Jean Paul Kamdem - Academia.edu (original) (raw)

Papers by Jean Paul Kamdem

In vitro antioxidant activity of stem bark of Trichilia catigua Adr. Juss………………………………………………………………... more In vitro antioxidant activity of stem bark of Trichilia catigua Adr. Juss……………………………………………………………………………………21 Chapter II: Catuaba (Trichilia catigua) prevents against oxidative damage induced by in vitro ischemia-reperfusion in rat hippocampal slices……………………………….34 Chapter III: Trichilia catigua (Catuaba) bark extract exerts neuroprotection against oxidative stress induced by different neurotoxic agents in rat hippocampal slices…..

Nitric Oxide, Jul 1, 2022

Evidence-based Complementary and Alternative Medicine, 2014

Duguetia furfuracea is frequently used as a medicinal plant in Brazil. However, studies have evid... more Duguetia furfuracea is frequently used as a medicinal plant in Brazil. However, studies have evidenced its cytotoxic, bactericide, and antitumor activities. In the present study we aimed to evaluate the potential toxicity of hydroalcoholic leaves extracts of D. furfuracea (HEDF) in a Drosophila melanogaster model. Toxicity was assessed as changes in locomotor performance, mitochondrial activity, oxidative stress, MAPKs phosphorylation, and apoptosis induction after exposure to HEDF concentrations (1-50 mg/mL) for 7 days. The phytoconstituents of the plant were screened for the presence of alkaloids, tannins, xanthones, chalcones, flavonoids, aurones, and phenolic acids. Exposure of adult flies to HEDF caused mitochondrial dysfunction, overproduction of ROS, and alterations in the activity of detoxifying enzymes GST, SOD and CAT. Induction of ERK phosphorylation and PARP cleavage was also observed, indicating occurrence of HEDF-induced cell stress and apoptotic cell death. In parallel, alterations in cholinesterase activity and impairments in negative geotaxis behavior were observed. Our study draws attention to the indiscriminate use of this plant by population and suggests oxidative stress as a major mechanism underlying its toxicity.

Brazilian Journal of Science, Nov 10, 2022

Paullinia cupana (Kunth), popularly known as guarana, is a plant species from the Amazon Region o... more Paullinia cupana (Kunth), popularly known as guarana, is a plant species from the Amazon Region of Brazil that stands out for being one of the most promising herbal medicines of the Brazilian flora since it has relevant biological properties. However, studies are still needed to use this species as a direct approach to evaluate aspects related to behavior and oxidative stress in invertebrate model animals. In this context, we aimed to evaluate the stimulant and the antioxidant effects of P. cupana in lobster cockroach Nauphoeta cinerea. For that, cockroaches were exposed to a diet separately supplemented by the decoction of P. cupana powder decoction at increasing concentrations of 1, 25, 50 and 100 mg/g for 42 days. Behavioral and biochemical assays were performed, respectively, to assess the locomotor/exploratory performance and oxidative stress marker levels of the cockroaches. They exhibited an outstanding increase in the locomotion performance and in the cell viability content, as well as in the protein and non-protein thiol levels. Moreover, there was a decrease in lipid peroxidation levels and in free Fe 2+ ion contents. Together, our results demonstrate the stimulant and the antioxidant capacity of P. cupana by acting positively in behavioral patterns and by regulating oxidative stress markers in lobster cockroach N cinerea. These findings encourage further laboratory analyzes in order to better enlighten the specific mechanisms of action attributed to guarana.

Cadernos de Cultura e Ciência, Nov 29, 2020

Resumo: Estudos demostraram que a cafeína, um alcaloide purina natural encontrado em mais de 60 t... more Resumo: Estudos demostraram que a cafeína, um alcaloide purina natural encontrado em mais de 60 tipos de plantas, tem sido associada com a redução do estresse oxidativo, sendo capaz de inibir a peroxidação lipídica nas células. No entanto, dependendo da dosagem e da frequência de uso, a cafeína pode ser tóxica para humanos e animais. Pesquisas usando modelos invertebrados demonstraram que altas doses de cafeína contribuem no aumento dos níveis de estresse oxidativo, desencadeando mudanças comportamentais e diminuição da expectativa de vida. Neste contexto, objetivou-se avaliar as alterações na taxa de mortalidade induzidas por cafeína em Drosophila melanogaster. Para tanto, foram utilizadas moscas machos e fêmeas, com 1 a 3 dias de vida, expostas à dieta suplementada com concentrações crescentes de cafeína (10, 25, 50 e 100 mM) durante 7 dias. A contagem do número de moscas mortas foi registrada diariamente e os testes foram realizados em triplicata. Ao final do período de exposição, foi possível perceber que a concentração de 100 mM de cafeína foi a mais tóxica para as moscas, evidenciado pelo aumento na taxa de mortalidade quando comparado ao grupo controle e aos demais grupos testados.

Industrial Crops and Products, Apr 1, 2014

ABSTRACT Anacardium microcarpum is consumed as infusion in the Brazilian folk medicine for the tr... more ABSTRACT Anacardium microcarpum is consumed as infusion in the Brazilian folk medicine for the treatment of various diseases in which free radicals assaults have been implicated in their etiology. However, there is no scientific report on this traditional claim. Thus, we investigated for the first time, its antioxidant activity as well as its potential toxic effects on human leukocytes and erythrocytes in vitro. In addition, qualitative and quantitative analyses of the classes of phytochemicals in the various fractions from A. microcarpum were carried out by HPLC–DAD. The results demonstrated that IC50 (for DPPH radical scavenging) varied from 27.88 ± 1.60 (AcOEt fraction) to 32.86 ± 3.05 μg/mL (EtOH fraction), and all the fractions strongly inhibited Fe2+ (10 μM)-induced lipid peroxidation in rat brain and liver homogenates. All the fractions were not cytotoxic to leukocytes and were able to prevent against 2 mM H2O2-induced cytotoxicity. Moreover, the fractions did not have any effect on human erythrocytes osmotic fragility, suggesting that A. microcarpum infusion can be consumed safely. Preliminary phytochemical analysis exhibited the presence of phenolics and flavonoids compounds as major phytochemical groups. Taking together, our results indicate that the popular use of A. microcarpum for preventive or therapeutic agents in pathologies where cell oxidative stress is implicated has a scientific basis.

Molecules, Jul 25, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Diabetes and Metabolic Syndrome: Clinical Research and Reviews, Apr 1, 2023

Food bioscience, Oct 1, 2022

Journal of Taibah University Medical Sciences, Dec 1, 2017

We found that the Federal University of Pernambuco (UFPE) and the Federal University of Ceara(UFC... more We found that the Federal University of Pernambuco (UFPE) and the Federal University of Ceara(UFC) were the most productive institutions, producing 17847 and 15048 documents, respectively. The number of papers published by each of these universities in the past six years represented more than 50% of their entire productivity. With regards to their scientific output in "Pharmacology, Toxicology and Pharmaceutics", UFC showed the highest number of published documents followed by UFPE and the Federal University of Paraı´ba (UFPB). UFC received the highest h-index (with and without self-citations) and number of citations and shared their most cited papers with foreign institutions from the USA and Germany. However, papers from UFC were published in journals with lower impact factors (2.322). Conclusions: The present study shows where each of these universities stands and can be helpful in identifying potential collaborators in these areas of knowledge.

Molecules, 2021

The species Cordia verbenacea DC (Boraginaceae), known as the whaling herb and camaradinha, is a ... more The species Cordia verbenacea DC (Boraginaceae), known as the whaling herb and camaradinha, is a perennial shrub species native to the Atlantic Forest. Its leaves are used in folk medicine as an anti-inflammatory, analgesic, antiulcerogenic and curative agent, in the form of teas or infusions for internal or topical use. The present study aimed to verify the cytotoxicity of the essential oil and the leishmanicidal and trypanocidal potential of C. verbenacea. The essential oil was characterized by GC-MS. The in vitro biological activity was determined by anti-Leishmania and anti-Trypanosoma assays. The cytotoxixity was determined using mammalian fibroblasts. The C. verbenacea species presented α-pinene (45.71%), β-caryophyllene (18.77%), tricyclo[2,2,1-(2.6)]heptane (12.56%) as their main compounds. The essential oil exhibited strong cytotoxicity at concentrations below 250 μg/mL (LC50 138.1 μg/mL) in mammalian fibroblasts. The potent anti-trypanosome and anti-promastigote activities...

Asian Pacific Journal of Tropical Biomedicine, 2019

Objective: To evaluate the antibacterial activity and neuroprotective capacity of the ethanolic a... more Objective: To evaluate the antibacterial activity and neuroprotective capacity of the ethanolic and aqueous extracts of Tarenaya spinosa (T. spinosa) as well as to determine and quantify some of its polyphenols by high performance liquid chromatography with diode-array detection (HPLC-DAD). Methods: The bacterial Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa strains, grown in Heart Agar Infusion, were tested. The drugs gentamicin, norfloxacin and imipenem were used to evaluate the modulating or antagonistic capacity of the T. spinosa extracts. The extract was analysed by HPLC-DAD to determine the main phenolic compounds. For the cell viability tests, individual heads of the Nauphoeta cinerea arthropod model were removed, homogenized in Trifluoromethyl ketone and centrifuged afterwards. Subsequently, 20 μL of NaNO2 were added to the biological material, except in the control group, to evaluate the protection capacity of the extracts. The homogenate of the insect heads was incubated for 2 h in tubes containing tetrazolium bromide. Results: HPLC-DAD demonstrated that the ethanolic extract of T. spinosa presented caffeic acid as the major compound. The ethanolic extract also showed neuroprotective effects at concentrations ≥ 10 μg/mL, while aqueous extract was shown to have a protective effect only at the concentration of 100 μg/mL. The aqueous extract demonstrated a clinically relevant antibacterial activity against the Staphylococcus aureus multidrug resistant strain - MDR, with MIC 512 μg/mL. However, when the extracts were associated with gentamicin and imipenem, a synergism was detected against Staphylococcus aureus and Escherichia coli MDR strains. Conclusions: Although it does not present an antibacterial action, the extracts of T. spinosa can be used in the pharmaceutical industries since its extracts show modulating action of drugs. Besides, these natural products have neuroprotective capacity.

Brazilian Journal of Science

Introduction: Among the botanical taxa that have species rich in essential oils, the Verbenaceae ... more Introduction: Among the botanical taxa that have species rich in essential oils, the Verbenaceae stands out. One species of this taxon, Lantana montevidensis (Spreng.) Briq., known as "chumbinho", is characterized by the presence of monoterpenes and sesquiterpenes, which together form the essential oils that have biological activities. Objective: To identify the chemical constituents of L. montevidensis essential oil and to evaluate its insecticidal activity against Nauphoeta cinerea . Methodology: L. montevidensis leaves were collected, dried and submitted to hydrodistillation, after which their chemical characterization was carried out by means of Gas Chromatography coupled to Mass Spectrometry (CG/MS). For the biological assay against cockroaches, nymphs with 20 days of age were submitted to different concentrations (50 - 1000 μg/mL of oil per air) and mortality was evaluated over 24 hours of EO exposure. As a positive control, ethanol (C 2 H 6 O) was used. Results: The...

Environmental science and pollution research international, Jan 8, 2017

Bioactive phytocompounds are studied by several bioactivities demonstrated, as their cytotoxic ef... more Bioactive phytocompounds are studied by several bioactivities demonstrated, as their cytotoxic effects. The aim of this work was to evaluate the phytochemical profile, the toxic effect using the Drosophila melanogaster animal model and the anti-inflammatory and antimicrobial effect of the Alternanthera brasiliana (EEAB) ethanol extract. The phytochemical profile was performed using HPLC. The cytotoxic effect was evaluated in vivo using D. melanogaster. The anti-inflammatory effect was determined by neurogenic and antiedematogenic assays, and the antimicrobial activity was assayed using a microdilution method to determine the minimum inhibitory concentration (MIC) of the EEAB alone and in association with antibiotics. The main compound identified on the EEAB was luteolin (1.93%). Its cytotoxic effect was demonstrated after 24 h in the concentrations of 10, 20 and 40 mg/mL. The extract demonstrated an antiedematogenic effect, with a reduction of the edema between 35.57 and 64.17%. The...

South African Journal of Botany, 2013

The present study evaluates the hypoglycemic, antiperoxidative and antihyperlipidemic activities ... more The present study evaluates the hypoglycemic, antiperoxidative and antihyperlipidemic activities of saponins from Solanum anguivi fruits in alloxan induced diabetes rats. Diabetic rats were treated with saponin (20-100 mg/kg) for 21 days. Results indicated that administration of saponins significantly reduced the elevated levels of glucose, decreased total cholesterol (TC), total triglycerides (TG), low density lipoprotein (LDL) and increased high density lipoprotein (HDL) in the serum towards normalcy when compared to the diabetic control (p b 0.05). In addition, saponins exhibited strong inhibition of lipid peroxidation and increased the levels of antioxidant enzymes (superoxide dismutase and catalase) in the serum, liver and pancreas when compared to the diabetic control (p b 0.05). Our results suggest that saponins from S. anguivi fruit can enhance the hypoglycemic, hypolipidemic and antioxidant properties in alloxan-induced diabetic rats, and may have the potential to be used in the prevention or in the management of diabetes.

Pharmacological Research, 2021

Http Www Theses Fr, 1988

La premiere partie de ce memoire est consacree a l'etude du comportement des circuits integre... more La premiere partie de ce memoire est consacree a l'etude du comportement des circuits integres logiques GaAs, aux temperatures cryogeniques. Notre approche a consiste a concevoir des portes logiques de base, adaptees a une structure de MESFET faiblement dopee, que nous avons mise au point compte tenu des modifications des proprietes du GaAs lorsqu'il est refroidi. Un modele en commutation du MESFET GaAs dependant de la temperature (de 77°K a 300°K), a ete deduit de l'etude theorique de la structure. Des portes logiques optimisees pour 77. K, ont ete concues puis simulees et realisees. La mobilite mesuree dans la couche active, varie de 5000 cm2 /V. S a 300°K, a 12000 cm2/V. S a 77°K, tandis que le temps de propagation par porte passe de 77 ps a 3ooK, a 38ps a 77K, pour un facteur de merite de 1pJ. Les resultats obtenus ont demontre que le facteur de merite ne depend pas de la temperature. Le bon accord theorie-experience obtenu sur les fonctions de transfert, la consommation par porte et les temps de propagation a permis de valider le modele du transistor. La seconde partie a porte sur l'etude et la conception a 300°K, de multiplexeurs haut debit integres sur GaAs en logique BFL (Buffered FET Logic). On effectue d'abord une analyse theorique du comportement des principales structures BFL, lorsque les periodes d'horloges sont voisines des temps de propagation, et on en deduit les conditions qui limitent leur montee en frequence. La notion d'impedance d'entree et de sortie d'une porte logique en regime de haute vitesse est definie, et leur methode de determination est proposee. Cette etude est ensuite appliquee a la conception et a la realisation de multiplexeurs a rang fixe ou programmable sur 2 a 4 entrees (342 a 472 composants par puce). Les debits numeriques mesures varient de 1. 5 a 2 Gbit/s, pour une consommation de 1W par puce. Pour terminer, on compare les performances de la logique cryogenique a celles de la logique destinee a la temperature ambiante.

Antioxidants, 2022

Thiazolidine compounds NJ20 {(E)-2-(2-(5-bromo-2-methoxybenzylidene)hydrazinyl)-4-(4-nitrophenyl)... more Thiazolidine compounds NJ20 {(E)-2-(2-(5-bromo-2-methoxybenzylidene)hydrazinyl)-4-(4-nitrophenyl)thiazole} and NW05 [(2-(benzo (d) (1,3) dioxol-4-ylmethylene)-N-(4-bromophenyl)-thiosemicarbazone] potentiated the effect of norfloxacin in resistant bacteria; however, there are no reports on their effects on Nauphoeta cinerea in the literature. The objective of this work was to evaluate the behavioral effects and oxidative markers of NW05 and NJ20 in lobster cockroach N. cinerea. To evaluate the behavioral study, a video tracking software was used to evaluate the locomotor points and the exploratory profile of cockroaches in the horizontal and vertical regions of a new environment. The total concentration of thiol and reduced glutathione (GSH), substances reactive to thiobarbituric acid (TBARS), free iron (II) content and mitochondrial viability were determined. The antioxidant potential was evaluated by the DPPH method. Both substances induced changes in the behavior of cockroaches, s...

Indian Journal of Traditional Knowledge (IJTK), Mar 3, 2021

The aim of this study was to investigate the use of medicinal plants by healers in Juazeiro do No... more The aim of this study was to investigate the use of medicinal plants by healers in Juazeiro do Norte, Northeast Brazil, as well as to understand their role in prayer/healing practices. 30 residents from 20 neighborhoods, 18 urban neighborhoods and 2 randomly selected rural locations, were interviewed using a sample method known as "snowball", with two pilot interviews being initially conducted, where for greater method reliability and for the analysis of the importance attributed to the plants by the respondents, a calculation to determine their Relative Importance (RI) index was used. The results indicate the use of 60 species distributed across 34 families. The most representative families were: Fabaceae (7), Lamiaceae (6) and Asteraceae (5), where 10 species (eight exotic and two native) obtained a Relative Importance (RI>1):