ANTIMICROBIAL AND ANTIPLASMODIAL ACTIVITIES OF A QUATERNARY COMPOUND FROM RITCHIEA CAPPAROIDES VAR. LONGIPEDICELLATA

Ritchiea capparoides var. longipedicellata (Capparidaceae) leaves are used in ethnomedicine in Western-Nigeria to treat infectious and parasitic diseases. This study was aimed at identifying the compound(s) that are responsible for the antimicrobial and antiplasmodial activities of the leaves and also to contribute to the chemistry of the plant species. A 70 % aqueous ethanolic extract of the leaves of R. longipedicellata was subjected to repeated liquid chromatographic methods on silica gel, Lobar RP-18 column and Sephadex LH -20 to isolate a Draggendorf positive compound. The compound was identified by 1H and 13C NMR, ultra-violet spectroscopy and polarimetry. The antimicrobial activity of the compound was evaluated using the microbroth dilution method while the antiplasmodial activity was carried out according to Trager and Jenson (1976). The minimum inhibitory concentration (MIC) was expressed in mg/ml. The isolated compound, leavo-isomer of stachydrine, inhibited the growth of Escherichia coli NCTC 8196 and Staphylococcus aureus NCTC 6571 at the MIC of 5 mg/ml. In the anti-malaria assay, the compound had inhibitory activity with the concentration required to cause 100% lethality being 0.667 mg/ml. Conclusion: The antibacterial and antiparasitic effects of quaternary ammonium compounds are well documented. However, this study is the first report of the presence and biological activities of this compound in this plant species which may justify the ethnomedicinal uses of the leaves

EVALUATION OF ANTITRYPANOSOMAL AND ANTI INFLAMMATORY ACTIVITIES OF SELECTED NIGERIAN MEDICINAL PLANTS IN MICE

The extracts of nine selected Nigerian medicinal plants were investigated on Trypanosoma brucei brucei infected mice. The anti-inflammatory properties of hexane fraction of the most promising U. chamae extract was assessed by acute oedema of the mice paw model while the modulatory effect of the extract on Delayed-Type Hypersensitivity (DTH) resp onse on in vivo leucocytes mobilization was evaluated. ‘Dose- probing acute toxicity tests’ established an oral and intraperitoneal LD50 for T. ivorensis stem bark as >1600 5000 mg/kg. Extracts of Khaya senegalensis, Harungana madagascariensis, Terminalia ivorensis, Curcuma longa, Ocimum gratissimum and Alcornea cordifolia showed weak anti-trypanosomal effect and did not exhibit significant clearance in parasitemia at the test dose administered compared with the positive control (Diminal®). However, the leaf extract of U. chamae and its hexane fraction demonstrated a significant response (P < 0.01). The fraction at 1000 mg/kg inhibited oedema by 107%. Uvaria. chamae demonstrated both anti-trypanosomal and anti-inflammatory properties by increasing the survival time of infected mice due to reduction in parasitemia caused by T. brucei brucei

ANTIPLASMODIAL ACTIVITIES OF ETHANOL AND ETHYL ACETATE STEM-BARK EXTRACT/FRACTION OF Blighia sapida K.D. KOENIG ON MICE INFECTED WITH Plasmodium berghei

Reduction and probably eradication of future occurrence of resistance in malarial parasite demand urgent attention towards the development of alternative antimalarial drugs with new mechanisms of action. In view of this, the study investigated the in vivo antiplasmodial activities of ethanol stem-bark extract and ethyl acetate fraction of Blighia sapida against Plasmodium berghei in mice, to provide scientific support for the ethnomedicinal uses of the plant. Ethanol extract (EE) and ethyl acetate fraction (EAF) of B.&nbsp; Sapida stem bark were evaluated for in vivo antimalarial activity, using mice model. EE at doses of 250, 500, 1000 mg/kg, and EAF at doses of 125, 250, 500 mg/kg body weight were administered orally. Pyrimethamine, Chloroquine, and Artemether served as positive controls while 0.9% normal saline was given to the negative control group. At doses of 250, 500, and 1000 mg/kg, EE produced chemosuppression of 90.72, 85.62, and 94.06% in prophylactics, 59.33, 75.33, and 82.89% in suppressive and in the curative model on Day 7, 59.46, 59.91, and 56.70% respectively. At doses of 125, 250, and 500 mg/kg, EAF produced chemosuppression of 45.95, 50.74, and 69.12% in prophylactics, 57.97, 66.11, and 81.06 in suppressive and in curative model 71.13, 74.52, and 82.80 % respectively. Results obtained were compared with the standard antimalaria drugs (89.46, 75.37, and 95.54% for pyrimethamine, chloroquine, and artemether, respectively). Results showed that the extract and fraction of B. Sapida possessed potent antiplasmodial activities at different doses considered, which supports its use as antimalarial ethnomedicinally. &nbsp

Extracts of six Rubiaceae species combined with rifampicin have good in vitro synergistic antimycobacterial activity and good anti-inflammatory and antioxidant activities

BACKGROUND : The Rubiaceae family has played a significant role in drug discovery by providing molecules with potential use as templates for the development of therapeutic drugs. This study was designed to study the in vitro synergistic effect of six Rubiaceae species in combination with a known anti-TB drug. The antioxidant and anti-inflammatory activity of these species were also evaluated to investigate additional benefits in antimycobacterial treatment. METHODS : The checkerboard method was used to determine the antimycobacterial synergistic activity of plant extracts combined with rifampicin. The antioxidant activity of extracts was determined by the 2,2-diphenyl- 1-picrylhydrazyl (DPPH) method. Anti-inflammatory activity via inhibition of nitric oxide (NO) production was performed in LPS-activated RAW 264.7 macrophages using the Griess assay. RESULTS : Combination of rifampicin with the crude extracts resulted in a 4 to 256-fold increase of activity of extracts. The crude extract of Cremaspora triflora produced the best synergistic effect with rifampicin, with a fractional inhibitory concentration (FIC) index of 0.08 against Mycobacterium aurum. Extracts of Psychotria zombamontana had the best antioxidant activity with an IC50 value of 1.77 μg/mL, lower than the IC50 of trolox and ascorbic acid (5.67 μg/mL and 4.66 μg/mL respectively). All the extracts tested inhibited nitric oxide (NO) production in a concentration dependent manner with the percentage of inhibition varying from 6.73 to 86.27 %. CONCLUSION : Some of the Rubiaceae species investigated have substantial in vitro synergistic effects with rifampicin and also good free radical scavenging ability and anti-inflammatory activity. These preliminary results warrant further study on these plants to determine if compounds isolated from these species could lead to the development of bioactive compounds that can potentiate the activity of rifampicin even against resistant mycobacteria.The University of Pretoria Institutional Research Theme for Animal and Zoonotic Diseases (IRT-AZD), National Research Foundation (NRF, Grant No 81010) and Medical Research Council (MRC) of South Africa provided funding to support this study. The National Research Foundation (NRF) provided a doctoral fellowship to AOA. The University of Pretoria provided a postdoctoral fellowship to JPD.http://www.biomedcentral.com/bmccom/plementalternmedam2017Paraclinical Science