Phytochemistry and in vitro pharmacological activities of South African Vitex (Verbenaceae) species

Triterpenoids and triterpenoid saponins from Vitex negundo and their anti-inflammatory activities

Seven undescribed polyoxygenated ursane-type triterpenoids (vitnegundins A-G), three undescribed triterpenoid saponins (vitnegundins H-J), and 17 known ones were isolated from an EtOH extract of the aerial parts of Vitex negundo L. The structures of the undescribed compounds were established by extensive spectroscopic analysis. The absolute configurations of vitnegundins A, B, and E were determined by single-crystal X-ray diffraction data. Vitnegundins B-D are pentacyclic triterpenoids possessing rare cis-fused C/D rings and vitnegundins C-H represent undescribed ursane-type triterpenoids with 12,19-epoxy moiety. In the biological activity assay, vitnegundin A, vitnegundin E, and swinhoeic acid displayed inhibitory effects against LPS-induced NO release in BV-2 microglial cells, with IC50 values of 11.8, 44.2, and 19.6 μM, respectively.

Vitex Genus as a Source of Antimicrobial Agents

Vitex L. is the largest genus of the Lamiaceae family, and most of its species are used in the traditional medicinal systems of different countries. A systematic review was conducted, according to the PRISMA methodology, to determine the potential of Vitex plants as sources of antimicrobial agents, resulting in 2610 scientific publications from which 141 articles were selected. Data analysis confirmed that Vitex species are used in traditional medicine for symptoms of possible infectious diseases. Conducted studies showed that these medicinal plants exhibited in vitro antimicrobial activity against Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Vitex agnus-castus L. and Vitex negundo L. have been the most studied species, not only against bacterial strains but also against fungi such as Aspergillus niger and Candida albicans, viruses such as HIV-1, and parasites such as Plasmodium falciparum. Natural products like agnucastoside, negundol, negundoside, and vitegnoside have been identified in Vitex extracts and their antimicrobial activity against a wide range of microbial strains has been determined. Negundoside showed significant antimicrobial activity against Staphylococcus aureus (MIC 12.5 µg/mL). Our results show that Vitex species are potential sources of new natural antimicrobial agents. However, further experimental studies need to be conducted.

The Current State of Knowledge in Biological Properties of Cirsimaritin

The search for natural plant-based products as new pharmacological alternatives to treat various human pathologies has taken on great importance for researchers and research laboratories. In this context, research has intensified to extract and identify natural molecules endowed with biological effects. The objective of this study is to review the source and pharmacological properties of cirsimaritin. The identification and isolation of this flavonoid from various natural sources, including medicinal plants such as Artemisia judaica, Cirsium japonicum, Lithocarpus dealbatus, Microtea debilis, and Ocimum sanctum, has been carried out and verified using different spectral techniques. Biological effect investigations are carried out with a wide variety of experimental models in vitro and in vivo and laboratory techniques. The results of these research works showed the biological properties of cirsimaritin including anticancer, antimicrobial, antidiabetic, antiparasitic, antioxidant, and anti-inflammatory effects. The mechanisms involved in the multiple activities of this molecule are diverse and include sub-cellular, cellular, and molecular levels. Indeed, this bioactive induces anti-inflammatory and antiproliferative effects by inhibiting cell membrane receptors, interference with signaling pathways, and inhibiting transcriptional factors such as Nf-κB involved in cell promotion and proliferation. In the light of these results, cirsimaritin appears as a promising and viable alternative natural bioactive drug to treat many pathological conditions.

Traditional uses, phytochemistry, and pharmacology of genus Vitex (Lamiaceae)

Vitex, the genus of the family Lamiaceae, comprises of about 230 species mostly distributed in the warm regions of Europe and temperate regions of Asia. Several Vitex species have been used as folk medicine in different countries for the treatment of various kinds of diseases and ailments. The main aim of this review is to collect and analyze the scientific information available about the Vitex species regarding their chemical constituents and pharmacological activities. The phytochemical investigation of various Vitex species has resulted in the isolation of about 556 chemical constituents belong to various chemical category viz. iridoids, diterpenoids, triterpenoids, flavonoids, lignans, sesquiterpenoids, monoterpenoids, ecdysteroids, and others. The crude extracts of different Vitex species as well as pure phytochemicals exhibited a wide spectrum of in-vitro and in-vivo pharmacological activities. In the present review, the scientific literature data on the ethnopharmacological, phytochemical, and pharmacological investigations on the genus Vitex are summarized. More attention should be given in future research to evaluate the pharmacological potential with detailed mechanism of actions for the pure compounds, extracts of plants from this genus. Moreover, their clinical study is needed to justify their use in modern medicine and to further exploring this genus for new drug discovery.

Vitex Diterpenoids: Structural Diversity and Pharmacological Activity

Plants of the genus Vitex (Verbenaceae) are mainly distributed throughout tropical and temperate regions, and many Vitex plants have been traditionally used in folk medicine. Plants of this genus are a rich source of diterpenoids, which not only displayed versatile structural diversity with potential chemotaxonomical significance but also exhibited a wide range of biological activities, mainly including in vitro cytotoxic, antiinflammatory, antimicrobial, hormone level-regulating and antiangiogenic activities. Recently, a series of bioactive diterpenoids, with interesting carbon skeletons, have been reported and gathered considerable interest. This article systematically reviewed diterpenoids isolated from the genus Vitex that appeared in the literature up to December 2018, critically highlighting their structural diversity and pharmacological activities. Up to now, a total of 154 diterpenoids with diverse structures have been isolated and identified from Vitex plants. The authors also summarized the reported structure-activity relationships of those well explored Vitex diterpenoids. Finally, the authors discussed the challenges and potential applications of these diterpenoids in the future.

Cirsimaritin, a lung squamous carcinoma cells (NCIH-520) proliferation inhibitor

Cirsimaritin is a dimethoxy flavone, which is present in Ocimum sanctum, Microtea debilis, Artemisia judaica, Cirsium japonicum, and Lithocarpus dealbatus. Its antiproliferative potential has been explored in breast and gall bladder cancer cell lines. However, no reports are available on skin and squamous lung carcinoma. Also, the complete mode of action is unknown. Therefore, in the present study, the anticancer potential of cirsimaritin is explored in organ-specific cell lines by using MTT assay. Further, the inhibitory potential and binding interaction with the selected targets were analyzed through in vitro and in-silico analysis. Cirsimaritin showed selective anticancer activity against NCIH-520 cell-line (IC₅₀ 23.29 µM), also inhibited the proliferation of other cell-lines up to 48% at 100 µM. In NCIH-520 cell-line, cirsimaritin significantly increased the apoptosis of the cells at both the tested concentrations (10 and 100 µM), which was confirmed by Annexin-V signifying the induction of late apoptosis. Besides, an increase in the ROS levels of 1.6 fold (10 µM) and 1.8 fold (100 µM), circimaritin also inhibits the activity of ODC and CATD with the IC₅₀ 57.30 and 68.22 µM respectively. It exhibited a good binding score with the selected targets, follow Lipinski's rule of five and non-mutagenic. Hence, cirsimaritin is a potent molecule, which inhibits the proliferation of lung squamous cell lines by inducing apoptosis. It also inhibited the activity of ODC and CATD responsible for the progression phase in the cancer cells. Communicated by Ramaswamy H. Sarma.

The Dietary Effect of Vitex agnus-castus Hydroalcoholic Extract on Growth Performance, Blood Biochemical Parameters, Carcass Quality, Sex Ratio and Gonad Histology in Zebrafish (Danio rerio)

The main purpose of this study was to consider the impact of Vitex agnus-castus hydroalcoholic extract, containing phytoestrogenic compounds on growth indices, sex ratio and histology of gonads of female Zebrafish. Fish larvae (4-day-old after hatching) were nourished with investigational diets (0 (control group T0), 5 g (T1), 10 g (T2) and 15 g (T3) kg−1 food) from first active feeding for 90 days. The results showed that Condition Factor (CF), Food Conversion Rate (FCR), Body Weight Gain (BWG), and Specific Growth Rate (SGR) were affected meaningfully by hydroalcoholic extract of Vitex agnus-castus (p < 0.05). These factors were significantly higher in compare to T3 treatment (p < 0.05). With increasing concentration of the extract in the diet, the ratio of female to male increased Treatment of T3 resulted in 87.23% feminization. Overall, this study suggests the use of T3 treatment achieves the best reproduction performance and a higher percentage of females in zebrafish as a model for aquaculture species. According to the results, the lowest levels of glucose and cholesterol were observed in T3 treatment and showed a significant changes with the control and treatments (p < 0.05).

A review of the traditional use of southern African medicinal plants for the treatment of malaria

ETHNOPHARMALOGICAL RELEVANCE

Malaria is one of the most prevalent and deadly parasitic diseases globally, with over 200 million new cases and nearly 500,000 deaths reported annually. It is estimated that approximately half of the world's population lives in malaria endemic areas. Malaria is substantially less prevalent in South Africa than in other African regions and the disease is limited to some regions of the Limpopo, Mpumalanga and KwaZulu-Natal provinces. However, it still has a significant impact on the health of the populations living in those regions. Traditional medicines have long been used in South Africa by multiple ethic groups and many people continue to rely on these natural therapies for their healthcare. The usage of South African medicinal plants in several traditional healing systems to treat malaria have been documented (particularly for Zulu and Venda traditional medicine), although ethnobotanical investigations of other ethnic groups living in endemic malaria areas remains relatively neglected.

AIM OF THE STUDY

To document the use of South African medicinal plants known to be used traditionally to treat Plasmodium spp. infections. We also critically reviewed the literature on the therapeutic properties of these and other South African plants screened against Plasmodium spp. parasites with the aim of highlighting neglected studies and fostering future research in this area.

MATERIALS AND METHODS

Books and ethnobotanical reviews were examined for medicinal plants used specifically for fever. Exclusion criteria were studies not involving southern African medicinal plants. Furthermore, while fever is a common symptom of malaria, if not accompanied by the term "malaria" it was not considered. Databases including PubMed, ScienceDirect, Scopus and Google Scholar were used to source research relevant to southern African plants and malaria. Exclusion criteria were those publications where full articles could not be accessed.

RESULTS

Eighty South African plant species were identified as traditional therapies for malaria. The majority of these species were documented in Zulu ethnobotanical records, despite malaria occurring in only a relatively small portion of the Zulu's traditional territory. Surprisingly, far fewer species were reported to be used by Venda, Ndebele, northern Sotho, Tsonga, Tswana, and Pedi people, despite them living in endemic malaria areas. Interestingly many of the identified species have not been investigated further. This review summarises the available ethnobotanical and laboratory research in this field, with the aim of promoting and focusing research on priority areas.

CONCLUSION

Although malaria remains a serious disease affecting millions of people, medicinal plants while used extensively, have not been given the attention warranted for further investigation.

Biosynthesis of bioactive diterpenoids in the medicinal plant Vitex agnus-castus

Vitex agnus-castus L. (Lamiaceae) is a medicinal plant historically used throughout the Mediterranean region to treat menstrual cycle disorders, and is still used today as a clinically effective treatment for premenstrual syndrome. The pharmaceutical activity of the plant extract is linked to its ability to lower prolactin levels. This feature has been attributed to the presence of dopaminergic diterpenoids that can bind to dopamine receptors in the pituitary gland. Phytochemical analyses of V. agnus-castus show that it contains an enormous array of structurally related diterpenoids and, as such, holds potential as a rich source of new dopaminergic drugs. The present work investigated the localisation and biosynthesis of diterpenoids in V. agnus-castus. With the assistance of matrix-assisted laser desorption ionisation-mass spectrometry imaging (MALDI-MSI), diterpenoids were localised to trichomes on the surface of fruit and leaves. Analysis of a trichome-specific transcriptome database, coupled with expression studies, identified seven candidate genes involved in diterpenoid biosynthesis: three class II diterpene synthases (diTPSs); three class I diTPSs; and a cytochrome P450 (CYP). Combinatorial assays of the diTPSs resulted in the formation of a range of different diterpenes that can account for several of the backbones of bioactive diterpenoids observed in V. agnus-castus. The identified CYP, VacCYP76BK1, was found to catalyse 16-hydroxylation of the diol-diterpene, peregrinol, to labd-13Z-ene-9,15,16-triol when expressed in Saccharomyces cerevisiae. Notably, this product is a potential intermediate in the biosynthetic pathway towards bioactive furan- and lactone-containing diterpenoids that are present in this species.

Antiplasmodial potential and quantification of aloin and aloe-emodin in Aloe vera collected from different climatic regions of India

BACKGROUND

In this study, Aloe vera samples were collected from different climatic regions of India. Quantitative HPTLC (high performance thin layer chromatography) analysis of important anthraquinones aloin and aloe-emodin and antiplasmodial activity of crude aqueous extracts was done to estimate the effects of these constituents on antiplasmodial potential of the plant.

METHODS

HPTLC system equipped with a sample applicator Linomat V with CAMAG sample syringe, twin rough plate development chamber (20 x 10 cm), TLC Scanner 3 and integration software WINCATS 1.4.8 was used for analysis of aloin and aloe-emodin amount. The antiplasmodial activity of plant extracts was assessed against a chloroquine (CQ) sensitive strain of P. falciparum (MRC-2). Minimum Inhibitory Concentration (MIC) of aqueous extracts of selected samples was determined according to the World Health Organization (WHO) recommended method that was based on assessing the inhibition of schizont maturation in a 96-well microtitre plate. EC (effective concentration) values of different samples were observed to predict antiplasmodial potential of the plant in terms of their climatic zones.

RESULTS

A maximum quantity of aloin and aloe-emodin i.e. 0.45 and 0.27 mg/g respectively was observed from the 12 samples of Aloe vera. The inhibited parasite growth with EC50 values ranging from 0.289 to 1056 μg/ml. The antiplasmodial EC50 value of positive control Chloroquine was observed 0.034 μg/ml and EC50 values showed by aloin and aloe-emodin was 67 μg/ml and 22 μg/ml respectively. A positive correlation was reported between aloin and aloe-emodin. Antiplasmodial activity was increased with increase in the concentration of aloin and aloe-emodin. The quantity of aloin and aloe-emodin was decreased with rise in temperature hence it was negatively correlated with temperature.

CONCLUSIONS

The extracts of Aloe vera collected from colder climatic regions showed good antiplasmodial activity and also showed the presence of higher amount of aloin and aloe-emodin in comparison to collected from warmer climatic sites. Study showed significant correlation between quantities of both the anthraquinones used as marker compounds and EC50 values of the different Aloe vera extracts. Although, both the anthraquinones showed less antiplasmodial potential in comparison to crude extracts of different Aloe vera samples. Diverse climatic factors affect the quantity of tested compounds and antiplasmodial potential of the plant in different Aloe vera samples.

Protective effect of cirsimaritin against streptozotocin-induced apoptosis in pancreatic beta cells

Objectives

Maintaining glucose homoeostasis is essential for the survival of cells. Despite the various health benefits of Korean thistle (Cirsium japonicum var. maackii), their effects on pancreatic β-cell apoptosis in type 1 diabetes mellitus and the underlying mechanisms remain unclear, and experimentally investigated in this study.

Methods

The effects of C. japonicum var. maackii and its active component cirsimaritin against streptozotocin (STZ)-induced cytotoxicity were assessed in INS-1 cells. By Western blotting analysis, protein expressions related to apoptosis were evaluated. The involvement of apoptosis was also confirmed with image-based cytometric assay and caspase activity tests.

Key findings

Cirsium japonicum var. maackii extract and cirsimaritin in non-toxic concentrations improved cell viability to near normal levels and protected INS-1 cells against STZ-induced damage. In addition, cirsimaritin reduced the intracellular oxidative stress induced by STZ. Cirsimaritin effectively suppressed apoptosis in pancreatic β cells by decreasing the activation of caspase-8 and caspase-3, BID and the DNA repair protein poly (ADP-ribose) polymerase (PARP) and increasing anti-apoptotic BCL-2 protein expression.

Conclusions

This study demonstrates the therapeutic potential and action mechanism of cirsimaritin for the prevention and treatment of type 1 diabetes mellitus.

Ethnomedicinal uses of plants for the treatment of malaria in Soon Valley, Khushab, Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

To best of our knowledge this is the first quantitative ethno-medicinal study with the aim of documenting the indigenous knowledge and practices of using plants for malarial therapy in Soon Valley, Khushab, Pakistan. In this Valley, malaria is among the major public health problems but, until now, the population still mostly relies on herbal medicine for treatment.

MATERIALS AND METHODS

Ethno-medicinal data were documented from 63 informants by using semi-structured questionnaires and interviewing the informants about their knowledge of plants regarding malaria and related symptoms. Documented data were evaluated using the quantitative ethno-botanical indices of frequency citation (FC), relative frequency of citation (RFC), percentage of respondents having knowledge (PRK) and Jaccard index (JI).

RESULTS

A total of 70 plant species belonging to 62 genera and 34 families were recorded as anti-malarial in the study area. Solanaceae was found to be the most cited family with 7 species, followed by Fabaceae, Rutaceae and Lamiaceae with 5 species each. Ocimum americanum and Solanum incanum were the species with the highest relative frequency of citation (RFC =0.25 each) and percentage of respondents having knowledge (PRK =25.4% each), followed by Grewia tenax (RFC =0.23, PRK =23.8%), which indicates that these plants are the best species with anti-malarial properties. The most highly cited life form was found to be herbs (56%). The dominant plant part used in preparations were leaves (49%). The main mode of utilization was decoction (47%) followed by infusion (29%). In comparison, maximum similarity index is found in our study with JI (16.83) followed by (13.13). Similarity percentage of plants uses ranges from 0.81 to 16.83 while dissimilarity percentage varies from 0% to 17.65%.

CONCLUSIONS

To the best of our knowledge seven plant species, viz. Withania coagulans, Fagonia cretica, Carthamus oxyacantha, Ehretia obtusifolia, Helianthus annuus, Olea ferruginea and Vitex trifolia, are reported from this region for the first time for the treatment of malaria. This first ethno-medicinal study highlights potential sources for the development of new antimalarial drugs from indigenous knowledge of medicinal plants found in the Soon Valley, Pakistan. Such investigations could be a subject for in vitro and in vivo anti-plasmodial screening to develop new plant-based antimalarial drugs and can also be evaluated for other biological activities and novel drug discoveries.

A Review on the Terpenes from Genus Vitex

The genus Vitex, which belongs to the Verbenaceae family, includes approximately 250 species. Some species of the genus Vitex have traditionally been used for the treatment of headaches, ophthalmodynia, coughs, asthma, premenopausal syndrome, etc. Chemical investigations indicate that the characteristic constituents of the genus Vitex are terpenes, and 210 of these compounds, including monoterpenoids, sesquiterpenoids, diterpenoids and triterpenoids, have been obtained from 12 species. Pharmacological studies had shown that these terpenes possess anti-inflammatory, antitumor, antibacterial, antioxidant activities, and so on. In this paper, the identity of these terpenes and their pharmacological effects are reviewed, which can provide references for further research regarding the chemistry and utilization of the Vitex species.

Croton megalobotrys Müll Arg. and Vitex doniana (Sweet): Traditional medicinal plants in a three-step treatment regimen that inhibit in vitro replication of HIV-1

ETHNOPHARMACOLOGICAL RELEVANCE

Human Immunodeficiency Virus (HIV) strains resistant to licensed anti-retroviral drugs (ARVs) continue to emerge. On the African continent, uneven access to ARVs combined with occurrence of side-effects after prolonged ARV therapy have led to searches for traditional medicines as alternative or complementary remedies to conventional HIV/AIDS management.

AIM OF THE STUDY

Here we characterize a specific three-step traditional HIV/AIDS treatment regimen consisting of Cassia sieberiana root, Vitex doniana root, and Croton megalobotrys bark by combining qualitative interviews of traditional medical knowledge users in Botswana with in vitro HIV replication studies.

MATERIALS AND METHODS

Crude extracts from a total of seven medicinal plants were tested for in vitro cytotoxicity and inhibition of wild-type (NL4.3) and ARV-resistant HIV-1 replication in an immortalized GFP-reporter CD4+ T-cell line.

RESULTS

C. sieberiana root, V. doniana root, and C. megalobotrys bark extracts inhibited HIV-1NL4.3 replication with dose-dependence and without concomitant cytotoxicity. C. sieberiana and V. doniana extracts inhibited HIV-1 replication by 50% at 84.8µg/mL and at 25µg/mL, respectively, while C. megalobotrys extracts inhibited HIV-1 replication by a maximum of 45% at concentrations as low as 0.05µg/mL. Extracts did not interfere with antiviral activities of licensed ARVs when applied in combination and exhibited comparable efficacies against viruses harboring major resistance mutations to licensed protease, reverse-transcriptase, or integrase inhibitors.

CONCLUSIONS

We report for the first time a three-step traditional HIV/AIDS regimen, used alone or in combination with standard ARV regimens, where each step exhibited more potent ability to inhibit HIV replication in vitro. Our observations support the "reverse pharmacology" model where documented clinical experiences are used to identify natural products of therapeutic value.

Antibacterial Labdane Diterpenoids from Vitex vestita

A large-scale in vitro screening of tropical plants using an antibacterial assay permitted the selection of several species with significant antibacterial activities. Bioassay-guided purification of the dichloromethane extract of the leaves of the Malaysian species Vitex vestita, led to the isolation of six new labdane-type diterpenoids, namely, 12-epivitexolide A (2), vitexolides B and C (3 and 4), vitexolide E (8), and vitexolins A and B (5 and 6), along with six known compounds, vitexolides A (1) and D (7), acuminolide (9), 3β-hydroxyanticopalic acid (10), 8α-hydroxyanticopalic acid (11), and 6α-hydroxyanticopalic acid (12). Their structures were elucidated on the basis of 1D and 2D NMR analyses and HRMS experiments. Both variable-temperature NMR spectroscopic studies and chemical modifications were performed to investigate the dynamic epimerization of the γ-hydroxybutenolide moiety of compounds 1-4. Compounds were assayed against a panel of 46 Gram-positive strains. Vitexolide A (1) exhibited the most potent antibacterial activity with minimal inhibitory concentration values ranging from 6 to 96 μM, whereas compounds 2 and 6-9 showed moderate antibacterial activity. The presence of a β-hydroxyalkyl-γ-hydroxybutenolide subunit contributed significantly to antibacterial activity. Compounds 1-4 and 6-9 showed cytotoxic activities against the HCT-116 cancer cell line (1 < IC50s < 10 μM) and human fetal lung fibroblast MRC5 cell line (1 < IC50s < 10 μM for compounds 1, 2, 7, 8, and 9).

Melanogenesis-inducing effect of cirsimaritin through increases in microphthalmia-associated transcription factor and tyrosinase expression

The melanin-inducing properties of cirsimaritin were investigated in murine B16F10 cells. Cirsimaritin is an active flavone with methoxy groups, which is isolated from the branches of Lithocarpus dealbatus. Tyrosinase activity and melanin content in murine B16F10 melanoma cells were increased by cirsimaritin in a dose-dependent manner. Western blot analysis revealed that tyrosinase, tyrosinase-related protein (TRP) 1, TRP2 protein levels were enhanced after treatment with cirsimaritin for 48 h. Cirsimaritin also upregulated the expression of microphthalmia-associated transcription factor (MITF) after 24 h of treatment. Furthermore, cirsimaritin induced phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in a dose-dependent manner after treatment for 15 min. The cirsimaritin-mediated increase of tyrosinase activity was significantly attenuated by H89, a cAMP-dependent protein kinase A inhibitor. These findings indicate that cirsimaritin stimulates melanogenesis in B16F10 cells by activation of CREB as well as upregulation of MITF and tyrosinase expression, which was activated by cAMP signaling. Finally, the melanogenic effect of cirsimaritin was confirmed in human epidermal melanocytes. These results support the putative application of cirsimaritin in ultraviolet photoprotection and hair coloration treatments.

Anti-inflammatory ursane- and oleanane-type triterpenoids from Vitex negundo var. cannabifolia

Six new polyoxygenated triterpenoids, cannabifolins A-F (1-6), and eight known triterpenoids, 7-14, were isolated from the leaves of Vitex negundo var. cannabifolia. The absolute configuration of cannabifolin A (1) was determined by single-crystal X-ray crystallographic analysis. Compounds 1 and 2 represent a class of rare natural pentacyclic triterpenoids bearing cis-fused C/D rings and are the first examples of 12,19-epoxy ursane- and oleanane-type triterpenoids. Compounds 3, 7, 8, and 14 exhibited inhibition of nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophages with IC50 values in the range 24.9-40.5 μM.

The genus Vitex: A review

The review includes 161 references on the genus Vitex, and comprises ethnopharmacology, morphology and microscopy, phytoconstituents, pharmacological reports, clinical studies, and toxicology of the prominent species of Vitex. Essential oils, flavonoids, iridoid glycosides, diterpenoides and ligans constitute major classes of phytoconstituents of the genus. A few species of this genus have medicinal value, among these, leaves and fruits of V. agnus-castus Linn. (Verbenaceae) has been traditionally used in treatment of women complaints. V. agnus-castus has also been included in herbal remedies, which are in clinical use to regulate the menstrual cycle, reduce premenstrual symptom tension and anxiety, treat some menopausal symptoms as well as to treat hormonally induced acne. Despite a long tradition of use of some species, the genus has not been explored properly. In the concluding part, the future scope of Vitex species has been emphasized with a view to establish their multifarious biological activities and mode of action.

Preliminary evaluation of the wound healing effect of Vitex doniana sweet (Verbenaceae) in mice

Vitex doniana is traditionally used in Togo to treat various diseases including wounds. The aim of this work was to evaluate the efficiency of Vitex doniana on cutaneous wound healing. Wounds were induced in ICR mice divided into four groups as following: Group I received carbopol 974P NF empty gel, Groups II and III were treated topically with carbopol gel containing 2.5% and 5% of Vitex doniana extract. Group IV received Betadine® 10% as standard drug. The efficacy of treatment was evaluated by planimetry and histological analysis. We secondary used the gel containing Vitex doniana at 2.5% and the pure extract at 10 mg/ml on the model of ear edema induced by xylene. Skin toxicity test was performed with the gel containing Vitex doniana at 5% and the pure extract at 30 mg/ml. Vitex doniana at 5% and 2.5% provided better wound contraction (91.14% and 86.38%) at day 12 post-excision when compared to control (51.15%). The results of histological evaluation supported the outcome of excision wound model. Moreover Vitex doniana inhibited significantly edema induced by xylene when compared to control (p< 0.05). In skin toxicity test, no abnormal symptoms were developed over 14 day-time period. Vitex doniana inhibits the topical inflammation and accelerate cutaneous wound repair.

In vitro antiplasmodial activity and cytotoxicity of extracts and fractions of Vitex madiensis, medicinal plant of Gabon

Vitex madiensis Oliv. (Lamiaceae) is traditionally used to treat malaria symptoms in Haut-Ogooué, Gabon. Leaves and stem barks extracts were obtained using dichloromethane (CH(2)Cl(2)), ethyl acetate (EtOAc) and methanol (MeOH) as extraction solvents and fractionated on silica gel column. The in vitro antiplasmodial activity of CH(2)Cl(2), EtOAc and MeOH extracts and fractions was evaluated against the chloroquine-resistant FCB strain and field isolates of Plasmodium falciparum using the DELI test. The cytotoxicity of the extracts was tested on MRC-5 and THP1 cells using the tetrazolium salt MTT colorimetric assay, and the selectivity index (SI) of each extract was calculated. CH(2)Cl(2) extract, the EA1 fraction from EtOAc extract of stem barks and cyclohexane (L(cycl)), dichloromethane (L(DM)) and butanol (L(but)) fractions from MeOH/H(2)O extract of leaves exhibited the highest in vitro antiplasmodial activity on FCB strain and field isolates (IC(50) from 0.53 to 4.87 μg/ml) with high selectivity index (of 20.15-1800). These data support the use of V. madiensis in malaria treatment along with continued investigations within traditional medicines in the search of new antimalarial agents. The EA1, C(6)H(12) and CH(2)Cl(2) fractions could be selected for future investigation or/and for the treatment of malaria symptoms after standardization.

Anti-inflammatory and enzyme inhibitory activities of a crude extract and a pterocarpan isolated from the aerial parts of Vitex agnus-castus

A new compound, 6a,11a-dihydro-6H-[1] benzofuro [3,2-c][1,3]dioxolo[4,5-g]chromen-9-ol was isolated from the ethyl acetate fraction of Vitex agnus-castus. The structure of this compound was identified with the help of spectroscopic techniques ((13)C NMR, (1)H NMR, HMBC, HMQC, NOESY and COSY). The compound showed low urease- (32.0%) and chymotrypsin- (31.4%) inhibitory activity, and moderate (41.3%) anti-inflammatory activity. The crude extract and various fractions obtained from the aerial parts of the plant were also screened for possible in vitro hemagglutination, antibacterial and phytotoxic activities. No hemagglutination activity against human erythrocytes was observed in crude extracts and fractions of V. agnus-castus. The fractions and crude methanolic extract showed moderate and low antibacterial activity. Exceptions were the CHCl(3) fraction, which showed significant antibacterial activity against Klebsiella pneumonia (81% with MIC(50)=2.19 mg/mL), the n-hexane fraction, which exhibited no activity against Salmonella typhi, and the CHCl(3) and aqueous fractions, which showed no activity against Bacillus pumalis. Moderate phytotoxic activity (62.5%) was observed by n-hexane fraction of V. agnus-castus against Lemna minor L at 1000 μg/mL.

In vitro antiplasmodial activity and toxicity assessment of some plants from Nigerian ethnomedicine

CONTEXT

The emergence and spread of Plasmodium falciparum-resistant parasites to nearly all available antimalarial drugs pose a threat to malaria control and necessitates the need to continue the search for new effective and affordable drugs. Ethnomedicine has been shown to be a potential source of antimalarial compounds or source of template for the synthesis of novel antimalarial molecules.

OBJECTIVE

The antiplasmodial activity and toxicity assessment of 30 plant extracts from eight medicinal plants identified in Nigerian ethnomedicine for the treatment of febrile illnesses were evaluated.

MATERIALS AND METHODS

In vitro antimalarial activity was evaluated using Plasmodium falciparum NF54 (sensitive to all antimalarial drugs) and K1 (chloroquine/pyrimethamine resistant) strains in the [(3)H]-hypoxanthine incorporation assay. Toxicity was determined against mammalian L6 cells using Alamar blue assay.

RESULTS

The ethyl acetate extract of leaves of Ocimum gratissimum Linn. (Labiatae) and hexane extract of stem bark of Trema orientalis (L.) Blume (Ulmaceae) showed the highest antiplasmodial activity (IC(50) 1.8-1.93 µg/mL) against P. falciparum K1 strain but elicited low cytotoxicity (selective index >10). However, hexane, ethyl acetate or methanol extracts of leaves of Terminalia catappa Linn. (Combretaceae), Jatropha curcas Linn. (Euphorbiaceae), Vitex doniana Sweet. (Verbenaceae) and stem bark of Vitex doniana displayed antiplasmodial activity (IC(50) 2.3-16.9 µg/mL) with good selectivity (21-120) for malaria parasites.

DISCUSSION AND CONCLUSION

The antiplasmodial activity of Terminalia catappa and Vitex doniana against P. falciparum K1 is being reported for the first time in Nigerian ethnomedicine and these plants could be potential source of antimalarial agents.

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.