Evaluating the anti-inflammatory potential of Tectaria cicutaria L. rhizome extract in vitro as well as in vivo

Ethnopharmacological relevance

The rhizome of Tectaria cicutaria has been used in the folklore system of Indian traditional medicine (Ayurveda) for the treatment of various disorders such as rheumatic pain, chest complaints, burns, sprain, poisonous bites, tonsilitis, toothache, gum complaints, cuts and wounds. The present work has for the first time tried to elucidate the anti-inflammatory potential of aqueous extract of Tectaria cicutaria rhizome (TCR_aq) in vitro as well as in vivo.

Materials and methods

Anti-inflammatory potential of TCR_aq was analyzed in vivo in carrageenan induced rat paw edema model. Serum antioxidant status in TCR_aq-treated as well as untreated control rodents was measured by oxygen radical absorbance capacity (ORAC) assay. In vitro experiments for analyzing the anti-inflammatory potential of TCR_aq were performed on murine macrophage cell line, RAW 264.7. Analysis of nitric oxide release in RAW 264.7 cells was done by Griess reaction. RT-PCR and western blotting experiment was performed to analyze the expression of iNOS. Expression of COX-2 and NFκB proteins was evaluated by western blotting.

Results

TCR_aq significantly reduced the paw volume in Sprague-Dawley rats at a dose of 200 mg/kg body weight, which was comparable with the standard diclofenac treatment. The rats treated with TCR_aq showed a significant increase in the serum antioxidant levels compared to the untreated control animals. TCR_aq was able to reduce the nitric oxide (NO) levels in RAW 264.7 cells that had been stimulated with lipopolysaccharide (LPS). This was accompanied by a corresponding decrease in iNOS expression at mRNA and protein level. Interestingly, TCR_aq was found to decrease the expression of COX-2 as well as the nuclear translocation of NFκB in RAW 264.7 cells.

Conclusion

Our study signifies the anti-inflammatory potential of Tectaria cicutaria and scientifically validates its traditional use in inflammatory conditions.     

An in vitro study on antiproliferative and antiestrogenic effects of Boerhaavia diffusa L. extracts

Ethnopharmacological relevance

Boerhaavia diffusa L. (Nyctinaceae) is a plant of tropical region used in Indian traditional medicine for the treatment of human ailments including abdominal tumor, jaundice, dyspepsia, menstrual disorders, etc. This plant also has antilymphoproliferative, antimetastatic and immunomodulatory effects.

Aim of the study

This study aimed to assess the antiproliferative and antiestrogenic properties of methanol extract of Boerhaavia diffusa (BME) in MCF-7 breast cancer cell lines.

Materials and methods

The effective concentration range of BME on cell viability was analyzed using MTT assay. Hydroxylapatite assay (HAP) was carried out to confirm the competitive binding of BME to the estrogen receptor (ER). The effect of BME on the expression of a selected estrogen responsive gene pS2 was analyzed by RT-PCR. The ability of BME to alter the cell cycle phases and distributions were studied using FACS analysis.

Results

Treatment with varying concentrations of BME (20–320 μg/mL) resulted in moderate to very strong growth inhibition in MCF-7 cell lines. BME competed with [³H]-estradiol for binding to ER with IC₅₀ value of 320 ± 25 μg/mL. RT-PCR analysis revealed that BME reduced the mRNA expression of pS2 indicating the antiestrogenic action of BME. BME treatment for 48 h resulted in a remarkable increase in the number of MCF-7 cells in the G0-G1 fraction from 69.1% to 75.8%, with a reciprocal decrease of cells in all other phases indicating cell cycle arrest at G0-G1 phase.

Conclusions

The results demonstrate that Boerhaavia diffusa possess antiproliferative and antiestrogenic properties and suggest that it may have therapeutic potential in estrogen dependent breast cancers.     

Ability of certain plant extracts traditionally used to treat ciguatera fish poisoning to inhibit nitric oxide production in RAW 264.7 macrophages

Aim of the study

Ciguatera fish poisoning (CFP) is an intertropical ichthyosarcotoxism that manifests in complex assortment of symptoms in humans. Ciguatoxins (CTXs), issued from Gambierdicus spp., are causative agents of this intoxication. We have recently demonstrated that a Pacific CTX (P-CTX-1B) strongly modulated iNOS expression, leading to overproduction of nitric oxide (NO) in RAW 264.7 murine macrophage cells. NO produced in large amounts is involved in a wide range of pathophysiological processes. Many traditional remedies are commonly used in the Pacific against CFP. In this context, bioassay-guided screening was carried out to study NO inhibiting capacity of 28 selected plant extracts.

Materials and methods

We prepared aqueous extracts of plants used in New Caledonia in the treatment of CFP and screened their NO inhibitory activity in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages.

Results

Among 28 plants tested, Euphorbia hirta (Euphorbiaceae), Syzygium malaccense (Myrtaceae), Schinus terebenthifolius (Anacardiaceae), Punica granatum (Punicaceae), Cerbera manghas (Apocynaceae), Vitex trifolia (Labiateae) and Ximenia americana (Olacaceae) showed inhibitory activity, validating their use as traditional remedies in CFP, and the potential for use in the treatment of conditions accompanied by NO overproduction.

Conclusion

These plants are promising candidates for further screening of their active compounds through activity-guided fractionation.     

Immuno-enhancement effects of ethanol extract from Cyrtomium macrophyllum (Makino) Tagawa on cyclophosphamide-induced immunosuppression in BALB/c mice

Ethnopharmacological relevance

Cyrtomium macrophyllum (Makino) Tagawa has been traditionally used as a herbal medicine for the treatment of various infectious diseases such as tapeworm infestation, colds, and viral diseases. However, no systematic study of the immunity of Cyrtomium macrophyllum ethanol extracts (CM) has yet been reported. The present work evaluates these traits.

Materials and methods

120 male BALB/c mice were divided into 6 groups of 20 mice each: (1) normal group (sterile physiological saline), which served as a blank control; (2) model group (Cyclophosphamide, CY) group (sterile physiological saline), which served as a negative control; (3) low-dose CM (50 mg/kg BW); (4) intermediate-dose CM (100 mg/kg BW); (5) high-dose CM (200 mg/kg BW); (6) CM group (200 mg/kg BW). CY (0.2 ml) was administered via intraperitoneal injection. The other regimens were administered via gavage in 0.2 ml solution. Phytochemical of CM was characterized by HPLC–LTQ-Orbitrap. The acute toxicity effect of the ethanol extract of Cyrtomium macrophyllum was also investigated.

Results

The spleen and thymus indices of mice receiving low, intermediate, and high doses of CM recovered more quickly than those of CY mice, and they did so in a dose-dependent manner. These mice also showed higher T cell and B cell proliferation responses and macrophage function than those of CY mice, and their serum levels of interleukin-6 and interferon-γ had become normal. In acute toxicity test, CM exhibited no mortality and behavioral changes in mice. Quantitative phytochemical analysis showed flavonoids, polyphenols, and tannins to be the major compounds present in the extract, at 27.64%, 30.87%, and 11.22%, respectively. We found that 16 compounds were characterized by the interpretation of their mass spectra obtained by the MS/MS.

Conclusion

The current study demonstrates that Cyrtomium macrophyllum ethanol extract improved immune function in CY-treated mice.     

In vitro and in vivo anti-inflammatory effect of Rhodomyrtus tomentosa methanol extract

Ethnopharmacological relevance

Rhodomyrtus tomentosa (Aiton) Hassk. is a representative Thai medicinal plant traditionally used in South Asian countries to relieve various inflammatory symptoms. However, no systematic studies on its anti-inflammatory activity and mechanisms have been reported.

Materials and methods

The effect of the methanol extract from the leaves of this plant (Rt-ME) on the production of inflammatory mediators [nitric oxide (NO) and prostaglandin E₂ (PGE₂)] and the molecular mechanism of Rt-ME-mediated inhibition, including target enzymes, were studied with RAW264.7, peritoneal macrophage, and HEK293 cells. Additionally, the in vivo anti-inflammatory activity of this extract was evaluated with mouse gastritis and colitis models.

Results

Rt-ME clearly inhibited the production of NO and PGE₂ in lipopolysaccharide (LPS)-activated RAW264.7 cells and peritoneal macrophages in a dose-dependent manner. According to RT-PCR, immunoblotting and immunoprecipitation analyses and a kinase assay with mRNA, whole cell extract, and nucleus lysates from RAW264.7 cells and mice, it was revealed that Rt-ME was capable of suppressing the activation of both nuclear factor (NF)-κB and activator protein (AP)-1 pathways by directly targeting Syk/Src and IRAK1/IRAK4.

Conclusion

Rt-ME could have anti-inflammatory properties by suppressing Syk/Src/NF-kB and IRAK1/IRAK4/AP-1 pathways and will be further developed as a herbal remedy for preventive and/or curative purposes in various inflammatory diseases.     

Identification of pongamol and karanjin as lead compounds with antihyperglycemic activity from Pongamia pinnata fruits

AIM OF THE STUDY: To identify pongamol and karanjin as lead compounds with antihyperglycemic activity from Pongamia pinnata fruits. MATERIAL AND METHODS: Streptozotocin-induced diabetic rats and hyperglycemic, hyperlipidemic and hyperinsulinemic db/db mice were used to investigate the antihyperglycemic activity of pongamol and karangin isolated from the fruits of Pongamia pinnata. RESULTS: In streptozotocin-induced diabetic rats, single dose treatment of pongamol and karanjin lowered the blood glucose level by 12.8% (p<0.05) and 11.7% (p<0.05) at 50mg /kg dose and 22.0% (p<0.01) and 20.7% (p<0.01) at 100mg/kg dose, respectively after 6h post-oral administration. The compounds also significantly lowered blood glucose level in db/db mice with percent activity of 35.7 (p<0.01) and 30.6 (p<0.01), respectively at 100mg/kg dose after consecutive treatment for 10 days. The compounds were observed to exert a significant inhibitory effect on enzyme protein tyrosine phosphatase-1B (EC 3.1.3.48). CONCLUSION: The results showed that pongamol and karangin isolated from the fruits of Pongamia pinnata possesses significant antihyperglycemic activity in Streptozotocin-induced diabetic rats and type 2 diabetic db/db mice and protein tyrosine phosphatase-1B may be the possible target for their activity.     

In vitro & in vivo assessment of a herbal formula used topically for bone fracture treatment

Aim of the study

A novel topical paste used for fracture healing (FH), consisting of the extracts of six herbs, Radix Dipsaci, Ramulus Sambucus Williamsii, Rhizoma Notoginseng, Flos Carthami, Rhizoma Rhei and Fructus Gardeniae, was developed according to the classical theory of traditional Chinese medicine. This study aimed to determine the effectiveness of this formula, and some of its important chemical components in the promotion of fracture healing. The transdermal transport of FH was also examined.

Materials and methods

The osteogenic, angiogenic and nitric oxide suppressing effects of FH and its important chemical marker components were assessed by using osteoblastosacroma UMR-106 cells, human umbilical vein endothelial cells (HUVEC) and murine macrophage RAW264.7 cells, respectively. The bone healing effects of the FH paste and its transdermal absorption were determined using a rabbit fracture model. The callus sizes, bone specific alkaline phosphatase levels and biomechanical properties of the healed bone were assessed.

Results

FH significantly increased the cell proliferation in UMR-106 and HUVEC cells and inhibited the nitric oxide production in murine macrophage in dose-dependent manner. Its important chemical components asperosaponin VI, ginsenoside Rg1 and emodin were shown to be acting positively in the respective in vitro studies. FH paste significantly improved the bone healing in the rabbit fracture model, as was indicated by the increases in callus size at weeks 2-5, and the elevations in bone specific alkaline phosphatase activities at weeks 5-6. The analysis using LC/MS/MS also showed the presence of important chemical marker components of the FH formula in the plasma after 8 weeks of topical treatment.

Conclusion

This study presents the first scientific evidence of the efficacy of a herbal paste in the promotion of fracture healing. There were evidences of transdermal transport of the chemical components, control the inflammation through nitric oxide inhibition, promotion of angiogenesis, and bone healing in the in vitro tests, as well as in the experimental animal.     

Three Chinese herbal medicines promote neuroproliferation in vitro, and reverse the effects of chronic mild stress on behavior,the HPA axis,and proliferation of hippocampal precursor cell in vivo

Ethnopharmacological relevance

The present study investigated whether Chinese herbal medicines (CHMs) could reverse the effects of chronic mild stress (CMS) in a depression-like mouse model.

Materials and methods

The effects of three Chinese herbals, Rhizome Chuanxiong, Radix Scutellaria and Radix Phellodendri on promoting neuroproliferation were evaluated in vitro first and followed by in vivo study of mice which were received by an experimental setting of CMS for 14 days. The effects of the three CHMs on depression were evaluated using a behavioral test, named a forced swimming test (FST). The possible anti-depressive mechanisms of these three CHMs, including the modulation of HPA axis and promoting the hippocampal precursor cell proliferation, were evaluated by measuring plasma corticosterone levels and BrdU incorporation.

Results

The in vitro results of MTS assay showed that Rhizome Chuanxiong, Radix Scutellaria and Radix Phellodendri could promote the proliferation of neural stem cells (NSCs) in a concentration-dependent manner. The oral administration of these three CHMs for 14 days reversed not only the elevation of plasma corticosterone levels and body weight loss, but also the decreasing of hippocampal precursor cell proliferation and abnormal behavior in the CMS induced depression-like mouse model.

Conclusion

These results indicated that Rhizome Chuanxiong, Radix Scutellaria and Radix Phellodendri have the potential to ameliorate depression. The possible mechanisms were the inhibition of HPA axis hyperactivity and the increasing of hippocampal precursor cell proliferation. These findings supported the multicomponent and multitargeted approach of Chinese herbal medicine.     

Anti-inflammatory and immunosuppressive effect of flavones isolated from Artemisia vestita

Aim of the study

Artemisia vestita is a common traditional Tibetan medicinal plant which has been used widely in China for treating various inflammatory diseases. Since little is known about its active components, the purpose of this study was to isolate and identify the immunosuppressive compounds from Artemisia vestita.

Materials and methods

A bioassay-guided isolation was performed with picryl chloride-induced contact hypersensitivity in mice. MTT assay and Flow cytometric analysis were used for determining Con A-induced lymphocyte proliferation and CD25 expression in T cells, respectively.

Results

The ethanol extract of the Artemisia vestita was found to possess significant inhibitory activity against the picryl chloride-induced contact hypersensitivity in mice. Then 4 fractions were isolated by macroporous adsorption resin and one of these fractions (AV3), which showed the highest activity in in vivo test, was further subjected to column chromatography. Nine known flavones were isolated and identified as pectolinarigenin (1), jaceosidin (2), cirsilineol (3), cirsimaritin (4), hispidulin (5), quercetin (6), 6-methoxytricin (7), acacetin (8), and apigenin (9). The structures of the 9 flavones were elucidated by spectral techniques. All the compounds were evaluated for their inhibitory activity on the proliferation and activation of T cells in vitro. Among the 9 flavones, cirsilineol (3), 6-methoxytricin (7) and apigenin (9) significantly inhibited T cell proliferation and activation in the bioassays.

Conclusion

The result suggests that cirsilineol, 6-methoxytricin and apigenin are the major active components in Artemisia vestita.     

Nrf2-dependent neuroprotective activity of diterpenoids isolated from Sideritis spp

Ethnopharmacological relevance

The species of the genus Sideritis are extensively used in the Mediterranean area in folk medicine for their digestive, antimicrobial, anti-inflammatory and antioxidant properties, among others. Moreover, Sideritis species as tea infusions are popularly known for improving memory function and cognitive ability. Diterpenoids are one of the most abundant and important pharmacological interest of the classes of natural products presented in these medicinal plants.

Aim of the study

To determine for the first time the neuroprotective effects, based on their antioxidant properties, of the three isolated major diterpenoids andalusol, conchitriol and lagascatriol in an oxidative stress model.

Materials and methods

H₂O₂ was used as oxidant inductor and rat adrenal pheochromocytoma PC12 cells as cellular model. Cell viability was measured using MTT and LDH assays, lipid peroxidation was determined by HPLC, GSH and GSSG levels assessed by fluorometric techniques, enzymatic activity and protein expression were determined by spectrofometric techniques and Western blot, respectively.

Results

Pretreatments with the three diterpenoids significantly attenuated H₂O₂-induced changes in mitochondrial integrity and activity (MTT assay), in cell membrane integrity (LDH assay) and in cell morphology. Moreover, these diterpenoids inhibited intracellular ROS production H₂O₂-induced, reduced lipid peroxidation and counteracted GSH/GSSG changes. Furthermore, both activities and protein expression of the endogenous antioxidant enzymes (CAT, SOD, GR, GPx and HO-1) were increased. The Nrf2 pathway was involved, at least in part, in the protective effects of these diterpenoids.

Conclusion

These findings suggest that these natural compounds provide significant antioxidant effects in PC12 under for counteracting the oxidative damage H₂O₂-induced and their potential role as useful agents for the prevention of those oxidative stress-mediated dementia disorders. Andalusol was the most active compound among the studied diterpenoids.     

A fraction of stem bark extract of Entada africana suppresses lipopolysaccharide-induced inflammation in RAW 264.7 cells

Ethnopharmacological relevance

Entada africana is a plant used in African traditional medicine for the treatment of stomachache, fever, liver related diseases, wound healing, cataract and dysentery.

Aims of the study

This study aimed at evaluating the anti-inflammatory activity of fractions of the stem bark extract of the plant using lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages model.

Materials and methods

The crude extract was prepared using the mixture CH₂Cl₂/MeOH (1:1, v/v) and fractionated by flash chromatography using solvents of increasing polarity to obtain five different fractions. The effects of the fractions on the cells viability were studied by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and their inhibitory activity against LPS-induced nitric oxide (NO) production screened by Griess test. The most active fraction was further investigated for its effects on reactive oxygen species (ROS) production using flux cytometry, the expression of inducible nitric oxide synthase (iNOS), pro-and anti-inflammatory cytokines (IL1β, TNFα, IL6, IL10 and IL13) by RT-PCR, and the activity of the enzyme p38 MAPK kinase by enzyme-linked immunosorbent assay (ELISA).

Results

The fractions presented no significant effect on the viability of macrophages at 100 μg/ml after 24 h incubation. The CH₂Cl₂/MeOH 5% (Ea5) fraction was found to be the most potent in inhibiting NO production with a half inhibition concentration (IC₅₀)=18.36 μg/ml, and showed the highest inhibition percentage (89.068%) in comparison with Baicalin (63.34%), an external standard at 50 μg/ml. Ea5, as well as Baicalin significantly (P<0.05) inhibited the expression of TNFα, IL6 and IL1β mRNA, attenuated mRNA expression of inducible NO synthase in a concentration-dependent manner, stimulated the expression of anti-inflammatory cytokines (IL10 and IL13), and showed a 30% inhibition of the activity of p38 MAPK kinase.

Conclusion

The results of the present study indicate that the fraction Ea5 of Entada africana possesses most potent in vitro anti-inflammatory activity and may contain compounds useful as a therapeutic agent in the treatment of inflammatory related diseases cause by over-activation of macrophages.     

Drynaria fortunei J. Sm. promotes osteoblast maturation by inducing differentiation-related gene expression and protecting against oxidative stress-induced apoptotic insults

Aim of the study

Drynaria fortunei J. Sm. is one variety of the traditional Chinese medical herb Gusuibu. This study was aimed to evaluate the effects of water extracts of Kunze on regulation of osteoblast maturation and its possible mechanisms.

Materials and methods

Primary osteoblasts prepared from neonatal rat calvarias were exposed to the water extracts of Kunze (WEK), and the cytotoxicity was assayed. Osteoblast maturation was evaluated by analyzing cell mineralization. RT-PCR was executed to determine the effects of WEK on regulation of osteoblast differentiation-related gene expression. Nitrosative stress and apoptotic cells were quantified using flow cytometry.

Results

Exposure of rat calvarial osteoblasts to WEK did not affect cell viability, but significantly promoted osteoblast mineralization. WEK induced osteoprogenitor proliferation-related insulin-like growth factor-1 mRNA, but did not affect collagen type 1 mRNA expression. Treatment with WEK likewise induced the expression of matrix maturation-related bone morphogenetic protein (BMP)-2 and BMP-6 mRNA. Consequently, WEK enhanced the levels of mineralization-related alkaline phosphatase, ostepontin, and osteocalcin mRNA in osteoblasts. In addition, exposure of osteoblasts to WEK alleviated nitrosative stress-caused apoptotic insults.

Conclusions

This study shows that WEK can promote osteoblast maturation by regulating bone differentiation-related gene expression and defending against nitrosative stress-induced apoptotic insults.     

Antimicrobial and antimalarial activity of Cussonia species (Araliaceae)

Ethnopharmacological relevance

Cussonia species are used in African traditional medicine mainly against pain, inflammation, gastro-intestinal problems, malaria and sexually transmitted diseases.

Aim of the study

To summarise ethnomedicinal uses of Cussonia and to find scientific evidence in support of selected main uses.

Materials and methods

Using the minimum inhibitory concentration (MIC) method, leaves of 13 Cussonia species, Schefflera umbellifera and Seemannaralia gerrardii were tested against pathogens associated with diarrhoea (Enterococcus faecalis and Escherichia coli), sexually transmitted infections (Neisseria gonorrhoeae and Trichomonas vaginalis) and general infectious diseases (Staphylococcus aureus and Pseudomonas aeruginosa). Antimalarial sensitivity was studied using Plasmodium falciparum and the [³H]-hypoxanthine incorporation assay. Cytotoxic effects on a T-cell leukaemia (Jurkat) cell line were determined using the tetrazolium-based cellular toxicity assay.

Results

Methanolic extracts were active against Pseudomonas aeruginosa (MIC of 1.0–1.5 mg/mL), Trichomonas vaginalis (MIC of 0.8–1.3 mg/mL) and Staphylococcus aureus (Cussonia arborea, 1.8 mg/mL). All samples were active against Neisseria gonorrhoeae (MIC of 0.02–0.7 mg/mL). The methanol extract of Cussonia arborea was the most active against Plasmodium falciparum (13.68 μg/mL) and showed anticancer properties (5.60 μg/mL).

Conclusions

The traditional use of Cussonia species to treat sexually transmitted diseases and Plasmodium infections appears to have a scientific basis.     

Cytotoxic and apoptotic activity of Cheilanthes farinosa (Forsk.) Kaulf. against human hepatoma,Hep3B cells

Aim of the study

Cheilanthes farinosa (Forsk.) Kaulf., family: Adianthaceae, is a fern of immense medicinal properties used in ethno-medicine. The Gaddis tribe of Himachal Pradesh, India, has been using this fern to treat liver damage. Aim of the current study was to determine the apoptosis inducing and cytotoxic activity, if any, of this fern towards hepatic cancer cells.

Materials and methods

Water extract of the plant was used in the study. MTT assay was performed in hepatocellular carcinoma cell line, Hep3B as well as murine macrophage cell line, RAW264.7 to analyze the cytotoxic activity of the plant. Further, the apoptosis inducing action of water extract of the plant was evaluated using comet assay, DNA fragmentation analysis, DAPI staining of chromatin and Annexin V-FITC staining.

Results

This plant was found to produce considerable cytotoxicity in hepatoma cell line, Hep3B without inducing substantial damage to non-cancerous cell line RAW264.7. In addition, this plant was found to induce apoptosis in Hep3B cells. This was substantiated by comet assay, DNA fragmentation analysis, DAPI staining of chromatin and Annexin V-FITC staining for detecting early stage of apoptosis.

Conclusions

This investigation shows that the water extract of Cheilanthes farinosa has antiproliferative and apoptotic activity in human liver cancer cells and is not deleterious towards non-cancerous macrophage cell line.     

Anti-leukemic activity of Wattakaka volubilis leaf extract against human myeloid leukemia cell lines

Ethnopharmacological relevance

Wattakaka volubilis has been traditionally used in Ayurvedic medicine in India for treatment of several ailments such as bronchial asthma, inflammations, tumors, piles, leucoderma, application to boils, rat bite etc.

Aim of the study

The present study was designed to investigate anti-leukemic activity of the crude aqueous methanolic extract and to identify active compounds from the leaves of Wattakaka volubilis.

Materials and methods

The leaves of Wattakaka volubilis were extracted with aqueous methanol. Liquid–liquid fractionation of the crude methanolic extract with different organic solvents was done and the fractions were screened for in vitro anti-leukemic activity using different leukemic cell lines. The active fractions were then subjected to chromatographic separation for isolation of bioactive compounds. Structure of isolated compound was elucidated by spectroscopic methods. The in vitro anti-leukemic activities of different extracts of the leaves and isolated compound WVP were studied in U-937, HL-60 and K-562 cell-lines by using cell count, MTT [(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] and DNA laddering assays, flow-cytometric and confocal microscopic techniques.

Results

Kaempferol-3-O-[α-l-rhamnopyranosyl-(1→4)-O-α-l-rhamnopyranosyl-(1→6)-O]-β-d-glucopyranoside (WVP) was isolated from crude leaves extract of Wattakaka volubilis. Both the n-butanolic extract (WVB) of Wattakaka volubilis and its isolate WVP were found to be responsible for in vitro anti-leukemic activity. The IC₅₀ values of WVB were found be 120, 100 and 50 (μg/ml) in U937, K562, and HL-60 cell lines, respectively. Whereas, the pure isolate WVP exhibited anti-leukemic activity with IC₅₀ values of 13.5, 10.8, and 13.2 (μg/ml) in U937, K562, and HL-60 cell lines, respectively. The flow-cytometric analysis confirms that the cell cycle arrest occurs at G1 phase in case of U937 and K562 cell lines and G2/M phase in case of HL60 cell lines. Similarly both confocal microsocopic analysis and DNA laddering assay confirm the apoptosis and cell cycle arrests of leukemic cells.

Conclusion

The overall results provide evidence for the ethnopharmacological relevance for use of the plant Wattakaka volubilis in developing novel agents for the treatment of leukemia.     

The biological activity and chemistry of the southern African Combretaceae

AIM OF THE STUDY: Members of the Combretaceae family are widely traded in the traditional medicine market in southern Africa. The family is also used for medicinal purposes in the rest of Africa and Asia for close to 90 medicinal indications. Many of these indications are related to treating infections. This contribution summarizes work done to date and identifies avenues for future research. MATERIALS AND METHODS: Substantial work has already been done on the chemistry of especially Combretum and Terminalia species over many years. During the last decade we have focussed on bio-assay guided isolation of biologically active compounds with the aim of producing new effective antimicrobial products. RESULTS AND DISCUSSION: Methods developed to facilitate this process and data on 25 compounds isolated from 7 species are presented. The large majority of compounds isolated were known, but the biological activities were not known. In practically all cases the antibacterial or antifungal activity of compounds isolated were much lower than expected from the activity of the crude extracts. It appears that synergism plays a role in antimicrobial activity of plant extracts and that the hope of isolating a single compound that can be used as a new agent to address antibiotic resistance has been frustrated. By simple manipulation such as selective extraction the activity of some crude extracts could however, be increased substantially and this offers a new approach to address antibiotic resistance via the herbal medicine industry. Practically all extracts obtained using intermediate polarity extractants had reasonable to very good activity with MICs as low as 40 microg/ml, validating the traditional use for infectious diseases. Aqueous extracts however, generally had hardly any activity. CONCLUSIONS: The Combretaceae contains a diversity of antimicrobial compounds. Because poor people usually have only water available as extractant, it raises the question how plants growing in poor rural communities can be used to treat infections more effectively, and what the mechanism of activity of aqueous extracts used to treat infections in traditional medicine are.