Antimicrobial properties of stem bark extracts from Phyllanthus muellerianus (Kuntze) Excell

A Benzimidazolium-Based Organic Cage with Antimicrobial Activity

Considering the wide interest in (benz)imidazolium-based drugs, we here report our study on a benzimidazolium-based organic cage as potential antimicrobial and antifungal agent. Cytotoxicity studies on a human derived cell line, SH-SY5Y, showed that the cage is not cytotoxic at all at the investigated concentrations. Anion binding studies demonstrated that the cage can bind anions (chloride and nitrate, in particular) both in organic solvent and 20%v D2O/CD3CN mixture. The cage was also tested as anionophore, showing a weak but measurable transport of chloride and nitrate across LUVs vesicles. Nonetheless, the compounds have antimicrobial activity towards Staphylococcus aureus (Gram-positive bacteria). This is probably the first organic cage studied as anionophore and antimicrobial agent.

Bio-Guided Fractionation of Stem Bark Extracts from Phyllanthus muellarianus: Identification of Phytocomponents with Anti-Cholinesterase Activity

A combination of flash chromatography, solid phase extraction, high-performance liquid chromatography, and in vitro bioassays was used to isolate phytocomponents endowed with anticholinesterase activity in extract from Phyllanthus muellarianus. Phytocomponents responsible for the anti-cholinesterase activity of subfractions PMF1 and PMF4 were identified and re-assayed to confirm their activity. Magnoflorine was identified as an active phytocomponent from PMF1 while nitidine was isolated from PMF4. Magnoflorine was shown to be a selective inhibitor of human butyrylcholinesterase—hBChE (IC₅₀ = 131 ± 9 μM and IC₅₀ = 1120 ± 83 μM, for hBuChE and human acetylcholinesterase—hAChE, respectively), while nitidine showed comparable inhibitory potencies against both enzymes (IC₅₀ = 6.68 ± 0.13 μM and IC₅₀ = 5.31 ± 0.50 μM, for hBChE and hAChE, respectively). When compared with the commercial anti-Alzheimer drug galanthamine, nitidine was as potent as galanthamine against hAChE and one order of magnitude more potent against hBuChE. Furthermore, nitidine also showed significant, although weak, antiaggregating activity towards amyloid-β self-aggregation.

Antibacterial and anti-inflammatory activity of bistort (Bistorta officinalis) aqueous extract and its major components. Justification of the usage of the medicinal plant material as a traditional topical agent

ETHNOPHARMACOLOGICAL RELEVANCE

Bistort rhizome (Bistorta officinalis) is a traditionally used plant material popular in Europe and Asia in the treatment of diarrhea and as a topical agent for skin conditions. It contains tannins mostly condensed flavan-3-ol derivatives. However, the in-depth phytochemical investigation of infusions from this plant materials is still lacking. Additionally, the scientific reports supporting the traditional topical application of bistort rhizome are scarce.

AIM OF THE STUDY

The major objective of the present study was to comprehensively investigate the chemical composition of infusion from subterranean parts of common bistort both using hyphenated chromatographic technique and isolation approach. Additionally, the influence of water extract on pro-inflammatory functions of human neutrophils was performed. As bacterial infections play a crucial role in the generation of skin inflammations the antimicrobial activity of the infusion and its major components was established.

MATERIAL AND METHODS

The chemical composition of the infusion was established using UHPLC-DAD-MS³ method. Major compounds which could not be identified using chromatographic analysis were isolated by column chromatography and preparative HPLC. Obtained pure phytochemicals were identified by NMR analysis. The influence of the extract and compounds on the cell viability and apoptosis was evaluated by flow cytometry. The release of pro-inflammatory cytokines after LPS stimulation was established by ELISA. Finally, the antimicrobial assays were performed by establishing MIC and MBC values using several bacterial strains.

RESULTS

The UHPLC analysis revealed the infusion contained mainly, galloyl glucose derivatives, procyanidins and chlorogenic acid. Several compounds were isolated and identified for the first time from the investigated plant material. It was shown that the infusion and its constituents influenced the release of proinflammatory cytokines such as IL-1β, TNF-α and IL-8 and also affected the viability and apoptosis of healthy cells. Both extract and isolated natural products displayed antimicrobial activity against skin pathogens.

CONCLUSIONS

The results obtained in the present study support that the infusions from common bistort influence key biological processes are crucial for skin conditions with the inflammatory background. The study justifies the traditional topical application of common bistort.

Hyal-1 inhibitors from the leaves of Phyllanthus muellerianus (Kuntze) Excell

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves and twigs from Phyllanthus muellerianus Kuntze Excell are known to exert anti-inflammatory and antipyretic properties as well as wound healing properties. During a wide screening for human hyaluronidase-1 inhibitors from natural sources leaf extracts from P. muellerianus turned out to show basic anti-hyaluronidase activity. A detailed investigation of this effect should rationalize the potential anti-inflammatory activity of the extract for improved wound healing.

AIM OF THE STUDY

The following study aimed to characterize the anti-Hyal-1 activity of the extract from P. muellerianus and to pinpoint the responsible natural products responsible for this bioactivity.

MATERIALS AND METHODS

Using cell surface displayed human Hyal-1 on Escherichia coli, the activity of inhibitors was determined by the stains-all assay method. A hydroalcoholic extract PWE from P. muellerianus was subjected to bioactivity-guided fractionation. Active compounds were characterized by means of mass spectrometry and NMR.

RESULTS

PWE exerts a concentration dependent inhibition of Hyal-1 with an IC₅₀ of 80 μg/mL. Bioassay-guided fractionation revealed 13 compounds from the two most active fractions, mainly ellagitannins and flavonoid glycosides. The most activeHyal-1 inhibitor was found to be the ellagitannin chebulanin 10 (IC₅₀ 132 μM). This represents the first description of chebulanin in P. muellerianus.

CONCLUSIONS

The hydroalcoholic extract of P. muellerianus, as well as several subfractions obtained during bioassay-guided fractionation showed strong activity against Hyal-1. The main activity can be correlated to the ellagitanin chebulanin. Additionally, also synergistic effects are observed, indicating that the traditional use of aqueous extracts of P. muellerianus is justified, rather than the use of the isolated tannins. The traditional use of the plant as an anti-inflammatory agent for improved wound-healing can be rationalized by the anti-Hyal-1 activities of its constituents.

Protective Influence of Phyllanthus Muellarianus on Ciprofloxacin-Induced Neurotoxicity in Male Rats

Phyllanthus muellarianus (Kuntze) Exell. (Euphorbiacea) leaves are widely used in the treatment of neurological disorders in Nigeria. We investigated the protective effect of aqueous leaf extract of Phyllanthus muellarianus on ciprofloxacin neurotoxicity in male rats. Control rats (Group A) received distilled water, Groups C-E According to the Animal grouping and treatment section, Group B did not receive P. muellarianus> rats were administered 100, 200, and 400 mg/kg body weight P. muellarianus, respectively, and Group F rats received 200 mg/kg body weight valproate orally for 7 days. In addition, groups B-F rats were orally administered ciprofloxacin for 7 days. Motor coordination and motor function were assessed using narrow beam and landing foot splay distance. The levels of neurotransmitter and oxidative stress biomarkers were also determined. Aqueous leaf extract of P. muellarianus significantly attenuated ciprofloxacin-mediated increases in narrow beam, landing foot splay distance, and gait scores. Ciprofloxacin-mediated depletion of acetylcholine and dopamine in the brains of rats was significantly annulled by P. muellarianus. Furthermore, the extract significantly reversed ciprofloxacin-mediated increases in acetylcholinesterase, monoamine oxidase A, and monoamine oxidase B by 73.13%, 71.52%, and 86.54%, respectively. The altered biomarkers of oxidative stress were significantly reversed by P. muellarianus. Overall, the results of this study show that P. muellarianus reversed ciprofloxacin-induced neurotoxicity by restoring ciprofloxacin-mediated alterations in acetylcholine, dopamine, acetylcholinesterase, monoaminergic enzymes, and oxidative stress biomarkers in the brains of rats.

Chemical Constituents, Anti-nociceptive and Anti-inflammatory Activities of Essential Oil of Phyllanthus muellerianus

The aim of the present study was to characterize the chemical composition and to evaluate the anti-inflammatory and anti-nociceptive properties of the essential oil from the leaves of Phyllanthus muellerianus (Kuntze) Exell. The essential oil was hydrodistilled and characterized by gas chromatography-flame ionization detection and gas chromatography coupled with mass spectrometry analyses. The anti-inflammatory activity was evaluated on carrageenan-induced rat paw edema while the anti-nociceptive test was based on hot plate analysis. The hydrodistillation afforded 0.09% (dry weight basis) of pale yellow oil. Thirty-eight compounds representing 94.8% were identified in the oil. The major components of the oil were hexahydrofarnesyl acetone (11.6%), isocaryophyllene (9.8%), and limonene (9.4%). The oils of P. muellerianus displayed anti-nociceptive effect at a rate independent of reaction time and dose ( P < 0.001). The rate of inhibition increased exponentially as the dose increases with optimum activity at 400 mg/kg. The carrageenan-induced edema model revealed the suppression of inflammatory mediators at a very high significant value ( P < 0.001) for all doses, showing activity comparable to a standard drug at 4 hours after carrageenan injection. Collectively, the essential oils depressed the nociceptors and most likely acted as centrally mediated opioid analgesics while the anti-inflammatory mechanisms of the oil might be related to the decrease in the level of iNOS, and cyclo-oxygenase-2 in the edema paw via the suppression of pro-inflammatory cytokines (TNF-α, IL1-β), NO, and PGE2 production. This study confirms the analgesics and inflammatory activities of P. muellerianus.

Hepatoprotective potential of Phyllanthus muellarianus leaf extract: studies on hepatic, oxidative stress and inflammatory biomarkers

CONTEXT

Leaves of Phyllanthus muellarianus (Kuntze) Exell. (Euphorbiacea) are widely used in the management of liver disorders in Nigeria. However, no there is no scientific validation to support this use.

OBJECTIVE

Hepatoprotective effect of Phyllanthus muellarianus aqueous leaf extract was investigated in acetaminophen-induced liver injury mice.

MATERIALS AND METHODS

Hepatoprotective effect of Phyllanthus muellarianus aqueous leaf extract was evaluated in acetaminophen-induced hepatic damage in Swiss albino mice using biomarkers of hepatocellular indices, oxidative stress, proinflammatory factors and lipid peroxidation. Mice received distilled water, 100, 200, or 400 mg/kg b.w of Phyllanthus muellarianus aqueous leaf extract, respectively, for seven days. Treatment groups were challenged with 300 mg/kg b.w of acetaminophen on the sixth day.

RESULTS

Oral administration of Phyllanthus muellarianus aqueous leaf extract significantly (p < 0.05) attenuates acetaminophen-mediated alterations in serum alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, albumin and total bilirubin by 76.56, 85.41, 89.39, 82.77 and 78.38%. Similarly, acetaminophen-mediated decrease in activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose 6-phosphate dehydrogenase were significantly attenuated in the liver of mice by 85.10, 80.81, 80.45, 76.23 and 95.22%, respectively. Increased levels of conjugated dienes, lipid hydroperoxides, malondialdehyde, protein carbonyl, fragmented DNA, tumor necrosis factor-α, interleukin-6 and -8 were significantly lowered by Phyllanthus muellarianus aqueous leaf extract.

CONCLUSION

Overall, results of this study show that Phyllanthus muellarianus halted acetaminophen-mediated hepatotoxicity due to its capability to enhance antioxidant enzymes.

Betulinic acid is a PPARγ antagonist that improves glucose uptake, promotes osteogenesis and inhibits adipogenesis

PPAR antagonists are ligands that bind their receptor with high affinity without transactivation activity. Recently, they have been demonstrated to maintain insulin-sensitizing and antidiabetic properties, and they serve as an alternative treatment for metabolic diseases. In this work, an affinity-based bioassay was found to be effective for selecting PPAR ligands from the dried extract of an African plant (Diospyros bipindensis). Among the ligands, we identified betulinic acid (BA), a compound already known for its anti-inflammatory, anti-tumour and antidiabetic properties, as a PPARγ and PPARα antagonist. Cell differentiation assays showed that BA inhibits adipogenesis and promotes osteogenesis; either down-regulates or does not affect the expression of a series of adipogenic markers; and up-regulates the expression of osteogenic markers. Moreover, BA increases basal glucose uptake in 3T3-L1 adipocytes. The crystal structure of the complex of BA with PPARγ sheds light, at the molecular level, on the mechanism by which BA antagonizes PPARγ, and indicates a unique binding mode of this antagonist type. The results of this study show that the natural compound BA could be an interesting and safe candidate for the treatment of type 2 diabetes and bone diseases.

In vitro evaluation of the wound healing activity of Drypetes klainei stem bark extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Drypetes klainei Pierre ex Pax is used in Cameroon by Baka Pygmies in the wound healing process and for the treatment of burns.

AIM OF THE STUDY

To validate the traditional use of D. klainei Pierre ex Pax stem bark extracts through the evaluation of their antimicrobial properties and their ability to improve wound healing process in fibroblast cell cultures.

MATERIALS AND METHODS

The antimicrobial properties of D. klainei extracts were evaluated against Staphylococcus aureus ATCC 6538, Streptococcus pyogenes ATCC 19615, Escherichia coli ATCC 10536, Candida albicans ATCC 10231, on the basis of the minimum inhibitory concentration (MIC) and the minimum bactericidal-fungicidal concentration (MBC-MFC) by the macrodilution method. The extracts abilities to accelerate wound healing were studied on murine and human fibroblasts in terms of cell viability and migration (scratch wound-healing assay).

RESULTS

All the extracts were non-toxic against the selected microorganisms at the tested concentrations, and significantly improve wound healing process in vitro, compared to untreated controls. However, the defatted methanol extract was active at lower concentrations, compared to the water extract.

CONCLUSIONS

The ability of both water and defatted methanol extracts to accelerate scratch wound closure in fibroblast cultures may support the traditional use of D. klainei stem bark in the treatment of skin lesions (such as burns) even if no antimicrobial activity was evidenced.

Isolation and characterization of the alkaloid Nitidine responsible for the traditional use of Phyllanthus muellerianus (Kuntze) Excell stem bark against bacterial infections

Phyllanthus muellerianus (Kuntze) Excell (family Euphorbiaceae) stem bark methanol extract inhibited the growth of Clostridium sporogenes and Streptococcus pyogenes, responsible for gas gangrene and suppurative and non suppurative diseases, respectively. After the HPLC fingerprint acquisition a bioguided fractionation of the defatted methanol extract allowed the isolation of six fractions whose activity was evaluated against the two pathogen bacteria. A further purification of the most active fraction afforded a pure compound responsible for the very interesting inhibitory activity against C. sporogenes and S. pyogenes (MIC 0.91 μM, MIC 3.64 μM). (1)H NMR and MS analytical techniques allowed the identification of the bioactive as Nitidine; this quaternary ammonium alkaloid was observed in the genus Phyllanthus for the first time. A study on Nitidine counter ion, performed using energy dispersive spectroscopy (EDS) coupled with scanning electron microscopy (SEM) was also carried out.

Avaliação da atividade anti-helmíntica de extratos brutos de plantas da Floresta Amazônica e Mata Atlântica brasileira sobre Haemonchus contortus

No mundo todo, as verminoses são causa de considerável prejuízo econômico na criação de ovinos. As perdas estão relacionadas ao retardo na produção, custos com tratamentos profiláticos e, em casos extremos, à morte dos animais. O objetivo deste trabalho foi verificar a ação anti-helmíntica de extratos vegetais sobre nematoides como alternativa terapêutica no tratamento da verminose em ovinos. Extratos orgânicos e aquosos foram obtidos de plantas nativas da Floresta Amazônica e Mata Atlântica, e foram testados na concentração de 100µg/mL em ensaios de toxicidade in vitro contra ovos de Haemonchus contortus e de 200µg/mL contra suas larvas. Na concentração estabelecida, apresentaram significante atividade relacionada à inibição de eclosão de ovos; em particular, o extrato orgânico de folhas e frutos de Trichilia sp. e o extrato aquoso dos órgãos aéreos de Phyllanthus attenuatus. Os resultados in vitro sugerem que extratos aquosos e orgânicos dessas plantas podem oferecer novas alternativas de controle da verminose em ovinos a partir de produtos naturais.

Recent acquisition of Helicobacter pylori by Baka pygmies

Both anatomically modern humans and the gastric pathogen Helicobacter pylori originated in Africa, and both species have been associated for at least 100,000 years. Seven geographically distinct H. pylori populations exist, three of which are indigenous to Africa: hpAfrica1, hpAfrica2, and hpNEAfrica. The oldest and most divergent population, hpAfrica2, evolved within San hunter-gatherers, who represent one of the deepest branches of the human population tree. Anticipating the presence of ancient H. pylori lineages within all hunter-gatherer populations, we investigated the prevalence and population structure of H. pylori within Baka Pygmies in Cameroon. Gastric biopsies were obtained by esophagogastroduodenoscopy from 77 Baka from two geographically separated populations, and from 101 non-Baka individuals from neighboring agriculturalist populations, and subsequently cultured for H. pylori. Unexpectedly, Baka Pygmies showed a significantly lower H. pylori infection rate (20.8%) than non-Baka (80.2%). We generated multilocus haplotypes for each H. pylori isolate by DNA sequencing, but were not able to identify Baka-specific lineages, and most isolates in our sample were assigned to hpNEAfrica or hpAfrica1. The population hpNEAfrica, a marker for the expansion of the Nilo-Saharan language family, was divided into East African and Central West African subpopulations. Similarly, a new hpAfrica1 subpopulation, identified mainly among Cameroonians, supports eastern and western expansions of Bantu languages. An age-structured transmission model shows that the low H. pylori prevalence among Baka Pygmies is achievable within the timeframe of a few hundred years and suggests that demographic factors such as small population size and unusually low life expectancy can lead to the eradication of H. pylori from individual human populations. The Baka were thus either H. pylori-free or lost their ancient lineages during past demographic fluctuations. Using coalescent simulations and phylogenetic inference, we show that Baka almost certainly acquired their extant H. pylori through secondary contact with their agriculturalist neighbors.

Isolation and characterization of bioactive compounds from plant resources: the role of analysis in the ethnopharmacological approach

The phytochemical research based on ethnopharmacology is considered an effective approach in the discovery of novel chemicals entities with potential as drug leads. Plants/plant extracts/decoctions, used by folklore traditions for treating several diseases, represent a source of chemical entities but no information are available on their nature. Starting from this viewpoint, the aim of this review is to address natural-products chemists to the choice of the best methodologies, which include the combination of extraction/sample preparation tools and analytical techniques, for isolating and characterizing bioactive secondary metabolites from plants, as potential lead compounds in the drug discovery process. The work is distributed according to the different steps involved in the ethnopharmacological approach (extraction, sample preparation, biological screening, etc.), discussing the analytical techniques employed for the isolation and identification of compound/s responsible for the biological activity claimed in the traditional use (separation, spectroscopic, hyphenated techniques, etc.). Particular emphasis will be on herbal medicines applications and developments achieved from 2010 up to date.

Anti-inflammatory, antimicrobial and antioxidant activities of Diospyros bipindensis (Gürke) extracts and its main constituents

ETHNOPHARMACOLOGICAL RELEVANCE

Diospyros bipindensis (Gürke) stem bark is used in Cameroon by Baka Pygmies for the treatment of respiratory disorders.

AIM OF THE STUDY

To assess the anti-inflammatory, antibacterial and antioxidant properties of constituents from the bark extracts through bioassay-guided fractionation.

MATERIALS AND METHODS

The anti-inflammatory activity of extracts, fractions and pure compounds was assessed through the inhibition of the pro-inflammatory mediator nuclear factor-kappa B (NF-κB) transcriptional activity and nitric oxide (NO) production. DPPH, ABTS and ORAC assays were used for determining the antioxidant properties. The activity against Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Klebsiella pneumoniae, was evaluated on the basis of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) by the macrodilution method.

RESULTS

The water extract showed antimicrobial activity against S. pneumoniae (MIC: 300 μg/ml) and S. pyogenes (MIC: 300 μg/ml). The dichloromethane extract efficiently inhibited NF-κB transcriptional activity and NO production and exhibited significant antioxidant activity in the ORAC assay. An interesting activity was also found against S. pneumoniae (MIC: 200 μg/ml), S. aureus (MIC: 400 μg/ml) and S. pyogenes (MIC: 200 μg/ml). The phytochemical investigation of the dichloromethane extract afforded plumbagin, canaliculatin, ismailin, betulinic acid and 4-hydroxy-5-methyl-coumarin as the main constituents. Plumbagin and ismailin were found to be responsible for the main biological activities observed.

CONCLUSIONS

These results may provide a rational support for the traditional use of Diospyros bipindensis stem bark in the treatment of respiratory disorders, since the anti-inflammatory, antimicrobial and antioxidant compounds isolated from the dichloromethane extract were also present in the traditional water extract.

Chemical composition and antimicrobial activity of Phyllanthus muellerianus (Kuntze) Excel essential oil

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus muellerianus (Kuntze) Excel (family Euphorbiaceae) stem bark is used in Cameroon by Baka pygmies as a remedy for wound healing and tetanus.

AIM OF THE STUDY

To characterize the chemical composition and to evaluate the antimicrobial properties of the essential oil of the plant.

MATERIALS AND METHODS

The essential oil was extracted from the stem bark by dynamic head space and by hydrodistillation and characterized by GC and GC-MS analyses. The antimicrobial activity was evaluated on the basis of the minimum inhibitory concentration (MIC) and the minimum bactericidal-fungicidal concentration (MBC-MFC) by the micro and macrodilution methods. The following bacteria and fungi were used: Clostridium sporogenes ATCC 3584, Staphylococcus aureus ATCC 6538, Streptococcus mutans ATCC 25175, Streptococcus pyogenes ATCC 19615, Escherichia coli ATCC 10536, Candida albicans ATCC 10231, Candida albicans LM 450, Trichophyton mentagrophytes LM 230, Trichophyton rubrum LM 237, Microsporum canis LM 324.

RESULTS

The hydrodistillation afforded 0.06% (dry weight basis) of pale yellow oil. Thirty-eight compounds representing 90.69% were identified. The major component (36.40%) was found to be (E)-isoelemicin, identified by comparison of its (1)H-NMR experimental data, with literature data. The oil showed good antibacterial activity against Clostridium Sporogenes, Streptococcus mutans and Streptococcus pyogenes with MIC ranging from 13.5 to 126 μg/ml. A weak antifungal activity (MIC 250 μg/ml) was found against Trichophyton rubrum, only.

CONCLUSIONS

The antimicrobial activity and the chemical composition of Phyllanthus muellerianus stem bark essential oil are reported for the first time.

Antimicrobial and toxicological activities of five medicinal plant species from Cameroon traditional medicine

BACKGROUND

Infectious diseases caused by multiresistant microbial strains are on the increase. Fighting these diseases with natural products may be more efficacious. The aim of this study was to investigate the in vitro antimicrobial activity of methanolic, ethylacetate (EtOAc) and hexanic fractions of five Cameroonian medicinal plants (Piptadeniastum africana, Cissus aralioides, Hileria latifolia, Phyllanthus muellerianus and Gladiolus gregasius) against 10 pathogenic microorganisms of the urogenital and gastrointestinal tracts.

METHODS

The fractions were screened for their chemical composition and in vivo acute toxicity was carried out on the most active extracts in order to assess their inhibitory selectivity. The agar well-diffusion and the micro dilution methods were used for the determination of the inhibition diameters (ID) and Minimum inhibitory concentrations (MIC) respectively on 8 bacterial species including two Gram positive species (Staphylococcus aureus, Enterococcus faecalis), and six Gram negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Shigella flexneri, Salmonella typhi) and two fungal isolates (Candida albicans, Candida krusei). The chemical composition was done according to Harbone (1976), the acute toxicity evaluation according to WHO protocol and the hepatic as well as serum parameters measured to assess liver and kidney functions.

RESULTS

The chemical components of each plant's extract varied according to the solvent used, and they were found to contain alkaloids, flavonoids, polyphenols, triterpens, sterols, tannins, coumarins, glycosides, cardiac glycosides and reducing sugars. The methanolic and ethylacetate extracts of Phyllanthus muellerianus and Piptadeniastum africana presented the highest antimicrobial activities against all tested microorganisms with ID varying from 8 to 26 mm and MIC from 2.5 to 0.31 mg/ml. The in vivo acute toxicity study carried out on the methanolic extracts of Phyllanthus muellerianus and Piptadeniastrum africana indicated that these two plants were not toxic. At the dose of 4 g/kg body weight, kidney and liver function tests indicated that these two medicinal plants induced no adverse effect on these organs.

CONCLUSION

These results showed that, all these plant's extracts can be used as antimicrobial phytomedicines which can be therapeutically used against infections caused by multiresistant agents. Phyllanthus muellerianus, Piptadeniastum africana, antimicrobial, acute toxicity, kidney and liver function tests, Cameroon Traditional Medicine.