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Background Boerhavia coccinea (Nyctaginaceae) is an herbaceous plant used for the treatment of pain. The aim of this study was to evaluate the antinociceptive and anti-inflammatory activities of the aqueous (AEBC) and ethanol (EEBC) extracts of Boerhavia coccinea as well as the major fractions (F1, F2 and F3) from EEBC. Methods The antinociceptive effect of the extracts and fractions was evaluated using formalin test. AEBC, EEBC and F1 were selected and further evaluated acutely (24 h) and chronically (16 days) in Complete Freund's Adjuvant (CFA)-induced persistent inflammatory pain for their antihyperalgesic and anti-inflammatory effects. They were administered orally (100 and 200 mg/kg/day) from 48 h following the intraplantar injection of 100 µL of CFA. After the 16 days of chronic treatment, rats' spinal cord and brain were collected for the evaluation of oxidative stress parameters namely nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT). Results AEBC, EEBC and F1 significantly inhibited the first and second phases of the formalin-induced pain. They significantly reduced the hyperalgesia both in acute and chronic treatments. These extracts showed no acute anti-inflammatory effect. AEBC and EEBC exhibited anti-inflammatory activities after repeated administration. AEBC, EEBC and F1 significantly reduced MDA level and significantly increased SOD and catalase activities, mainly in the spinal cord. AEBC and EEBC also reduced the NO production in the spinal cord. Conclusions Boerhavia coccinea extracts and F1 possess potent antinociceptive activity which is not related to their anti-inflammatory properties. Their antioxidant effects may contribute to these activities in chronic treatment.

Background: Antimicrobial resistance is a serious threat against humankind and the search for new therapeutics is needed. This study aims to investigate the antimicrobial and antioxidant activities of ethanol extracts and compounds isolated from Dissotis senegambiensis and Amphiblemma monticola, two Cameroonian Melastomataceae species traditionally used for the treatment of fever, malaria and infectious diseases., Methods: The plant extracts were prepared by maceration in ethanol. Standard chromatographic and spectroscopic methods were used to isolate and identify fourteen compounds from the two plant species [1-6 (from D. senegambiensis), 3, 4 and 7-14 (from A. monticola)]. A two-fold serial micro-dilution method was used to determine the minimum inhibitory concentration (MIC) against four bacterial strains including two resistant bacterial strains, methicillin resistant S. aureus (MRSA3) and methicillin resistant S. aureus (MRSA4) and three yeast strains., Results: The fractionation of EtOH extracts afforded fourteen compounds belonging to triterpenoid and phenolic derivatives. The ethanol extracts, compounds 3, 5-8, 10 and the mixture of 10 + 12 were active against all the tested bacterial and fungal species. Compound 7 (MIC = 16-32 μg/mL) and 10 (MIC = 8-16 μg/mL) displayed the largest antibacterial and antifungal activities, respectively. Compounds 7, 10 and the mixture of 10 + 12 showed prominent antibacterial activity against methicillin- resistant S. aureus (MRSA) which is in some cases equal to that of ciprofloxacin used as reference antibacterial drug. Compound 8 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and butylated hydroxytoluene used as reference antioxidants. The tested samples were non-toxic to normal cells highlighting their good selectivity., Conclusions: The result of this investigation reveals the potential of D. senegambiensis and A. monticola as well as the most active compounds in the search for new antimicrobial and antioxidant agents. So, further investigations are needed.