Larvicidal activities of hydro-ethanolic extracts of three Cameroonian medicinal plants against Aedes albopictus

Objective To investigate the larvicidal activity of Syzygium guineense (Myrtaceae) (S. guineense), Monodora myristica and Zanthoxylum heitzii (Rutaceae) (Z. heitzii) extracts against Aedes albopictus (Ae. albopictus). Methods The larvicidal activity of the hydro-ethanolic extracts from these plant species was assessed at three different concentrations (50, 100 and 200 mg/L) on first-instar of Ae. albopictus larvae in comparison with untreated controls. Mortality rate was recorded daily for a period of 12 days. The values of LC50 and lethal time killing 50% of the tested individuals (LT50) were calculated using the log-probit analysis. Results The root extract of S. guineense exhibited the best activity with 100% mortality after 8 days of treatment at 200 mg/L, followed by the fruit extract of Z. heitzii with 83.33% mortality at the same concentration. Nonetheless, larvae were most susceptible to the fruit extract of Z. heitzii both in terms of LC50 (39.89 mg/L) and LT50 (145.68 h). A statistically significant difference between the control and the group treated at 200 mg/L was noticed in all the extracts. Conclusions The present study shows that the hydro-ethanolic extracts of S. guineense, Monodora myristica and Z. heitzii tested have significant larvicidal activity. These preliminary results are of great interest and some of these plant species can be proposed for the formulation of new bioinsecticides to control Ae. albopictus populations

Larvicidal activity of steroidal saponins from Dracaena arborea on Aedes albopictu

Developing of new and improved mosquito control methods, that are economically sustainable and effective, is a critical requirement in the management of vector-borne epidemic diseases. Aedes albopictus is one of the main vectors of various important pathogens in the tropics, which now have the potential to also spread in temperate regions, owing to the environmental and climate changes in act. We report about the isolation of steroidal saponins from Dracaena arborea, evidencing their larvicidal activity against A. albopictus by biological essays. In specific, spiroconazole A demonstrated the best larvicidal activity, showing LT50 value of 57.23 hours at 25 ppm. We finally discuss about the value of this finding

Risk assessment of hepatotoxicity among tuberculosis and human immunodeficiency virus/AIDS-coinfected patients under tuberculosis treatment

Objective/background: Tuberculosis (TB) is a worldwide public health problem. It is a contagious and grave disease caused by Mycobacterium tuberculosis. Current drugs such as isoniazid, pyrazinamide, and rifampicin used for the treatment of tuberculosis are potentially hepatotoxic and can lead to drug hepatitis. In order to improve the follow-up of TB patients in Cameroon, we carried out a study which aimed to evaluate the hepatotoxicity risk factors associated with anti-TB drugs. Methods: The studies were performed on 75 participants who had visited the Loum District Hospital located in the littoral region of Cameroon for their routine consultation. Participants have been selected based on pre-established criteria of inclusion and exclusion. Prior to the informed consent signature, patients were given compelling information about the objective and the result output of the study. They were questioned about antioxidant food and alcohol consumption as well as some clinical signs of hepatotoxicity such as fever, nausea, vomiting, and tiredness. The collected blood was tested for the determination of biochemical markers (transaminases and C-reactive protein) using standard spectrophotometric methods. Results: Biochemical analysis of samples showed a significant increase (p < .05) of aspartate aminotransferase and alanine aminotransferase values in TB patients coinfected with human immunodeficiency virus/AIDS (33.28±16.58UI/L and 30.84±17.17UI/L, respectively) compared with the respective values of the controls (16.35±5.31UI/L and 16.45±4.83UI/L). Taking individually, the liver injury patient percentage of TB patients was significant compared to TBC when considering alanine aminotransferase and aspartate aminotransferase parameters. When considering risk factors, antioxidant food consumption significantly reduced the liver injury patient percentage for the above parameters, whereas an opposite situation was observed with alcohol consumption between TB-coinfection and TB patients. Regarding the C-reactive protein results, the percentage of positive tests was very high among coinfected patients (40%) compared with the control (15%). The interactions between parameters related to alcohol consumption and intake of antioxidant foods showed a slight decrease in activity compared with interactions without food. Conclusion: The results showed that human immunodeficiency virus status and alcohol consumption constitutes aggravating factors for the occurrence of hepatic toxicity. In addition, the consumption of antioxidant foods simultaneously with TB drugs help in reducing the hepatotoxic effects of these drugs

Free radicals quenching potential, protective properties against oxidative mediated ion toxicity and HPLC phenolic profile of a Cameroonian spice: Piper guineensis

Considerations on antioxidants derived from plants have continuously increased during this decade because of their beneficial effects on human health. In the present study we investigated the free radical scavenging properties of extracts from Piper guineense (P. guineense) and their inhibitory potentials against oxidative mediated ion toxicity. The free radical quenching properties of the extracts against [1,1-diphenyl-2-picrylhydrazyl (DPPH·−), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS·−), hydroxyl radical (HO·−), nitric oxide (NO·−)] radical and their antioxidant potentials by FRAP and phosphomolybdenum were determined as well as their protective properties on liver enzymes. The phenolic profile was also investigated by HPLC. The results obtained, revealed that the extracts significantly inhibited the DPPH, NO, HO and ABTS radicals in a concentration depending manner. They also showed a significant ferrous ion chelating ability through FRAP and phosphomolybdenum antioxidant potential. Their polyphenol contents varied depending on the type of extracts and the solvent used. The hydroethanolic extracts (FFH) and the ethanolic extracts (FFE) of P. guineense leaves showed the higher level of phenolic compounds respectively of 21.62 ± 0.06 mg caffeic acid/g dried extract (CAE/g DE) and 19.01 ± 0.03 CAE/g DE. The HPLC phenolic compounds profile revealed a higher quantity of Eugenol, quercetin, rutin and catechin in the stem than in the leaves. The presence of these molecules could be responsible of the protective potentials of P. guineense extracts against lipid peroxidation and SOD, catalase and peroxidase. In conclusion, P. guineense extracts demonstrated significant antioxidant property and may be used as a prospective protector against metal related toxicity

In vitro antioxidant properties, free radicals scavenging activities of extracts and polyphenol composition of a non-timber forest product used as spice: Monodora myristica

BACKGROUND: Excessive production of free radicals causes direct damage to biological molecules such as DNA, proteins, lipids, carbohydrates leading to tumor development and progression. Natural antioxidant molecules from phytochemicals of plant origin may directly inhibit either their production or limit their propagation or destroy them to protect the system. In the present study, Monodora myristica a non-timber forest product consumed in Cameroon as spice was screened for its free radical scavenging properties, antioxidant and enzymes protective activities. Its phenolic compound profile was also realized by HPLC. RESULTS: This study demonstrated that M. myristica has scavenging properties against DPPH',OH',NO', and ABTS'radicals which vary in a dose depending manner. It also showed an antioxidant potential that was comparable with that of Butylated Hydroxytoluene (BHT) and vitamin C used as standard. The aqueous ethanol extract of M. myristica barks (AEH); showed a significantly higher content in polyphenolic compounds (21.44 ±0.24 mg caffeic acid/g dried extract) and flavonoid (5.69 ± 0.07 quercetin equivalent mg/g of dried weight) as compared to the other studied extracts. The HPLC analysis of the barks and leaves revealed the presence of several polyphenols. The acids (3,4-OH-benzoic, caffeic, gallic, O- and P- coumaric, syringic, vanillic), alcohols (tyrosol and OH-tyrosol), theobromine, quercetin, rutin, catechine and apigenin were the identified and quantified polyphenols. All the tested extracts demonstrated a high protective potential on the superoxide dismutase (SOD), catalase and peroxidase activities. CONCLUSION: Finally, the different extracts from M. myristica and specifically the aqueous ethanol extract reveal several properties such as higher free radical scavenging properties, significant antioxidant capacities and protective potential effects on liver enzymes

Homozygote drepanocytosis: Ferric status and inflammation in world and Africa: Review article and meta analysis

Abstract Background and Aims Major sickle cell syndromes are subjected to a high frequency of hemolysis, infections, oxidative stress, and vasooclusive crises which promote inflammation and iron balance disorders. We aimed to systematically review and analyze the studies in this patients addressing in general, and Africa in particular. Methods The systematic review of published articles in the Pubmed and Google Scholar databases was carried out according to the recommendations of the PRISMA model. The case‐control articles have been included. The data extracted from the articles were analyzed using statistical software R. The standardized mean difference (SMD) was used to assess the extent of the disease on the different variables studied. Results At the end, 128 articles were obtained; but only 33 were elligible for meta‐analysis. A SMD of −1.79 was obtained for hemoglobin between the sickle cell patients and the controls due to the deviation from the overall mean hemoglobin in the cases (8 ± 2 g/dL) and in controls (13 ± 3 g/dL). Sickle cell disease showed a significant extent on ferritin [SMD = 2.61; (95% confidence interval, CI: 2.39–2.83); (p < 0.01)] compared to non‐sickle cell patients thus describing a higher risk for sickle cell sufferer to have ferritin disorders. The included studies also described the influence of sickle cell anemia on serum iron [SMD = 1.52; (95% CI: 1.32–1.76); (p < 0.01)] compared to normal subjects. The high risk of inflammation has been described as higher in sickle cell patients [SMD = 0.38; (95% CI: 0.25–0.50)], reflecting the moderate extent of sickle cell disease on inflammation. Conclusion Patients with major sickle cell syndrome in inflammation have a higher risk of iron profile disorders compared to the normal population. Further studies are needed to explore mechanisms for preventing the deleterious effects of iron from this hemolysis, for example haptoglobin genotyping

Relationship between Higher Atherogenic Index of Plasma and Oxidative Stress of a Group of Patients Living with Sickle Cell Anemia in Cameroon

Dyslipidemia is highly prevalent in sickle cell anemia (SCA) patients and is one of the major risk factors for cardiovascular diseases induced by oxidative stress in Africa. The aim of this research was to investigate the correlation between higher atherogenic index of plasma (API) and oxidative stress in a group of patients living with SCA in Cameroon. Methods. A group of 85 homozygote SS patients (male and female) were enrolled at the Central hospital of Yaounde in Cameroon between May and October 2017. After informed consent through the signature of a consent form was obtained, the plasma was collected to determine the lipid profile while the lysate solution of RBC was used to explore some markers of oxidative stress using spectrophotometric methods. Results. Among the 85 patients included in our study, the mean age was 30 ± 5 years and the female to male ratio was 0.97. The majority of the patients (52–81%) had dyslipidaemia, and 22.4% of the patients demonstrated a higher level of atherogenic index of plasma. The patients with a higher level of total cholesterol (TC) (>240 mg/dl) and low-density lipoprotein (LDL-C) (>159 mg/dl) had at least 1,334 fold of malondialdeheyde (MDA) concentration than those with normal level. Also in the same patients, the higher atherogenic plasmatic index (API) significantly (p<0.05) increased with the concentration of MDA. Except HDL-C, the other parameters of lipid profile had significant (p<0.05) correlation with reduced glutathione (GsH) and total antioxidant capacity (TAC). The significant (p<0.05) and linear regression was found between the increased MDA and higher API. Conclusion. Dyslipidemia increases oxidative stress and higher API which leads to coronary vascular disease in patients with SCA