Antimicrobial and antivirulence saponins of Mimusops laurifolia leaves.

Mimusops laurifolia is a native species restricted to the Red Sea mountains and Gulf of Aden. Its leaves contain saponins with wide range of biological activities. The presented research aimed to prepare saponins-rich extract from n-butanol fraction of M. laurifolia leaves and screen it for promising antimicrobial activities. Minimum inhibitory concentration (MIC) of the prepared saponins against Candida albicans, and their potential anti-pathogenic and antivirulence effects were determined. Different concentrations of the saponins-rich extract were investigated for their antimicrobial potential, particularly against C. albicans, using the agar well diffusion method. To assess the potential antivirulence and antipathogenic effects, we carried out molecular docking of the bioactive saponins against four key enzymes in C. albicans, which are involved in virulence and/or pathogenicity. Different concentrations of the investigated mixture showed notable antifungal activity against C. albicans with an MIC value of 6.4 µg ml-1. Docking analysis of the investigated saponins showed their affinity toward the docked enzymes, particularly saponin 1 with secreted aspartic proteinase 3 and saponin 6 with secreted aspartic proteinase 5. Thereafter, the stability of these two protein-ligand interactions was investigated using molecular dynamics (MD) simulation. The molecular interactions between saponins and the enzymes' active sites were analyzed and discussed.

Hepatoprotective role of myricitrin isolated from Mimusops elengi Linn. leaves extract on γ-radiation-induced liver damage in rats: Phyto-biochemical investigations.

The hepatoprotective effects of methanol extract of Mimusops elengi Linn. (M. elengi L.) leaves and isolated pure myricitrin (3-, 4-, 5-, 5, 7-five hydroxyflavone-3-O-α-l-rhamnoside) (Myr) were evaluated in male rats exposed to γ-irradiation. The extraction of M. elengi L. leaves was performed using ethyl acetate (EtOAC). Seven groups of rats were used: control group, irradiated (IRR) group (6 Gy of γ-rays in a single dose), vehicle group (oral administration of 0.5% carboxymethyl cellulose for 10 days), EtOAC extract group (100 mg/kg body weight of extract, orally for 10 days), EtOAC + IRR group (administration of extract and exposure to γ-rays on Day 7), Myr group (50 mg/kg body weight Myr, orally for 10 days), and Myr + IRR group (administration of Myr and exposure to γ-rays on Day 7). High-performance liquid chromatography and 1H-nuclear magnetic resonance were used to isolate and characterize the compounds from M. elengi L. leaves. Enzyme-linked immunosorbent assay was used for biochemical analyses. Identified compounds were Myr, myricetin 3-O-galactoside, myricetin 3-O-rahmnopyranoside (1 → 6) glucopyranoside, quercetin, quercitol, gallic acid, α-,ß-amyrin, ursolic acid, and lupeol. Serum aspartate transaminase and alanine transaminase activities were significantly increased, while serum protein and albumin levels were significantly decreased after irradiation. Hepatic levels of tumor necrosis factor-α, prostaglandin 2, inducible nitric oxide synthase, interleukin-6 (IL-6), and IL-12 were increased following irradiation. Improvements were observed in most serological parameters after treatment with extract or pure Myr, with histological analyses confirming decreased liver injury in treated rats. Our study demonstrates that pure Myr has a greater hepatoprotective effect than M. elengi leaf extracts against irradiation-induced hepatic inflammation.

Mimusops elengi (Bakula) Gelatinolytic Protease and its Plasmin-like Action on the Blood Clot.

BACKGROUND: Mimusops elengi, popularly known as Bakula in Ayurvedic Medicine, is a member of the Sapotaceae family. Concerning the traditional and Ayurvedic medicinal use of Mimusops elengi leaves, especially in wound healing and oral care, the plausible presence of proteolytic activity in an aqueous Mimusops elengi leaf extract was investigated in our study. METHODS: Mimusops elengi Gelatinolytic Protease was named after fractioning the extract. The Zymogram assay validated the gelatin specificity. The effect of MEGP on the wound healing process was investigated using a different assay. RESULTS: The presence of protease with gelatinolytic & caseinolytic activity at 62.53±1.43 U/h and 15.31±0.64 U/h, respectively. The aqueous enzyme fraction was named Mimusops elengi Gelatinolytic Protease (MEGP). The specificity of gelatin was confirmed by zymogram. Gelatinolytic activity of MEGP was also higher than that of trypsin at 27.96±0.38 U/h. MEGP was 49.14±1.61 % inhibited by PMSF, indicating the predominant presence of serine proteases. The optimal pH and temperature for MEGP were found to be 8 and 37°C, implying that it is an alkaline protease. MEGP dissolved the blood clot at a rate of 8.41±1.04 U/h, which is higher than the trypsin clot-dissolving rate of 1.027±0.04 U/h. The plasma clot hydrolytic capacity is confirmed when MEGP hydrolyzes alpha-polymer subunits in a dose-dependent manner. CONCLUSION: This investigation shows that MEGP has a plasmin-like activity that possesses a significant role in clot disintegration and other wound ailments, warranting its use in traditional Indian medicine.

Mimusops elengi Flower-Mediated Green Silver Nanoparticles Control Staphylococcus aureus and Acinetobacter baumannii.

The use of antibiotics against infection-causing bacteria is inactivated, due to the presence of antibiotic-degrading enzymes. These enzymes resist the action of antibiotics and make difficult for the already existing antibiotics to break the drug resistance. Hence, there is a need to formulate alternate therapies against the enzymes providing multidrug resistance to bacteria including Staphylococcus aureus and Acinetobacter baumannii. A silver nanoparticle coated with the natural compounds is a way of finding an alternative to the traditional antibiotics. Objective of the study was to identify and assess Mimusops elengi's floral silver nanoparticles (MENP) for its effective antibacterial activity. The methods involved were in silico analysis involving screening by ADME; drug likeness and docking of ligand to the protein (CrtM and CTX-M-15); in vitro analysis which included silver nanoparticle preparation; characterization by UV-Vis spectrum; SEM, FT-IR, DLS, and antimicrobial assays which include agar well diffusion, minimum inhibitory concentration, minimum bactericidal concentration, and anti-biofilm assays. The compounds present in the flower extract were identified and their usability against the enzymes under study was assured by silico screening. The in vitro analysis furthermore supports through showing potent antibacterial activity of MENP against selected organisms. Hence both in silico and in vitro studies reveal that MENP can be used as an alternative to break multidrug resistance.

Differential Expression of Platelet Activation Markers, CD62P and CD63, after Exposure to Breast Cancer Cells Treated with Kigelia Africana, Ximenia Caffra and Mimusops Zeyheri Seed Oils In Vitro.

Cancer patients, including breast cancer patients, live in a hypercoagulable state. Chemo- and hormone- therapy used in the treatment of breast cancer increases the risk of thrombosis. Due to differences in health care services between developed and developing countries, the survival rate of women with breast cancer in developing countries is low. Consequently, ethnomedicines are used and their efficacy as potential alternatives are being scientifically explored. The seed oils of Kigelia africana, Ximenia caffra and Mimusops zeyheri have anti-proliferative effects on hormone-dependent (MCF-7) and cytotoxic effects on hormone-independent (MDA-MB-231) breast cancer cells. In this study, we determined if these seed oils reduce the thrombogenic ability of breast cancer cells by measuring the platelet surface expression of the activation-specific antigens CD62P and CD63. MDA-MB-231 and MCF-7 cells were pretreated with the seed oils before being exposed to whole blood of human female volunteers. An increase in CD62P and CD63 expression following whole blood exposure to untreated breast cancer cells was observed. Treated MDA-MB-231 cells reduced CD62P and CD63 expression while treated MCF-7 cells increased CD62P and decreased CD63 expression. Kigelia africana, Ximenia caffra and Mimusops zeyheri seed oils are able to reduce the thrombogenic ability of MDA-MB-231 breast cancer cells.

Investigating the Antioxidant and Cytocompatibility of Mimusops elengi Linn Extract over Human Gingival Fibroblast Cells.

Background-chlorhexidine (CHX) is most commonly used as a chemical plaque control agent. Nevertheless, its adverse effects, including teeth discoloration, taste alteration and calculus build-up, limit its use and divert us to medicinal herbs. The purpose of the study was to evaluate the phytochemical composition, antioxidant potential, and cytotoxic effects of Mimusops elengi Linn extract (ME) over normal human cultured adult gingival fibroblasts (HGFs). Methods-in vitro phytochemical screening, total flavonoid content, antioxidant potential by DPPH and Nitric Oxide (NO) radical scavenging activity, and cytotoxic effects of ME extracts over HGF were explored. The viability of HGF cells was determined using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT), neutral red uptake, and trypan blue assay after treatment with different concentrations of CHX and ME (0.3125 to 10 µg/mL). Results-ME showed some alkaloids, glycosides, saponins and flavonoids exhibited relatively moderate-to-good antioxidant potential. Increasing the concentration of CHX and ME from 0.3125 to 10 µg/mL reduced cell viability from 29.71% to 1.07% and 96.12% to 56.02%, respectively. At higher concentrations, CHX reduced the viability of cells by 52.36-fold compared to ME, revealed by MTT assay. At 10 µg/mL concentration, the mean cell viability of CHX and ME-treated cells was 2.24% and 57.45%, respectively, revealed by a neutral red assay. The viability of CHX- and ME-treated HGF cells estimated at higher concentrations (10 µg/mL) using trypan blue assay was found to be 2.18% and 47.36%, respectively. A paired t-test showed significance (p < 0.05), and one-way ANOVA difference between the mean cell viability of CHX- and ME-treated cells at different concentrations. One-way ANOVA confirmed the significant difference between the viability of CHX- and ME-treated cells. Conclusions-The cytoprotective and antioxidant effects of ME emphasize its potential benefits. Therefore, it could emerge as a herbal alternative and adjunct to conventional oral hygiene methods, that can diminish periodontal tissue destruction.

Chitosan composite microparticles: A promising gastroadhesive system for taxifolin.

Taxifolin possesses gastroprotective property but is characterized by low water solubility, is instabile in alkaline medium, and is degraded by the intestinal bacteria flora. The purpose of the work was therefore to produce a gastroadhesive formulation to prolong taxifolin residence time and release in the stomach. We first demonstrated that taxifolin is stable in simulated gastric fluid with or without pepsin and mucus, and is able to cross pig gastric mucus layer and stomach mucosa. Next, gastromucoadhesive microparticles composed of Syloid® AL-1 mesoporous silica, chitosan and HPMC were produced using spray-drying. Microparticles were characterized by a spherical shape and a mean volume-equivalent diameter around 12 µm. The optimized microparticles were able to release taxifolin and to adhere to pig stomach mucosa for 5 h.

Influence on the effect of titanium dioxide nanoparticles as an additive with Mimusops elengi methyl ester in a CI engine.

The current investigation has been aimed at the effective utilization of the alternative renewable feedstock towards propelling the diesel engine. A novel alternative feedstock, which is abundantly present in the south of India, Mimusops elengi was identified for this present investigation. The study was initiated with 20% of Mimusops elengi and methyl ester (B20) was blended with fossil diesel fuel on a volume basis. Moreover, it was observed that on the trade-off between the performance characteristics; the emission quantity was marginally higher. Concentrating on the environmental pollution caused by the diesel engine, an oxygenated nano additive, titanium oxide, was doped with the base fuel at different mass fractions of 25, 50, 75, and 100 parts per million (ppm). The result observed states that B20 with 25 ppm of titanium oxide nanoparticle (B20 + 25 ppm) established a 3.60% improvement in BTE (brake thermal efficiency) as equated with B20; furthermore, it resulted in 14.2% and 17.4% reduction in hydrocarbon and smoke emission, respectively, though it resulted in a marginal penalty of 14.72% in NOx.

Elemental composition and nutritional value of the edible fruits of Transvaal red milkwood (Mimusops zeyheri) and impact of soil quality.

Mimusops zeyheri is widely used in traditional medicine and for nourishment. Consequently, the elemental composition, including heavy metals concentrations in M. zeyheri fruits, sampled from industrial and mining areas in Gauteng and North West Province, South Africa, was determined. The results showed soil concentrations to be in decreasing order of K > Na > Ca > Mg > Fe > Al > Zn > Mn > Cu > Cr > Sr > Pb > As > Li > Ni ≈ Co > Rb > U > Bi > Ga > Be > Tl > Mo > Ba > Ag > Cd. Geoaccumulation indices showed moderate contamination by Cd that did not accumulate in the fruits whilst principal component analysis revealed metals in soils to originate from different anthropogenic sources in the area. The plant controlled uptake of metals to meet metabolic needs and levels of toxic metals was low making the fruits suitable for human consumption, even if picked from sites close to mining areas. Nutritional value of the fruits highlighted their positive contribution to the diet and showed them to be rich in Cr and Mn.

Influence of plant extracts mixed with endodontic sealers on the growth of oral pathogens in root canal: An in vitro study.

INTRODUCTION: Microbes are considered as the primary etiological agents in endodontic diseases. Ways of reducing these agents are root canal debridement and antibacterial filling materials. One of the factors in determining the success of endodontic treatment previously was sealing root canals with materials possessing potent bactericidal effect. Due to cytotoxic reactions of sealers and their inability to eliminate bacteria completely from dentinal tubules, trend to use natural plants extracts have been introduced. AIM: To compare antimicrobial activity of endodontic sealers added to herbal extracts. MATERIALS AND METHOD: Three sealers mixed with three herbal extracts were evaluated against seven strains of bacteria at various time intervals using Agar Diffusion Test. The mean zones of inhibition were measured. STATISTICAL ANALYSIS: All statistical analysis was performed using the SPSS 15 statistical software version, Chicago. Intergroup comparison was evaluated using Kruskal Walls test along with Mann Whitney U test. The Intragroup comparison was evaluatd using Friedman test along with Wilcoxon test. RESULTS: Statistically significant zones of bacterial growth inhibition were observed largest with Zinc Oxide Eugenol based sealer when mixed with Glycyrrhiza glabra (Licorice) followed in descending order by zinc oxide eugenol based sealer mixed with Tinospora cordifolia (Guduchi) and Mimusops elengi (Bakul) respectively. CONCLUSION: Zinc Oxide Eugenol based sealer with herbal extracts produced largest inhibitory zones followed in descending order by Resin based sealer and Calcium hydroxide along with three herbal extracts respectively.

Two new aromatic glycosides, elengiosides A and B, from the flowers of Mimusops elengi.

Two new aromatic glycosides, elengiosides A (1) and B (2), were isolated from the methanolic extract of the flowers of Mimusops elengi (Sapotaceae) together with 26 known compounds. Their stereostructures were elucidated based on their spectroscopic properties and chemical evidence. Among the isolates, a phenylethanoid glycoside, undatuside C (14), was found to exhibit hyaluronidase inhibitory activity.

Elemental composition and nutritional value of the edible fruits of coastal red-milkwood (Mimusops caffra) and impact of soil quality on their chemical characteristics.

In this study, the elemental distribution of essential and toxic elements in the soil and fruits of the indigenous plant species, Mimusops caffra, from ten sites along the KwaZulu-Natal east coast was investigated using inductively coupled plasma-optical emission spectrometry. This was done to determine the nutritional value of the fruits as well as to evaluate the impact of soil quality on elemental uptake by the plant. The elemental concentrations in the fruits (in descending order) were found to be K > Na > Ca > Mg > Si > Al > Fe > Zn > Mn > Ni > Cr > Cu > Pb > Mo > Sb > As > Se > V > Cd > Co. The results show that approximately 10 g of fruit would contribute more than 85% towards the recommended dietary allowance for Fe and Si for most adults. The proximate chemical composition revealed the fruits to contain approximately 84% moisture, 4.7% ash, 6.9% protein, 1.7% oil and 2.7% carbohydrates. The study indicates that the fruits of this indigenous plant species are a good source of essential elements with low levels of potentially toxic elements (Pb, As and Cd) which makes the plant a good indigenous food source especially for vulnerable communities that need food security.

Aqueous fruit extract of Mimusops elengi causes reversible suppression of spermatogenesis and fertility in male mice.

Antifertility efficacy of oral administration of aqueous fruit extract of Mimusops elengi (200, 400 and 600 mg kg(-1) body weight/day for 35 days) was evaluated in Parkes strain male mice. Various reproductive end points such as histopathology, sperm parameters, testosterone level, haematology, serum biochemistry and fertility indices were assessed; activities of 3ß- and 17ß-hydroxysteroid dehydrogenases, and immunoblot expressions of StAR and P450scc in the testis were also assessed. Histologically, testes in Mimusops-treated mice showed nonuniform and diverse degenerative changes in the seminiferous tubules; both affected and normal tubules were observed in the same sections of testis. The treatment had adverse effects on testicular hydroxysteroid dehydrogenases and StAR and P450scc, serum level of testosterone and on motility, viability and number of spermatozoa in cauda epididymis. However, serum levels of alanine aminotransferase, aspartate aminotransferase and creatinine, and haematological parameters were not affected by the treatment. Also, libido was not affected in treated males, but their fertility was markedly suppressed. By 56 days of treatment withdrawal, the alterations caused in the above parameters recovered to control levels, suggesting that Mimusops treatment causes reversible suppression of spermatogenesis and fertility in Parkes mice. Further, there were no detectable signs of toxicity in treated males.

Mediterranean fruit fly on Mimusops zeyheri indigenous to South Africa: a threat to the horticulture industry.

BACKGROUND: Claims abound that the Transvaal red milkwood, Mimusops zeyheri, indigenous to areas with tropical and subtropical commercial fruit trees and fruiting vegetables in South Africa, is relatively pest free owing to its copious concentrations of latex in the above-ground organs. On account of observed fruit fly damage symptoms, a study was conducted to determine whether M. zeyheri was a host to the notorious quarantined Mediterranean fruit fly (Ceratitis capitata). RESULTS: Fruit samples were kept for 16-21 days in plastic pots containing moist steam-pasteurised growing medium with tops covered with a mesh sheath capable of retaining emerging flies. Microscopic diagnosis of the trapped flies suggested that the morphological characteristics were congruent with those of C. capitata, which was confirmed through cytochrome c oxidase I (COI) gene sequence alignment with a 100% bootstrap value and 99% confidence probability when compared with those from the National Centre for Biotechnology Information database. CONCLUSION: This study demonstrated that M. zeyheri is a host of C. capitata. Therefore, C. capitata from infestation reservoirs of M. zeyheri fruit trees could be a major threat to the tropical and subtropical fruit industries in South Africa owing to the fruit-bearing nature of the new host. © 2015 Society of Chemical Industry.

Eco-friendly control of malaria and arbovirus vectors using the mosquitofish Gambusia affinis and ultra-low dosages of Mimusops elengi-synthesized silver nanoparticles: towards an integrative approach?

Mosquito-borne diseases represent a deadly threat for millions of people worldwide. However, the use of synthetic insecticides to control Culicidae may lead to high operational costs and adverse non-target effects. Plant-borne compounds have been proposed for rapid extracellular synthesis of mosquitocidal nanoparticles. Their impact against biological control agents of mosquito larval populations has been poorly studied. We synthesized silver nanoparticles (AgNP) using the aqueous leaf extract of Mimusops elengi as a reducing and stabilizing agent. The formation of AgNP was studied using different biophysical methods, including UV-vis spectrophotometry, TEM, XRD, EDX and FTIR. Low doses of AgNP showed larvicidal and pupicidal toxicity against the malaria vector Anopheles stephensi and the arbovirus vector Aedes albopictus. AgNP LC50 against A. stephensi ranged from 12.53 (I instar larvae) to 23.55 ppm (pupae); LC50 against A. albopictus ranged from 11.72 ppm (I) to 21.46 ppm (pupae). In the field, the application of M. elengi extract and AgNP (10 × LC50) led to 100 % larval reduction after 72 h. In adulticidal experiments, AgNP showed LC50 of 13.7 ppm for A. stephensi and 14.7 ppm for A. albopictus. The predation efficiency of Gambusia affinis against A. stephensi and A. albopictus III instar larvae was 86.2 and 81.7 %, respectively. In AgNP-contaminated environments, predation was 93.7 and 88.6 %, respectively. This research demonstrates that M. elengi-synthesized AgNP may be employed at ultra-low doses to reduce larval populations of malaria and arbovirus vectors, without detrimental effects on predation rates of mosquito natural enemies, such as larvivorous fishes.

Gastroprotective bio-guiding study of fruits from Mimusops balata.

Mimusops spp. is used as plant-based antiulcer drugs in Indian traditional medicine. In this study, a bio-guiding study of methanolic extracts of Mimusops balata edible fruits was performed to identify an antiulcer gastric compound. The gastric lesions induced by HCl/ethanol in mice were significantly improved by methanolic extract from seed (MESe, 300 mg/kg), but not by methanolic extract from peel (MEPe, 300 mg/kg) or pulp (MEPu, 300 mg/kg), when compared to the vehicle group. Treatment with MESe also decreased gastric ulceration induced by indomethacin. The antiulcerogenic activity of MESe appears to involve the maintainance of GSH levels, reduction of LPO content, inhibition of neutrophil migration (as evidenced by a decrease in the MPO activity) and a potent free radical scavenger activity (IC50 = 3.4 µg/ml). Moreover, MESe decrease the gastric volume, pH, total acidity, and pepsin activity in the gastric juice. Exceptionally, MESe showed a high content of phenolic compound, identified by layer chromatography and Folin-Ciocalteu reagent. Considering the better pharmacological and phytochemical profile, MESe was successively partitioned and resulted in isolation and identification of a constituent, the flavonoid taxifolin, identified by spectroscopic methods ((1)H, (13)C NMR, and HPLC). Taxifolin also inhibited the ulcerogenic effect of HCl/ethanol at a low dose of 1.14 mg/kg and inhibited in vitro H+/K(+)-ATPase activity by 41% at a concentration of 100 µg/ml. Taken together, these results evidenced the gastroprotective potential of fruits from M. balata and showed that this effect is exclusive to the seeds.

Antimicrobial and antioxidant activities of Mimusops elengi seed extract mediated isotropic silver nanoparticles.

The present study reports the use of Mimusops elengi (M. elengi) fruit extract for the synthesis of silver nanoparticles (Ag NPs). The synthesized Ag NPs was initially noticed through visual color change from yellow to reddish brown and further confirmed by surface plasmonic resonance (SPR) band at 429 nm using UV-Visible spectroscopy. Morphology and size of Ag NPs was determined by Transmission Electron Microscopy (TEM) analysis. X-ray Diffraction (XRD) study revealed crystalline nature of Ag NPs. The prolonged stability of Ag NPs was due to capping of oxidized polyphenols which was established by Fourier Transform Infrared Spectroscopy (FTIR) study. The polyphenols present in M. elengi fruit extract was analyzed by High Pressure Liquid Chromatography (HPLC) and the results revealed the presence of ascorbic acid, gallic acid, pyrogallol and resorcinol. In order to study the role of these polyphenols in reducing Ag+ ions to Ag NPs, analyses of extracts before reduction and after reduction were carried out. In addition, the synthesized Ag NPs were tested for antibacterial and antioxidant activities against Staphylococcus aureus (S. Aureus) and Escherichia coli (E. coli). Ag NPs showed good antimicrobial activity against both gram positive (S. aureus) and gram negative (E. coli) bacteria. It also showed good antioxidant activity as compared to ascorbic acid as standard antioxidant.

Anti-HIV-1 integrase activity of Mimusops elengi leaf extracts.

CONTEXT: Integrase (IN) is one of the three human immunodeficiency virus type 1 (HIV-1) enzymes that, together with a reverse transcriptase and protease, allow the virus to reproduce itself after infecting the host cells. Any new knowledge on inhibitors of this enzyme could provide essential clues for the development of anti-HIV drugs. OBJECTIVE: To evaluate the anti-HIV-1 IN activity of some Thai medicinal plant extracts, and to isolate the active compounds from the extract that possessed the strongest anti-HIV-1 IN activity. MATERIALS AND METHODS: Ethanol extracts of eight Thai medicinal plants (10-100 µg/mL) were evaluated for their inhibitory effect against HIV-1 IN. An extract of Mimusops elengi L. (Sapotaceae) leaves that possessed the strongest anti-HIV-1 IN activity was fractionated to isolate the active compounds by an anti-HIV-1 IN assay-guided isolation process. RESULTS AND DISCUSSION: The leaf extract from M. elengi had the strongest anti-HIV-1 IN activity with an IC50 value of 62.1 µg/mL. A bioassay-guided isolation of the active compounds from M. elengi leaf extract resulted in the isolation of active compounds, identified as a mixture of gallocatechin and epigallocatechin. This mixture of gallocatechin and epigallocatechin showed satisfactory anti-HIV-1 IN activity with an IC50 value of 35.0 µM. A flavanol glycoside, mearnsitrin was also isolated but was inactive at a concentration of 100 µM.

Anti-plasmodial activity of some Zulu medicinal plants and of some triterpenes isolated from them.

Mimusops caffra E. Mey. ex A.DC and Mimusops obtusifolia Lam (both members of the Sapotaceae family), and Hypoxis colchicifolia Bak (family Hypoxidaceae) are used by traditional healers in Zululand to manage malaria. Anti-plasmodial investigation of the crude extracts and some triterpenes isolated from the plants showed activity against a chloroquine sensitive (CQS) strain of Plasmodium falciparum (D10). Among the crude extracts the leaves of M. caffra exhibited the highest activity, with an IC50 of 2.14 µg/mL. The pentacyclic tritepenoid ursolic acid (1), isolated from the leaves of M. caffra was the most active compound (IC50 6.8 µg/mL) as compared to taraxerol (2) and sawamilletin (3) isolated from the stem bark of M. obtusifolia (IC50 > 100). Chemical modification of the ursolic acid (1) to 3ß-acetylursolic acid (4) greatly enhanced its anti-plasmodial activity. Compound 4 reduced parasitaemia against Plasmodium berghei by 94.01% in in vivo studies in mice. The cytotoxicity of 3ß-acetylursolic acid (IC50) to two human cell lines (HEK293 and HepG2) was 366.00 µg/mL and 566.09 µg/mL, respectively. The results validate the use of these plants in folk medicine.