Antibacterial and dermal toxicological profiles of ethyl acetate extract from Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae)

In-vitro Bactericidal Activity of a Novel Plant Source Plumeria pudica against Some Human and Fish Pathogenic Bacteria

BACKGROUND

The only remedy for up surging problem of antibiotic resistance is the discovery of antibacterial agents of natural origin.

OBJECTIVE

The present study was aimed at finding antibacterial potential of crude and solvent extracts of mature leaves of Plumeria pudica.

METHODS

Antibacterial activity of three different solvent extracts were evaluated in four human and four fish pathogenic bacteria by measuring the zone of inhibition and determining Minimum Inhibitory Concentration and Minimum Bactericidal Concentration values. Standard antibiotics were used as positive control. Preliminary phytochemical screening of most effective extract i.e., ethyl acetate extract, Fourier Transform Infra Red analysis and GC-MS analysis of the Thin Layer Chromatographic (TLC) fraction of ethyl acetate extract were done meticulously. All experiments were done thrice and analyzed statistically.

RESULTS

Crude leaf extracts and solvent extracts caused good inhibition of bacterial growth in all selected bacteria. Ethyl acetate extract showed highest inhibition zones in all tested strains with maximum inhibition (19.50±0.29 mm) in Escherichia coli (MTCC 739). MBC/MIC of the extracts indicated that all three solvent extracts were bactericidal. Preliminary phytochemical tests revealed the presence of tannins, steroids and alkaloids and FT-IR analysis revealed presence of many functional groups namely alcoholic, amide, amine salt and aldehyde groups. From the GC-MS analysis of TLC fraction of ethyl acetate extract, five different bioactive compounds e.g., 2,4-ditert -butylphenyl 5-hydroxypentanoate, Oxalic acid; allyl nonyl ester, 7,9-Ditert-butyl-1-oxaspiro(4,5)deca-6,9-diene- 2,8-dione, Dibutyl phthalate and 2,3,5,8-tetramethyl-decane were identified.

CONCLUSION

Leaf extracts of P. pudica contain bioactive compounds that can be used as broad spectrum bactericidal agent.

Acute and 28-Day Repeated-Dose Oral Toxicity Assessment of Abelmoschus moschatus Medik. in Healthy Wistar Rats

Abelmoschus moschatus Medik. (family: Malvaceae) has a long history of being used as a folk medicine in Sri Lanka. Despite the therapeutic use of this plant in traditional medicine, leaves of A. moschatus have not been subjected to scientific evaluation of toxicity/adverse effects in vivo. Thus, the present study was aimed to assess the acute and 28-day repeated-dose oral toxic effects of hexane (55 mg/kg), ethyl acetate (75 mg/kg), butanol (60 mg/kg), and aqueous (140 mg/kg) leaf extracts of A. moschatus in Wistar rats. Furthermore, identification of phytochemical constituents and determination of in vitro total antioxidant activity of the selected leaf extracts of A. moschatus were carried out. Repeated-dose oral administration of hexane and aqueous plant extracts produced no significant changes in the hematological profile and in selected biochemical parameters compared to the untreated healthy rats (p > 0.05). The administration of ethyl acetate and butanol extracts resulted in significant changes in some of the hematological parameters (p < 0.05), whereas biochemical parameters were not changed (p > 0.05). No significant changes in the relative organ weight of treated rats were observed (p > 0.05) except in the kidneys of Wistar rats treated with the ethyl acetate extract of A. moschatus (p < 0.05). Normal morphology with no signs of hemorrhages, necrosis, or inflammatory cell infiltrations was observed in the vital organs selected during the assessment of histopathology on H and E-stained tissue sections upon the treatment of selected extracts. Alkaloids were absent in the selected leaf extracts excluding the health risk for harmful alkaloids. The highest total antioxidant activity was reported in the butanol extract. In conclusion, the hexane and aqueous extracts of A. moschatus were completely nontoxic, whereas butanol and ethyl acetate extracts showed statistically significant changes in some hematological parameters and in relative organ weight of kidneys in healthy Wistar rats.

Effect of Fractioning on Antibacterial Activity of Enantia chlorantha Oliver (Annonaceae) Methanol Extract and Mode of Action

Infectious diseases caused by bacteria constitute the main cause of morbidity and mortality throughout the world and mainly in developing countries. In this work, the influence of fractioning and the mode of action of stem barks methanol extract of Enantia chlorantha were investigated. The aim was to optimize the antibacterial activity of the methanol extract. The extract was prepared by maceration of barks powder in methanol. Fractioning was done using increasing solvents polarity. Standard phytochemical methods were used for phytochemical screening. Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentration (MBC) of the methanol extract and fractions were determined using broth microdilution method. The studied mode of action of both methanol extract and n-butanol fraction included antibiofilm activity, H+-ATPase-mediated proton pumping assay, salt tolerance, and cells cycle. The methanol extract of E. chlorantha stem barks was found to be active on all the bacteria tested (32 ≤ MIC ≤ 512 μg/mL), its activity being significant (MIC < 100 μg/ml) out of 5 of the 28 clinical isolates used. Salmonella enterica serovar paratyphi A was the most sensitive (32 μg/mL). Compared to the extract and other fractions, the n-butanol fraction was found to be more active (32 ≤ MIC ≤ 256). Significant antibacterial activity of this fraction was observed out of 10 of the 28 bacterial isolates and 3 out of 7 bacterial strains. Lowest MIC values (32 μg/ml) of this fraction were obtained with Escherichia coli (136), Pseudomonas aeruginosa (CIP 76110), and Salmonella enterica serovar typhi 9. The methanol extract of E. chlorantha and its n-butanol fraction revealed several modes of action including the prolongation of the latency phase of the bacterial growth, the inhibition of the pump with protons H⁺ - ATPases bacterial, the loss of the salt tolerance of the Staphylococcus aureus, and inhibition of the formation of the bacterial biofilm. The present results showed that the n-butanol fraction of the methanol stem barks extract of E. chlorantha possess the essential antibacterial components and could best be used to fight against bacterial infections as compared to methanol extract.

Toxicological studies of stem bark extract from Schefflera barteri Harms (Araliaceae)

BACKGROUND

The use of herbal medicines as complements or alternatives to orthodox medicines has been on the increase. There has been the erroneous belief that these medicines are free from adverse effects. Schefflera barteri is popularly used in the West region of Cameroon for the treatment of various diseases such as diarrhea, spasm, pneumonia and animals bite. Considering the ethnopharmacological relevance of this plant, this study was designed to investigate the possible toxic effects of the stem bark extract of S. barteri.

METHODS

The extract was prepared by maceration of stem bark dry powder in methylene chloride/methanol mixture. Phytochemical analysis was performed by chemical reaction method. Oral acute toxicity study was carried out by administering single geometric increasing doses (2 to 16 g/kg body weight) of plant extract to Swiss albino mice. For sub-acute toxicity study, repeated doses (100, 200, 400 and 800 mg/kg bw) of plant extract were given to Wistar albino rats for 28 consecutive days by oral route. At the end of the treatment period, hematological and biochemical parameters were assessed, as well as histopathological studies.

RESULTS

Phytochemical analysis of stem bark extract of S. barteri revealed the presence of anthocyanins, anthraquinons and saponins. Acute toxicity results showed that the LD50 was greater than 16000 mg/kg. Sub-acute treatment significantly (P < 0.05) increased the level of serum transaminase, proteins and HDL cholesterol. On the other hand, the extract significantly (P < 0.05) reduced the level of leucocytes as well as neutrophils, basophils and monocytes in female. No significant variation of serum creatinine, LDL cholesterol, serum triglycerides as well as liver, spleen, testicles and ovaries proteins was noted. Histopathological analysis of organs showed vascular congestion, inflammation of peri-portal and vacuolization of hepatocytes at the level of the liver. Leucocytes infiltration of peri-portal veins were noticed on lungs and liver cells as well as inflammatory peri-bronchial and basal membranes seminar tube merely joined on lungs and testis respectively.

CONCLUSION

The results suggest that acute administration of the stem bark extract of S. barteri is associated with signs of toxicity, administration over a long duration provokes hepatotoxicity, testes and lungs toxicities.

Ethnobotanical survey of medicinal plants used for pregnant women׳s health conditions in Menoua division-West Cameroon

ETHNOPHARMACOLOGICAL RELEVANCE

In Cameroon, most women use traditional medicine for the treatment of pregnancy and childbirth complaints. In order to identify some of the medicinal plants locally used to alleviate these complaints, an ethnobotanical survey was undertaken in five villages of Menoua Division (West-Cameroon).

MATERIALS AND METHODS

Interviews were conducted through structured questionnaires among 24 traditional healers and 179 women living either in the town of Dschang or in 4 neighboring villages. After having recorded the interviewee personal information on issues related to medicinal plants utilization, a literature investigation on their therapeutic or pharmacological effects and phytochemical composition was conducted.

RESULTS

A total of 88 medicinal plants species used to treat 24 conditions occurring during or after pregnancy and belonging to 70 genera or 34 families were recorded. Maximum medicinal uses of plants are reported for the treatment of the following ailments: swelling of legs and ankles (23%), facilitation of delivery (22%), cleaning of the baby (12%). Most herbal remedies are prepared with the leaves (30%), leaves+stems (28%) and whole plant (23%) as maceration (76%). The majority of women who used medicinal plants were very satisfied (75 %) and it is reported that most of these plants are used in the treatment of women health conditions.

CONCLUSION

Many herbal remedies used for the treatment of pregnant women׳s health conditions in Menoua division-West Cameroon have been revealed. It would therefore be judicious for our government and research institution to evaluate the therapeutic and toxicological potentials of these plants in order to valorize their use.

Herbal Insomnia Medications that Target GABAergic Systems: A Review of the Psychopharmacological Evidence

Insomnia is a common sleep disorder which is prevalent in women and the elderly. Current insomnia drugs mainly target the γ-aminobutyric acid (GABA) receptor, melatonin receptor, histamine receptor, orexin, and serotonin receptor. GABA_A receptor modulators are ordinarily used to manage insomnia, but they are known to affect sleep maintenance, including residual effects, tolerance, and dependence. In an effort to discover new drugs that relieve insomnia symptoms while avoiding side effects, numerous studies focusing on the neurotransmitter GABA and herbal medicines have been conducted. Traditional herbal medicines, such as Piper methysticum and the seed of Zizyphus jujuba Mill var. spinosa, have been widely reported to improve sleep and other mental disorders. These herbal medicines have been applied for many years in folk medicine, and extracts of these medicines have been used to study their pharmacological actions and mechanisms. Although effective and relatively safe, natural plant products have some side effects, such as hepatotoxicity and skin reactions effects of Piper methysticum. In addition, there are insufficient evidences to certify the safety of most traditional herbal medicine. In this review, we provide an overview of the current state of knowledge regarding a variety of natural plant products that are commonly used to treat insomnia to facilitate future studies.

Antifungal and antioxidant activity of Crassocephalum bauchiense (Hutch.) Milne-Redh ethyl acetate extract and fractions (Asteraceae)

BACKGROUND

Crassocephalum bauchiense is a flowering plant, found in the West Region of Cameroon. Previous studied has highlighted the antibacterial and the dermal toxicological safety as well as the immunomodulatory activities of the ethyl acetate extract of its dry leaves. As an extension of the previous researches, the current work has been undertaken to evaluate the in vitro antifungal and antioxidant activities of C. bauchiense dried leaves ethyl acetate extract and fractions.

METHODS

The extract was obtained by maceration in ethyl acetate and further fractionated into six fractions labeled F1 to F6 by flash chromatography. The antifungal activity of the extract and fractions against yeasts and dermatophytes was evaluated using broth microdilution method. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and β-carotene - linoleic acid assays.

RESULTS

The extract (MIC = 0.125 - 4 mg/ml) was found to be more active on dermatophytes and yeasts compared to the fractions. The ethyl acetate extract and fractions exhibited strong scavenging activity on DPPH (CI50 = 28.57 - 389.38 μg/ml). The fractions F3 and F6 expressed best antioxidant activity on DPPH radicals compared to the crude extract.

CONCLUSION

The results of these findings clearly showed that C. bauchiense ethyl acetate extract has a significant antifungal and antioxidant activity. It is therefore a source of active compounds that might be used as antifungal and antioxidant agents.

Antibacterial activity of various honey types of Algeria against Staphylococcus aureus and Streptococcus pyogenes

OBJECTIVE

To assess the in vitro antibacterial activity of honey from different geographical location on Gram negative organisms.

METHODS

Different concentrations (Undiluted honey, 10 %, 30%, 50% and 70% wt/vol) of honey were studied in vitro using Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes), briefly, two-fold dilutions of honey solutions were tested to determine the minimum inhibitory concentration (MIC) against each type of microorganism, followed by more assays within a narrower dilution range to obtain more precise MIC values. MICs were determined by both visual inspection and spectrophotometric assay at 620 nm. These honey samples were compared with standard antibiotics like ampicillin, penicillin G, amoxicillin, gentamycin, tobramycin, erythromycin and chloramphenicol was determined by the disc diffusion method.

RESULTS

The diameter of zone of the inhibition (ZDI) of honey has various concentrations tested for the isolates ranged 0-46 mm for S. aureus, 0-44 mm for S. pyogenes. While the MIC (%) ranged 12%-95%, 25%-73% respectively.

CONCLUSIONS

Algeria honey, in-vitro, possess antibacterial activity.

Antibacterial Activity of Myristica fragrans against Oral Pathogens

Myristica fragrans Houtt is mostly cultivated for spices in Penang Island, Malaysia. The ethyl acetate and ethanol extracts of flesh, mace and seed of Myristica fragrans was evaluated the bactericidal potential against three Gram-positive cariogenic bacteria (Streptococcus mutans ATCC 25175, Streptococcus mitis ATCC 6249, and Streptococcus salivarius ATCC 13419) and three Gram-negative periodontopathic bacteria (Aggregatibacter actinomycetemcomitans ATCC 29522, Porphyromonas gingivalis ATCC 33277, and Fusobacterium nucleatum ATCC 25586). Antibacterial activities of the extracts was determined by twofold serial microdilution, with minimum inhibitory concentrations (MIC) ranging from 1.25 to 640 mg/mL and 0.075 to 40 mg/mL. The minimum bactericidal concentration (MBC) was obtained by subculturing method. Among all extracts tested, ethyl acetate extract of flesh has the highest significant inhibitory effects against Gram-positive and Gram-negative bacteria with mean MIC value ranging from 0.625 to 1.25 ± 0.00 (SD) mg/mL; P = 0.017) and highest bactericidal effects at mean MBC value ranging from 0.625 mg/mL to 20 ± 0.00 (SD) mg/mL. While for seed and mace of Myristica fragrans, their ethanol extracts exhibited good antibacterial activity against both groups of test pathogens compared to its ethyl acetate extracts. All of the extracts of Myristica fragrans did not show any antibacterial activities against Fusobacterium nucleatum ATCC 25586. Thus, our study showed the potential effect of ethyl acetate and ethanol extracts from flesh, seed and mace of Myristica fragrans to be new natural agent that can be incorporated in oral care products.