Acylated pregnane glycosides from Caralluma tuberculata and their antiparasitic activity

In Silico and In Vitro Screening of Some Pregnane Glycosides Isolated from Certain Caralluma Species as SARS-COV-2 Main Protease Inhibitors

SARS-CoV-2 caused pandemic represented a major risk for the worldwide human health, animal health and economy, forcing extraordinary efforts to discover drugs for its prevention and cure. Considering the extensive interest in the pregnane glycosides because of their diverse structures and excellent biological activities, we investigated them as antiviral agents against SARS-COV-2. We selected 21 pregnane glycosides previously isolated from the genus Caralluma from Asclepiadaceae family to be tested through virtual screening molecular docking simulations for their potential inhibition of SARS-CoV-2 Mpro. Almost all target compounds showed a more or equally negative docking energy score relative to the co-crystallized inhibitor X77 (S=-12.53 kcal/mol) with docking score range of (-12.55 to -19.76 kcal/mol) and so with a potent predicted binding affinity to the target enzyme. The activity of the most promising candidates was validated by in vitro testing. Arabincoside C showed the highest activity (IC50=35.42 μg/ml) and the highest selectivity index (SI=9.9) followed by Russelioside B (IC50=50.80 μg/ml), and Arabincoside B (IC50=53.31 μg/ml).

Hexagonosides A-F: Pregnane glycosides isolated from Caralluma hexagona

Chemical investigation of Caralluma hexagona Lavranos, a wild plant growing in Yemen, led to the isolation of four previously undescribed acylated pregnane glycosides, hexagonosides A-D (1-4), together with two sets of mixtures (hexagonosides E and F), each set consists of three interconvertible pregnane glycoside isomers, hexagonosides E (5a-c) and F (6a-c). The chemical structures of the isolated pregnane glycosides were elucidated by extensive 1D/2D NMR and HRESI-MS analysis, featuring 6'-O-benzoyl-1'-O-β-glucosyl residue at aglycone C-20; while aglycone C-3 was substituted with disaccharide sugar chain (1, 2, 5a-c) or a trisaccharide sugar chain (3, 4, 6a-c). Metabolites E and F included an extra benzoyl substitution in C-20 glucosyl residue which is migrating between the OH groups of C-2', C-3' and C-4' resulting in equilibrating conformations (5a-c and 6a-c) when incubated in HPLC solvent, which we confirmed by the analytical study.

Correlation between secondary metabolites of Iris confusa Sealy and Iris pseudacorus L. and their newly explored antiprotozoal potentials

BACKGROUND

In the last few decades, the use of plant extracts and their phytochemicals as candidates for the management of parasitic diseases has increased tremendously. Irises are aromatic and medicinal plants that have long been employed in the treatment of different infectious diseases by traditional healers in many cultures. This study aims to explore the potential of three common Iris species (I. confusa Sealy, I. pseudacorus L. and I. germanica L.) against infectious diseases. Their in vitro antiprotozoal potency against Plasmodium falciparum, Trypanosoma brucei brucei, T. b. rhodesiense, T. cruzi and Leishmania infantum beside their cytotoxicity on MRC-5 fibroblasts and primary peritoneal murine macrophages were examined.

METHODS

The secondary metabolites of the tested extracts were characterized by UPLC-HRMS/MS and Pearsons correlation was used to correlate them with the antiprotozoal activity.

RESULTS

Overall, the non-polar fractions (NPF) showed a significant antiprotozoal activity (score: sc 2 to 5) in contrast to the polar fractions (PF). I. confusa NPF was the most active extract against P. falciparum [IC50 of 1.08 μg/mL, selectivity index (S.I. 26.11) and sc 5] and L. infantum (IC50 of 12.7 μg/mL, S.I. 2.22 and sc 2). I. pseudacorus NPF was the most potent fraction against T. b. rhodesiense (IC50 of 8.17 μg/mL, S.I. 3.67 and sc 3). Monogalactosyldiacylglycerol glycolipid (18:3/18:3), triaceylglycerol (18:2/18:2/18:3), oleic acid, and triterpenoid irridals (spirioiridoconfal C and iso-iridobelamal A) were the top positively correlated metabolites with antiplasmodium and antileishmanial activities of I. confusa NPF. Tumulosic acid, ceramide sphingolipids, corosolic, maslinic, moreollic acids, pheophytin a, triaceylglycerols, mono- and digalactosyldiacylglycerols, phosphatidylglycerol (22:6/18:3), phosphatidylcholines (18:1/18:2), and triterpenoid irridal iso-iridobelamal A, were highly correlated to I. pseudacorus NPF anti- T. b. rhodesiense activity. The ADME study revealed proper drug likeness properties for certain highly corelated secondary metabolites.

CONCLUSION

This study is the sole map correlating I. confusa and I. pseudacorus secondary metabolites to their newly explored antiprotozoal activity.

Quadrangulosides A-F: new pregnane glycosides from Caralluma quadrangula

The phytochemical investigation of Caralluma quadrangula aerial parts yielded six new pregnane glycosides, quadrangulosides A-F (1-6), in addition to nine known pregnane glycosides and three known flavone glycosides. Structures of isolated phyto-constituents were elucidated via spectroscopic 1D-, 2D-NMR and spectrometric ESI-MS spectra.

12,20-Epoxypregnane Glycosides from the Roots of Oxypetalum caeruleum

The MeOH extract from dried roots of Oxypetalum caeruleum (Apocynaceae, formerly known as Asclepiadaceae) plants yielded twenty new pregnane glycosides, some of which had a new 12,20-epoxy type aglycone. The structures of these compounds were established using NMR, MS spectroscopic analysis and chemical evidence.

Russelioside A, a Pregnane Glycoside from Caralluma tuberculate, Inhibits Cell-Intrinsic NF-κB Activity and Metastatic Ability of Breast Cancer Cells

Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a potential target for inflammatory-breast cancer treatment as it participates in its pathogenesis, such as tumor initiation, progression, survival, metastasis, and recurrence. In this study, we aimed to discover a novel anti-cancer treatment from natural products by targeting NF-κB activity. Using the 4T1-NFκB-luciferase reporter cell line, we tested three pregnane glycosides extracted from the herb Caralluma tuberculata and discovered that Russelioside A markedly suppressed NF-κB activity in breast cancer. Russelioside A inhibited NF-κB (p65) transcriptional activity and its phosphorylation. Following NF-κB inhibition, Russelioside A exerted anti-proliferative and anti-metastatic effects in breast cancer cells in vitro. Moreover, it inhibited the NF-κB constitutive expression of downstream pathways, such as VEGF-b, MMP-9, and IL-6 in 4T1 cells. In addition, it reduced the metastatic capacity in a 4T1 breast cancer model in vivo. Collectively, our conclusions reveal that Russelioside A is an attractive natural compound for treating triple-negative breast cancer growth and metastasis through regulating NF-κB activation.

Comprehensive polyoxypregnane glycosides report in Caralluma quadrangula using UPLC-ESI-Q-TOF and their antioxidant effects in human plasma

ETHNOPHARMACOLOGICAL RELEVANCE

Caralluma quadrangula (Forssk.) N.E.Br. (Syns: = Stapelia quadrangula Forssk. = Monolluma quadrangula Forssk.) is an indigenous member of the genus Caralluma and it is a rather common species on rocky hillsides in the southwestern part of Saudi Arabia. Several members of this genus have found medicinal uses in the treatment of rheumatism, diabetes, leprosy and as antiseptics and disinfectants. All parts are edible but rather more bitter and can cause diarrhea.

AIM OF THE STUDY

The present report was tentatively elucidated the structure of acylated and non-acylated polyoxypregnane glycosides from Caralluma quadrangula.

MATERIALS AND METHODS

The analyses were performed using an electrospray-ionization quadrupole time-of-flight (ESI-Q-TOF) mass spectrometer in both positive and negative ionization modes to explore fragmentation pathways. The antioxidant and prooxidant properties of the different mobility portions of human plasma were evaluated in vitro using thiobarbituric acid reactive substance assay (TBARS).

RESULTS

The analyses showed sixty-five characteristic ion peaks which could be more efficient to assignment the aglycones and fragmentation sequences of sugar moieties. The used ionization modes provided consistent and/or complementary information for most of the pregnane glycosides, their fragmentation sequences, and their aglycones. A DFT Study was performed to elucidate the neutral loss of H₂O molecules sequences from aglycones and the esterification linkage.

CONCLUSIONS

This report could be useful to reduce material consuming and time in phytochemistry analysis of the different medicinal plants. The two portions significantly depleted TBARS were subjected to autoperoxidation assay in the presence of hydrogen peroxide.

Caralluma edulis (Apocynaceae): A comprehensive review on its Traditional uses, Phytochemical profile and pharmacological effects

Caralluma edulis is a well-known species of the genus Caralluma from Apocynaceae, commonly known as chunga. Caralluma species are mostly succulent perennial herbs, several of which are edible species. The plant has an outstanding therapeutic background in the traditional system of treatment. It has been recommended for the treatment of a number medical disorder such as hypertension, Alzheimer disease, rheumatism, gastric problems and leprosy. Traditionally the stem was boiled in water and this extract was then used to cure diabetes. The pharmacological effects of C.edulis have also been explored in various in vitro and in vivo experiments. In this regard, the extract of the plant exhibited strong antioxidant activity, analgesic, against inflammation as well as xylene mediated ear edema for topical effects. The significant anti-hyperlipidemic effect of the plant extract is also reported. However, the extract was found insignificant in the reversal of alloxan-induced diabetes in rabbit model at test doses. These pharmacological effects are strongly supported by the presence of different bioactive phytochemicals in the plant. These groups of compounds include sterols, terpenoids, flavonoids, and pregnane glycosides. C.edulis is a very potential member of the genus Caralluma with strong traditional history, phytochemistry and phytopharmacology, needed further exploration for clinically used lead compounds. In this review, we have focused to combined different reported data on the traditional uses of the plant, phytochemical profile and pharmacological effects in different experimental assay and subsequent future prospects.

Russelioside B: a Pregnane Glycoside with Pharmacological Potential

Pregnanes and pregnane glycosides or their esters are well-studied secondary metabolites, many of them exhibit immunomodulator, anticancer, antidiabetic, antarthritic, antiulcer, anti-nociceptive, hypolipidemic, anti-inflammatory, and antibacterial properties. Pregnane glycosides are widely distributed in the families Apocyanaceae and Asclepiadaceae. Plant members of the genus Caralluma R.Br., Apocynaceae, are among the most studied species because of uses in traditional medicine or as food. They are a rich source of pregnane glycosides, as russelioside B. However, the bioactivity profile of this pregnane glycoside has not been reviewed until now. The present review aims to summarize the most important pharmacological and therapeutic applications of russelioside B with specific emphasis on the mechanism of actions associated with its administration in preclinical models. Russelioside B has many pharmacological effects including antidiabetic, anti-obesity, anti-nociceptive, antiulcer, anti-inflammatory, anti-arthritis effects, and antibiofilm, and wound healing activities. Despite its outstanding pharmacotherapeutic potential, russelioside B has never been tested in clinical trials. This review indicates that russelioside B is a potentially promising bioactive candidate, but further deeper mechanistic studies and clinical trials are needed in the future to elucidate its interaction with receptors of specific genes.

C21 Steroidal Glycosides from the Roots of Oxypetalum caeruleum

The MeOH extract from dried roots of Oxypetalum caeruleum (Apocynaceae) plants yielded seventeen new pregnane glycosides, some of which had the acylated-ramanone or -isoramanone type aglycone. The structures of these compounds were established using NMR, MS spectroscopic analysis and chemical evidence.

Herbal Medicines for Diabetes Management and its Secondary Complications

Diabetic Mellitus (DM) is a metabolic disorder that is concerning for people all over the world. DM is caused due to lack of insulin or ineffective production of insulin in the pancreas. A total of 463 million people were reported to have diabetes mellitus in 2019 and this number is predicted to rise up to 578 million by the year 2030 and 700 million by 2045. High blood sugar gives rise to many complications like diabetic retinopathy, diabetic nephropathy, atherosclerosis, hypercoagulability, cardiovascular disease, coronary heart disease, abdominal obesity, hypertension, hyperlipidemia, cerebrovascular disease, coronary artery disease, foot damage, skin complications, Alzheimer's disease, hearing impairment, and depression. These life-threatening complications make diabetes more severe than other diseases. Many synthetic drugs have been developed, but still, a complete cure is not provided by any of the molecules. Continuous use of some synthetic agents causes severe side effects, and thus the demand for non-toxic, affordable drugs still persists. Traditional treatments have been an extremely valued source of medicine all over human history. These are extensively used throughout the world, indicating that herbs are a growing part of modern and high-tech medicines. The World Health Organization (WHO) has listed a total of 21,000 plants, which are used for medicinal purposes around the world. Among them, more than 400 plants are available for the treatment of diabetes. Despite the fact that there are many herbal drugs available for treating diabetes, only a small number of these plants have undergone scientific and medical evaluation to assess their efficacy. Trigonella foenum-graecum, Allium sativum, Caesalpinia bonduc, Ferula assafoetida,etc., are some of the medicinal plants used for antidiabetic therapy. The presence of phenolic compounds, flavonoids, terpenoids, and coumarins is responsible for the antidiabetic nature of the medicinal plants. These constituents have shown a reduction in blood glucose levels. Pycnogenol, acarbose, miglitol, and voglibose are some of the examples of marketed drugs, which are obtained from natural origin and used as antidiabetic drugs. The active principles derived from the plants work through many antidiabetic mechanisms, which include inhibition of α-glucosidase, α-amylase, and protein tyrosine phosphatase 1B activities. One of the major advantages of herbal drugs is the low level of side effects attributed to these medicines, and this attracted various researchers to develop new molecules for the treatment of diabetes. In this review, recent advances in the field of herbal drugs to treat diabetes, prevent secondary complications from arising due to diabetes, and various herbal molecules in different stages of clinical trials will be emphasized upon.

Phytochemical Study on Antioxidant and Antiproliferative Activities of Moroccan Caralluma europaea Extract and Its Bioactive Compound Classes

Background

Caralluma europaea (C. europaea) is a medicinal plant used in Moroccan popular medicine. Objective of the Study. The present work was aimed at identifying the chemical composition and the antioxidant and antiproliferative activities of hydroethanolic and bioactive compound classes of C. europaea) is a medicinal plant used in Moroccan popular medicine. Materials and Methods. The chemical composition was analyzed using HPLC. The antioxidant power was determined using both DPPH and FRAP assays. The antiproliferative activity was effectuated against cancerous cells using WST-1.

Results

The chemical analysis showed the presence of bioactive constituents such as quercetin, myricetin, and hesperetin. The polyphenol and flavonoid contents were estimated at 51.42 mg GA/g and 20.06 mg EQ/g, respectively. The EC₅₀ values of FRAP assay of hydroethanolic, flavonoid, saponin, and mucilage extracts were 5.196 mg/ml, 4.537 mg/ml, 3.05 mg/ml, and 6.02 mg/ml, respectively. The obtained IC₅₀ values with the DPPH test were 1.628 mg/ml, 1.05 mg/ml, 1.94 mg/ml, and 9.674 mg/ml, respectively. Regarding MDA-MB-231, saponins were highly effective even with the lowest concentration (15.62 μg/ml). The flavonoids decreased the cell viability with IC₅₀ values of 43.62 ± 0.06 μg/ml). The flavonoids decreased the cell viability with IC₅₀ values of 43.62 ± 0.06 μg/ml). The flavonoids decreased the cell viability with IC₅₀ values of 43.62 ± 0.06 

Conclusion

The present results suggest that C. europaea) is a medicinal plant used in Moroccan popular medicine.

Antimalarial alkaloid from Hypoestes forskaolii

Following on from previous studies, we brought further our quest for anti-malarial agents isolated from plants grown in the Saudi Arabian Peninsula. Methanolic extracts were prepared from eighteen Saudi plants and then tested in vitro to assess their anti-malarial effects on Plasmodium falciparum K1, (a chloroquine-resistant strain) as well as their cytotoxicity on MRC5 (human diploid embryonic lung cell line) cells. Moderate anti-malarial activity was observed in extracts prepared from Hypoestes forskaolii (Vahl) R. Br. (IC50 value of 5.5 μg/ml) and Rhus retinorrhaea (IC50: 7.71 μg/ml). The remaining sixteen plant extracts appeared to be inactive (IC50 > 12.5 μg/ml). A novel phenanthro-quinolizidine alkaloid, 15β-hydroxycryptopleurine-N-oxide, was isolated from H. forskaolii using bio-guided fractionation procedures. Chloroquine-resistant (K1) and chloroquine-sensitive (FCR3) strains of P. falciparum appeared very sensitive to the anti-malarial activity of 15β-hydroxycryptopleurine-N-oxide, giving IC50 of 6.11 and 5.13 nM respectively. It showed cytotoxicity against MRC5 "IC50 of 24.45 nM" with selectivity indices of 4.0 and 4.76 against K1 and FCR3 strains, respectively. It is our understanding that this is the first account on phenanthro-quinolizidine alkaloids anti-malarial activity on a chloroquine-resistant P. falciparum strain.

Microscopic investigations and pharmacognostic techniques for the standardization of Caralluma edulis (Edgew.) Benth. ex Hook.f

Herbal medicines frequently suffer with quality controversies because of similar species or varieties. This often leads to sophistication or admixture of the crude drug as they share various look alike physical features. Commercially, stalks of Caralluma edulis are commonly adulterated with other species because of their analogous morphology. In the present research, the microscopic standardization of the drug was performed by structural, histological, and anatomical features. Pharmacognostical characterization was carried out by physicochemical (moisture content, swelling index, pH value, ash values, and extractive values) and fluorescence analysis. The chemical characterization by UV-Visible, Fourier transform infrared spectroscopy, and high-performance liquid chromatography was also performed that disclosed the chief phytoconstituents of the herbal drug. The above mentioned constraints, being reported for the first time in C. edulis, are substantial in establishing the microscopic and pharmacopoeial standards for future identification and authentication.

The binding proximity of methyl β-lilacinobioside isolated from Caralluma retrospiciens with topoisomerase II attributes apoptosis in breast cancer cell line

The alterations in somatic genomes that controls the mechanism of cell division as a main cause of cancer, and then the drug that specifically toxic to the cancer cells further complicates the process of the development of the widely effective potential anticancer drug. The side effects of the drug as well as the radiotherapy used for the treatment of cancer is severe; therefore, the search of the natural products from the sources of wild plants having anticancer potential is become immense importance today. The ethno-medicinal survey undertaken in Al-Fayfa and Wadi-E-Damad region of southern Saudi Arabia revealed that the Caralluma retrospiciens (Ehrenb.) N.E.Br. (family Apocynaceae) is being used for the treatment of cancer by the native inhabitants. The biological evaluation of anticancer potential of bioassay-guided fractionations of methanolic extract of whole plant of C. retrospiciens against human breast adenocarcinoma cell line (MCF-7) followed by characterization using spectroscopic methods confirmed the presence of methyl β-lilacinobioside, a novel active constituent reported for the first time from C. retrospiciens, is capable of inhibition of cell proliferation and induction of apoptosis in MCF-7 cells by regulating ROS mediated autophagy, and thus validated the folkloric claim. Based on a small-scale computational target screening, Topoisomerase II was identified as the potential binding target of methyl β-lilacinobioside.

In vitro antiprotozoal activity of some medicinal plants against sleeping sickness, Chagas disease and leishmaniasis

AIM

Antiprotozoal activity of 36 medicinal plants was evaluated.

MATERIALS & METHODS

In vitro potency against Trypanosoma brucei brucei, T. b. rhodesiense, T. cruzi and Leishmania infantum beside cytotoxicity on MRC-5 fibroblasts were determined.

RESULTS & CONCLUSION

Maytenus parviflora showed the highest activity against T. b. brucei (IC₅₀ of 0.6 μg/ml) and T. b. rhodesiense (IC₅₀ of 0.5 μg/ml) with low cytotoxicity (CC₅₀ of 30 μg/ml). Saussurea costus and Commiphora wightii, showed pronounced potency against T. cruzi with an IC₅₀ of 3.6 and 2.5 μg/ml, respectively. Jatropha pelargonifolia and Solanum villosum exhibited pronounced activity toward L. infantum with an IC₅₀ of 3.2 and 2.0 μg/ml, respectively. M. parviflora, S. costus, C. wightii, J. pelargonifolia and S. villosum showed relevant selectivity.

Ethnobotany of Anti-hypertensive Plants Used in Northern Pakistan

Hypertension is one of the most important factors responsible for cardiovascular ailments worldwide. It has been observed that herbal products and alternative herbal therapies played a significant role in decreasing hypertension. The aim of the current study is to provide significant ethnopharmacological information, both qualitative and quantitative on medicinal plants related to hypertension from Northern Pakistan. The documented data were quantitatively analyzed for the first time in this area. A total of 250 participants were interviewed through semi-structured discussions and questionnaires. Quantitative indices including FC (Frequency citation), FIV (Family importance value), RFC (Relative frequency of citation) and DCI (Disease Consensus index) were calculated. A total of 192 plant species, belonging to 77 families were reported to be used in treatment of hypertension in Northern Pakistan. The most dominant life form reported was herbs (54%), with decoction (72 reports) and leaves (55.1%) were commonly utilized plant part. Highest FIV was recorded in Lamiaceae (327 FIV). RFC ranged from 0.08 to 1.08% while DCI varied from 0.233 to 0.000. In this study original data was compared with thirty one previous national and international published papers from neighboring region to compare the medicinal uses and obtain some novel plant species. About 42% of the medicinal plant species were reported for the first time in treatment of hypertension in comparison to these 31 published papers. Different phytochemical activities of antihypertensive plants were also reported from literature. This research work documents the traditional knowledge of medicinal plants usage and provides baseline in designing clinical trials and pharmacological analysis for treatment of hypertension.

Antidiabetic potential of Caralluma europaea against alloxan-induced diabetes in mice

Medicinal plants play an important role in the management of diabetes mellitus especially in developing countries where resources are lacking. Herbal of natural origin, unlike the synthetic compounds, are more effective, safer and have less side effects. For continuing research on biological properties of Moroccan medicinal plants, the present work was undertaken to evaluate the potential and mechanism of the antidiabetic activity of the Caralluma europaea methanolic extract in alloxan-induced diabetic mice. A high-performance liquid chromatography technique (HPLC) was used to identify and quantify the major phenolic compounds in the methanolic extract. The in vitro antioxidant property was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging method, reducing power and ß-carotene-linoleic acid assays. The acute toxicity of the extract was evaluated by giving it orally to mice at single doses of 200, 500, 1000, 2000 mg/kg body weight. The antidiabetic effect was conducted on Swiss albino mice. Diabetes was induced with single intraperitonial injection of alloxan monohydrate (200 mg/kg body weight) and animals were treated with methanol extract at a dose of 250 mg/kg and 500 mg/kg body weight. The blood glucose levels were measured and histopathological analysis of pancreas was performed to evaluate alloxan-induced tissue injuries. The main phenols identified and quantified in the extract were ferulic acid, quercetine, 3,4 dihydroxybenzoic acid, rutin, epigallocatechin, and catechin. Ferulic acid was found to be the main phenolic compound ant its proportion was up to 52% of total phenolic compounds, followed by quercetin (36%). The result showed that methanol extract exhibited an antioxidant effect. Acute toxicity studies revealed that C. europaea extract was safe up 2000 mg/kg body weight and approximate LD₅₀ is more than 2000 mg/kg. Moreover, the methanol extract prevented the diabetogenic effect of alloxan and decreased significantly the blood glucose level (P < 0.001) in treated mice. Morphometric study of pancreas revealed that C. europaea extract protected significantly the islets of Langerhans against alloxan-induced tissue alterations.

Traditional uses of medicinal plants practiced by the indigenous communities at Mohmand Agency, FATA, Pakistan

BACKGROUND

Plant-derived products have an imperative biological role against certain pathogenic organisms and were considered to be a major source of modern drugs. Rural people residing in developing countries are relying on traditional herbal medical system due to their strong believe and minimum access to allopathic medicines. Hence, ethnomedicinal knowledge is useful for the maintenance of community's based approaches under this medical system. Present study was carried out in an unexplored remote tribal area of Pakistan to investigate and document the existing ethnomedicinal knowledge on local flora.

METHODS

Data was collected through semi-structured questionnaires from the community members and local herbalists. Use reports (URs) were counted for each species and analyzed through Linear Regression between the number of URs per family and number of plant species per family.

RESULTS

A total of 64 medicinal plant species were recorded belonging to 60 genera and 41 families. Most frequently used plant families in ethnomedicines were Lamiaceae (8 species) and Asteraceae (7 species). Highest URs were recorded for Caralluma tuberculata N.E. Br. (49 URs) being followed by Thymus serphyllum L. (49 URs), Fagonia cretica L. (47 URs), Plantago lanceolata L. (45 URs), Periploca aphylla Decne. (44 URs), Citrullus colocynthis (L.) Schrad. (44 URs), and Sideroxylon mascatense (A.DC.) T.D.Penn. (44 URs). New ethnomedicinal uses were reported for Boerhaavia elongata Brandegee and Fumaria officinalis L. with confidential level of URs from the study area. Nineteen groups of health conditions were recorded during the course of study being treated with medicinal plants. Maximum number of 30 plant species was used to treat digestive problems. Most widely practiced mode of drugs' preparation and administration was powder. Leaves (30% plants) were the most frequently used plant parts in the preparation of ethnomedicinal recipes.

CONCLUSIONS

Current study is an important addition to the field of ethnomedicines. The study reports important medicinal plants from an area, which has not been investigated previously. Traditional knowledge is restricted to health practitioners and elder community members. This knowledge is at the verge of extinction because younger generation is not taking interest in its learning and preservation process. Hence, there is a dire need to phytochemically and pharmacologically test the investigated taxa for the validation of traditional knowledge.

Phytochemical analysis and effects on ingestive behaviour of a Caralluma fimbriata extract

Caralluma fimbriata Wall. is currently used as a "natural slimming" food supplement, likely due to its content in pregnane glycosides. In the present study, a commercially available Caralluma fimbriata extract (Slimaluma^®; CFE, 100 mg/kg) has been evaluated for its ability to affect the ingestive behaviour in female rats, also with reference to the modulation of the brain neuropeptides NPY and ORX.The interference of CFE with α-amylase and lipase enzymes has been investigated in vitro, as possible peripheral mechanism of action. Also, the chemical composition of CFE has been assessed by NMR and spectrophotometric analysis. Results from in vivo study showed that CFE induced effects neither on blood parameters, nor on liver and gut histomorphology. Interestingly, a reduction in body weight gain with an increase in water intake and hypothalamic levels of NPY and ORX peptides were found. Phytochemical analysis, showed CFE contained about 12% of pregnane glycosides and 1.3% of polyphenols. Present results suggest possible effects of C. fimbriata on ingestive behaviour, likely mediated by central and peripheral mechanisms.

Toxicological Evaluation of the Aqueous Extract of Caralluma europaea and Its Immunomodulatory and Inflammatory Activities

Background:

Caralluma europaea (CE) has been studied for its chemical constituents, and no information is available on its toxicity or its pharmacological activities.

Objective:

To determine the toxicity of an aqueous extract of CE stems in vitro and in vivo after acute and subchronic oral gavages in Swiss albino's mice and its immunomodulatory and inflammatory activities.

Materials and Methods:

The extract was administrated in single oral dose at 5 g/kg body weight for the acute toxicity test and by gavages daily at doses of 1, 2.5, or 5 g/kg for 30 consecutive days for the subchronic toxicity test. The immunomodulatory activities and inflammatory activities were tested by the evaluation of hemagglutination antibodies (HAs) titers and delayed-type hypersensitivity (DTH) response.

Results:

For the dose of 1 g/kg, no visible toxic effects were observed. However, for the higher doses, clinical observations of toxicity were noted after 1 week of treatment. This was confirmed by the biochemical parameters values and the histology analyses of the spleen, liver, and kidney tissues. The high cellular mortality rate in vitro when treated with CE extract confirmed their toxicity potential. There was also increase of “HA titer” and “DTH” response in mice treated with nontoxic dose of CE (1 g/kg) compared to control group. This immune activity was confirmed by the high number of lymphocytes infiltrates noted in the different organs.

Conclusion:

We conclude that CE at the dose up of 1 g/kg produced toxic effect in mice that induced an immune inflammatory reaction.

SUMMARY

Caralluma europaea (CE) has been studied for its chemical constituents, and no information is available on its toxicity or its pharmacological activities. The objective is to determine the toxicity of an aqueous extract of CE stems in vitro and in vivo after acute and subchronic oral gavages in Swiss albino's mice and its immunomodulatory and inflammatory activities. For the dose of 1 g/kg, no visible toxic effects were observed. However, for the higher doses, clinical observations of toxicity were noted after 1 week of treatment. This was confirmed by the biochemical parameters values and the histology analyses of the spleen, liver, and kidney tissues. The high cellular mortality rate in vitro confirmed their toxicity potential. There was also increase of “hemagglutination antibody titer” and “delayed-type hypersensitivity” response in mice treated with nontoxic dose of CE (1 g/kg) compared to control group. This immune activity was confirmed by the high number of lymphocytes infiltrates noted in the different organs. We conclude that CE at the dose up of 1 g/kg produced toxic effect in mice that induced an immune inflammatory reaction.

Abbreviations Used: CE: Caralluma europaea, ALT: Alanine aminotransferase, AST: Aspartate aminotransferase, RRBCs: Rat red blood cells, DTH: Delayed-type hypersensitivity response, PBS: Phosphate buffer solution.

Traditional management of diabetes in Pakistan: Ethnobotanical investigation from Traditional Health Practitioners

ETHNOPHARMACOLOGICAL RELEVANCE

The uses of anti-diabetic plants are well anchored in the traditional health care system of Pakistan. To the best of our knowledge, this is the first ethno-botanical study about the uses of plants for the treatment of diabetes. The aim of the study is to record indigenous knowledge on anti-diabetic plants from Traditional Health Practitioners (THPs) and diabetic patients. In addition, it is aimed to ascertain and validate the traditional uses of anti-diabetic plants by citing pharmacological activities and phytochemical constitutes from previously published literature.

MATERIALS AND METHODS

The ethno-medicinal data was documented during 14 field surveys, each comprising of 10 days, from 3 regions of Pakistan (Islamabad, Khyber Pukhtoonkhwa and Deserts of Sindh). In total, 113 THPs and 44 diabetic patients were interviewed using open-ended and semi-structured questionnaires. Quantitative indices, including Relative Frequency of Citation percentage (RFC %) and Disease Consensus Index (DCI) were calculated. The documented data is authenticated by comparing with 28 published articles on ethno-botanical aspects and many pharmacological studies.

RESULTS

In total, 120 plant species belonging to 50 families were reported. The ethno-botanical results indicated that Moraceae (11 species); herb (56 reports) is dominant life form; the leaves (56 reports) are the most used plant part and decoction (24%) is the preferred mode of preparation. The quantitative analysis shows that RFC% ranges from 14 to 42 and DCI varies from 0.15 to 0.74. By comparing to previous studies, 64 species are reported new in traditional treatment of DM; 40 species are new to pharmacological evidence and 3 species are new to phytochemical studies.

CONCLUSIONS

This study recoded the significant indigenous knowledge about anti-diabetic plants among the THPs and diabetic patients in Pakistan. This type of ethno-botanical knowledge on traditional use of anti-diabetic plants is an important step in designing detailed pharmacological and clinical trials for Diabetes Miletus treatment. It is recommended that further pharmacological and phytochemical analysis should be conducted on those species which lack previous references in literature and have highest Frequency of Citation (FC), Disease Consensus Index (DCI) and Relative Frequency of Citation percentage (RFC%).

Evaluation of the in vitro antiplasmodial, antileishmanial, and antitrypanosomal activity of medicinal plants used in saudi and yemeni traditional medicine

The antiplasmodial, antileishmanial, and antitrypanosomal activity of twenty-five medicinal plants distributed in Saudi Arabia and Yemen was evaluated. The plants were extracted with methanol and screened in vitro against erythrocytic schizonts of Plasmodium falciparum, intracellular amastigotes of Leishmania infantum and Trypanosoma cruzi, and free trypomastigotes of T. brucei. To assess selectivity, cytotoxicity was determined on MRC-5 cells. Criteria for activity were an IC₅₀ < 10 μg/mL and high selectivity (SI). Seven plants showed interesting antiprotozoal activity in one or more models. Extracts of Caralluma penicillata and Acalypha ciliata showed fairly good activity against P. falciparum with IC₅₀ of 6.7 and 10.8 μg/mL and adequate selectivity (SI > 9.6 and >5.9). Interesting activity against L. infantum was obtained with Verbascum bottae (IC₅₀ of 3.2 μg/mL, SI 10.2) and Solanum glabratum (IC₅₀ 8.1 μg/mL, SI 3.4). The extracts of C. penicillata, Leucas virgata, Loranthus regularis, and V. bottae exhibited moderate activity against T. brucei (IC₅₀ 8.5, 8.1, 8.3, and 2.3 μg/mL; SI > 7.6, 7.7, 4.3, and >14.1). These results partly support the traditional use of some of the selected medicinal plants and warrant further investigations into the putative active constituents.

A review on ethnobotany, phytochemistry and pharmacology of plant genus C aralluma R. Br

Objectives

C aralluma is a xerophytic genus used as traditional medicine for the treatment of diabetes, inflammation, leprosy, obesity and rheumatism. Objectives of this review are to establish a relationship between traditional uses and scientific studies by critically evaluating the available fragmented literature on ethnobotany, pharmacology, phytochemistry and toxicology of genus Caralluma.

Key findings

Ethnomedical uses of Caralluma have been recorded from various countries such as China, India, Iran and Pakistan for six major classes of diseases including diabetes and gastrointestinal disorders. This review indicated the efficacy of genus Caralluma in several in vitro and in vivo pharmacological properties such as antimicrobial, antioxidant and anticancer activity. These bioactivity might be due to the presence of certain classes of compounds in genus Caralluma including pregnane glycosides, flavonoid glycosides and flavones.

Summary

Traditional uses and scientific evaluation of Caralluma indicates that it is one of the most widely used genus in some parts of the world. Further studies on the structural activity relationship of some of the isolated compound may improve their biological potency as well as scientific exploitation of traditional uses of the genus.

Safety Assessment of a Hydroethanolic Extract of Caralluma fimbriata

This toxicological assessment evaluated the safety of a hydroethanolic extract prepared from Caralluma fimbriata (CFE), a dietary supplement marketed worldwide as an appetite suppressant. Studies included 2 in vitro genotoxicity assays, a repeated dose oral toxicity study, and a developmental study in rats. No evidence of in vitro mutagenicity or clastogenicity surfaced in the in vitro studies at concentrations up to 5000 μg of extract/plate (Ames test) or 5000 μg of extract/mL (chromosomal aberration test). No deaths or treatment-related toxicity were seen in the 6-month chronic oral toxicity study in Sprague-Dawley rats conducted at 3 doses (100, 300, and 1000 mg/kg body weight (bw)/d). The no observed effect level for CFE in this study was considered to be 1000 mg/kg bw/d. A prenatal developmental toxicity study conducted at 3 doses (250, 500, and 1000 mg/kg bw/d) in female Sprague-Dawley rats resulted in no treatment-related external, visceral, or skeletal fetal abnormalities, and no treatment-related maternal or pregnancy alterations were seen at and up to the maximum dose tested. CFE was not associated with any toxicity or adverse events.

Antihyperglycemic activity of Caralluma tuberculata in streptozotocin-induced diabetic rats

The current study aimed at evaluating the potential and mechanisms of the antidiabetic activity of the methanolic extract (ME) of Caralluma tuberculata as well as its chloroform (CF), n-butanol (BF) and the remaining water fractions (RFs) in streptozotocin-induced diabetic rats. The antidiabetic activity was evaluated through assessing fasting blood glucose (FBG), insulin levels, oral glucose tolerance test (OGTT), glucose utilization by isolated rat psoas muscle, gut glucose absorption and G-6-Pase activity in isolated rat liver microsomes. Both ME and RF showed the highest potency, where ME had superior activity. The mechanism underlying the observed antihyperglycemic activity of ME could be attributed, at least in part, to enhanced skeletal muscle utilization of glucose, inhibition of hepatic gluconeogenesis and stimulation of insulin secretion. ME was standardized through LC-MS analysis for its major pregnanes.

Acylated pregnane glycosides from Caralluma quadrangula

In a previous study, the methanolic extract as well as the chloroform fraction of the aerial parts of Caralluma quadrangula (Forssk.) N.E.Br. indigenous to Saudi Arabia showed significant in vitro cytotoxic activity against breast cancer (MCF7) cell line. In a biologically-guided fractionation approach, four acylated pregnane glycosides were isolated from the chloroform fraction of C. quadrangula. The structures of the isolated compounds were elucidated by the analysis of their MS and NMR data. The compounds were identified as 12,20-di-O-benzoylboucerin 3-O-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (1), 12,20-di-O-benzoylboucerin 3-O-β-D-cymaropyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (2), 12,20-di-O-benzoylboucerin 3-O-β-D-glucopyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (3) and 12,20-di-O-benzoyl-3β,5α,12β,14β,20-pentahydroxy-(20R)-pregn-6-ene 3-O-β-D-glucopyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-canaropyranosyl-(1→4)-β-D-cymaropyranoside (4). The isolated compounds were tested for their cytotoxic activity against breast cancer (MCF7) cell line.

Study of the in vitro antiplasmodial, antileishmanial and antitrypanosomal activities of medicinal plants from Saudi Arabia

The present study investigated the in vitro antiprotozoal activity of sixteen selected medicinal plants. Plant materials were extracted with methanol and screened in vitro against erythrocytic schizonts of Plasmodium falciparum, intracellular amastigotes of Leishmania infantum and Trypanosoma cruzi and free trypomastigotes of T. brucei. Cytotoxic activity was determined against MRC-5 cells to assess selectivity. The criterion for activity was an IC₅₀ < 10 μg/mL (<5 μg/mL for T. brucei) and a selectivity index of ≥4. Antiplasmodial activity was found in the extracts of Prosopis juliflora and Punica granatum. Antileishmanial activity against L. infantum was demonstrated in Caralluma sinaica and Periploca aphylla. Amastigotes of T. cruzi were affected by the methanol extract of Albizia lebbeck pericarp, Caralluma sinaica, Periploca aphylla and Prosopius juliflora. Activity against T. brucei was obtained in Prosopis juliflora. Cytotoxicity (MRC-5 IC₅₀ < 10 μg/mL) and hence non-specific activities were observed for Conocarpus lancifolius.

Acylated pregnane glycosides from Caralluma sinaica

Caralluma sinaica is sold on local markets of Saudi Arabia for various health benefits however no phytochemical study has specifically been performed on this species. NMR and UHPLC-ESI-TOF-MS profilings of the ethanolic extract of the whole plant reveal a very complex phytochemical composition dominated by pregnanes. Detailed information on its constituents was obtained after isolation. Six pregnane glycosides were obtained and characterized based on the extensive spectroscopic analysis (including IR, ¹H NMR, ¹³C NMR and MS data), in addition to ten known compounds (seven pregnanes and three flavonoids). The compounds were identified as 12β-O-benzoyl-20-O-acetyl boucerin-3-O-6-deoxy-3-O-methyl-β-D-glucopyranosyl-(1-->4)-β-D-cymaropyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-O-tigloyl-20-O-acetyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-O-benzoyl-20-O-acetyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-β-D-digitalopyranosyl-(1-->4)-β-D-cymaropyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-O-benzoyl-20-O-acetyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-hevetopyranosyl-(1-->4)-β-D-cymaropyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-O-benzoyl-20-O-tigloyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-β-D-cymaropyranoside, 12β-20-O-dibenzoyl boucerin-3-O-β-D-glucopyranosyl-(1-->4)-β-D-cymaropyranosyl-(1-->4)-β-D-cymaropyranoside. Finally, the isolated compounds were evaluated for their quinone reductase induction.

In vitro antitrypanosomal activity of plant terpenes against Trypanosoma brucei

During the course of screening to discover antitrypanosomal compounds, 24 known plant terpenes (6 sesquiterpenes, 14 sesquiterpene lactones and 4 diterpenes) were evaluated for in vitro antitrypanosomal activity against Trypanosoma brucei brucei. Among them, 22 terpenes exhibited antitrypanosomal activity. In particular, α-eudesmol, hinesol, nardosinone and 4-peroxy-1,2,4,5-tetrahydro-α-santonin all exhibited selective and potent antitrypanosomal activities in vitro. Detailed here in an in vitro antitrypanosomal properties and cytotoxicities of the 24 terpenes compared with two therapeutic antitrypanosomal drugs (eflornithine and suramin). This finding represents the first report of promising trypanocidal activity of these terpenes. Present results also provide some valuable insight with regard to structure-activity relationships and the possible mode of action of the compounds.

Novel acylated steroidal glycosides from Caralluma tuberculata induce caspase-dependent apoptosis in cancer cells

AIM OF THE STUDY

Pregnane glycosides are potent cytotoxic agents which may represent new leads in the development of anti-tumour drugs, particularly in the treatment of breast cancer, because of the structural similarity to estrogenic agonists. Caralluma species are natural sources of a wide variety of pregnane glycosides. The aim of the study was to isolate, using an activity-guided fractionation approach, novel pregnane glycosides for testing on breast cancer and other tumour lines.

MATERIALS AND METHODS

The effect of crude extracts, specific organic fractions and isolated compounds from Caralluma tuberculata was tested on the growth and viability of MCF-7 estrogen-dependent, and MDA-MB-468 estrogen-independent breast cancer cells, Caco-2 human colonic cells, HUVECs and U937 cells. Neutral red uptake and MTT assays were used. Apoptosis was detected by Western blot of poly-(ADP ribose) polymerase (PARP) as were other markers of nuclear fragmentation (DNA ladder assay, staining of cells with nuclear dye DAPI). The involvement of caspases was investigated using the pan-caspase inhibitor Z-VAD-FMK.

RESULTS

The ethyl acetate fraction of Caralluma tuberculata was found to be the most potent anti-proliferative fraction against all three cancer cell lines. Two novel steroidal glycosides were isolated from the active fraction after a series of chromatographic experiments. The structure of the isolated compounds was elucidated solely based on 2D-NMR (HMBC, HETCOR, DQF-COSY) and MS spectral analysis as compound 1: 12-O-benzoyl-20-O-acetyl-3β,12β,14β,20β-tetrahydroxy-pregnan-3-ylO-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1 → 4)-3-methoxy-β-D-ribopyranoside, and as compound 2: 7-O-acetyl-12-O-benzoyl-3β,7β,12β,14β-tetrahydroxy-17β-(3-methylbutyl-O-acetyl-1-yl)-androstan-3-ylO-β-D-glucopyranosyl-(1 → 4)-6-deoxy-β-D-allopyranosyl-(1 → 4)-β-D-cymaropyranosyl-(1 → 4)-β-D-cymapyranosyl-(1→ 4)-β-D-cymaropyranoside. Compound 1 (pregnane glycoside) and compound 2 (androstan glycoside) induced apoptosis at <25 μM after 48 h as assessed by cell shrinkage, PARP cleavage, DNA fragmentation, and reversal with the caspase inhibitor.

CONCLUSIONS

Two novel steroid glycosides isolated from Caralluma tuberculata possess moderate, micromolar cytotoxic activity on breast cancer and other cells in vitro, which may indicate a source of activity in vivo of interest to future drug design.

Norrish-Prins reaction as a key step in the synthesis of 14β-hydroxy-5α (or 5β or Δ(5,6))-pregnane derivatives

Numerous bioactive glycosteroids are characterized by aglycones bearing a 14β-hydroxy pregnane skeleton like boucerin and isoramanone. In general, the syntheses of the latter are achieved by acidic hydrolysis of the corresponding glycosteroids. These aglycones were also obtained by a combined Norrish type I-Prins reaction starting from the corresponding 12-keto-pregnane derivatives. However, for the Norrish-Prins reaction, no reports describe the influence of the A/B ring junction (cis or trans or Δ(5,6) double bond) or the influence of the substitution pattern at position 20. Herein, we describe the use of Norrish type I-Prins reactions to synthesize isoramanone and boucerin derivatives and their A/B cis and trans analogs. The influence of the parameters mentioned above is also presented. These studies showed that the A/B ring junction has little influence on the Norrish type I-Prins reaction but that the substitution pattern at position 20 is important. The presence of a dioxolane group induced not only the formation of the desired 14β-hydroxy pregnane derivatives in the highest yields but also the formation of new spiro derivatives.

Minor pregnanes from Caralluma adscendens var. gracilis and Caralluma pauciflora

Phytochemical investigation of Caralluma adscendens var. gracilis and Caralluma pauciflora (Asclepiadaceae) whole plant extracts allowed to isolate one pregnane glycoside and two pregnanes characterized as 12β,20-O-dibenzoyl-5α,6-dihydrosarcostin β-oleandropyranosyl-(1→4)-β-cymaropyranosyl-(1→4)-β-digitoxypyranosyl-(1→4)-β-cymaropyranosyl-(1→4)-β-cymaropyranoside (1), 12β-O-benzoyl-3β,11α,14β,20R-pentahydroxy-pregn-5-ene (2), and 11α-O-benzoyl-3β,12β,14β,20R-pentahydroxy-pregn-5-ene (3), respectively. Their structural characterization was obtained on the basis of extensive NMR spectral studies. Three known pregnane glycosides along with lupeol and β-sitosterol were also isolated and characterized.

In vivo antimalarial activities of glycoalkaloids isolated from Solanaceae plants

CONTEXT

Malaria is one of the most common and serious protozoan tropical diseases. Multi-drug resistance remains pervasive, necessitating the continuous development of new antimalarial agents.

OBJECTIVE

Many glycosides, such as triterpenoid saponins, were shown to have antimalarial activity against Plasmodium falciparum in vitro. This study was to elucidate the ability of five glycoalkaloids against Plasmodium yoelii and develop new antimalarial lead compounds.

MATERIALS AND METHODS

Glycoalkaloids were isolated from three kinds of Solanaceae plants: chaconine and solanine were isolated from Solanum tuberosum L. sprouts, solamargine and solasonine from Solanum nigrum L. fruit, tomatine from Lycopersicon esculentum Mill. fruit. The five isolated glycoalkaloids were evaluated against Plasmodium yoelii 17XL in mice with 4-day parasitemia suppression test in different concentrations.

RESULTS

Chaconine showed a dose-dependent suppression of malaria infection, ED50, 4.49 mg/kg; therapeutic index (TI), approximately 9. At a dose of 7.50 mg/kg, the parasitemia suppressions of chaconine, tomatine, solamargine, solasonine and solanine were 71.38, 65.25, 64.89, 57.47 and 41.30%, respectively. At 3.75 mg/kg, the parasitemia suppression of chaconine was 42.66%, but the derivative, chaconine-6-O-sulfate, appeared to show no antimalarial activity. Simultaneous administration of chaconine and solanine in 1:1 did not show any synergistic effects.

DISCUSSION AND CONCLUSION

The results showed that the glycoalkaloids with chacotriose (chaconine and solamargine) were more active than those with solatriose (solanine and solasonine). Chaconine was the most active among the five glycoalkaloids. We propose that the activity is dependent upon non-specific carbohydrate interactions. The 6-OH of chaconine is important for antimalarial activity.

Essential oil composition of stems and fruits of Caralluma europaea N.E.Br. (Apocynaceae)

The essential oil of the stems and fruits of Caralluma europaea (Guss.) N.E.Br. (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analyzed. The analyses allowed the identification and quantification of 74 volatile compounds, of which 16 were aromatic and 58 non-aromatic. Stems and fruits contained 1.4% and 2.7% of aromatic compounds respectively, while non-aromatic were 88.3% and 88.8%. Non-aromatic hydrocarbons were the most abundant compounds in both organs, followed by fatty acids. Data showed differences in the profiles between stems and fruits which shared only eighteen compounds; stems accounted for 38 compounds while fruits for 53. Fruits showed a higher diversity especially in aromatic compounds with twelve versus four in stems. Among the volatiles identified in stems and fruits of C. europaea 26 are present in other taxa of Apocynaceae, 52 are semiochemicals for many insects, and 21 have antimicrobial activity. The possible ecological role of the volatiles found is briefly discussed.

Antimalarial compounds isolated from plants used in traditional medicine

Objectives

This review covers the compounds with antiplasmodial activity isolated from plants published from 2005 to the end of 2008, organized according to their phytochemical classes. Details are given for substances with IC50 values ≤ 11 μM.

Key findings

Malaria is a major parasitic disease in many tropical and subtropical regions and is responsible for more than 1 million deaths each year in Africa. The rapid spread of resistance encourages the search for new active compounds. Nature and particularly plants used in traditional medicine are a potential source of new antimalarial drugs as they contain molecules with a great variety of structures and pharmacological activities.

Summary

A large number of antimalarial compounds with a wide variety of structures have been isolated from plants and can play a role in the development of new antimalarial drugs. Ethnopharmacological approaches appear to be a promising way to find plant metabolites that could be used as templates for designing new derivatives with improved properties.

Antitrypanosomal activity of some pregnane glycosides isolated from Caralluma species

Pregnane glycosides previously isolated from genus Caralluma (C. Penicillata, C. tuberculata and C. russelliana) were tested for their antitrypanosomal activity. Penicilloside E showed the highest antitrypanosomal activity (IC(50) 1.01 microg/ml) followed by caratuberside C (IC(50) 1.85 microg/ml), which exhibited the highest selectivity index (SI 12.04). It was noticed that acylation is required for the antitrypanosomal activity while glycosylation at C-20 has no significant effect on the activity.