Abimbola Sowemimo

Antiinflammatory, analgesic and antioxidant activities of Cyathula prostrata (Linn.) Blume (Amaranthaceae).

ETHNOPHARMACOLOGICAL RELEVANCE Cyathula prostrata (Linn) Blume (Amaranthaceae) is an annual herb widely used traditionally in the treatment of various inflammatory and pain related health disorders in Nigeria. The aim of this study is to evaluate the anti-inflammatory, analgesic and antioxidant activities of the methanolic extract of Cyathula prostrata (Linn) Blume. MATERIALS AND METHODS The anti-inflammatory (phorbol 12-myristate 13-acetate (PMA)-induced reactive oxygen species (ROS), lipopolysaccharide (LPS) induced nitric oxide production in U937 macrophages, LPS-induced COX-2 expression, carrageenan-induced rat paw oedema, arachidonic acid-induced ear oedema and xylene-induced ear oedema), analgesic (acetic acid-induced writhing and hot plate tests) and antioxidant activities (DPPH [1,1-diphenyl-2-picrylhydrazyl] and lipid peroxidation assays) activities of the plant extract were investigated. RESULTS The methanolic extract of Cyathula prostrata did not show inhibitory activity in the in vitro PMA-induced reactive oxygen species, LPS-induced nitric oxide production and LPS-induced COX-2 expression assays. In the in vivo anti-inflammatory assays, the extract (50, 100 and 200mg/kg) showed a significant (P<0.05) dose-dependent inhibition in the carrageenan, arachidonic acid and xylene-induced tests. Cyathula prostrata produced a significant (P<0.05, 0.001) dose-dependent inhibition in the acetic acid and hot plate analgesic tests respectively. The plant extract did not exhibit any antioxidant activity in the DPPH and lipid peroxidation assays. CONCLUSION The results suggest that the methanolic extract of Cyathula prostrata possesses anti-inflammatory and analgesic activities and this authenticates the use of the plant in the traditional treatment of ailments associated with inflammation and pain.

Antiproliferative and apoptosis inducing activity of Markhamia tomentosa leaf extract on HeLa cells

ETHNOPHARMACOLOGICAL RELEVANCE Markhamia tomentosa (Benth) K. Schum ex. Engl. (Bignoniaceae), a tree widely dispersed in West Tropical Africa, is used traditionally to treat various diseases as it possesses antimicrobial, antioxidant, analgesic, anticancer and anti-inflammatory activities. MATERIALS AND METHODS This study evaluates the cytotoxic effect and underlying mechanisms of the ethanolic extract of Markhamia tomentosa on HeLa and MCF-7 cancer cell lines and non-cancerous Vero cell line. Brine shrimp lethality test was used for preliminary screening. Cytotoxicity was determined using the MTT assay and IC50 was calculated. Effect of Markhamia tomentosa on the cell cycle was monitored by flow cytometry and the apoptosis-induction capability confirmed by exposure of phosphatidylserine to the outer leaflet of the plasma membrane. Loss of mitochondrial membrane potential was analysed by flow cytometry using JC-1. RESULTS Markhamia tomentosa was toxic to brine shrimps with LD50 of 31.62µg/ml. Cell viability and growth of HeLa cells was inhibited by the extract with an IC50 of 189.1±1.76µg/ml at 24h post treatment. However, no cytotoxic effect was observed in MCF-7 and Vero cell lines. The extract induced cell cycle arrest in HeLa cells in the G0/G1 phase resulting in cell death after 24h exposure. Induction of apoptosis in HeLa cells was substantiated by Annexin V-FITC/PI double staining showing phosphatidylserine translocation and depolarisation of the mitochondrial membrane potential by flow cytometry of JC-1 stained cells. CONCLUSION The ethanolic extract of Markhamia tomentosa induces G0/G1 in HeLa cells followed by induction of the intrinsic pathway of apoptosis.

Anti-inflammatory activity of Markhamia tomentosa (Benth.) K. Schum. Ex Engl. ethanolic leaf extract.

ETHNOPHARMACOLOGICAL RELEVANCE The leaves of Markhamia tomentosa (Benth.) K. Schum (Bignoniaceae) are used traditionally for the treatment of oedema and rheumatoid arthritis in Nigeria. AIM OF THE STUDY The aim of the work was to investigate the anti-inflammatory activity of the ethanolic leaf extract of Markhamia tomentosa. MATERIALS AND METHODS The extract was screened using the carrageenan-induced paw oedema in rats, xylene-induced oedema in mice and the formalin-induced oedema in mice at 50, 100, 200mg/kg doses p.o respectively. The mechanism by which the extract mediated the anti-inflammatory activity was assessed using the histamine-induced rat paw oedema and serotonin-induced rat paw oedema at the highest dose (200mg/kg). RESULTS The results showed that the extract produced a significant dose-dependent inhibition in carrageenan-induced, xylene-induced and the formalin tests. The extract exerted a significant inhibition of 54.55% (P<0.0001) and 42.11% (P<0.01) at 90 min in the histamine-induced and serotonin-induced rat paw oedema models respectively. CONCLUSIONS These findings suggest that the ethanolic leaf extract of Markhamia tomentosa possesses anti-inflammatory activity possibly mediated by histamine. The results justify the use of the plant in the preparation of ethno medicines used in the treatment of ailments associated with inflammation.

Anticonvulsant activity of the methanolic extract of Justicia extensa T. Anders.

ETHNOPHARMACOLOGICAL RELEVANCE To investigate the anticonvulsant activity of the leaf extract of Justicia extensa T. Anders used traditionally in the treatment of convulsion. MATERIALS AND METHODS The anticonvulsant activity of the methanolic extract of Justicia extensa (50, 100 and 200 mg/kg, p.o.) was assessed in strychnine-induced (STR) and picrotoxin-induced (PCT) convulsion models in mice. Diazepam (1 mg/kg) and phenobarbitone (2 mg/kg) were used as reference drugs respectively. RESULTS The extract showed no toxicity and significantly prolonged (p<0.01-0.05) the onset and reduced the duration of the seizures induced by picrotoxin (5 mg/kg, i.p.) in a dose dependent manner. Phenobarbitone completely inhibited the seizures in this model. Similarly, in the seizures induced by strychnine (1 mg/kg, i.p.), the extract also prolonged the onset and reduced the duration of the seizures though not in a dose dependent manner. Diazepam failed to inhibit the strychnine-induced seizures. The plant extract however showed a significantly higher anticonvulsant activity at 100 and 200 mg/kg in comparison with diazepam. CONCLUSIONS The results obtained from this work suggest that Justicia extensa has anticonvulsant activity and this supports the use of the plant traditionally in the treatment of convulsion.

Studies on the anti-inflammatory and anti-nociceptive properties of Blepharis maderaspatensis leaves

Blepharis maderaspatensis (L.) B. Heyne ex Roth, Acanthaceae, is a procumbent or scrambling perennial herb used traditionally for treatment of snakebites, wounds, edema and gout. The anti-inflammatory and anti-nociceptive properties of the ethanol extract of the whole plant of B. maderaspatensis was investigated using carrageenan-induced paw edema in rats, xyleneinduced edema in mice, mouse writhing and tail clip tests respectively. The effect of the extract on inflammatory mediators, serotonin and histamine, using the most active dose (75 mg/kg) was also carried out. The results showed that the extract of B. maderaspatensis in carrageenan-induced test caused a significant inhibition (84.5%, 90 min) of paw edema at a dose of 75 mg/kg while the xylene-induced test caused a significant inhibition (62.65%) at 50 mg/kg. The histamine-induced test showed significant inhibition (90.9%, 90 min) while serotonin-induced test showed moderate inhibition (54.10%, 180 min). In the mouse writhing and tail clip tests, the extract produced a significant inhibition of 66.21% and 15.81% at 75 mg/kg, respectively. These results collectively demonstrate that the ethanol extract of B. maderaspatensis possesses anti-inflammatory and anti-nociceptive properties, and this supports the ethnopharmacological use of the plant in the treatment of inflammation.

Review of the phytochemical and pharmacological studies of the Genus Markhamia

Natural product compounds obtained from medicinal plants have been great contributions in the discovery of numerous clinically useful drugs. Markhamia species have been reportedly used by many cultures in human and veterinary traditional medicines. The five identified species of Markhamia, that is, Markhamia lutea, Markhamia obtusifolia, Markhamia stipulata, Markhamia tomentosa, and Markhamia zanzibarica have been the subject of chemical investigations that have led to the characterization of their secondary metabolites. Plants of the genus with the identified phytoconstituents, including phenylpropanoid glycosides (PhGs), terpenoids, phytosterols, lignans, quinones, and flavonoids, have been claimed to possess antiviral, antifungal, antiprotozoal, analgesic, antiinflammatory, and cytotoxic activities. In vitro and in vivo pharmacological research studies have reported the validation of the medicinal properties of plants of this genus. The present review analyzes published data from the ethnomedicinal, phytochemical, and pharmacological studies of plants of the genus Markhamia.

Antiproliferative mechanism of the methanolic extract of Enterolobium cyclocarpum (Jacq.) Griseb. (Fabaceae).

ETHNOPHARMACOLOGICAL RELEVANCE Enterolobium cyclocarpum (Jacq.) Griseb. is a tropical tree that has folkloric implications against many ailments and diseases including cancer. MATERIALS AND METHODS To explore the ethnopharmacological claims against cancer, the cytotoxicity of the methanolic extract of the leaves, was investigated using the brine shrimp lethality assay, MTT assay using cervical (HeLa) and breast (MCF7) cancer cell lines, cell cycle analysis and Annexin V-FITC/PI assay. RESULTS In the brine shrimp lethality assay, the extract showed cytotoxic activity with LC50 value of 31.63 µg/mL. Significant growth inhibition was observed in both cell lines with IC50 values of 2.07 ± 1.30 µg/mL and 11.84 ± 1.18 µg/mL for HeLa and MCF7, respectively. Cell cycle analysis indicated that HeLa cells were arrested in the G2/M phase while MCF7 cells arrested in the G1/G0 phase. The Annexin V-FITC/PI assay revealed phosphatidylserine translocation in both cell lines and thus apoptosis induction upon treatment with the extract. CONCLUSION The study demonstrated the potential antiproliferative activity of Enterolobium cyclocarpum thereby supporting the traditional claim and provides basis for further mechanistic studies and isolation of active constituents.

Biological activities and nutritional value of Tapinanthus bangwensis leaves

The cytotoxic and antioxidant properties of the ethanolic extract and fractions of the leaves of Tapinanthus bangwensis were evaluated. The investigation of their total phenol and flavonoid contents, proximate analysis and their mineral composition were also carried out. In the brine shrimp lethality assay, the ethyl acetate and dichloromethane fractions showed cytotoxic activity with LD 50 values of 11.22 and 15.84 μg/ml, respectively. The ethyl acetate and dichloromethane fractions exhibited significant cytotoxic effects towards HeLa cells with IC 50 values of 24.25 and 24.43 μg/ml respectively. In the DPPH assay, the ethyl acetate fraction showed the highest activity while the butanol fraction showed the highest activity in the metal chelating and the lipid peroxidation assays. The quantitative analysis gave the total phenol and flavonoid contents in the range of 13.38 to 668.65 mg gallic acid equivalent (GAE)/g and 0.53 to 34.52 mg quercetin equivalent (QE)/g, respectively. For the proximate analysis, the crude fibre, carbohydrate, protein, total ash and moisture content values were 58.03, 17.80, 7.79, 13.70 and 0.60%, respectively while iron occurred in the highest amount and sodium in the least in the mineral composition analysis. These results demonstrate the cytotoxic and antioxidant activities of T. bangwensis leaves and support the traditional use of the plant in cancer treatment. Keywords: Tapinanthus bangwensis , brineshrimp, HeLa, antioxidant

Cytotoxic compounds from the leaves of Combretum paniculatum Vent

Combretum paniculatum Vent. (Combretaceae) is a shrub that is widespread in tropical Africa. It is used locally in the treatment of carcinomous tumors. The cytotoxic activity of pheophorbide a and pheophorbide a-methyl ester isolated from the leaves of C. paniculatum were investigated. In vitro cytotoxicity of the compounds were evaluated against HT-29, MCF-7 and HeLa cancer cell lines using the methyl thiazolyl tetrazolium (MTT) assay and peripheral blood mononuclear cells. Cell cycle analysis was performed using propidium iodide staining and flow cytometry. Pheophorbide a was more toxic to MCF-7 and HeLa cells than its methyl ester, while the opposite result was seen in HT-29 cells. The methyl ester killed all the peripheral blood mononuclear cells from healthy donor blood while less inhibition was observed with pheophorbide a. Both compounds induced cell cycle arrest in HeLa cells in the G0/G1 phase, with pheophorbide a-methyl ester yielding a more enhanced G1/G0 arrest. After 24 h of exposure, the percentage of HeLa cells in the G0/G1 phase was 38.5% in vehicle control cells, 55.9% in pheophorbide a and 70.0% in pheophorbide a-methyl ester treated cells. The in vitro effect of C. paniculatum on cancer cell lines may be ascribed to the presence of pheophorbide a and its methyl ester. They exert this effect through the induction of cell cycle arrest in the G0/G1 phase of the cell cycle.

Antifungal and antiproliferative activities of endophytic fungi isolated from the leaves of Markhamia tomentosa

Abstract Context: Plants harbor endophytes with potential bioactivity. Markhamia tomentosa (Benth) K. Schum ex. Engl. (Bignoniaceae) is reported to possess antioxidant, anti-inflammatory and anticancer activities. Objective: The antifungal and antiproliferative properties of endophytic fungi extracts and fractions from M. tomentosa were evaluated. Material and methods: Endophytic fungi were isolated from the leaves of M. tomentosa and identified by ITS-rDNA sequence analysis. The antagonistic effect of the fungal strains was investigated against pathogenic fungi viz, Fusarium oxysporum, Sclerotinia sclerotiorium, Rhizoctonia solani, and Botrytis cinerea using the dual culture assay for 5–7 days. Antiproliferative effect of the fungal extracts and fractions (3.91–250 μg/mL) on HeLa cancer cell line was tested and IC50 was calculated. Poisoning food assay and antifeedant activity against the pathogenic fungi and Spodoptera litura larvae, for 7 days and 2 h, respectively, was also tested at concentrations of 250, 500 and 1000 μg/mL. Results: Fungal endophytes Trichoderma longibrachiatum and Syncephalastrum racemosum were isolated from the leaves of M. tomentosa. Isolated endophytic fungal strains and solvent extracts showed MIC value of 1000 μg/mL against tested pathogenic fungi in the dual culture and poisoning food assays. Methanol fraction of S. racemosum isolate showed the most effective antiproliferative activity with IC50 of 43.56 μg/mL. Minimal feeding deterrent activity against S. litura larvae was also observed. Discussion and conclusion: These findings showed that the leaves of Markhamia tomentosa harbor strains of endophytic fungi with promising health benefits, and suggest their antifungal and antiproliferative effects against pathogenic fungi and HeLa cancer cell line.