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.

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.