worldwide and is caused by Xanthomonas oryzae pv. oryzae (Xoo). The aim of the present study was to examine if the Xoo virulence pathotypes obtained using phenotypic pathotyping could be confirmed using molecular approach. After screening of 60 Operon primers with genomic DNA of two Xoo isolates (virulent pathotype, Vr, and mildly virulent pathotype, MVr), 12 Operon primers that gave reproducible and useful genetic information were selected and used to analyze 50 Xoo isolates from 7 West African countries. Genetic analysis revealed two major Xoo virulence genotypes (Mta and Mtb) with Mta having two subgroups (Mta1 and Mta2). Mta1 (Vr1) subgroup genotype has occurrence in six countries and Mta2 (Vr2) in three countries while Mtb genotype characterized mildly virulence (MVr) Xoo isolates present in five countries. The study revealed possible linkage and correlation between phenotypic pathotyping and molecular typing of Xoo virulence. Xoo virulence genotypes were known to exist within country and there was evidence of Xoo pathogen migration between countries. Durable resistance rice cultivars would need to overcome both Mta and Mtb Xoo virulence genotypes in order to survive after their deployment into different rice ecologies in West Africa.