Ethnopharmacological Uses, Phytochemistry, and Pharmacological Properties of Croton macrostachyus Hochst. Ex Delile: A Comprehensive Review

Medicinal Plants Used by Oromo Community in Kofale District, West-Arsi Zone, Oromia Regional State, Ethiopia

Purpose

The purpose of this study was to record the utilization of medicinal plants by the Oromo people in the Kofale District, Oromia Regional State, Ethiopia, to control human and animal health problems.

Methods

Data regarding the use of medicinal plants were collected using ethnobotanical methods from 84 traditional medicine practitioners and 304 general informants sampled employing purposive and systematic random sampling methods, respectively, in the Kofale District. Data were analyzed using different indices, including a preference ranking exercise, informant consensus factor (ICF), fidelity level (FL) and relative popularity level (RPL).

Results

In the district, 106 medicinal plants were claimed to be used for the treatment of 43 human and 18 livestock illnesses, of which 75 (71%) were used to manage human health problems, 23 (21.5%) were used to treat both human and livestock ailments and eight (7.5%) were utilized to treat manage livestock health problems. Most (76.4%) plants were harvested from the wild. Leaves were the most commonly used plant part (55.6%) in remedy preparations. Skin diseases scored the highest ICF value (0.97), followed by gastrointestinal disorders (ICF = 0.95), cancer (ICF = 0.93), and hemorrhoids (ICF = 0.91). Medicinal plants that record the highest fidelity level (FL) (100%) and rank order priority (ROP) (100%) values included Justicia schimperiana, Embelia schimperi, Ekebergia capensis and Datura stramonium, which have been used to treat liver disorders, tapeworm infections, babesiosis, and rabies, respectively. There were significant differences (p<0.05) in the mean numbers of medicinal plants claimed by different social groups: older, illiterate, and traditional medicine practitioners reported higher mean numbers of medicinal plants than younger, literate, and general informants, respectively.

Conclusion

This study indicated the richness of medicinal plant species in Kofale District. Medicinal plants with the highest FL and ROP values and those used to treat disease categories with the highest ICF values should be prioritized in future phytochemical and pharmacological investigations.

Influence of socio-demographic factors on medicinal plant knowledge among three selected ethnic groups in south-central Ethiopia

BACKGROUND

The influence of socio-demographic variables was widely explored to evaluate their impact on indigenous and local ethnobotanical knowledge. However, the studies conducted in Ethiopia mainly focused on rural areas. They were limited to exploring and documenting ethnobotanical knowledge and the associated impacts of socio-demographic variables in rural-urban interface areas among ethnic groups. Hence, this study aimed to document plant-based indigenous and local ethnomedicinal knowledge and the associated impacts of socio-demographic variables among selected three ethnic groups in south-central Ethiopia.

METHODS

Ethnobotanical data were collected using semi-structured interviews with 189 key informants, floristic species inventories, and field observations. Quantitative approaches were used to evaluate the use values (UV) of the most important medicinal plants, the informant consensus factor (ICF), fidelity level (FL), relative popularity level (RPL), and rank-order priority (ROP). Statistical tests were applied to evaluate the influences of socio-demographic factors and associations between variables on local ethnobotanical knowledge across ethnic groups in different informant categories.

RESULTS

Statistical analysis revealed significant differences (p < 0.05) in the mean number of medicinal plants reported among age categories. There was also a positive association between the respondent's age and plant knowledge acquisition. Croton macrostachyus Hochst. ex Delile, Albizia gummifera C.A.Sm., Zingiber officinale Roscoe, Aloe macrocarpa Tod., Gymnanthemum amygdalinum (Delile) Sch.Bip., Calpurnia aurea (Aiton) Benth, and Allium sativum L. had the highest use values among ethnic groups. The highest informant consensus factor values were recorded for circulatory system disorders (0.68) followed by febrile illness and reproductive organ complications (0.66 each) across the three studied ethnic groups. The highest FL, RPL, and ROP values were noted for Lactuca inermis Forssk., Moringa stenopetala (Baker f.) Cufod., Withania somnifera (L.) Dunal, Allium sativum L., Citrus limon (L.) Osbeck, Ricinus communis L., Schinus molle L., Antiaris toxicaria (J.F.Gmel.) Lesch., Brucea antidysenterica J.F.Mill., Echinops kebericho Mesfin, Ocimum jamesii Sebald, Afrocarpus falcatus (Thunb.) C.N.Page, Searsia natalensis (Bernh. ex Krauss) F.A.Barkley, and Ricinus communis L. across ethnic groups in the study areas, which showed the conformity of knowledge on species curing potential and their prevalent uses.

CONCLUSION

The study revealed that the ethnic groups of Gedeo, Oromo, and Sidama have considerable indigenous and local ethnobotanical knowledge practices. Statistical analysis shown high variation in the acquisition of local ethnobotanical knowledge among age groups, which boosted our understanding of the effects of socio-demographic factors on the local ethnobotanical knowledge dynamics. Thus, this finding advocates for efforts to repair the observed generation gap via continued professional support and educating local communities to preserve traditional knowledge and practices through systematic documentation.

Croton macrostachyus Leaf Extract-Mediated Green Synthesis of ZnO Nanoparticles and ZnO/CuO Nanocomposites for the Enhanced Photodegradation of Methylene Blue Dye with the COMSOL Simulation Model

The photodegradation of organic pollutants using metal oxide-based catalysts has drawn great attention as an effective method for wastewater treatment. In this study, zinc oxide nanoparticles (ZnO NPs) and zinc oxide/copper oxide nanocomposites (ZnO/CuO NCs) were fabricated using the leaf extract of Croton macrostachyus as a nontoxic, natural reducing and stabilizing agent. The synthesized samples were characterized by employing X-ray diffraction, microscopic, spectroscopic, and electrochemical methods. The results confirmed the successful synthesis of ZnO NPs and ZnO/CuO NCs with well-defined crystalline structures and morphologies. The prepared samples were tested for the photodegradation of methylene blue (MB) dye under visible light irradiation. Compared to ZnO NPs, ZnO/CuO NCs showed greatly improved photocatalytic performances, particularly with the sample prepared with the 20 mol % Cu precursor (97.02%). The enhancement could be related to the formed p-n heterojunction, which can suppress the recombination of charge carriers and extend the photoresponsive range. A theoretical study of the photocatalytic activity of ZnO/CuO NCs against MB dye degradation was also conducted by using COMSOL Multiphysics software. The results of the simulation are in reasonable agreement with those of the experiment. This study contributes to the development of sustainable and effective photocatalytic materials that are suitable for application in environmental remediation, particularly in the treatment of wastewater.

Traditional Herbal Remedies in the Management of Metabolic Disorders in Ethiopia: A Systematic Review of Ethnobotanical Studies and Pharmacological Activities

Background

MetS are common throughout the world, including Ethiopia. These have traditionally been treated using medicinal plants, particularly in rural areas where they are freely accessible. This systematic review tried to investigate the treatment of MetS with Ethiopian medicinal herbs and made recommendations for more validation research. A careful analysis of the literature was also conducted on the therapeutic effects of these and other Ethiopian medicinal plants with hepatoprotective and antihypertensive activities.

Methods

The relevant keywords "Ethnomedicinal + hypertension," "Ethnopharmacological + hypertension," "Ethnomedicinal + hepatitis, jaundices, and liver disease," "Ethnopharmacological + hepatic disorder," and "Ethnomedicinal + weight loss" were used to search for relevant articles in the major electronic scientific databases, including PubMed, Science Direct, Web of Science, and Google Scholar. The search strategy included all articles with descriptions that were accessible until April 30, 2022. The study's subjects, methods, or year of publication were no restrictions in the search. The outcomes were compiled using descriptive statistics.

Results

Fifty-four (54) studies were examined in the review that satisfied the inclusion and exclusion criteria for the treatment of MetS in Ethiopia. The most often used ethnobotanical plant species for the treatment of hypertension and hepatic disorders were Moringa stenopetala and Croton macrostachyus. Both hepatic and hypertensive disorders were treated more frequently with leaves (52% and 39%, respectively) than with roots (20% and 13%, respectively). Some intriguing studies came from an ethnobotanical investigation into medicinal herbs' hepatoprotective and antihypertensive properties. The most often investigated medicinal plant for its antihypertensive effects is Moringa stenopetala.

Conclusion

The study revealed that Ethiopians often use anti-MetS herbal remedies. We advocate the experimental validation of the commonly used medicinal plants with the identification of active compounds and the development of effective alternative drugs for the treatment of MetS.

In vitro anti-HIV and cytotoxic effects of pure compounds isolated from Croton macrostachyus Hochst. Ex Delile

Croton macrostachyus is an important plant in traditional African medicine, widely utilized to treat a variety of diseases. In Kenya, HIV-infected patients use leaf and root decoctions of the plant as a cure for cough, back pain, bleeding, skin diseases, warts, pneumonia, and wounds. This study aimed to evaluate the anti-HIV activities and cytotoxic effects of extracts and chemical constituents isolated from C. macrostachyus. In our previous study we demonstrated that the hexane, CH₂Cl₂, ethyl acetate and methanol soluble fractions of a 1:1 v/v/ CH₂Cl₂/MeOH crude extracts of the leaves and stem bark of C. macrostachyus exhibited potent anti-HIV activities against HIV-1 with IC₅₀ values ranging from 0.02–8.1 μg/mL and cytotoxicity effects against MT-4 cells ranging from IC₅₀ = 0.58–174 μg/mL. Hence, hexane soluble extract of 1:1 v/v/ CH₂Cl₂/MeOH crude extract of the leaves of C. macrostachyus, that was more potent against HIV-1 at IC₅₀ = 0.02 μg/mL was subjected to column chromatography leading to the isolation of 2-methoxy benzyl benzoate (1), lupenone (2), lupeol acetate (3), betulin (4), lupeol (5), sitosterol (6) and stigmasterol (7). Lupenone (2), lupeol acetate (3) and betulin (4) exhibited anti-HIV-1 inhibition at IC₅₀ = 4.7 nM, 4.3 and 4.5 μg/mL respectively. The results obtained from this study support the potential of C. macrostachyus, as a source of anti-HIV constituents.

Analysis of total phenolic contents, flavonoids, antioxidant and antibacterial activities of Croton macrostachyus root extracts

Plants are good sources of various bioactive substances and have significant importance for the discovery of new drugs. In this study, Croton macrostachyus plant roots from six different sites in the Central Gondar Zone, Ethiopia, were collected; and their phenolic and flavonoid contents, as well as antioxidant and antibacterial activities were investigated. Total phenolics and flavonoid contents of the root extracts were determined by the Folin-Ciocalteu and aluminum chloride methods, respectively. The antioxidant activity was determined by the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging method. Moreover, the antibacterial activities were evaluated by disk diffusion method. Results revealed that total polyphenols and flavonoid contents were in the range of 802 ± 53-1557 ± 75 mg GAE/100 g and 342 ± 26-745 ± 32 mg CE/100 g, respectively. Root extracts of C. macrostachyus were found to have higher antioxidant activities ranging from 3.53 ± 0.38 to 6.38 ± 0.62 mg AAE/g sample. They also showed inhibition zones of 5.8, 6.2, 5.9 and 6.0 mm for Staphylococcus aurous, Staphylococcus pneumonia, Escherichia coli and Klebsiella pneumonia, and had equivalent potency with the reference Gentamicin antibiotic. Pearson correlation result indicated a strong relationship between total polyphenol contents and their respective antioxidant activities. This study articulates that the root extracts accumulated a substantial quantity of polyphenols and bears a considerable antioxidant activity.

A Systematic Review of Medicinal Plants of Kenya used in the Management of Bacterial Infections

Kenya’s vision 2030 partly aims at ensuring adequate health care for all, and the integration of traditional healthcare practices into the national healthcare system would present a more rapid alternative towards the realization of universal health coverage in Kenya. Currently, research on Kenyan medicinal plants with potential antibacterial activity remains vastly fragmented across numerous literature studies and databases; thus, it is imperative to collate and appraise these data for the ease of future research and possible clinical application. Objective. This review aims at exploring and compiling research evidence on medicinal plants used in the management of bacterial infections in Kenya, with a focus on their efficacy and safety. Methodology. A comprehensive web-based systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was executed to highlight the Kenyan medicinal plants used for the management of bacterial infections in Kenya. This review includes studies published until January 2021 from the PubMed, Science Direct, AJOL, and Google Scholar databases. Results. A total of 105 Kenyan medicinal plants belonging to 43 families have their in vitro activity against various human pathogenic bacteria evaluated. Plants from the Lamiaceae, Rutaceae, and Fabaceae families were the most commonly studied. Aloe secundiflora, Toddalia asiatica, Senna didymobotrya, Warbugia ugandensis, Tithonia diversifolia, Fuerstia africana, Olea africana, and Harrisonia abyssinica were the plants frequently evaluated within Kenya. The plants with the strongest antimicrobial activities were Toddalia asiatica, Hagenia abyssinica, Ocimum gratissimum, Harrisonia abyssinica, Senna didymobotrya, Olea Africana, Camellia sinensis, and Tarmarindus indica. Conclusion. Based on a published work, it is evident that traditional medicine is seemingly an acceptable and efficient system among Kenyan communities in the management of bacterial infections. Kenya’s rich biodiversity with diverse secondary metabolites presents a promising source of new therapeutic alternatives with possibly different mechanisms of action against bacteria.

HIV-1 Integrase Inhibitory Effects of Major Compounds Present in CareVid™: An Anti-HIV Multi-Herbal Remedy

In our continued study on the anti-HIV activity of compounds present in CareVid^TM, we report the HIV-1 integrase ((HIV-1 IN) inhibitory effects of pellitorine (1), oleuropein (2), magnoflorine (3), crotepoxide (4), ent-kaurane-16β,17-diol (5), crotocorylifuran (6), lupeol (7), betulin (8), and ellagic acid (9) in an in vitro enzyme assay, and in an in silico study. Ellagic acid, pellitorine, lupeol, and betulin showed an in vitro percentage inhibition against HIV-1 IN of 21.1%, 19.0%, 18.5%, and 16.8%, respectively, at a standard concentration of 25 μg/mL. However, from a pharmacokinetic perspective, ellagic acid has poor bioavailability, due to rapid elimination in metabolism in the gut microbiome. It was postulated that known gut catabolites of ellagic acid, urolithin A (10) and urolithin B (11) could be more promising candidates in exploring the anti-HIV activity of ellagic acid-rich medicinal species consumed orally. On the contrary, urolithin A and urolithin B demonstrated lower activity with comparison to ellagic acid. The binding affinity of compounds 1–9, urolithin A, and urolithin B against the catalytic domain of HIV-1 IN was also explored by in silico methods. Docking studies showed oleuropein as the best candidate, with a predicted energy of binding of ΔG −5.81 kcal/mol, while ellagic acid showed moderate predicted inhibition (ΔG −4.38 kcal/mol) caused by the interaction between the carbonyl and the key Mg²⁺ ion in the active site.

HIV-1 Reverse Transcriptase Inhibition by Major Compounds in a Kenyan Multi-Herbal Composition (CareVid™): In Vitro and In Silico Contrast

CareVid is a multi-herbal product used in southwest Kenya as an immune booster and health tonic and has been anecdotally described as improving the condition of HIV-positive patients. The product is made up of roots, barks and whole plant of 14 African medicinal plants: Acacia nilotica (L.) Willd. ex Delile (currently, Vachelia nilotica (L.) P.J.H Hurter & Mabb.), Adenia gummifera (Harv.) Harms, Anthocleista grandiflora Gilg, Asparagus africanus Lam., Bersama abyssinica Fresen., Clematis hirsuta Guill. & Perr., Croton macrostachyus Hochst. ex Delile, Clutia robusta Pax (accepted as Clutia kilimandscharica Engl.), Dovyalis abyssinica (A. Rich.) Warb, Ekebergia capensis Sparm., Periploca linearifolia Quart.-Dill. & A. Rich., Plantago palmata Hook.f., Prunus africana Hook.f. Kalkman and Rhamnus prinoides L’Her. The objective of this study was to determine the major chemical constituents of CareVid solvent extracts and screen them for in vitro and in silico activity against the HIV-1 reverse transcriptase enzyme. To achieve this, CareVid was separately extracted using CH₂Cl₂, MeOH, 80% EtOH in H₂O, cold H₂O, hot H₂O and acidified H₂O (pH 1.5–3.5). The extracts were analysed using HPLC–MS equipped with UV diode array detection. HIV-1 reverse transcriptase inhibition was performed in vitro and compared to in silico HIV-1 reverse transcriptase inhibition, with the latter carried out using MOE software, placing the docking on the hydrophobic pocket in the subdomain of p66, the NNRTI pocket. The MeOH and 80% EtOH extracts showed strong in vitro HIV-1 reverse transcriptase inhibition, with an EC₅₀ of 7 μg·mL⁻¹. The major components were identified as sucrose, citric acid, ellagic acid, catechin 3-hexoside, epicatechin 3-hexoside, procyanidin B, hesperetin O-rutinoside, pellitorine, mangiferin, isomangiferin, 4-O-coumaroulquinic acid, ellagic acid, ellagic acid O-pentoside, crotepoxide, oleuropein, magnoflorine, tremulacin and an isomer of dammarane tetrol. Ellagic acid and procyanidin B inhibited the HIV-1 reverse transcription process at 15 and 3.2 µg/mL⁻¹, respectively. Docking studies did not agree with in vitro results because the best scoring ligand was crotepoxide (ΔG = −8.55 kcal/mol), followed by magnoflorine (ΔG = −8.39 kcal/mol). This study showed that CareVid has contrasting in vitro and in silico activity against HIV-1 reverse transcriptase. However, the strongest in vitro inhibitors were ellagic acid and procyanidin B.

Evaluation of the antiulcerogenic activity of hydromethanol extracts of Solanum incanum L. (Solanaceae) leaves and roots in mice; single and repeated dose study

Objective

The aim of this study was to evaluate the antiulcer activity of hydromethanol extracts of Solanum incanum L. (Solanaceae) leaves and roots in mice.

Methods

The antiulcerogenic activity of the plant extracts were evaluated using Pylorus ligation and ethanol induced gastric ulcers in fasted mice. Data were analyzed using one way ANOVA, and P-values <0.05 were considered statistically significant.

Result:Pylorus ligation-induced ulcer

Single dose and repeated daily dose administration of the leaf and root extracts for 10 days didn't significantly (P > 0.05) affect pH, total acidity and volume of gastric secretion. Single dose of both extracts significantly reduced ulcer score (P = 0.036) and ulcer index (leaf, P = 0.037; root, P = 0.041) at the dose of 400 mg/kg. Similarly, significant reduction in ulcer score was observed after repeated daily treatment with 200 mg/kg (P = 0.030) and 400 mg/kg (P = 0.005) of the leaf extract and 400 mg/kg (P = 0.005) of the root extract. In addition, repeated administration of 400 mg/kg of the leaf (P = 0.004) and root (P = 0.005) extracts significantly reduced ulcer index.

Ethanol-induced ulcer

Single dose of both extracts significantly reduced ulcer score at the dose of 200 mg/kg (leaf, P = 0.017; root, P = 0.036) and 400 mg/kg (leaf, P = 0.001; root, P = 0.001). Similarly, 200 mg/kg (leaf, P = 0.002; root, P = 0.018) and 400 mg/kg (leaf, P = 0.001; root, P = 0.001) of the extracts significantly reduced ulcer index after single dose treatment. Repeated daily treatment with leaf and root extracts for ten days caused a significant (P = 0.037, 0.001 and 0.001 for 100, 200 and 400 mg/kg leaf extract; P = 0.026, 0.018 and 0.001 for 100, 200 and 400 mg/kg root extract, respectively) reduction in ulcer score. In addition, both extracts significantly (P = 0.041, 0.004 and 0.000 for 100, 200 and 400 mg/kg leaf extract; P = 0.038, 0.008 and 0.000 for 100, 200 and 400 mg/kg root extract, respectively) reduced ulcer index after 10 days of treatment.

Conclusion

This study has revealed hydromethanol extracts of Solanum incanum leaves and roots have antiulcerogenic activity using in vivo models. The antiulcer activity of the plant is not related to acid anti-secretory action, suggesting the plant may have cytoprotective effect on the gastric mucosa.

Evaluation of the Diuretic Activity of Aqueous and 80% Methanol Extracts of Croton macrostachyus(Euphorbiaceae) Leaves in Saline-Loaded Rats

Background

Croton macrostachyus (Euphorbiaceae) extract is a folk medicine traditionally used for treating a number of disorders, including edematous conditions. The present study aimed to evaluate the diuretic effects of aqueous and 80% methanol leaf extracts of Croton macrostachyus in saline-loaded rats.

Methods

Rats of either sex were randomly assigned into eight groups of eight animals per group. The animals were treated with vehicle (distilled water), standard (furosemide 10 mg/kg), and three doses (100, 200, and 400 mg/kg) of aqueous and 80% methanol leaf extracts after loading of normal saline (15 mL/kg). Then, urine volume, electrolyte concentration, and pH were measured as parameters of evaluation. Concentrations of urinary Na⁺ K⁺, and Cl^– were determined and Na⁺:K⁺ and Cl⁻:Na⁺ + K⁺ ratios calculated to reveal possible mechanisms.

Results

The aqueous extract at 200 mg/kg had produced significant diuresis by hour 3, while the same dose of 80% methanol extract had produced substantial diuresis by the end of hour 4. Both extracts at 400 mg/kg produced significant diuresis from hour 2 to hour 5. In terms of effect on electrolysis, 400 mg/kg aqueous extract produced significant natriuresis, and a kaliuresis effect was observed for both extracts at higher doses and 200 mg/kg aqueous extract.

Conclusion

The findings collectively indicated that both aqueous and 80% methanol extract showed significant diuretic activity, thereby justifying the plant’s traditional use as a diuretic agent.

Ethnoveterinary for food-producing animals and related food safety issues: A comprehensive overview about terpenes

Alternatives to the use of conventional veterinary drugs in food-producing animals have gained attention, such as the use of natural products (NPs), mainly to soften the risks to the animal, the environment, and consumer's health. Although NPs have consistent advantages over conventional drugs, they cannot be considered risk free under food safety matters. In this way, this document presents a comprehensive overview of the importance of considering both the pharmacological and toxicological properties of the constituents of a NP from plants intending the standardization and regulation of its use in food-producing animals. Terpenes are the most diverse class of natural substances present in NP of vegetal origin with a broad range of biological activities that can be explored in veterinary science; however, certain plants and terpenes also have significant toxic effects, a fact that can harm the health of animals and consequently generate economic losses and risks for humans. In this context, this review gathered scientific data of vegetal species of importance to ethnoveterinary for food-producing animals, which produce terpenes, its biological effects, and their implications on food safety issues for consumers. For this, more than 300 documents were selected from different online scientific databases. The present data and discussion may contribute to the rational commercial exploration of this class of NPs in veterinary medicine.

Protective Effect of Croton macrostachyus (Euphorbiaceae) Stem Bark on Cyclophosphamide-Induced Nephrotoxicity in Rats

Background

Cyclophosphamide is an alkylating antineoplastic agent and its major limitation is injury to normal tissue, leading to multiple organ toxicity, including kidney, heart, liver and reproductive toxicity. Croton macrostachyus (Euphorbiaceae) has been used in Ethiopian traditional medicine to manage renal diseases.

Objective

The present study aims to assess the protective effect of the stem bark extract and solvent fractions of Croton macrostachyus on cyclophosphamide-induced nephrotoxicity in rats.

Methods

Nephrotoxicity was induced using cyclophosphamide 200 mg/kg i.p injection on the first day of the experiment. The negative control groups were administered with cyclophosphamide alone (200 mg/kg, i.p.). The crude extracts were administered at three dose levels (100, 200, and 400 mg/kg), while aqueous and ethyl acetate fractions were given at two dose levels (100 and 200 mg/kg). Excepting the normal control, all groups were subjected to cyclophosphamide toxicity on the first day.

Results

Treatment with crude extract 100 mg/kg and ethyl acetate fraction significantly decreased kidney-to-body weight ratio (P < 0.001). In addition, treatment with Croton macrostachyus crude extract and solvent fractions significantly decreased serum blood urea nitrogen (BUN) level (P < 0.001). Treatment with 100 and 200 mg/kg of ethyl acetate fraction significantly decreased serum creatinine level. Histopathological results confirmed the protective effect of the crude extract and solvent fractions of Croton macrostachyus.

Conclusion

Croton macrostachyus possesses nephroprotective activities and it could be a possible source of treatment for cyclophosphamide-induced nephrotoxicity.

In vitro Antioxidant and in vivo Hepatoprotective Activities of Root Bark Extract and Solvent Fractions of Croton macrostachyus Hochst. Ex Del. (Euphorbiaceae) on Paracetamol-Induced Liver Damage in Mice

Background

Liver disease is a major public health threat, particularly in developing countries. Several medicinal plants and formulations have been claimed to have liver protective activities. The present study aimed to evaluate in vitro antioxidant and in vivo hepatoprotective activities of root bark extracts of Croton macrostachyus (Euphorbiaceae).

Methods

Free radical scavenging activity of crude extract and solvent fractions of the plant was conducted using the DPPH assay method. Hepatoprotective activities of the crude extract and solvent fractions of the plant were carried out based on paracetamol-induced liver damage in mice. Serum biomarkers (AST, ALT, ALP, total bilirubin and total protein) were assessed to find out the effect. Histopathological examination was also carried out for all groups of mice to further confirm the findings.

Results

Antioxidant assay revealed that the crude extract, aqueous fraction and chloroform fraction of Croton macrostachyus exhibited free radical scavenging activity with IC₅₀ values of 128.6, 168.9, and 406 µg/mL, respectively. Pretreatment of the mice with the crude extract and solvent fractions of Croton macrostachyus significantly reduced ALP (p<0.001), ALT (p<0.001), and AST (p<0.001) levels at all the administered doses compared to the toxic group. The crude extract and chloroform fraction decreased total bilirubin level at doses of 200 mg/kg (P<0.05) and 400 mg/kg (P<0.001). Pretreatment of the mice with 400 mg/kg of the crude extract and aqueous fraction elevated total protein value compared to the paracetamol treated group (P<0.05). The hepatoprotective activities of the plant extracts were confirmed by histopathological studies.

Conclusion

From this study, it can be concluded that the crude extract and solvent fractions of Croton macrostachyus demonstrated antioxidant and hepatoprotective activities.

Physico-chemical, antioxidant and anti-microbial properties of some Ethiopian mono-floral honeys

Honey has been widely used to treat several human pathogens. However, all honeys may not have equal potencies against different human pathogens. The purpose of the current work was to investigate the physico-chemical and antimicrobial qualities of some mono-floral honeys from Ethiopia against some human pathogen bacteria and fungi. In the study, seven different botanical origin honeys were used of which some were from plants known for their medicinal properties. The samples were tested for their major physico-chemical properties (sugar profiles, total free acids, pH, color, electric conductivity and total soluble substances) and their medicinal values as total antioxidant capacity, total phenolic content and antimicrobial properties as minimum inhibitory concentration against some human pathogens, following standard protocols. Generally, the average values of the physico-chemical properties of the samples were within the acceptable ranges of world honey quality values. The average total antioxidant value of the samples was 320.3 ± 15.1 with range of 225.4 ± 12.8-465.7 ± 21.8 μM Fe(II)/100g. Relatively higher values 421.5 ± 23.4 and 465.7 ± 21.8μM Fe(II)/100g recorded for Croton macrostachyus and Vernonia amygalina honeys respectively. The average phenolic contents of the samples varied from 233.3 ± 24.0 to 693.3 ± 26.8 mgGAE/kg and relatively higher values recorded for C. macrostachys and V. amygdalina honeys. The significant proportion of the tested samples showed strong antimicrobial qualities inhibiting the growth of tested pathogens at concentration of 10.5%-28.6% of MIC (% v/v). Honeys from medicinal plants (C. macrostachys and V. amygdalina) relatively showed more antimicrobial properties which could be due to the presence of plant specific phytochemicals which require further investigations.

Evaluation of Antiulcer Activity of 80% Methanol Extract and Solvent Fractions of the Root of Croton macrostachyus Hocsht: Ex Del. (Euphorbiaceae) in Rodents

Background

Peptic ulcer disease causes significant mortality and morbidity. Plant kingdom provides a useful source for the development of new antiulcer agents. Croton macrostachyus is traditionally used to treat peptic ulcer in Ethiopia. This study aimed to evaluate the antiulcer activity of C. macrostachyus root extracts in rodents using different models.

Methods

The crude extract was obtained by cold maceration in 80% methanol and fractionated with chloroform, ethyl acetate, and distilled water. The antiulcer activity was evaluated using pylorus ligation-induced ulcer model in Sprague Dawley rats and acidified ethanol-induced ulcer model in Swiss albino mice. The test groups received three doses (100, 200, and 400 mg/kg) of the crude extract and fractions for 7 days before induction of ulcer. Positive controls received omeprazole 30 mg/kg for the pylorus ligation-induced ulcer model and sucralfate 100 mg/kg for the acidified ethanol-induced ulcer model. Negative controls received vehicle (2% tween 80).

Results

The crude hydromethanolic extract of C. macrostachyus showed significant (p < 0.05) antiulcer activity on both pyloric ligation and HCl/ethanol-induced ulcer in rats and mice. It has antisecretary effect (p < 0.001) as well. All three administered doses of chloroform fraction (p < 0.05) and only higher doses of ethyl acetate fraction (p < 0.05) possessed significant antiulcer activity. In contrast, the aqueous fraction did not have significant antiulcer effect at all tested doses.

Conclusion

The present study demonstrated that the crude extract, chloroform, and ethyl acetate fractions possessed significant dose-dependent antiulcer activity.

Chemical Constituents from Croton Species and Their Biological Activities

The genus Croton belongs to the Euphorbiaceae family, which comprises approximately 1300 species. Many Croton species have been used as folk medicines. This review focuses on the chemical constituents from Croton species and their relevant biological activities, covering the period from 2006 to 2018. A total of 399 new compounds, including 339 diterpenoids, were reported. Diterpenoids are characteristic components of the Croton species. These isolated compounds exhibited a broad spectrum of bioactivities, including cytotoxic, anti-inflammatory, antifungal, acetylcholinesterase inhibitory, and neurite outgrowth-promoting properties. The present review provides a significant clue for further research of the chemical constituents from the Croton species as potential medicines.

Antimalarial Activity of Croton macrostachyus Stem Bark Extracts against Plasmodium berghei In Vivo

There is an increasing need for innovative drug and prophylaxis discovery against malaria. The aim of the present study was to test in vivo antiplasmodial activity of Croton macrostachyus H. (Euphorbiaceae) stem bark extracts from Kenyan folkloric medicine. Inbred Balb/c mice were inoculated with erythrocytes parasitized with Plasmodium berghei (ANKA). Different doses (500, 250, and 100 mg/kg) of C. macrostachyus ethyl acetate, methanol, aqueous, and isobutanol extracts were administrated either after inoculation (Peters' 4-day suppressive test) or before inoculation (chemoprotective test) of the parasitized erythrocytes. All the extracts showed significant suppression of parasitemia compared to control (p < 0.001): for the ethyl acetate extract in the range of 58–82%, for the methanol extract in the range of 27–68%, for the aqueous extract in the range of 24–72%, and for the isobutanol extract in the range of 61–80%. Chemoprotective effect was significant (p < 0.001) and the suppression caused by the ethyl acetate extract was between 74 and 100%, by the methanol extract between 57 and 83%, and by the isobutanol extract between 86–92%. The study showed that it is possible to inhibit the growth of the parasites by various stem bark extracts of C. macrostachyus in Balb/c mice supporting the folkloric use of the plant against malaria.