Ximenia americana: Economic Importance, Medicinal Value, and Current Status in Ethiopia

Ximenia americana is one of the most valuable wild edible plants in the world. In different countries, it is utilized as food, medicine, an essential oil source, and the industrial component to other products. In Ethiopia, it was one of the most known and very important plants for a long period of time. It was utilized as food, a medicinal plant, and animal feed. It was also one of the most economically important and culturally valuable plants. But nowadays, it is not adequately available in the country due to deforestation problem in the years. In addition, its economic importance, current status, and medicinal roles are not well documented and understood. As for research studies, it is concluded that unless a collective effort is taken, the existence of this plant is under severe threat and needs to have some measures. This review article is aimed at addressing the abovelined topics in detail and to pinpoint and explain the importance and status of Ximenia americana.

Studies on Ethanol Extracts of Olax subscorpioidea Against Carbon Tetrachloride-Induced Hepatotoxicity in Rats

<b>Background and Objective:</b> Liver disease orchestrated by noxious chemicals are serious health problems the world over. Traditionally, there are claims that ethanol extracts of leaves and stem barks of <i>Olax subscorpioidea</i> are used in the treatment of hepatic disorders. Thus, it investigated the impacts of ethanol extract of leaves and stem bark of <i>Olax subscorpioidea</i> against carbon tetrachloride (CCl₄)-induced liver damage in rats. <b>Materials and Methods:</b> Liver toxicity was induced by intraperitoneal injection of 2.5 mg kg¹ b.wt., of CCl₄ in experimental rats. Rats were treated with 200, 400 and 800 mg kg¹ dose ethanol leaves and stem bark of <i>Olax subscorpioidea</i>, respectively after induction of liver damage. <b>Results:</b> Obtained results showed a significant rise in the serum levels of Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Malondialdehyde (MDA) and bilirubin as well as decreased Albumin (ALB), Superoxide Dismutase (SOD), Catalase (CAT), reduced Glutathione (GSH) in CCl₄-challenged rats. Treatment with the extracts attenuated serum levels of AST, ALT, ALP, MDA and bilirubin in addition to increased activities of SOD, CAT and the levels of ALB and GSH when compared to the CCl₄ group. Histopathological studies demonstrated that the extracts ameliorated liver necrosis and inflammation due to CCl₄ insult. <b>Conclusion:</b> These results concluded that ethanol extract of leaves and stem bark of <i>Olax subscorpioidea </i>may reduce hepatic oxidative injury caused by CCl₄ by its antioxidant potentials.

Phytochemical study, molecular docking, genotoxicity and therapeutic efficacy of the aqueous extract of the stem bark of Ximenia americana L. in the treatment of experimental COPD in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ximenia americana L. is popularly known as yellow plum, brave plum or tallow wood. All the parts of this plant are used in popular medicine. Its reddish and smooth bark are used to treat skin infections, inflammation of the mucous membranes and in the wound healing process.

OBJECTIVE

Verification of phytochemical profile, the molecular interaction between flavonoid, (-) epi-catechin and 5-LOX enzyme, by means of in silico study, the genotoxic effect and to investigate the pharmacological action of the aqueous extract of the stem bark of X. americana in pulmonary alterations caused by experimental COPD in Rattus norvegicus.

MATERIALS AND METHODS

The identification of secondary metabolites was carried out by TLC and HPLC chromatographic methods, molecular anchoring tests were applied to analyze the interaction of flavonoid present in the extract with the enzyme involved in pulmonary inflammation process and the genotoxic effect was assessed by comet assay and micronucleus test. For induction of COPD, male rats were distributed in seven groups. The control group was exposed only to ambient air and six were subjected to passive smoke inhalations for 20 min/day for 60 days. One of the groups exposed to cigarette smoke did not receive treatment. The others were treated by inhalation with beclomethasone dipropionate (400 mcg/kg) and aqueous and lyophilized extracts of X. americana (500 mg/kg) separately or in combination for a period of 15 days. The structural and inflammatory pulmonary alterations were evaluated by histological examination. Additional morphometric analyses were performed, including the alveolar diameter and the thickness of the right ventricle wall.

RESULTS

The results showed that the aqueous extract of the bark of X. americana possesses (-) epi -catechin, in silico studies with 5-LOX indicate that the EpiC ligand showed better affinity parameters than the AracA ligand, which is in accordance with the results obtained in vivo studies. Genotoxity was not observed at the dose tested and the extract was able to stagnate the alveolar enlargement caused by the destruction of the interalveolar septa, attenuation of mucus production and decrease the presence of collagen fibers in the bronchi of animals submitted to cigarette smoke.

CONCLUSION

Altogether, the results proved that the aqueous extract of X. americana presents itself as a new option of therapeutic approach in the treatment of COPD.

Eglerisine, a Novel Sesquiterpenoid Tropolone from Dulacia egleri with Antiproliferative Effect against an Acute Myeloid Leukemia Lineage

Chemical investigation of the stems of Dulacia egleri resulted in the isolation of eglerisine (1: ), a compound with a rare sesquiterpenoid tropolone skeleton. Its structure was determined by analysis of spectrometric and spectroscopic data, including HRESIMS, 1D, and 2D NMR. The antiproliferative effects of eglerisine were tested in human leukemia lineages. In the Kasumi-1 lineage, an acute myeloid leukemia cell line, eglerisine reduced cell metabolism, as determined by the resazurin assay. Eglerisine did not induce cell death by either apoptotic or necrotic mechanisms. However, a reduction of the absolute number of cells was observed. Eglerisine induced cell cycle arrest after 72 h of treatment by phosphorylation of H2AX histone, reducing the S phase and increasing the G2 phase of the cell cycle.

An Overview on the Properties of Ximenia Oil Used as Cosmetic in Angola

Ximenia (Ximenia americana L.) is a shrub, or small tree, native from Africa and spread across different continents. In Angola, the seeds oil is used by local populations, to prevent sunburn, to smooth and hydrate the skin, and to give it a pleasant color and elasticity, to prevent stretch marks, in pregnant woman, and also as hair conditioner. Herein, an oil sold in the region (LPO), and two others extracted in laboratory, from seeds collected in the same region, were investigated in terms of their composition, chemical properties, UV transmission. The three oils are similar although the LPO is more acidic, 0.48 mg KOH/g. GC-MS analysis indicated that the major components are the fatty acids, oleic (31.82%), nervonic (11.09%), ximenic (10.22%), and hexacosa-17,20,23-trienoic acids (14.59%). Long chain fatty acids, n ≥ 20, accounted for 51.1% of the total fatty acids. A thin film of the oil showed a reduction in transmittance from 200 to 300 nm. Viscosity studies of the LPO indicated that at normal temperature of skin, the oil can be spread over the skin as a thin film. At concentrations up to 10 µg/mL, the LPO is not toxic to human keratinocytes, suggesting the safety of this oil.

Isolation and structure elucidation of cyclopeptide alkaloids from the leaves of Heisteria parvifolia

Heisteria parvifolia Sm. is prescribed in traditional medecine against numerous diseases in Côte d'Ivoire. Due to the shortcoming in scientifical knowledge of use of this species, our investigations revealed five undescribed cyclopeptide alkaloids added to one known derivative namely anorldianine. These compounds were elucidated by 1D and 2D-NMR experiments and comparison with literature data, and confirmed by HR-ESI-MS. Cytotoxic activity evaluation of these compounds against the chronic myeloid leukemia (K565) cell line exhibited an antiproliferative activity with cell growth inhibition from 13% to 46%.

Transcriptome analysis reveals crucial genes involved in the biosynthesis of nervonic acid in woody Malania oleifera oilseeds

BACKGROUND

Malania oleifera Chun et Lee (Olacaceae), an evergreen broad-leaved woody tree native to southwest China, is an important oilseed tree. Its seed oil has a high level of nervonic acid (cis-tetracos-15-enoic acid, over 60%), which is essential for human health. M. oleifera seed oil is a promising source of nervonic acid, but little is known about the physiological and molecular mechanisms underlying its biosynthesis.

RESULTS

In this study, we recorded oil accumulation at four stages of seed development. Using a high-throughput RNA-sequencing technique, we obtained 55,843 unigenes, of which 29,176 unigenes were functionally annotated. By comparison, 22,833 unigenes had a two-fold or greater expression at the fast oil accumulation stage than at the initial stage. Of these, 198 unigenes were identified as being functionally involved in diverse lipid metabolism processes (including de novo fatty acid synthesis, carbon chain elongation and modification, and triacylglycerol assembly). Key genes (encoding KCS, KCR, HCD and ECR), putatively responsible for nervonic acid biosynthesis, were isolated and their expression profiles during seed development were confirmed by quantitative real-time PCR analysis. Also, we isolated regulatory factors (such as WRI1, ABI3 and FUS3) that are putatively involved in the regulation of oil biosynthesis and seed development.

CONCLUSION

Our results provide novel data on the physiological and molecular mechanisms of nervonic acid biosynthesis and oil accumulation in M. oleifera seeds, and will also serve as a starting point for biotechnological genetic engineering for the production of nervonic acid resources.

Efficacy of plants extracts from the Cerrado against adult female of Dermacentor nitens (Acari: Ixodidae)

Dermacentor nitens tick is commonly found in the equine auditory canal, where it causes economic losses due to its direct damage, causing blood spoliation, stress, transmission of pathogens, and predisposition to myasis and secondary bacterial infection in its hosts. In this study we evaluated the effect of ethanolic extracts of Cerrado plants on biological parameters of engorged females of D. nitens. Ethanolic extracts were prepared from the leaves of Schinopsis brasiliensis, Piptadenia viridiflora, Ximenia americana, and Serjania lethalis at 25-150 mg mL^-1. Groups of 10 engorged adult females were treated with these extracts and compared with a control containing distilled water and another control with organophosphate, using five replicates for each group. Compared with the control with water, S. lethalis and X. americana extracts at 100 and 150 mg mL^-1 significantly inhibited the posture ability. Differently, extracts of S. brasiliensis and P. viridiflora were the most effective in inhibiting larval hatching. Extracts of X. americana and P. viridiflora showed effective inhibition of reproductive parameters of the tick, presenting dose-dependent effect with IC₉₀ 78.86 and 78.94 mg mL^-1, respectively. Theses effective extracts contained low condensed tannin levels and their HPLC chromatograms revealed the presence of flavonoids. The efficacies of P. viridiflora and X. americana extracts were higher than 90% indicating that these extracts are promising as alternative agents for D. nitens control.

Effect of ginger, Paullinia cupana, muira puama and l- citrulline, singly or in combination, on modulation of the inducible nitric oxide- NO-cGMP pathway in rat penile smooth muscle cells

INTRODUCTION

COMP-4 is a natural compound-based dietary supplement consisting of the combination of ginger, Paullinia cupana, muira puama and l-citrulline, which when given long-term has been shown in the aged rat to a) upregulate iNOS in the penile smooth muscle cells (SMC), b) reverse the corporal SMC apoptosis and fibrosis associated with corporal veno-occlusive dysfunction (CVOD), and c) improve resulting erectile function. To elucidate the mechanism of how COMP-4 and its individual components modulate the iNOS-cGMP pathway, an in vitro study was conducted using a rat corporal primary SMC culture to determine its effect on NOS, soluble guanylate cyclase (sGC), cGMP and the phosphodiesterase 5 enzyme (PDE5).

MATERIALS AND METHODS

Primary SMC cultures using the explant technique were initiated by cutting small pieces of corporal tissue from 8 week old Sprague-Dawley rats. The SMC were grown in Dulbecco media with 20% fetal calf serum. The SMC were then incubated with or without COMP-4 (0.69 mg/ml) or its ingredients alone (ginger: 0.225 mg/ml; muira puama, Paullinia cupana and l-citrulline each at 0.9 mg/ml) for up to 24 h mRNA and protein were extracted and used for the determination of NOS, sGC and PDE5 content. cGMP content was determined by ELISA. L-NIL (4 μM) was used as an inhibitor of iNOS activity.

RESULTS

Compared to the control values, COMP-4 upregulated expression of cGMP by 85%, induced a 42 fold increase in sGC as well as a 15 fold increase in both iNOS protein and mRNA content while it decreased both PDE5 mRNA and protein content each by about 50%. L-NIL completely inhibited the effect of COMP-4 on cGMP production. When compared with each of the individual four components of COMP-4, it appears that COMP-4 itself had the most profound effect in modulating each one the specific steps within the iNOS-cGMP pathway.

CONCLUSIONS

This in vitro study demonstrates that COMP-4 is capable of activating the endogenous cellular iNOS-cGMP pathway within the CSM cells, which is theorized to be responsible for reducing the fibrosis and apoptosis as well as the CVOD observed in the aging rat penis. Further studies will be necessary in order to determine whether supplementation of COMP-4 on a daily basis may be beneficial in halting or reversing this aging related erectile dysfunction in the clinical setting.

Contribution of Secondary Metabolites to the Gastroprotective Effect of Aqueous Extract of Ximenia americana L. (Olacaceae) Stem Bark in Rats

Ximenia americana L. (Olacaceae) is used in ethnomedicine as cicatrizant and for the treatment of gastric disorders. This study identified the chemical constituents of the aqueous extract of X. americana (XaAE) and evaluated its antiulcerogenic activity. After lyophilization, XaAE was analyzed by liquid chromatography-mass spectrometry (LC-MS) and its antiulcerogenic effect was evaluated in acute gastric lesions induced by ethanol, acidified ethanol, and indomethacin. Antisecretory action, mucus production and the participation of sulfhydryl groups (-SH) and nitric oxide (NO) were also investigated. The chromatographic analysis identified procyanidins B and C and catechin/epicatechin as major compounds. Oral administration of XaAE (100, 200 and 400 mg/kg) inhibited the gastric lesions induced by ethanol (76.1%, 77.5% and 100%, respectively), acidified ethanol (44.9%, 80.6% and 94.9%, respectively) and indomethacin (56.4%, 52.7% and 64.9%, respectively). XaAE reduced gastric contents and acidity (51.4% and 67.7%, respectively) but did not alter the production of gastric mucus. The reduction of the -SH and NO groups promoted by N-ethylmaleimide (NEM) and Nω-nitro-l-arginine-methyl-ester (L-NAME) respectively, reduced the gastroprotective effect of XaAE. In conclusion, XaAE has gastroprotective activity mediated in part by -SH, NO and antisecretory activity. This antiulcer action was initially correlated to its major constituents, procyanidins B and C and catechin/epicatechin.

HPLC-DAD finger printing, antioxidant, cholinesterase, and α-glucosidase inhibitory potentials of a novel plant Olax nana

BACKGROUND

The medicinal importance of a novel plant Olax nana Wall. ex Benth. (family: Olacaceae) was revealed for the first time via HPLC-DAD finger printing, qualitative phytochemical analysis, antioxidant, cholinesterase, and α-glucosidase inhibitory assays.

METHODS

The crude methanolic extract of O. nana (ON-Cr) was subjected to qualitative phytochemical analysis and HPLC-DAD finger printing. The antioxidant potential of ON-Cr was assessed via 1,1-diphenyl,2-picrylhydrazyl (DPPH), 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS) and hydrogen peroxide (H2O2) free radical scavenging assays. Furthermore, acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities were performed using Ellman's assay, while α- glucosidase inhibitory assay was carried out using a standard protocol.

RESULTS

The qualitative phytochemical analysis of ON-Cr revealed the presence of secondary metabolites like alkaloids, flavonoids, tannins, sterols, saponins and terpenoids. The HPLC-DAD finger printing revealed the presence of 40 potential compounds in ON-Cr. Considerable anti-radical activities was revealed by ON-Cr in the DPPH, ABTS and H2O2 free radical scavenging assays with IC50 values of 71.46, 72.55 and 92.33 μg/mL, respectively. Furthermore, ON-Cr showed potent AChE and BChE inhibitory potentials as indicated by their IC50 values of 33.2 and 55.36 μg/mL, respectively. In the α-glucosidase inhibition assay, ON-Cr exhibited moderate inhibitory propensity with an IC50 value of 639.89 μg/mL.

CONCLUSIONS

This study investigated Olax nana for the first time for detailed qualitative phytochemical tests, HPLC-DAD finger printing analysis, antioxidant, anticholinesterase and α-glucosidase inhibition assays. The antioxidant and cholinesterase inhibitory results were considerable and can provide scientific basis for further studies on the neuroprotective and anti-Alzheimer's potentials of this plant. ON-Cr may further be subjected to fractionation and polarity guided fractionation to narrow down the search for isolation of bioactive compounds.

Aqueous extract of Securidaca longipendunculata Oliv. and Olax subscropioidea inhibits key enzymes (acetylcholinesterase and butyrylcholinesterase) linked with Alzheimer's disease in vitro

CONTEXT

Plants have historically been used to treat neurodegerative diseases which include Alzheimer's disease.

OBJECTIVE

This study investigated the antioxidant properties and inhibitory effect of aqueous extracts of Securidaca longipendunculata root and Olax subscropioidea leaf on the cholinergic system in rat brain in vitro.

MATERIALS AND METHODS

Aqueous extracts (1:20 w/v) of S. longipendunculata root and O. subscropioidea leaf was prepared and the ability of the extract to inhibit the activities of acetylcholinesterase and butyrylcholinesterase was evaluated as well as antioxidants as typified by 2,2-azino-bis-(3-ethylbenthiazoline-6-sulphonic acid (ABTS^•) radical scavenging ability and Fe chelation spectophotometrically.

RESULTS

ABTS^• radical scavenging ability showed that S. longipendunculata (0.075 Mmol TEAC/100 g) had a higher scavenging ability than O. subscropioidea (0.07 Mmol TEAC/100 g). Also, the Fe²⁺chelating ability of both extracts revealed that S. longipendunculata (IC₅₀=105.57 g/mL) had a significantly (p < 0.05) higher Fe²⁺chelating ability than O. subscropioidea (IC₅₀=255.84 g/mL). Extracts of S. longipendunculata and O. subscropioidea inhibited acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. However, S. longipendunculata (IC₅₀=108.02 g/mL) has the higher AChE inhibitory activity than O. subscropioidea (IC₅₀=110.35 g/mL). Also, both extracts inhibit BChE activity in vitro but S. longipendunculata (IC₅₀=82.55 g/mL) had a higher BChE inhibitory activity than O. subscropioidea (IC₅₀=108.44 g/mL).

DISCUSSION AND CONCLUSIONS

The mechanism by which S. longipendunculata root and O. subscropioidea leaf perform their anti-Alzheimer's disease activity may be by their inhibition on the key enzymes linked to this disease.

Hepatoprotective and hypoglycemic effects of a tannin rich extract from Ximenia americana var. caffra root

BACKGROUND

Liver diseases and diabetes are serious health disorders associated with oxidative stress and ageing. Some plant polyphenols can lower the risk of these diseases.

PURPOSE

We investigated the phytochemical profiling of a root extract from Ximenia americana var. caffra using HPLC-PDA-ESI-MS/MS. The antioxidant activities in vitro were investigated. The hepatoprotective activities were studied in rat models with d-galactosamine (d-GaIN)-induced hepatotoxicity and the antidiabetic activities in STZ-diabetic rats were also investigated.

MATERIALS AND METHODS

HPLC-PDA-ESI-MS/MS was used to identify plant phenolics. The antioxidant activities in vitro were determined using DPPH and FRAP assays. The in vivo hepatoprotective activities were determined for d-GaIN-induced hepatotoxicity in rats. We determined the liver markers alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT), liver peroxidation product malondialdehyde (MDA), glutathione content (GSH), albumin and total bilirubin concentration. The histopathological changes in rat liver were also studied. The antidiabetic activities were also investigated in STZ-diabetic rats and serum glucose, serum insulin hormone, and lipid peroxides were determined.

RESULTS

The root extract is rich in tannins with 20 compounds including a series of stereoisomers of (epi)catechin, (epi)catechin-(epi)catechin, (epi)catechin-(epi)catechin-(epi)catechin, and their galloyl esters. Promising antioxidant potential was observed in vitro in DPPH assay with EC₅₀ of 6.5 µg extract / 26 µg raw material and in FRAP assay with 19.54 mM FeSO₄ compared with ascorbic acid (EC₅₀ of 2.92 µg/ml) and quercetin (FeSO₄ 24.04 mM/mg), respectively. Significant reduction of serologic enzymatic markers and hepatic oxidative stress markers such as ALT, AST, MDA, GGT, and total bilirubin, as well as elevation of GSH and albumin were observed in rats with d-galactosamine-induced liver damage treated with the extract. These findings agree with a histopathological examination suggesting a hepatoprotective potential for the root extract. The root extract can mediate an antidiabetic effect by reducing elevated blood glucose and serum lipid peroxides levels and by increasing insulin in STZ-diabetic rats by -107, -31.1, +11.3%, respectively.

CONCLUSIONS

The results of this study suggest that the tannin-rich extract from Ximenia americana var. caffra could be an interesting candidate for the treatment of several health disorders associated with oxidative stress such as hepatocellular injury and diabetes.

Three indigenous plants used in anti-cancer remedies, Garcinia kola Heckel (stem bark), Uvaria chamae P. Beauv. (root) and Olax subscorpioidea Oliv. (root) show analgesic and anti-inflammatory activities in animal models

ETHNOPHARMACOLOGICAL RELEVANCE

Phytochemicals with anti-oxidative and anti-inflammatory properties are known to inhibit tumour initiation, promotion and progression. Hence, there is an increasingly-convincing rationale for employing remedies containing those phytochemicals in the treatment of cancers and also as analgesic and anti-inflammatory adjuvants in therapy. The plants Garcinia kola Heckel (Clusiaceae), stem bark; Uvaria chamae P. Beauv. (Annonaceae), root; and Olax subscorpioidea Oliv. (Olacaceae), root, have been documented to be part of various indigenous anti-cancer regimens.

AIM OF THE STUDY

To determine if the three plants exhibit significant anti-oxidative and anti-inflammatory properties.

MATERIALS AND METHODS

Using established models, the analgesic and anti-inflammatory activities of the three plants were investigated.

RESULTS

Pre-treatment with the plant extracts at 100, 200 and 400mg/kg produced inhibition of writhes; G. kola and U. chamae showed no significant effect on formalin-induced pain, but O. subscorpioidea produced inhibition in both phases of the formalin test. Similarly, while G. kola and U. chamae did not produce any significant inhibitory effect in the xylene-induced ear oedema model, the oedema was significantly reduced by O. subscorpioidea pre-treatment. However, all the three plants significantly inhibited the time-dependent increase in paw circumference in the carrageenan- and formaldehyde-induced rat paw oedema tests, with peak effects observed at 400mg/kg, 6h after the induction of oedema, comparable in some cases to the effects of two standard drugs, the non-steroidal anti-inflammatory drug diclofenac and the anti-inflammatory antibiotic doxycycline.

CONCLUSION

We conclude that the three plant extracts possess analgesic and anti-inflammatory properties, thus providing a scientific rationale for their inclusion in some traditional anti-cancer regimens.

Ximenia caffra Sond. (Ximeniaceae) in sub-Saharan Africa: A synthesis and review of its medicinal potential

ETHNOPHARMACOLOGICAL RELEVANCE

Ximenia caffra Sond. (Ximeniaceae), commonly known as "sour plum" is traditionally used, both topically and orally to treat a wide range of human diseases and ailments such as wounds, sexually transmitted infections (STIs), infertility, stomach ache, fever, eye problems, diarrhoea, bilharzia, menorrhagia, malaria, intestinal worms, impotence and coughs. The bark and fruits are used by small-scale farmers as ethnoveterinary medicine to treat dermatophilosis, foot rot, saddle sores and control ectoparasites. Oil from X. caffra seed is traditionally used as a moisturiser, soap and shampoo for dry, fragile and damaged hair.

AIM OF THE REVIEW

The aim of this study was to comprehensively summarize the research that has been done on the botany, ethnomedicinal uses, phytochemistry and biological activities of X. caffra in different locations throughout its geographical range in the sub-Saharan African region so as to understand its importance and potential in primary healthcare systems.

MATERIALS AND METHODS

This study was carried out using a comprehensive and systematic literature search on the ethnomedicinal uses, phytochemistry and biological activities of the species throughout its distributional range. Literature sources included papers published in international journals, reports from international, regional and national organizations, conference papers, books and theses. PubMed and Scopus, search engines such as Google Scholar and online collection ScienceDirect were used.

RESULTS

This study showed that X. caffra is used as traditional medicine in 83.3% of the countries in tropical Africa where it is indigenous. A total of 65 human and animal ailments and diseases are recorded for X. caffra, with a high degree of consensus for wounds, sexually transmitted infections (STIs), infertility, stomach ache, fever, eye problems, diarrhoea, bilharzia, menorrhagia, malaria, intestinal worms and coughs. Phytochemical investigation of X. caffra revealed that the species has various compounds including flavonoids, phenols, phytosterols, tannins and fatty acids. Different plant parts, aqueous and organic extracts exhibited anti-amoebic, antibacterial, antifungal, anti-inflammatory, antioxidant, antiparasitic, antiproliferative, HIV-1 reverse transcriptase (RT) inhibitory, insecticidal, non-mutagenic and toxicity activities.

CONCLUSION

In this review, the ethnomedicinal uses, phytochemistry, biological activities and toxicity of different extracts and compounds of X. caffra have been summarized. Although many of the ethnomedicinal uses of X. caffra have been validated by phytochemical and pharmacological studies, there are still some gaps where current knowledge could be improved. There are very few to nil experimental animal studies, randomized clinical trials and target-organ toxicity studies involving X. caffra and its derivatives that have been carried out so far. At the present moment, there is not sufficient evidence to interpret the specific chemical mechanisms associated with some of the documented biological activities of the species. Therefore, future studies should identify the bioactive components, details of the molecular modes or mechanisms of action, pharmacokinetics and physiological pathways for specific bioactives of X. caffra.

Sesquiterpenoid tropolone glycosides from Liriosma ovata

Two new sesquiterpenoid tropolone glycosides, liriosmasides A (1) and B (2), along with two known compounds, secoxyloganin and oplopanpheside C, were isolated from a methanol extract of the roots of Liriosma ovata. The structures of 1 and 2 were elucidated by spectroscopic methods including 1D and 2D NMR and by high-resolution mass spectrometry involving an ultra-high-performance liquid chromatography-quadrupole-orbital ion trap mass spectrometric (UHPLC-Q-Orbitrap MS) method. Compound 1 showed weak inhibitory activity against HIV RNase H.

Antinociceptive property of Olax subscorpioidea Oliv (Olacaceae) extract in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Olax subscorpioidea is a shrub or tree found in Nigeria, and other parts of Africa. It is used in the management of inflammatory disorder, mental illness, convulsion, pain, and cancer. However, there is dearth of information on scientific basis for its folkloric use in the management of pain. Therefore, the study was designed to investigate the antinociceptive property of the extract of Olax subscorpioidea (EOS) leaves in mice.

MATERIALS AND METHODS

Antinociceptive activity of EOS (12.5-50 mg/kg, i.p.) was investigated using acetic acid induced abdominal writhing, tail immersion, hot plate and formalin tests.

RESULTS

Extract of Olax subscorpioidea produced significant dose dependent inhibition of writhing frequency [F(4,20)=155.9, p<0.0001] and significant dose dependent inhibition of neurogenic and inflammatory pains [F(4,20)=116.7, p<0.0001; F(4,20)=40.05, p<0.0001]. It also produced a significant dose dependent prolongation of the latent period and reaction times in tail immersion and hot plate tests in mice [F(4,20)=19.49, p<0.0001; F(4,20)=97.95, p<0.0001].

CONCLUSION

Olax subscorpioidea possessed potent analgesic action, mediated centrally and peripherally, thus justifying its use in the management of pain.

Riproximin's activity depends on gene expression and sensitizes PDAC cells to TRAIL

Riproximin (Rpx) is a type II ribosome inactivating protein, which was investigated for its activity in pancreatic ductal adenocarcinoma (PDAC) in a panel of 17 human and rat PDAC cell lines and in rat pancreatic cancer liver metastasis. Cytotoxicity in response to Rpx was determined by MTT assay, apoptosis by flow cytometry and qRT-PCR for apoptosis related genes, and the modulation of the transcriptome was monitored by micro array analysis. The combination effect of Rpx and TRAIL was assessed by MTT assay. Rpx showed high but varying cytotoxicity in PDAC cells. Based on overall gene expression, the sensitivity of these cells was linked to genes involved in apoptosis. Furthermore, based on the affinity of Rpx for CEA, the expression of carcinoembryonic antigen-related cell adhesion molecule (CEACAM) genes was significantly related to Rpx's cytotoxicity in cells with CEACAM gene expression. Exposure of Suit2-007 cells to Rpx induced the mRNA expression of members of signaling pathways initiating from most death receptors, and down modulation of TRAIL. Apoptosis was increased as shown by FACS analysis. Combination of Rpx with TRAIL resulted in a synergistic cytotoxic effect in human Suit2-007 and rat ASML cells, as evidenced by a 6-fold lower tumor cell survival than expected from an additive combination effect. Treatment of BDX rats bearing intra-portally implanted Suit2-007 cells showed a highly significant anticancer effect and indicated an application of Rpx against pancreatic cancer metastasis to the liver. These data favor further evaluation of Rpx as anticancer agent in PDAC.

Evaluation of riproximin binding properties reveals a novel mechanism for cellular targeting

Riproximin is a cytotoxic type II ribosome-inactivating protein showing high selectivity for tumor cell lines. Its binding to cell surface glycans is crucial for subsequent internalization and cytotoxicity. In this paper, we describe a unique mechanism of interaction and discuss its implications for the cellular targeting and cytotoxicity of riproximin. On a carbohydrate microarray, riproximin specifically bound to two types of asialo-glycans, namely to bi- and triantennary complex N-glycan structures (NA2/NA3) and to repetitive N-acetyl-D-galactosamine (GalNAc), the so-called clustered Tn antigen, a cancer-specific O-glycan on mucins. Two glycoproteins showing high riproximin binding, the NA3-presenting asialofetuin and the clustered Tn-rich asialo-bovine submaxillary mucin, were subsequently chosen as model glycoproteins to mimic the binding interactions of riproximin with the two types of glycans. ELISA analyses were used to relate the two binding specificities of riproximin to its two sugar binding sites. The ability of riproximin to cross-link the two model proteins revealed that binding of the two types of glycoconjugates occurs within different binding sites. The biological implications of these binding properties were analyzed in cellular assays. The cytotoxicity of riproximin was found to depend on its specific and concomitant interaction with the two glycoconjugates as well as on dynamic avidity effects typical for lectins binding to multivalent glycoproteins. The presence of definite, cancer-related structures on the cells to be targeted determines the therapeutic potency of riproximin. Due to its cross-linking ability, riproximin is expected to show a high degree of specificity for cells exposing both NA2/NA3 and clustered Tn structures.

Benzophenone glycosides and epicatechin derivatives from Malania oleifera

A new benzophenone C-glycoside, malaferin A (1), and two new epicatechin derivatives, malaferin B (2) and malaferin C (3), together with five known compounds were isolated from Malania oleifera. In addition, (-)-epicatechin-3-O-benzoate (6) was isolated for the first time from a natural resource. Structures of 1-3 were determined on the basis of their spectroscopic methods, including 1D and 2D NMR techniques. All of the compounds were evaluated for anti-HIV activities.

Bioactive polyphenols in Ximenia americana and the traditional use among Malian healers

ETHNOPHARMACOLOGICAL RELEVANCE

Ximenia americana is a medicinal bushy, spiny shrub or small tree used in Mali in West Africa for treatment of various diseases, most common are infectious and inflammatory ailments.

AIMS OF THE STUDY

(1) To perform an ethnopharmacological survey on the traditional use of Ximenia americana among healers in Mali. (2) To isolate and identify chemical constituents from the ethanol extract of Ximenia americana leaves and to study their radical scavenging and enzyme inhibitory effects.

MATERIALS AND METHODS

In five different districts in Mali, 38 healers were interviewed about their medicinal use of Ximenia americana. An aqueous ethanol extract of the leaves of this tree was prepared and further fractionated with liquid-liquid extraction, VersaFlash and Sephadex LH-20 column chromatography, and preparative HPLC. Isolated compounds were identified by 1D and 2D NMR spectroscopy. Extracts, subfractions and isolated compounds were investigated as DPPH radical scavengers and as inhibitors of xanthine oxidase and 15-lipoxygenase.

RESULTS

Major areas of use by Malian healers were against throat infection, amenorrhea and as tonic. Fractionation of the ethanol extract led to the isolation and identification of the cyanogenic glycoside sambunigrin (1), which is previously known from the plant. Additionally, gallic acid (2) and the gallotannins β-glucogalline (3) and 1,6-digalloyl-β-glucopyranose (4) were found. The following flavonoids were isolated: quercetin (5), quercitrin (quercetin-3-O-α-rhamnopyranoside) (6), avicularin (quercetin-3-O-α-arabinofuranoside) (7), quercetin-3-O-β-xylopyranoside (8), quercetin-3-O-(6″-galloyl)-β-glucopyranoside (9) and kaempferol-3-O-(6″-galloyl)-β-glucopyranoside (10). The flavonoids were active both as enzyme inhibitors and DPPH radical scavengers.

CONCLUSION

Sambunigrin (1) was the main compound in the EtOAc soluble fraction of the alcoholic extract of Ximenia americana leaves. Gallic acid (2), gallotannins (3-4) and flavonoids (5-10) were identified for the first time in the genus Ximenia. The identified compounds may give a rationale for the traditional use of Ximenia americana in Mali. Healers interviewed reported the use against throat infections, amenorrhea, as tonic, for wound healing and against pain.

Suppression of Caco-2 and HEK-293 cell proliferation by Kigelia africana, Mimusops zeyheri and Ximenia caffra seed oils

Animal-derived oils and purified fatty acids, but not indigenous fruit-tree-derived seed oils, have been used to study cell growth and differentiation. In this study, we determined the effects of the Kigelia africana, the Mimusops zeyheri and the Ximenia caffra seed-oil on cell proliferation in culture. Human colon adenocarcinoma (Caco-2) and human embryonic kidney (HEK-293) cells were maintained and treated with various concentrations (0, 20, 40, 80, 100 and 120 mg/l) of K. africana, M. zehyeri and X. caffra seed oil. The trypan blue dye exclusion method was used to determine cell growth 48-hours after oil treatment. All three tree seed oils suppressed both Caco-2 and HEK-293 cell growth in a dose-dependent manner. Importantly, the tree seed oils did not cause increased cell death as the number of dead cells remained unchanged under control and oil-treated conditions. K. africana oil significantly suppressed Caco-2 cell growth compared to HEK-293 cell growth at all oil concentrations, whereas M. zeyheri and X. caffra seed oils significantly suppressed HEK-293 and Caco-2 cell growth, only at a concentration of 80 mg/l. The suppression of Caco-2 and HEK-293 cell proliferation by K. africana, M. zeyheri and X. caffra seed oils suggest a potential antiproliferative effect of these tree seed oils on the two cell lines.

Eight new clerodane diterpenoids from the bark of Ptychopetalum olacoides

Eight new clerodane type diterpenoids, named 7-oxo-kolavelool (1), 7alpha-hydroxykolavelool (2), 6alpha,7alpha-dihydroxykolavenol (3), 12-oxo-hardwickiic acid (4), ptycholide I (5), ptycholide II (6), ptycholide III (7), and ptycholide IV (8) were isolated from the MeOH extract of the bark of a Brazilian medicinal plant, Ptychopetalum olacoides. The structures of 1-8 were elucidated by analyzing spectroscopic data and by comparing their NMR data with those of the previously reported compounds kolavelool (la), kolavenol (3a), hardwickiic acid (4a), and ptychonolide (5a). Compounds 5 and 6 existed as a 1:1 mixture of inseparable epimers at C-15.

The Amazonian herbal Marapuama attenuates cognitive impairment and neuroglial degeneration in a mouse Alzheimer model

Alzheimer's disease (AD) is expected to affect more than 22 million people worldwide by 2025, causing devastating suffering and enormous costs to families and society. AD is a multifactorial disease, with a complex pathological mosaic. In rodents, AD-like dementia can be induced by cerebral microinjection of Aβ peptide, leading to amyloid deposits, amnesia and various features of neurodegeneration. Marapuama (Ptychopetalum olacoides) is regarded as a "brain tonic" in the Amazon region and shows a nootropic profile in rodents.

AIM OF THE STUDY

Because a specific extract (POEE) of Marapuama was shown to possess promnesic and anti-amnesic properties, the aim of this study was to verify if POEE is also effective against Aβ(1-42)-induced cognitive deficit in mice. Additionally, Aβ deposits (Congo red), GFAP immunoreactivity (immunohistochemistry), and neurodegenerative changes in the hippocampal pyramidal layer (Nissl) were examined as measures of Aβ(1-42)-induced neurodegeneration.

MATERIALS AND METHODS

CF1 mice were subjected to the experimental Alzheimer model with the Aβ(1-42) i.c.v. administration. The effects of POEE 800 mg/kg were evaluated over 14 consecutive days of treatment.

RESULTS

The data show that 14 days of oral treatment with POEE (800 mg/kg) was effective in preventing Aβ-induced cognitive impairment, without altering the levels of BDNF and with parallel reductions in Aβ deposits and astrogliosis. CA1 hippocampus loss induced by Aβ(1-42) was also diminished in POEE-treated mice.

CONCLUSION

This study offers evidence of functional and neuroprotective effects of two weeks treatment with a Ptychopetalum olacoides extract against Aβ peptide-induced neurotoxicity in mice. Given the multifactorial nature of neurodegeneration, the considerable potential for an AChE inhibitor displaying associated neuroprotective properties such as here reported warrants further clinic evaluation.

Anti-stress effects of the "tonic"Ptychopetalum olacoides (Marapuama) in mice

With the recognition that high levels of sustained stress are associated with the natural course of countless illnesses, effective anti-stress agents have gained importance. Improved endurance to particularly stressful periods is one of the medicinal claims for Marapuama (Ptychopetalum olacoides Bentham, PO), a popular Amazonian herbal. The purpose of this study was to evaluate if PO possesses anti-stress properties. To this end, an extract from PO (POEE) was evaluated on anxiety and glucose levels in mice submitted to the unpredictable chronic mild stress (UCMS) paradigm. POEE did not present anxiolytic effects, but was able to prevent (p<0.01) the UCMS-induced anxiety as assessed by the light/dark test (time spent in the lit area, POEE 100 and 300mg/kg 235.9+/-20.6s and 250.4+/-17.4s, respectively, compared to DMSO 104.7+/-24.4s). Likewise, although POEE did not induce noticeable effects on glycemia, it effectively (p<0.01) prevented the UCMS-induced hyperglycemia (POEE 100 and 300mg/kg 106.4+/-6.7mg/dl and 107.3+/-3.3mg/dl, respectively, compared to DMSO 134.6+/-5.9mg/dl). Additionally, POEE (50-200mg/kg i.p. and 800mg/kg p.o.) significantly (p<0.01 and p<0.05, respectively) increased the time to hypoxia-induced convulsion (by 38%, 51%, 59% and 27%, respectively for i.p. and p.o. treatments). The data indicate that POEE counteracts some of the effects brought about by chronic stress. This study combined with the identified antioxidant and neuroprotective properties, as well as the claimed benefits associated with stressful periods suggest that Ptychopetalum olacoides (Marapuama) might possess adaptogen-like properties.

Clerodane diterpenoids with NGF-potentiating activity from Ptychopetalum olacoides

Four new clerodane-type diterpenoids, ptychonolide (1), 20-O-methylptychonal acetal (2), and an equilibrium mixture of ptychonal hemiacetal (3) and ptychonal (4), were isolated from the MeOH extract of the bark of a Brazilian plant, Ptychopetalum olacoides. The structure of 1 was elucidated as a clerodane-type diterpenoid on the basis of spectroscopic data, whereas 2 was assigned to an acetal derivative of 1. Compounds 3 and 4 existed as an equilibrium mixture. A mixture of compounds 3 and 4 was found to exhibit neurite outgrowth-promoting activities on NGF-mediated PC12 cells at concentrations ranging from 0.1 to 10.0 microM.

Effects of Marapuama in the chronic mild stress model: further indication of antidepressant properties

ETHNOPHARMACOLOGY RELEVANCE

Ptychopetalum olacoides Bentham (PO) (Olacaceae), known as Marapuama, is regarded as a "nerve tonic" in the Amazon. Traditional uses include states of lassitude with noticeable lack of desire/motivation, and to manage particularly stressful (physical and/or psychological) circumstances. Suggestive of antidepressant activity, we have established that a specific PO ethanol extract (POEE) significantly decreases immobility in the tail suspension and forced swimming tests.

AIM OF THE STUDY

The aim of this study was to verify the effects of POEE in the unpredictable chronic mild stress (UCMS) depression model in mice, given the construct and face values of the UCMS as an experimental model of depression and the traditional use of this species.

MATERIALS AND METHODS

Over 6 weeks BALB/c mice were subjected to the UCMS protocol. The effects of POEE (50, 100, 300mg/kg, p.o.) and imipramine (20mg/kg, i.p.) were evaluated in relation to coat state, splash-test grooming, and corticosterone levels.

RESULTS

The coat state degradation, decreased grooming and increased serum corticosterone induced by UCMS were prevented by POEE and imipramine treatments.

CONCLUSION

In addition to supporting traditional claims and previously reported antidepressant properties for POEE, this study shows that POEE prevents stress-induced HPA hyperactivity.

Isoprenoid glycosides from Liriosma ovata

A methanol extract of the dried bark of Liriosma ovata afforded two new isoprenoid glycosides, a eudesmane sesquiterpene, 1alpha(beta- d-glucopyranosyloxy)eudesma-3alpha,4beta, 11-triol ( 1), and a C 13-norisoprenoid, 3alpha,6alpha-dihydroxymegastigman-7-en-9-one 3- O-beta- d-apiofuranosyl-(1-->6)-beta- d-glucopyranoside ( 2), as well as a known constituent, isopropyl-beta- d-apiofuranosyl-(1-->6)-beta- d-glucopyranoside ( 3). The structures of 1 and 2 were determined using spectroscopic methods. The methanol extract had a significant topical anti-inflammatory activity (ID 50, dose inducing 50% edema inhibition = 780 microg/cm (2)) about 8 times less than that of indomethacin (ID 50, 93 microg/cm (2)) assayed by the croton oil ear test in mice. In addition, the chloroform extract and compounds 1 and 2 showed weak antimicrobial activity against S taphylococcus aureus (MIC = 5.1, 2.1, and 4.0 mg/mL, respectively) using a broth microdilution assay.

Identification of very long chain unsaturated fatty acids from Ximenia oil by atmospheric pressure chemical ionization liquid chromatography-mass spectroscopy

A method is described for the enrichment of very long chain unsaturated fatty acids from total fatty acids of Ximenia oil and their identification as picolinyl esters by means of liquid chromatography-mass spectrometry with atmospheric pressure chemical ionization (LC-MS/APCI). The method is based on the use of preparative reversed phase HPLC and their subsequent identification by microbore LC-MS/APCI. The combination of these two techniques was used to identify unusual unsaturated VLCFAs up to tetracontenoic acid. All four positional isomers of tetratriacontenoic acid were also synthesized to unambiguously confirm their structure.

Promnesic effects of Ptychopetalum olacoides in aversive and non-aversive learning paradigms

Homemade remedies with Ptychopetalum olacoides (PO) roots are used by Amazonian peoples for treating various age-related conditions. We previously reported that Ptychopetalum olacoides ethanol extract significantly improved step-down inhibitory avoidance long-term memory in adult and reversed memory deficits in aging mice. Adding to previous data, this study shows that a single i.p. administration of Ptychopetalum olacoides ethanol extract (POEE 50 and 100 mg/kg) improved step-down inhibitory avoidance short-term memory (STM) 3 h after training in adult (2.5 month) mice; comparable results were obtained with POEE given p.o. at 800 mg/kg. Moreover, memory improvement was also observed in aging (14 months) mice presenting memory deficit as compared to adult mice. Furthermore, POEE (100 mg/kg) improved non-aversive memory systems in adult mice in an object recognition paradigm. Consistently with its traditional use this study add to previously reported data and reinforces that POEE facilitates memory processes. Although the acetylcholinesterase inhibitory properties described for this extract may be of relevance for improving memory processes, the molecular mechanism(s) underlying the memory improvement here reported needs further scrutiny.

Bee pollen sensitivity in airborne pollen allergic individuals

BACKGROUND

Physicians who practice alternative medicine often prescribe bee pollen as a food supplement and a treatment for various ailments.

OBJECTIVES

To determine the qualitative and quantitative composition of bee pollen and to investigate the cutaneous reactivity of atopic patients to bee pollen extracts.

METHODS

The absolute number of pollen grains per gram of bee pollen was calculated, and morphologic identification of the botanical family was performed. Five extracts of bee pollen were prepared for skin prick testing, according to standard methods. Two hundred two volunteers participated in the study; 145 were atopic patients with respiratory allergy. The remaining 57 were healthy volunteers or nonatopic patients and served as a control group. All participants underwent skin prick testing with a standard battery of 6 aeroallergens (olive, grasses mix, Parietaria, mugwort, Dermatophagoides pteronyssinus, and Dermatophagoides farinae) and with all homemade bee pollen extracts.

RESULTS

All samples of bee pollen contained Oleaceae pollen in high concentrations. Small amounts of anemophilous pollen (Compositeae, Chenopodiaceae) were detected in various samples. A strong positive correlation was observed between cutaneous reactivity to bee pollen extracts and olive, grasses, and mugwort.

CONCLUSIONS

Bee pollen contains a large amount of pollen, which belongs to various allergenic families of plants. Bee pollen retains its allergenic potential as demonstrated by strong cutaneous responses to bee pollen extracts observed in atopic patients in contrast to nonatopic subjects. Regarding pollen allergic individuals, further studies are needed to evaluate the safety of ingesting large amounts of bee pollen.

UV spectrophotometric determination of bioflavonoids from a semisolid pharmaceutical dosage form containing Trichilia catigua Adr. Juss and Ptychopetalum olacoides Bentham standardized extract: analytical method validation and statistical procedures

A precise, accurate, and sensitive UV spectrophotometric method was developed and validated for routine quantification of total bioflavonoids, expressed as rutin, from a topical oil-in-water pharmaceutical emulsion containing the extract of Trichilia catigua Adr. Juss and Ptychopetalum olacoides Bentham. The method was validated experimentally, and the data were treated rigorously by statistical analysis. The following analytical parameters were assessed: linearity, specificity, intra- and interrun precision measured as relative standard deviation (RSD, %), intra- and interrun accuracy (E, %), recovery (Rec., %), limit of detection (LOD, microg/mL), and limit of quantification (LOQ, microg/mL). The UV spectrophotometric method was linear (r = 0.9995) for standard rutin over the concentration range of 5.0-15.0 microg/mL with specificity for total bioflavonoids (expressed as rutin) at 361.0 nm with an absence of interferents from the complex matrix; RSD of < or = 1.79%, intrarun (E = 97.88 +/- 1.75 to 99.0 +/- 0.33%) and interrun (E = 98.38 +/- 1.12 to 100.79 +/- 1.30%) accuracy; Rec. = 98.64 +/- 0.42 to 100.74 +/- 0.41%; LOD = 0.20 microg/mL; and LOQ = 0.30 microg/mL.

Identification and characterization of riproximin, a new type II ribosome‐inactivating protein with antineoplastic activity from Ximenia americana

The aim of this study was to identify and characterize the active component(s) of Ximenia americana plant material used to treat cancer in African traditional medicine. By a combination of preextraction, extraction, ion exchange and affinity chromatography, a mixture of two cytotoxic proteins was isolated. Using degenerated primers designed on the de novo sequence of two tryptic peptides from one of these proteins, a DNA fragment was amplified and the sequence obtained was used to determine the complete cDNA sequence by the RACE method. Sequence analysis and molecular modeling showed that the new protein, riproximin, belongs to the family of type II ribosome inactivating proteins. These results are in good agreement with the ability of riproximin to inhibit protein synthesis in a cell-free system, as well as with the cytotoxicity of riproximin, as demonstrated by its IC50 value of 0.5 pM in MCF7, 1.1 pM in HELA and 0.6 pM in CC531-lacZ cells. To assess the antineoplastic efficacy of the purified riproximin in vivo, the CC531-lacZ colorectal cancer rat metastasis model was used. Significant anticancer activity was found after administration of total dosages of 100 (perorally) and 10 (intraperitoneally) pmol riproximin/kg. These results suggest that riproximin has distinct potential for cancer treatment.

Identification of potent anticancer activity in Ximenia americana aqueous extracts used by African traditional medicine

The antineoplastic activity of a plant powder used in African traditional medicine for treating cancer was investigated by analyzing the activity of various extracts in vitro. The most active, aqueous extract was subsequently subjected to a detailed investigation in a panel of 17 tumor cell lines, showing an average IC50 of 49 mg raw powder/ml medium. The sensitivity of the cell lines varied by two orders of magnitude, from 1.7 mg/ml in MCF7 breast cancer cells to 170 mg/ml in AR230 chronic-myeloid leukemia cells. Immortalized, non-tumorigenic cell lines showed a marginal sensitivity. In addition, kinetic and recovery experiments performed in MCF7 and U87-MG cells and a comparison with the antineoplastic activity of miltefosine, gemcitabine, and cisplatinum in MCF7, U87-MG, HEp2, and SAOS2 cells revealed no obvious similarity between the sensitivity profiles of the extract and the three standard agents, suggesting a different mechanism of cytotoxicity. The in vivo antitumor activity was determined in the CC531 colorectal cancer rat model. Significant anticancer activity was found following administration of equitoxic doses of 100 (perorally) and 5 (intraperitoneally) mg raw powder/kg, indicating a 95% reduced activity following intestinal absorption. By sequencing the mitochondrial gene for the large subunit of the ribulose bis-phosphate carboxylase (rbcL) in DNA from the plant material, the source plant was identified as Ximenia americana. A physicochemical characterization showed that the active antineoplastic component(s) of the plant material are proteins with galactose affinity. Moreover, by mass spectrometry, one of these proteins was shown to contain a stretch of 11 amino acids identical to a tryptic peptide from the ribosome-inactivating protein ricin.

Diterpenoid, steroid, and triterpenoid agonists of liver X receptors from diversified terrestrial plants and marine sources

It has been demonstrated that liver X receptors (LXR) play a significant role in cholesterol homeostasis. Agonists of LXR are expected to increase cellular cholesterol efflux, lower LDL, and raise HDL levels. Screening of a natural product library of plant extracts using a LXR-SPA binding assay and bioassay-guided fractionation of a number of plant and marine gorgonian extracts led to the isolation of a number of active compounds. These included acanthoic acid (1) and alcohol (2), viperidone (3), polycarpol (4), rosacea acid (5), a cycloartane derivative (6), a new cycloartane analogue (7), betulinic acid (8), and gorgostane derivatives (9, 10, and 11). Of these compounds, 1, 4, and 11 exhibited potent binding affinity for alpha-receptor with IC(50) values of 0.25, 0.12, and 0.07 microM, respectively. Functionally they also showed strong coactivator association stimulation for LXRalpha receptor with EC50 values of 0.18, 0.03, and 0.05 microM, respectively. They also exhibited 15-, 8-, and 13-fold induction of the alpha-receptor in a transactivation assay in HEK-293 cells, respectively. In general these compounds were selective for the LXR alpha-receptor over the beta-receptor in all assays and were much better stimulators of the alpha-receptor than the endogenous steroid ligands.

Cyclohexanoid protoflavanones from the stem-bark and roots of Ongokea gore

Phytochemical investigation of root and stem-bark of the West African medicinal plant Ongokea gore resulted in the isolation of four novel flavonoids with an unusual cyclohexyl substituent instead of the common aromatic ring B. The structures of the isolated compounds were elucidated by spectroscopic methods, mainly 1D and 2D NMR, and subsequently, the structures were corroborated by chemical conversion to (-)-(S)-sakuranetin. The absolute configurations, and preferred conformations were determined by NOE experiments and CD measurements.

Neuroprotective effects of Ptychopetalum olacoides Bentham (Olacaceae) on oxygen and glucose deprivation induced damage in rat hippocampal slices

Alcoholic infusions of Ptychopetalum olacoides Bentham (PO, Olacaceae) are used in traditional medicine by patients presenting age associated symptoms and those recovering from stroke. The aim of this study is to evaluate the neuroprotective properties of PO ethanol extract (POEE) using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation). Mitochondrial activity, an index of cell viability, was assessed by the MTT assay; in addition, the free radicals content was estimated by the use of dichlorofluorescein diacetate as probe. The OGD ischemic condition significantly impaired cellular viability, and increased free radicals generation. In non-OGD slices, incubation with POEE (0.6 microg/ml) increased (approximately 40%) mitochondrial activity, without affecting free radicals levels. In comparison to OGD controls, slices incubated with POEE (0.6 microg/ml) during and after OGD exposure had significantly increased cellular viability. In addition, at this same concentration, POEE prevented the increase of free radicals content induced by OGD. In view of the fact that respiratory chain inhibition and increased generation of free radicals are major consequences of the ischemic injury, this study suggests that Ptychopetalum olacoides contains useful neuroprotective compounds and, therefore, deserves further scrutiny.