N-Methylneolitsine as a new and potent acetylcholinesterase inhibitor of Cissampelos pareira Linn. aerial parts: bioassay-guided isolation and quantitative densitometric analysis

The rising geriatric population is expected to increase the demand for drugs treating neurodegenerative diseases. The present work is aimed to discover acetylcholinesterase (AChE) inhibitors from Cissampelos pareira Linn. aerial parts (Family: Menispermaceae). Bioassay-guided isolation, AChE inhibition study and estimation of the therapeutic marker in different parts of raw herbs were conducted. The structure of the compound (1) was elucidated as N-methylneolitsine by using NMR (1D and 2D) and ESI-MS/MS spectral data, which is a new natural analogue of neolitsine. It showed good AChE inhibition with an IC50 value of 12.32 µg/mL. It was densitometrically estimated to be 0.074 - 0.33% in aerial parts of C. pareira, collected from various locations. The alkaloid reported here could be potentially useful for the treatment of various neurodegenerative diseases and the aerial part of C. pareira could be used as a promising ingredient for various preparations treating neurodegenerative diseases.

Clerodane diterpenoids with in-vitro anti-neuroinflammatory activity from the tuberous root of Tinospora sagittata (Menispermaceae)

Twenty-six clerodane diterpenoids have been isolated from T. sagittata, a plant species of traditional Chinese medicine Radix Tinosporae, also named as "Jin Guo Lan". Among them, there are eight previously undescribed clerodane diterpenoids (tinotanoids A-H: 1-8), and 18 known diterpenoids (9-26). The absolute configurations of compounds 1, 2, 5, 8, 13, 17 and 20 were determined by single-crystal X-ray diffraction. Compound 1 is the first example of rotameric clerodane diterpenoid with a γ-lactone ring which is constructed between C-11 and C-17; meanwhile, compounds 3 and 4 are two pairs of inseparable epimers. Compounds 2, 12 and 17 demonstrated excellent inhibitory activity on NO production against LPS-stimulated BV-2 cells with IC50 values of 9.56 ± 0.69, 9.11 ± 0.53 and 11.12 ± 0.70 μM, respectively. These activities were significantly higher than that of the positive control minocycline (IC50 = 23.57 ± 0.92 μM). Moreover, compounds 2, 12 and 17 dramatically reduced the LPS-induced upregulation of iNOS and COX-2 expression. Compounds 2 and 12 significantly inhibited the levels of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 that were increased by LPS stimulation.

Clerodane Furanoditerpenoids from Tinospora bakis (A.Rich.) Miers (Menispermaceae)

Tinospora bakis (A.Rich.) Miers (Menispermaceae) has traditionally been used to alleviate headaches, rheumatism, mycetoma, and diabetes, among others. Despite its extensive use, the active components of the plant have never been investigated. In this work, a series of furanoditerpenoids (1-18) and five compounds from other classes (19-23) were isolated from T. bakis. Notably, two new compounds were discovered and named: tinobakisin (1) and tinobakiside (10). Their molecular structures were elucidated with NMR, MS, UV, IR, and ECD spectra. Additionally, known compounds (2-9 and 11-23) were corroboratively identified through spectral comparisons with previously reported data, while highlighting and addressing some inaccuracies in the prior literature. Remarkably, compounds 6, 7, 13, and 17 exhibited a superior anti-glycation effect, outperforming established agents like rutin and quercetin in a lab model of protein glycation with glucose. The overall findings suggest that furanoditerpenoids play a crucial role in the antidiabetic properties of T. bakis. This research marks the first comprehensive phytochemical investigation of T. bakis, opening the door for further investigation into furanoditerpenoids and their biological mechanisms.

Biochemical and histological insights of 1,4-polyisoprene isolated from Sphenocentrum jollyanum pierre (menispermaceae) stem in wound healing activity in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Sphenocentrum jollyanum whole stem extract is used traditionally in combination with its leaves to treat chronic wounds and also ameliorate conditions that exacerbate wounds such as diabetes mellitus.

AIM OF THE STUDY

The study isolated the major wound healing bioactive compound from the non-polar fraction of S. jollyanum extract and evaluated the in vivo wound healing activity of a 0.10% w/w 1,4-polyisoprene-based ointment in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

The major bioactive constituent of S. jollyanum was isolated using a wound healing activity-guided approach and characterized the compound using 1D and 2D-NMR spectroscopic techniques. The wound healing activity study adopted both excision (wound contraction) and incision (biochemical) models.

RESULTS

In the excision model, the 1,4-polyisoprene caused 99% wound closure and restored the excised wound on day 12. On the 6th and 12th post-wounding days, 1,4-polyisoprene caused a significant (p < 0.001) elevation in the tensile strength (486 g) of the incision wound compared with the control (388 g). The biochemical (hexosamine and hydroxyproline) and antioxidant/inflammatory (ascorbic acid, superoxide dismutase, and glutathione peroxidase) parameters increased significantly while malondialdehyde was down-regulated in the wounds treated with 1,4-polyisoprene compared with control. The histological analysis of tissue sections taken from the edge and center of the wounds at 0-12 days post wounding revealed an increased tissue regeneration, accelerated collagen formation, and epidermal regeneration without edema or inflammation on the 12th day.

CONCLUSION

The major wound healing constituent of S. jollyanum is 1,4-polyisoprene and the study has provided a new class of compounds for further optimization.

A Review of Fibraurea tinctoria and Its Component, Berberine, as an Antidiabetic and Antioxidant

Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia caused by resistance to insulin action, inadequate insulin secretion, or excessive glucagon production. Numerous studies have linked diabetes mellitus and oxidative stress. People with diabetes usually exhibit high oxidative stress due to persistent and chronic hyperglycemia, which impairs the activity of the antioxidant defense system and promotes the formation of free radicals. Recently, several studies have focused on exploring natural antioxidants to improve diabetes mellitus. Fibraurea tinctoria has long been known as the native Borneo used in traditional medicine to treat diabetes. Taxonomically, this plant is part of the Menispermaceae family, widely known for producing various alkaloids. Among them are protoberberine alkaloids such as berberine. Berberine is an isoquinoline alkaloid with many pharmacological activities. Berberine is receiving considerable interest because of its antidiabetic and antioxidant activities, which are based on many biochemical pathways. Therefore, this review explores the pharmacological effects of Fibraurea tinctoria and its active constituent, berberine, against oxidative stress and diabetes, emphasizing its mechanistic aspects. This review also summarizes the pharmacokinetics and toxicity of berberine and in silico studies of berberine in several diseases and its protein targets.

Alkaloids in genus stephania (Menispermaceae): A comprehensive review of its ethnopharmacology, phytochemistry, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Approximately 60 species of the genus Stephania (Menispermaceae) are distributed worldwide. Among these, 39 species are located in South and Southwest China; in particular, these plants are rich in alkaloids and were used in traditional Chinese medicine (TCM) against numerous ailments.

AIM OF THIS REVIEW

The purpose of this study was to provide organized information on the ethnopharmacological uses as well as the phytochemical, pharmacological, and toxicological evaluation of the alkaloids derived from plant species included in the genus Stephania. In addition, we aimed to provide comprehensive basic knowledge on the medicinal properties of these plants and establish meaningful guidelines for further research.

MATERIALS AND METHODS

Information related to the Stephania genus was collected from scientific databases, such as Web of Science, PubMed, Baidu Scholar, and China Academic Journals (CNKI), within the last 20 years on phytochemistry, pharmacology, and toxicology of the plants in genus Stephania. Furthermore, information was obtained from the Pharmacopoeia of the People's Republic of China. Chinese Pharmacopoeia and Flora of China.

RESULTS

Plant species belonging to the genus Stephania have been mentioned as traditional remedies and various alkaloidal compounds have been identified and isolated, including aporphine, proaporphine, morphinane, hasubanane, protoberberine, benzylisoquinoline, and bisbenzylisoquinoline and among others. The isolated alkaloidal compounds reportedly exhibited promising pharmacological properties, such as antimicrobial, antiviral, antitumor, antioxidant, antihyperglycemic, anti-inflammatory, antinociceptive, anti-multidrug resistance, neuroprotective, and cardioprotective activities.

CONCLUSIONS

The genus Stephania is widely used in TCM. The ethnopharmacological uses, phytochemistry, and pharmacology of the Stephania sp. Described in this review demonstrated that these plants contain numerous alkaloids and active constituents and display myriad pharmacological activities. Typically, research on the plants' pharmacological activity focuses on parts of the plants and the associated compounds. However, many Stephania species have rarely been studied, and the ethnomedicinal potential of those discovered has not been scientifically evaluated and needs to be further elucidated. Furthermore, quality control and toxicology studies are warranted in the future.

Effect of aqueous extract from root and leaf of Sphenocentrum jollyanum pierre on wounds of diabetic rats: Influence on wound tissue cytokines, vascular endothelial growth factor and microbes

ETHNOPHARMACOLOGICAL RELEVANCE

Sphenocentrum jollyanum is a flowering plant of the Menispermaceae family with bright yellow roots and wedged-shaped leaves. The plant is reputed to possess exceptional wound healing properties and used in folkloric medicine to dress chronic wounds.

AIM OF THE STUDY

Wound repair in a hyperglycemic state is known to be impaired and delayed making treatment a difficult challenge. This study sought how the aqueous extracts of root and leaf of Sphenocentrum jollyanum facilitated wound healing by modulating pro-inflammatory cytokines, vascular endothelial growth factor and microbial colonization on excision wound created in diabetic rats.

METHODS

Diabetes (blood glucose >250 mg/dl) was induced by feeding normal rats with high fat diet for 14 days after which intraperitoneal injection of low dose streptozotocin (35 mg/kg b.w.) was administered. Wounds were subsequently created and treatments administered afterwards for 14 days.

RESULTS

Administration of Sphenocentrum jollyanum root and leaf extracts both orally and topically (100 and 200 mg/kg b.w) significantly (p < 0.05) reduced secretion of pro-inflammatory cytokines (TNF-α, IL-6), number of microbial colonies (CFU/ml × 10²), activity of myeloperoxidase and significantly increased growth factor secretion on wounds of the diabetic rats. Histological evaluations of wound tissues of treated diabetic rats revealed matured tissue granulation, presence of new blood vessels, collagen and fibroblast with fewer inflammatory cells.

CONCLUSION

The use of Sphenocentrum jollyanum effectively enhanced wound healing which may be related to constituents identified by GC-MS analysis and can thus, be suggested as a therapeutic agent for diabetic wound management.

In Vitro and In Silico Evaluation of Cholinesterase Inhibition by Alkaloids Obtained from Branches of Abuta panurensis Eichler

Alkaloids are natural products known as ethnobotanicals that have attracted increasing attention due to a wide range of their pharmacological properties. In this study, cholinesterase inhibitors were obtained from branches of Abuta panurensis Eichler (Menispermaceae), an endemic species from the Amazonian rainforest. Five alkaloids were isolated, and their structure was elucidated by a combination of 1D and 2D 1H and 13C NMR spectroscopy, HPLC-MS, and high-resolution MS: Lindoldhamine isomer m/z 569.2674 (1), stepharine m/z 298.1461 (2), palmatine m/z 352.1616 (3), 5-N-methylmaytenine m/z 420.2669 (4) and the N-trans-feruloyltyramine m/z 314.1404 (5). The compounds 1, 3, and 5 were isolated from A. panurensis for the first time. Interaction of the above-mentioned alkaloids with acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes was investigated in silico by molecular docking and molecular dynamics. The molecules under investigation were able to bind effectively with the active sites of the AChE and BChE enzymes. The compounds 1–4 demonstrated in vitro an inhibitory effect on acetylcholinesterase with IC50 values in the range of 19.55 µM to 61.24 µM. The data obtained in silico corroborate the results of AChE enzyme inhibition.

Antioxidant, Antibacterial, and Anti-diabetic Activity of Green Synthesized Copper Nanoparticles of Cocculus hirsutus (Menispermaceae)

The emergence of new technologies has led to the discovery of the biological properties of nanoparticles through green approach. In the present investigation, we report the potential antibacterial, antioxidant, and anti-diabetic properties of copper nanoparticle (CuNPs) synthesized by reducing 3 mM copper acetate solution with aqueous leaf extract of Cocculus hirsutus. A colour change from deep brown to dark greenish brown indicated the formation of copper nanoparticles. The so-formed CuNPs were characterized by employing UV spectroscopy, FTIR, SEM, and EDX analyses which described sheet-like structure morphology having typical size of 63.46 nm. Later, the synthesized CuNPs efficiency was evaluated against bacterial pathogens, and was found highly toxic to B. subtilis and S. aureus strains. The synthesized CuNPs were examined through H₂O₂ and PMA assays which demonstrated the highest free radical scavenging activity. Besides, the resulted CuNPs revealed the higher anti-diabetic efficacy in both the [Formula: see text]-amylase and [Formula: see text] -glucosidase inhibition assays (64.5% ± 0.11 and 68.5% ± 0.11, respectively). Finally, our findings report that C. hirsutus can be exploited as a source for green synthesis of CuNPs, having potent in vitro antioxidant, antibacterial, and anti-diabetic properties.

Tiliacora racemosa leaves induce oxidative stress mediated DNA damage leading to G2/M phase arrest and apoptosis in cervical cancer cells SiHa

ETHNOPHARMACOLOGICAL RELEVANCE

The Menispermaceae plant Tiliacora racemosa is immensely popular in Indian traditional Ayurvedic medicine as "Krishnavetra" for its remarkable anti-cancerous property, and is commonly used by tribal population for the treatment of skin infections, snake bites and filariasis.

AIM OF THE STUDY

This present study intends to identify the modus operandi behind the cytotoxic activity of Tiliacora racemosa leaves in cervical cancer cells SiHa. Focus has been instilled in the ability of the plant extract to target multiple signaling pathways leading to cell cycle arrest and cell death in SiHa cells, followed by a pharmacological characterization to identify the bioactive principle.

MATERIALS AND METHODS

T. racemosa leaves extracted in methanol, ethyl acetate, hexane and aqueous solvent were screened for cytotoxicity in HeLa, SiHa, C33A (cervical cancer cells) and HEK cells by MTT assay. SiHa cells were treated with the most potent extract (TRM). Cellular morphology, clonogenic and wound healing potential, presence of intracellular ROS and NO, lipid peroxidation, activity of cellular antioxidants (SOD, CAT, GSH), DNA damage detection by comet assay and localisation of γ-H2AX foci, intracellular expression of PARP-1, Bax/Bcl2 and caspase-3, loss in mitochondrial membrane potential by JC1 (flow cytometry) and Rh123 (microscopy), cell cycle analysis, Annexin-FITC assay, AO/EtBr microscopy and apoptotic proteome profiling were undertaken in the treated cells. All the related proteins were studied by immunoblots. Effect of NAC (ROS-scavenger) on cell viability, DNA damage and apoptosis were studied. Phytochemical characterization of all TR extracts was followed by LC-MS analysis of TRM and isolated alkaloid of TR was assessed for cytotoxicity.

RESULTS

The methanol extract of T. racemosa (TRM) rich in bisbenzylisoquinoline and other alkaloids impeded the proliferation of cervical cancer cells SiHa in vitro through disruption of cellular redox homeostasis caused by increase in cellular ROS and NO with concomitant decrease in the cellular antioxidants. Double-stranded DNA damage was noted from γH2AX foci accumulation and Parp-1 activation leading to ATM-Chk2-p53 pathway arresting the cells at G2/M-phase through cyclin B1 inhibition. The mitochondrial membrane potential was also disturbed leading to caspase-3 dependent apoptotic induction by both extrinsic and intrinsic pathway. Immunoblots show TRM also inhibited PI3K/Akt and NFκB pathway. NAC pre-treatment rescued the cell viability proving DNA damage and apoptosis to be direct consequences of ROS overproduction. Lastly, the therapeutic potential of T. racemosa is was hypothesized to be possibly derived from its alkaloid content.

CONCLUSION

This study proves the age old ethnnopharmacological anticancer role of T. racemosa. The leaf extracts inhibited the anomalous proliferation of SiHa cells by virtue of G2/M-phase cell cycle arrest and apoptotic cell death. Oxidative stress mediated double stranded DNA damage paved the way towards apoptotic cell death through multiple routes, including PI3K/Akt/NFκB pathway. The abundant alkaloid content of T. racemosa was denoted as the probable responsible cytotoxic principle.

Cognitive-enhancing effects of fibrauretine on Aβ1-42-induced Alzheimer's disease by compatibilization with ginsenosides

Fibrauretine is the main active ingredient in rattan stems of Fibraurea recisa Pierre. The aim of this study was to evaluate the cognitive-enhancing effects and underlying molecular mechanisms of fibrauretine compatibilized with ginsenosides on Alzheimer's disease (AD) induced in mice with amyloid β-protein (Aβ_1-42)_. The results showed that the spatial learning and memory abilities of AD mice were significantly enhanced after combined treatment with fibrauretine and ginsenosides using the Morris water maze test. The levels of acetylcholinesterase (AChE) and phosphorylated Tau protein (p-Tau) in brain tissue and the levels of nitric oxide (NO), malondialdehyde (MDA), and N-terminal pro-brain natriuretic peptide (NT-proBNP) in plasma were significantly increased in Aβ_1-42-induced AD mice, and these effects were reversed after combined treatment with fibrauretine and ginsenosides. By contrast, a significant increase in the levels of catalase (CAT), superoxide dismutase (SOD), choline acetyltransferase (ChAT) and glutathione peroxidase (GSH-Px) was observed in the combined treatment group. The results of haematoxylin and eosin (H&E) staining, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) analysis, immunohistochemistry (IHC) and Western blot analysis showed that the apoptosis rate, Bax, nuclear factor kappa-B p65 (NF-κBp65), cleaved caspase-3 and cleaved caspase-9 expression levels were obviously decreased and that the Bcl-2 expression levels were significantly increased in the hippocampi of mice treated with fibrauretine and ginsenosides. The results of this study show that the ameliorative effect of fibrauretine against AD can be significantly enhanced by compatibilization with ginsenosides. The underlying molecular mechanisms of fibrauretine may be related to antioxidation and anti-apoptosis.

Pharmacological activity of Curarea toxicofera in combination with classical antimalarial treatments

ETHNOPHARMACOLOGICAL RELEVANCE

In the Leticia-Amazonas area, Uitoto indigenous people use a preparation of Curarea toxicofera (Wedd) Barneby & Krukoff (Menispermaceae) alone or combined with prescribed medications to prevent and treat malaria.

AIM OF STUDY

To determine the in vitro and in vivo antiplasmodial activity of traditional preparations of Curarea toxicofera alone and in combination with classical antimalarials.

MATERIAL AND METHODS

The traditional preparation was evaluated in vitro against P. falciparum FCR3 CQ resistant strain, alone and combined. The preparation was further administered orally alone or combined with chloroquine and artesunate in mice infected with Plasmodium berghei ANKA strain on the four-day antimalarial test model.

RESULTS

The herbal remedy used alone was able to significantly decrease the parasitemia both in vitro (IC₅₀ 7.3 µg/ml) and in vivo (ED₅₀ 328 mg/Kg) but it was less active than chloroquine (IC₅₀ 0.29 µg/ml in vitro and ED₅₀ 2.3 mg/Kg/day in vivo), and than artesunate (IC₅₀ 0.002 µg/ml and ED₅₀ 3.7 mg/Kg/day). Interestingly it presented synergism with chloroquine in vitro (Combination Index: 0.39) and in vivo; and was additive with artesunate in vitro (Combination Index: 0.94) and in vivo.

CONCLUSION

The traditional preparation showed potential as an antimalarial and, when used in combination, does not negatively affect the efficacy of the drugs evaluated. Pre-clinical studies should be conducted with a standardized preparation to confirm its efficacy and safety alone and in combination with chloroquine and artesunate.

Anti-inflammatory and antinociceptive effect of Pachygone ovata leaves

CONTEXT

Pachygone ovata (Poir.) Miers ex Hook. F. et Thoms (Menispermaceae) is a rich source of bioactive bisbenzylisoquinoline and aporphine alkaloids.

OBJECTIVE

This study investigates the in vitro and in vivo anti-inflammatory and antinociceptive potential of Pachygone ovata leaves.

MATERIALS AND METHODS

Lipoxygenase (LOX) assay for anti-inflammatory activity was conducted using MeOH, EA, H and Aq extracts; followed by alkaloid isolation. The anti-inflammatory potential was determined using carrageenan-induced paw oedema and formalin tests for evaluation of Pachygone ovata analgesic effect. Different doses (100, 300 and 400 μg/kg) were administered orally to Wistar rats for a period of one week, once daily.

RESULTS

MeOH and EA extract efficiently inhibited LOX (IC₅₀ 1.43 and 2.15 μg/mL, respectively). MeOH extract had better inhibiting capacity (57%) than indomethacin (51%) in carrageenan induced rats. MeOH extract (300 μg/kg) significantly reduced the increased levels of nitric oxide (8 ± 0.57 M), total leukocyte count (4.5 ± 0.05 cells 10³/cells) and C-reactive protein (55 ± 0.45 mg/mL). There was a decrease in various serum biochemical markers (ALT, AST). Histopathological studies revealed reduction in oedema and decreased cellular infiltration on supplementation with MeOH extract. Furthermore, MeOH extract (300 μg/kg) and alkaloid fraction (400 μg/kg) effected both phases (neurogenic and inflammatory) of formalin injected models.

DISCUSSION AND CONCLUSION

Inflammatory mediators play a key role in inflammation; therefore, keeping it in control is of utmost importance. The usefulness of Pachygone ovata leaves on pain and inflammation has been described, probably due to its effect on inflammatory mediators and high alkaloid content.

In vitro and in vivo antimalarial activity and cytotoxicity of extracts and fractions from the leaves, root-bark and stem-bark of Triclisia gilletii

ETHNOPHARMACOLOGICAL RELEVANCE

To evaluate the in vitro antiplasmodial activity and cytotoxicity, and the in vivo activity of extracts and fractions from the leaves, root-bark and stem-bark of Triclisia gilletii (De Wild) Staner (Menispermaceae), used in traditional medicine against malaria.

MATERIALS AND METHODS

The aqueous and 80% MeOH extracts, and a series of fractions and subfractions from the leaves, stem and root-bark of Triclisia gilletii were tested in vitro for their antiplasmodial activity against a Congolese-sensitive strain of Plasmodium falciparum, against the chloroquine and pyrimethamine-resistant K1 strain of Plasmodium falciparum, for cytotoxicity against MRC-5 cells, and in vivo in mice infected with Plasmodium berghei berghei.

RESULTS

Many samples from the three plant parts exhibited pronounced activity against the Congolese chloroquine-sensitive strain of Plasmodium falciparum with some IC50 values <0.02 µg/ml, and against the K1 strain, with some IC50 <0.25; the selectivity was higher against the Congolese strain. At oral doses of 200 and 400mg/kg body weight in infected mice, the aqueous, 80% methanol and total alkaloid extracts from the three plant parts produced more than 65% and 75% chemosuppression, respectively. The antiplasmodial activity of these three plant parts of Triclisia gilletii can at least in part be attributed to bisbenzylisoquinoline alkaloids, and supports its use for the treatment of uncomplicated malaria in traditional medicine.

Antiplasmodial activity and cytotoxicity of Albertisia delagoensis

Leaves and rhizome methanol extracts of Albertisia delagoensis tested positive against Plasmodium falciparum, with a very low cytotoxic activity in leaves against the Graham cell line.

Hypotensive effect and toxicology of the extract from Coscinium fenestratum (Gaertn.) Colebr

The water extract from Coscinium fenestratum (Gaertn.) Colebr. (CF extract) was tested for hypotensive and vasorelaxant effects. Acute and subchronic toxicity as well as motor activity of CF extract were also evaluated. The present study demonstrates that CF extract is effective in reducing blood pressure in anesthetized normotensive rats. This effect is shown to be dose-related and rapid in onset. The extract showed an endothelium-dependent and independent vasorelaxant activity in isolated aortic rings precontracted with phenylephrine (1 microM) and KCl (60 mM). The capacity of L-NAME (100 microM), an inhibitor of nitric oxide synthase, to reduce the vasorelaxant action of the extract indicates the involvement of nitric oxide. In the acute toxicity test, an oral dose of 5000 mg/kg of the CF extract did not produce mortality or significant changes of the general behavior of animals and gross appearance of internal organs of rats. Similarly, in the subchronic toxicity test, an oral dose of 2500 mg/kg/day of the CF extract given to rats for 90 days did not cause any significant change of any of the parameters observed when compared with those of the control animals. Moreover, the CF extract did not produce any effect on the central nervous system when spontaneous motor activity in rats was assessed. However, because some average hematological and blood chemistry values were found to be statistically different, further studies, including chronic toxicity test, should be done to confirm the safety of this plant when it is used over a long period of time.

Alkaloids and amides from Triclisia sacleuxii

A new alkaloid, named gasabiimine (1), together with four known bisbenzyltetrahydroisoquinoline alkaloids (phaeanthine, 1,2-dehydroapateline, N-methylapateline, O-methylcocsoline) has been isolated from the roots of Triclisia sacleuxii. The structure of the new alkaloid was elucidated by spectroscopic data analysis.

Anti-inflammatory activities of the methanol extracts and an isolated furanoditerpene constituent of Sphenocentrum jollyanum Pierre (Menispermaceae)

Sphenocentrum jollyanum crude extracts and an isolated constituent were evaluated for anti-inflammatory activity using the carrageenan-induced hind paw oedema of healthy adult albino rats and utilizing the oral route of administration. The fruit methanol extract (79.58% inhibition at 200 mg kg(-1)) gave a higher anti-inflammatory activity than the root extract (53.75% inhibition at 200 mg ml(-1)). Further purification of the most active fruit methanol extract (MFE) led to the isolation of three furanoditerpenes identified as columbin, isocolumbin, fibleucin (uv, ir, nmr and ms) as well as a flavonoid-rich fraction (FDE). Both columbin (67.08% inhibition at 20 mg kg(-1), p<0.05) and FDE (76.25% inhibition at 200 mg kg(-1); p<0.05) gave significant anti-inflammatory activities in comparable range with reference acetylsalicylic acid (72.5% inhibition at 100 mg kg(-1)). The results provide some justification for the folkloric uses of Sphenocentrum jollyanum in the treatment of inflammatory-based diseases across the West African sub-region.

Biologically active bisbenzylisoquinoline alkaloids from the root bark of Epinetrum villosum

Methanol and water extracts of the root of Epinetrum villosum (Exell) Troupin (Menispermaceae) were found to exhibit antimicrobial and antiplasmodial activities. Investigation of the active methanol fraction led to the isolation of four bisbenzylisoquinoline alkaloids, i.e., cycleanine, cycleanine N-oxide, isochondodendrine and cocsoline. Structures were established by spectroscopic methods. Cocsoline displayed antibacterial and antifungal activities (MIC values of 1000-15.62 and 31.25 microg/ml, respectively). Isochondodendrine was found to have the most potent antiplasmodial activity (IC50 = 0.10 microg/ml), whereas the IC50 on HCT-116 human colon carcinoma cells was 17.5 microg/ml (selectivity index 175). Cycleanine acted against HIV-2 (EC50=1.83 microg/ml) but was at least 10-fold less active against HIV-1. Cycleanine N-oxide showed no activity towards all tested microorganisms.

Antibacterial effects of Coscinium fenestratum

Antibacterial activity of Coscinium fenestratum is mainly due to the presence of berberine.

Anti-ulcer and anti-oxidant activity of pepticare, a herbomineral formulation

Pepticare, a herbomineral formulation of the Ayurveda medicine consisting of the herbal drugs: Glycyrrhiza glabra, Emblica officinalis and Tinospora cordifolia, was tested for its anti-ulcer and anti-oxidant activity in rats. Effects of various doses (125, 250, 500 and 1000mg/kg, p.o.) of Pepticare were studied on gastric secretion and gastric ulcers in pylorus-ligation and on ethanol-induced gastric mucosal injury in rats. The reduction in ulcer index in both the models along with the reduction in volume and total acidity, and an increase in the pH of gastric fluid in pylorus-ligated rats proved the anti-ulcer activity of Pepticare. It was also found that Pepticare was more potent than G. glabra alone in protecting against pylorus-ligation and ethanol-induced ulcers. The increase in the levels of superoxide dismutase, catalase, reduced glutathione and membrane bound enzymes like Ca2+ ATPase, Mg2+ ATPase and Na+ K+ ATPase and decrease in lipid peroxidation in both the models proved the anti-oxidant activity of the formulation. Thus it can be concluded that Pepticare possesses anti-ulcer activity, which can be attributed to its anti-oxidant mechanism of action.

Antidiabetic activity of alcoholic stem extract of Coscinium fenestratum in streptozotocin-nicotinamide induced type 2 diabetic rats

The antidiabetic potential of the alcoholic stem extract of Coscinium fenestratum Colebr. (Menispermaceae), a medicinal plant widely used in the traditional Ayurveda and Siddha systems of medicine for the treatment of diabetes mellitus was evaluated in the STZ-nicotinamide induced type 2 diabetic model. Graded doses of the alcoholic stem extract were administered to normal and experimental diabetic rats for 12 days. Significant (p < 0.05) reduction in fasting blood glucose levels were observed in the normal as well as in the treated diabetic animals. Serum insulin levels were not stimulated in the animals treated with the extract. In addition, changes in body weight, serum lipid profiles, thiobarbituric acid reactive substance levels, glycosylated hemoglobin and liver glycogen levels assessed in the extract treated diabetic rats were compared with diabetic control and normal animals. Significant results were observed in the estimated parameters, thereby justifying the use of the plant in the indigenous system of medicine.

Antibacterial, antifungal, antiplasmodial, and cytotoxic activities of Albertisia villosa

Albertisia villosa (Menispermaceae) is a subtropical medicinal plant that is widely used in traditional African medicines against various diseases. Three known bisbenzylisoquinoline alkaloids; cycleanine, cocsoline, and N-desmethylcycleanine have been identified. Cycleanine, the most abundant (85%) of all identified bisbenzylisoquinoline alkaloids, accounts for all of the activity of the crude drug. The biological screening of cycleanine and the root bark alkaloidal extract revealed potent antibacterial, antifungal, antiplasmodial, and cytotoxic activities. These results may partly explain and support the use of Albertisia villosa root barks for the treatment of malaria and other infectious diseases in traditional Congolese medicine.

Mechanisms involved in the vasodilator effect of curine in rat resistance arteries

The vasodilator effect of curine was investigated in the rat small mesenteric arteries. In either endothelium-intact or endothelium-denuded mesenteric arteries, curine induced a concentration-dependent relaxation in rings pre-contracted with noradrenline (10 microM; IC 50 = 4.8 +/- 1.3 microM and 4.8 +/- 1.5 microM, respectively) and KCl (80 mM; IC 50 = 6.0 +/- 1.3 microM and 13.0 +/- 5.6 microM, respectively). Curine also inhibited (IC 50 = 4.6 +/- 0.9 microM) the concentration-response curves induced by noradrenaline. Contractions dependent on calcium-influx elicited by KCl (80 mM) and noradrenaline (10 microM) were inhibited by curine (10 microM). Finally, contractions induced by noradrenaline (10 microM), in calcium-free medium, were strongly inhibited by curine (10 microM). The above results suggest that the inhibition of influx of calcium ions through voltage-operated calcium channels and non-selective channels, and mobilization of intracellular calcium stores sensitive to noradrenaline are involved in the vasodilator effect of curine.

(+)-Tiliarine, a selective in vitro inhibitor of human melanoma cells

Five diphenylbisbenzylisoquinoline (DBBI) alkaloids, tiliacorinine, tiliacorine, nor- tiliacorinine A, tiliarine and tiliamosine were isolated from the ethanol extract of the roots of Tiliacora racemosa Colebr. and identified by spectral techniques. Of these (+)-tiliarine is the only one which exhibited a selective inhibitory effect against human melanoma cells (G 361) and had no activity on normal human fibroblasts (CCD 974 SK). The activity of (+)-tiliarine against the human melanoma cell line was not much modified in the presence of calcium chloride.

Roraimine: a bisbenzylisoquinoline alkaloid from Cissampelos sympodialis roots

The roots of Cissampelos sympodialis yielded Roraimine (1), a novel bisbenzylisoquinoline alkaloid and liriodenine (2), a known oxoaporphine alkaloid.

Mechanism of the vasodilator effect of 12-O-methylcurine in rat aortic rings

The vasodilator effects of 12-O-methylcurine (OMC), a bisbenzylisoquinoline alkaloid isolated from Chondrodendron platyphyllum (Menispermaceae), and its respective mechanism of action were investigated in rat aorta. In either endothelium-intact or endothelium-denuded aortic rings, OMC induced concentration-dependent relaxation in vessels pre-contracted with 0.1 microM phenylephrine (IC50 = 63.2+/-8.8 microM and 73.9+/-5.3 microM, respectively), 100 microM 5-hydroxytryptamine (IC50=49.6+/-13 microM and 49.9+/-10 microM, respectively) and 50 mM KCl (IC50= 19.9+/-6.8 microM and 21.1+/-4.5 microM, respectively). OMC also inhibited in a concentration-dependent and non-competitive manner the concentration-response curves induced by CaCl2 in high K+ (IC50 = 16.7+/-1.6 microM). In addition, OMC (100 microM) strongly inhibited phenylephrine-induced contractions dependent on calcium influx in the absence and presence of nifedipine (10 microM). In Ca2+-free medium, the transient contractions induced by phenylephrine (0.1 microM) were strongly inhibited by OMC (100 microM), whereas those induced by caffeine (20 mM) were not altered. H-89 (1 microM) and Rp-8-pCPT-cGMPs (3 microM), selective inhibitors of protein kinase A and G, respectively, did not change the relaxant effect of OMC in aortic rings pre-contracted with phenylephrine. Finally, OMC induced a concentration-dependent relaxation (IC50 = 62.8+/-12.5 microM) of the sustained contractions induced by the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate in normal, but not in Ca2+-free, solution. The above results suggest that OMC induces a vasodilator effect in rataortic rings by a mechanism independent of the presence of functional endothelium and dependent on the influx of calcium ions through voltage- and receptor-operated calcium channels. Furthermore, it can also be suggested that the inhibition of calcium influx activated by protein kinase C is involved in the vasodilator effect of OMC.

Antioxidant effect of Coscinium fenestratum in carbon tetrachloride treated rats

Antioxidant effect of methanol extract of Coscinium fenestratum stem powder was examined using carbon tetrachloride-intoxicated rat liver as the experimental model. Hepatotoxic rats were treated with the methanol extract for 90 days (daily, orally at the dose of 60 mg/kg body weight). Lipid peroxidation in carbon tetrachloride-administered rats was evidenced by a marked elevation in the levels of thiobarbituric acid reactive substances and diene conjugates, and also a profound diminution in glutathione content in the liver. Rats co-administered with the methanol extract retained an almost normal level of these constituents. The decreased activities of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase in carbon tetrachloride-intoxicated rats, and its retrieval towards near-normalcy in the methanol extract co-administered animals revealed the effectiveness of Coscinium fenestratum in combating oxidative stress due to hepatic damage. The findings provide a rationale for further studies on isolation of active principles and its pharmacological evaluation.

Diuretic, laxative and toxicity studies of Cocculus hirsutus aerial parts

The aqueous extract of the Cocculus hirsutus aerial parts (100 and 200 mg/kg, p.o.) showed significant diuretic activity and laxative effect in rats. The acute toxicity, orally evaluated in mice, was found to be higher than 3000 mg/kg.