Antibiotic-potentiation, antioxidant, cytotoxic, anti-inflammatory and anti-acetylcholinesterase potential of Antidesma madagascariense Lam. (Euphorbiaceae)

Antidesma madagascariense Lam. (AM) is used in the treatment and management of a panoply of human diseases. Leaf decoction, acetone extracts and fractions of AM were evaluated for antimicrobial, antioxidant, anti-inflammatory, cytotoxicity and acetylcholinesterase (AChE) inhibitory activity. The antibiotic potentiating activity of crude acetone extract (AE) was assessed against ATCC bacterial strains of Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923 using standard antibiotics. Decoction extract showed significant inhibitory activity against Acinetobacter spp. (MIC: 0.25 mg/mL) which had higher inhibitory effect compared to the positive control Streptomycin (MIC: 1.00 mg/mL). Acetone and decoction extracts inhibited the growth of Candida albicans (MIC: 4.00 mg/mL). All fractions of AE showed broad spectrum activity against ATCC and clinical strains (MIC 0.03–4.00 mg/mL). The results of the combination pro- files of the AE with Ciprofloxacin, Chloramphenicol and Streptomycin revealed synergistic interactions (FICI ≤ 0.50) against P. aeruginosa. Crude decoction, acetone extract and fractions were found to be potent reducing agent as well DPPH radical scavenger and ABTS cation scavenger. A significant correlation between DPPH, ABTS and total phenolic content (p b 0.05, r=−0.75 and −0.82 respectively) was recorded. Three fractions namely DCM:MeOH (85:15) (F5), DCM:MeOH (95:05) (F3) and DCM (F2) [IC50 0.02–0.09 mg/mL] demonstrated significant anti-inflammatory activity as compared to the positive control, diclofenac sodium [IC50 0.18 (0.10–0.31) mg/mL]. AE and its fractions showed AChE inhibitory activities at an IC50 of 35.92–492.6 μg/mL. Cytotoxicity study against Vero cells revealed that AE and hexane fraction were non-cytotoxic while decoction showed cytotoxic effect. Further studies are required to explore the potential of AM crude extracts and fractions as natural source of antimicrobial, antioxidant, anti-inflammatory agents as well as AChE inhibitors.http://www.elsevier.com/locate/sajb2018-07-31hb2017Plant Production and Soil Scienc

Antibiotic-potentiating activity, phytochemical profile, and cytotoxicity of Acalypha integrifolia Willd. (Euphorbiaceae)

Acalypha integrifolia Willd. (Euphorbiaceae) (AI), an indigenous medicinal plant of the Mascarene Islands is traditionally used to manage infectious diseases. The authors aimed to evaluate the antimicrobial, antibiotic-potentiating activity and cytotoxicity of AI. Decoction as traditionally used and organic extracts (hexane, dichloromethane, ethyl acetate, and methanol) of AI leaves were screened for their antimicrobial activity against nine ATCC strains and 10 clinical isolates. A fractional inhibitory concentration index (FICI) was determined to establish any synergistic interaction between the extracts and antibiotics using the variable ratio analysis method. The phytochemical profile was established using chemical and thin-layer chromatography methods. The decoction and methanolic extracts inhibited the growth of all tested bacteria (minimum inhibitory concentration (MIC) ranged between 0.06–2.00 mg/ml). The methanolic extract showed potent antibacterial activity against Escherichia coli (EC) (MIC: 0.06 mg/ml), Pseudomonas aeruginosa (MIC: 0.50 mg/ml), and Staphyloccocus aureus (SA) (MIC: 0.06 mg/ml). The highest antibacterial activity was observed against clinical isolates of Enterococcus faecalis, S. aureus, and Methicillin-Resistant S. aureus (MRSA) (MIC: 0.50 mg/ml). Moderate antifungal activity was observed against Candida albicans. Combination profiles of the extract with Ciprofloxacin, Chloramphenicol, and Streptomycin showed synergistic action (FICI ≤ 0.50) against ATCC strains of EC and SA. Decoction and methanolic extracts showed low cytotoxicity against normal adult African green monkey kidney cells. Data obtained tends to corroborate with the reported traditional usage of the plant. Since the leaf decoction is traditionally used against skin infections as well as consumed for its astringent and purgative properties, the reported data tend to correlate with the low cytotoxicity as well as its anti-infective property. There may also be the potential towards the discovery of novel antimicrobial compounds.https://www.elsevier.com/locate/hermed2019-03-01hj2018Plant Production and Soil Scienc

Antimicrobial, antioxidant and cytotoxic evaluation of two underutilised food plants : Averrhoa bilimbi L. (Oxalidaceae) and Phyllanthus acidus L. Skeels (Phyllanthaceae)

Averrhoa bilimbi (P1) and Phyllantus acidus (P2) are traditionally used in the management of various diseases in several cultures. Leaf (L) and fruit (F) extracts (decoction, hexane, dichloromethane, ethyl acetate- EtOAc and methanol) were prepared and investigated for their antimicrobial, antioxidant and cytotoxic properties in vitro. P1 and P2 extracts showed broad spectrum activity against ATCC bacterial strains and clinical isolates. P1L and P2F EtOAc extracts inhibited the growth of ATCC strains of S. aureus and V. parahaemolytius (MIC = 250 μg/ml). P1F EtOAc extract was found active against ATCC strains of E. coli and S. aureus (MIC = 250 μg/ml). P1F was active against all tested clinical isolate strains with maximum inhibition against S. aureus ((MIC = 130 μg/ml). Hexane and EtOAc extracts of P2F showed activity against clinical isolate strains of S. aureus ((MIC = 130 and 250 μg/ml, respectively). P2F hexane extract displayed antimicrobial activity against MRSA at MIC value similar to that of streptomycin (250 μg/ml). Furthermore, the antioxidant activity of the different extracts was assessed using DPPH, ABTS and the FRAP assay. The cytotoxicity of the decoction and methanol extracts were also determined using normal adult African green monkey kidney cells (Vero cells). Leaf decoction of P1 showed DPPH radical scavenging activity at an IC50 of 5.30 μg/ml, which was comparable to the positive control, ascorbic acid (IC50: 5.89 μg/ml). Leaf extracts of P1 were better hydrogen donors compared to leaf and fruit extracts of P2. The methanol and decoction extracts of P1L showed low activity against the ABTS cation at an IC50 value of 39.26 and 31.68 μg/ml, respectively. The P2L and P2F extracts were unable to scavenge ABTS cation radicals. The FRAP values for P2L and P2F extracts were in the range of 59.83–120.89 and 23.98–90.71 TE μM, respectively. Decoction and methanol extracts showed no toxicity at the highest concentration tested. In conclusion, data amassed from the present investigation could open new avenues for research and may serve as the basis for the development of novel drugs.https://www.elsevier.com/locate/bab2020-03-01hj2019Plant Production and Soil Scienc

An insight into Cochlospermum planchonii extracts obtained by traditional and green extraction methods: Relation between chemical compositions and biological properties by multivariate analysis

In African traditional medicine Cochlospermum planchonii is used to manage various diseases such as malaria, diarrhoea, jaundice, infections and inflammation, hence presents the potential to be a good source of bioactive compounds. In this study, traditional and green extraction techniques have been used namely green extraction (homogenizer assisted extraction (HAE) and Sonication (SON)) and conventional extraction (Maceration (MAC), and Soxhlet (SOX)). Extracts prepared from aerial parts were studied for the total phenolic, flavonoids, total antioxidant and enzyme inhibitory properties also relating their biological properties and chemical content by multivariate analysis. The total phenolic contents obtained were in the order of HAE (221.78 mg gallic acid equivalent (GAE)/g) > SON (202.64 mg GAE/g) > SOX (190.28 mg GAE/g) > MAC (187.45 mg GAE/g). The highest flavonoid content (rutin equivalent (RE)) was obtained by SOX (65.67 \ub1 0.43 mg rutin equivalent (RE)/g). The highest antioxidant activity was recorded for HAE. C. planchonii extracts showed inhibitory activity against acetylcholinesterase (8.46\u20138.56 mg galantamine equivalent (GALAE)/g), tyrosinase (165.76\u2013171.10 mg kojic acid equivalent (KAE)/g) and \u3b1-amylase (1.18\u20131.30 mmol acarbose equivalent (ACAE)/g) enzymes. It was found that the observed enzyme inhibitory properties was dependent on the type of extraction methods. Only SOX extract presented \u3b1-glucosidase inhibition (21.26 mmol ACAE/g) suggesting potential studies of this extract as antidiabetic. Liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MSn) was used for the qualitative analysis of the samples, allowing the quantification of gallic acid, prodelphynidins and flavonol derivatives. Based on multivariate analysis, green extraction techniques (HAE and SON) were different from conventional techniques (MAC and SOX). Results showed the usefulness of green extraction techniques for obtaining bioactive enriched fractions and tend to highlight the need for additional investigations to fully explore the potential usefulness of C. planchonii as source of antioxidant, antidiabetic and whitening agent as well as cholinesterase inhibitors

Chemical characterization and multidirectional biological effects of different solvent extracts of arum elongatum: in vitro and in silico approaches

Arum elongatum (Araceae) is widely used traditionally for the treatment of abdominal pain, arterial hypertension, diabetes mellitus, rheumatism and hemorrhoids. This study investigated the antioxidant properties, individual phenolic compounds, total phenolic and total flavonoid contents (HPLC/MS analysis), reducing power and metal chelating effects of four extracts obtained from A. elongatum (ethyl acetate (EA), methanol (MeOH), methanol/water (MeOH/water) and infusion). The inhibitory activity of the extracts were also determined against acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase and glucosidase enzymes. The MeOH/water extracts contained the highest amount of phenolic contents (28.85 mg GAE/g) while the highest total flavonoid content was obtained with MeOH extract (36.77 mg RE/g). MeOH/water demonstrated highest antioxidant activity against DPPH⋅ radical at 38.90 mg Trolox equivalent per gram. The infusion extract was the most active against ABTS+⋅ (133.08 mg TE/g). MeOH/water extract showed the highest reducing abilities with the CUPRAC value of 102.22 mg TE/g and the FRAP value of 68.50 mg TE/g. A strong metal chelating effect was observed with MeOH/water extract (35.72 mg EDTAE/g). The PBD values of the extracts ranged from 1.01 to 2.17 mmol TE/g. EA extract displayed the highest inhibitory activity against AChE (2.32 mg GALAE/g), BChE (3.80 mg GALAE/g), α-amylase (0.56 mmol ACAE/g) and α-glucosidase (9.16 mmol ACAE/g) enzymes. Infusion extract was the most active against tyrosinase enzyme with a value of 83.33 mg KAE/g. A total of 28 compounds were identified from the different extracts. The compounds present in the highest concentration were chlorogenic acids, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, isoquercitrin, delphindin 3,5-diglucoside, kaempferol-3-glucoside and hyperoside. The biological activities of A. elongatum extracts could be due to the presence of compounds such as gallic acid, chlorogenic acids, ellagic acid, epicatechin, catechin, kaempferol, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, quercetin, isoquercitrin, and hyperoside. Extracts of A. elongatum showed promising biological activities which warrants further investigations in an endeavor to develop biopharmaceuticals