Antidiarrheal Activity of Dissotis multiflora (Sm) Triana (Melastomataceae) Leaf Extract in Wistar Rats and Subacute Toxicity Evaluation

Anti‐shigellosis activity of the aqueous extract of garlic, clove and fenugreek

Shigellosis causes severe diarrhea and, in some cases, death in children. In this study, we investigated the in vitro and in vivo anti‐shigellosis efficacy of some aqueous herbal extracts or their chosen mixtures, including fenugreek seed, black seed, clove, garlic, and ginger. The antibacterial potential was assessed by well diffusion and microdilution assays. The extracts' minimum inhibitory concentrations ranged from 0.39 to 12.5 mg/ml. The water extract of garlic and combinations of garlic with either fenugreek or clove extracts had the highest antibacterial efficacy, hence these extracts were chosen for the in vivo investigation. Rats were given a Shigella dysenteriae inoculum and then administrated two doses (100 and 200 mg/kg bw) of the selected herbal extracts or the antibiotic ciprofloxacin (20 mg/kg bw) to treat Shigellosis in vivo. The results showed that garlic and clove extract mixtures (G6, 200 mg/kg bw), garlic and fenugreek mixtures (G7 and G8, 100 and 200 mg/kg bw), and ciprofloxacin group (G9, 20 mg/kg bw) had the best anti‐Shigellosis efficacy. G7 (garlic and fenugreek mixtures (100 mg/kg bw) outperformed almost all other groups evaluated. This group had lower defecation frequency, lower stool‐Shigella loudness, restored body weight, recovered hematological, and liver and kidney functions, besides exhibited no anatomical alterations in the colon tissue that were comparable to the uninfected group. As a result, in the treatment of Shigella, this extract combination may be suggested as a viable therapeutic alternative to antibiotics.

Toxicity and Activity of Ethanolic Leaf Extract of Paullinia pinnata Linn (Sapindaceae) in Shigella flexneri-Induced Diarrhea in Wistar Rats

Herbal products from Paullinia pinnata Linn are widely used in African folk medicine to treat several infectious diseases. Although the extracts from this plant has been shown to possess antimicrobial potential, their activity in infectious diarrhea is less reported. Diarrhea was induced by oral administration of 1.2 × 10⁹ CFU/mL of Shigella flexneri to the rats. The infected rats were treated for 5 days with the doses of 111.42, 222.84, and 445.68 mg/kg of P pinnata. The level of biochemical parameters was assessed and histology of organs examined by 14 days subacute toxicity. S flexneri stool load was considerably reduced after 4 days of treatment with the dose of 445.68 mg/kg, 5 days at the dose of 222.84 mg/kg for the extract, and 2 days with ciprofloxacin. The dose of 111.42 mg/kg appeared efficient after 5 days of treatment. The creatinine level increased at the dose of 445.68 mg/kg in both male and female rats and decrease at the dose of 222.84 mg/mL in female rats while an increase was noted in the male rats. Liver and kidney histology were modified at the dose of 445.68 mg/kg while no change was observed at the doses of 111.42 and 222.84 mg/kg. P pinnata leaf extract is efficient against infectious diarrhea at 111.42 mg/kg without side effect.

Inverse Molecular Docking Study of NS3-Helicase and NS5-RNA Polymerase of Zika Virus as Possible Therapeutic Targets of Ligands Derived from Marcetia taxifolia and Its Implications to Dengue Virus

Dengue and Zika are two mosquito-borne diseases of great impact on public health around the world in tropical and subtropical countries. DENV and ZIKV belong to the Flaviviridae family and the Flavivirus genus. Currently, there are no effective therapeutic agents to treat or prevent these pathologies. The main objective of this work was to evaluate potential inhibitors from active compounds obtained from Marcetia taxifolia by performing inverse molecular docking on ZIKV-NS3-helicase and ZIKV-NS5-RNA polymerase as targets. This computational strategy is based on renormalizing the binding scores of the compounds to these two proteins, allowing a direct comparison of the results across the proteins. The crystallographic structures of the ZIKV-NS3-helicase and ZIKV-NS5-RNA-polymerase proteins share a great similarity with DENV homologous proteins. The P-loop active site of the crystallographic structure of ZIKV-NS3-helicase presents a high percentage of homology with the four dengue serotypes. It was found that most ligands of the active compounds (5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone (5DP); 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone (5HH); myricetin-3-O-rhamnoside (M3OR)) from Marcetia taxifolia had a better affinity for ZIKV-NS3-helicase than for ZIKV-NS5-RNA polymerase, as indicated by the negative multiple active site correction (MASC) score, except for M3RG that showed a higher affinity for ZIKV-NS5-RNA polymerase. On the other hand, the AutoDock Vina scores showed that M3OR had the highest score value (-9.60 kcal/mol) and the highest normalized score (1.13) against ZIKV-NS3-helicase. These results in silico demonstrated that the nonstructural proteins NS3-helicase and NS5-RNA polymerase, which share similar molecular structures between the selected viruses, could become therapeutic targets for some bioactive compounds derived from Marcetia taxifolia.

A 90-Day Oral Toxicity Study of an Ethanolic Root Extract of Caesalpinia bonduc (L.) Roxb. in Wistar Rats

Background

Plant medicine is the oldest form of health care known to mankind; hence, studies on their safety for use are essential for the control of adverse drug effects. In Benin, Caesalpinia bonduc is one of many medicinal plants used as aphrodisiac, and for treatment of various ailments including prostatic hyperplasia. Despite its numerous ethnomedicinal benefits, toxicological information associated with its chronic use is currently limited.

Objective

The present study therefore assessed the toxicity of an ethanolic root extract of Caesalpinia bonduc in Wistar rats.

Methods

Caesalpinia bonduc root extract was administered by oral gavage at doses of 31.25, 125, and 500 mg/kg/day for 90 days to male Wistar rats, after which body weight changes, food consumption, urinary parameters, hematological and blood biochemical parameters, organ weights changes, gross pathology, and histopathology of vital organs were assessed.

Results

There were no death or abnormal clinical signs, no significant changes in body weight gain or urinary parameters, and no changes in necropsy and histopathology findings of vital organs associated with extract treatment. However, some indices such as erythrocytes, total cholesterol, and aspartate amino transferase increased in rats treated with high doses of the extract, as well as relative weight of testes, followed by a decrease in food intake and prostate relative weight.

Conclusion

The results indicate that an ethanolic root extract of Caesalpinia bonduc does not cause significant adverse effects and suggest its tolerability up to 500 mg/kg for daily administration of 90 days.

LC-MS Analysis, 15-Lipoxygenase Inhibition, Cytotoxicity, and Genotoxicity of Dissotis multiflora (Sm) Triana (Melastomataceae) and Paullinia pinnata Linn (Sapindaceae)

This study aims to evaluate the anti-inflammatory, cytotoxicity, and genotoxicity activities of Dissotis multiflora (Sm) Triana and Paullinia pinnata Linn used traditionally in Cameroon to treat infectious diseases. Phytochemical screening was carried out using the LC-MS procedure. The ferrous oxidation-xylenol orange (FOX) assay was used to determine the 15-lipoxygenase (15-LOX) inhibitory activity of the plant samples. The tetrazolium-based colorimetric (MTT) assay was performed using Vero cells. The Ames test was carried out using Salmonella typhimurium TA98 and TA100 tester strains. LC-MS chromatogram of D. multiflora led to the identification of four known compounds, namely, 5-(3,5-dinitrophenyl)-2H-tetrazol (2), 2,2'-{[2-(6-amino-9H-purine-9-yl)ethyl]imino}diethanol (14), 1,2,5-oxadiazolo [3,4-b]pyrazine, 5,6-di (3,5-dimethyl-1-piperidyl) (19), and nimbolinin D (20) while four compounds were also identified in P. pinnata known as 2-hydroxycarbamoyl-4-methyl-pentanoic acid (2), pheophorbide A (16), 1-[4-({2-[(1-methyl-1H-indol-5-yl)amino]-4-pyrimidinyl}oxy)-1-naphthyl]-3-[1-(4 methylphenyl)-3-(2-methyl-2-propanyl)-1H-pyrazol-5-yl]urea (17), and nimbolinin D (18). D. multiflora and P. pinnata inhibited 15-LOX activity in concentration-dependent manner. The LC₅₀ (concentration that kills 50% of cells) values of the extracts ranged from 0.13 ± 00 to 1 ± 00 mg/mL for P. pinnata and D. multiflora, respectively. P. pinnata was cytotoxic at concentrations tested while D. multiflora was not. The selectivity index (SI) values ranged from 0.16 to 10.30 on Vero cell lines. No genotoxic effect was observed against both strains tested. These extracts are sources of compounds which can be used to control infectious diseases and associated inflammation. However, caution should be taken while using P. pinnata for medicinal purposes.