Can Crude Oil Exploration Influence the Phytochemicals and Bioactivity of Medicinal Plants? A Case of Nigerian Vernonia amygdalina and Ocimum gratissimum.

The Nigerian Niger-Delta crude oil exploration often results in spills that affect indigenous medicinal plant biodiversity, likely changing the phytochemical profile of surviving species, their bioactivity or toxicity. In crude oil-rich Kokori and crude oil-free Abraka, classic examples of indigenous plants occupying the medicine-food interface include Vernonia amygdalina (VAL) and Ocimum gratissimum leaves (OGL). These plants are frequently utilised during pregnancy and in anaemia. To date, no scientific investigation has been reported on the potential changes to the phytochemical or bioactivity of the study plants. To discuss the similarities and dissimilarities in antisickling bioactivity and phytochemicals in VAL and OGL collected from Kokori (VAL-KK and OGL-KK) and Abraka (VAL-AB and OGL-AB), in silico, in vitro and comparative UPLC-QTOF-MS analysis was performed. Nine unique compounds were identified in OGL-KK, which have never been reported in the literature, while differences in antisickling potentials were observed in VAL-KK, OGL-KK and, VAL-AB, OGL-AB. Our findings show that VAL-AB and OGL-AB are richer and more diverse in phytochemicals and displayed a slightly higher antisickling activity than VAL-KK and OGL-KK. Ligand-based pharmacophore modelling was performed to understand the potential compounds better; this study may provide a basis for explaining the effect of crude oil spills on secondary metabolites and a reference for further research.

Spermicidal Constituents of Ethanolic Extract of Sacoglottis gabonensis Stem Bark.

AIM: To isolate the spermicidal constituents of Sacoglottis gabonensis. MATERIALS AND METHODS: The ethanolic extract with partitioned fractions of Sacoglottis gabonensis stem bark were subjected to sperm immobilization assay. The most active EtOAc fraction was further purifi ed by column and Semi-Preparative High Performance Liquid Chromatography to give compounds which were characterized by spectroscopic methods (UV, LC/MS, and NMR). The compound(s) was also tested for sperm immobilization activity. RESULTS: The ethanolic extract showed 100% signifi cant (p < 0.05) sperm immobilization activity at a concentration of 30 mg/mL at 20 s compared to both negative and positive controls. The most active ethyl acetate fraction yielded methyl 3,5-dihydroxy-4-methoxybenzoate, eriodictyol and bergenin. Bergenin had 100% sperm immobilization activity at 20 mg/mL in 60 s which was signifi cant (p < 0.05) also when compared to the positive and negative control while methyl 3,5-dihydroxy- 4-methoxybenzoate, eriodictyol were not active. CONCLUSION: The active spermicidal constituent in Sacoglottis gabonensis stem bark extract is bergenin. However, methyl 3,5-dihydroxy-4-methoxybenzoate and eriodictyol showed no activity. This plant is known for its aphrodisiac action; hence, caution may have to be exercised in its use because of its spermicidal eff ect.

In vitro and in vivo antimicrobial evaluation of alkaloidal extracts of Enantia chlorantha stem bark and their formulated ointments.

The in vitro and in vivo antimicrobial evaluation of the formulated ointment of alkaloidal extract of Enantia chlorantha Oliv. (Annonaceae) was the concern of this study. The alkaloidal fraction of the stem bark extract was formulated into simple ointment using British Pharmacopoeia formula for preparation of simple ointment. Agar diffusion and agar dilution methods were used for the in vitro antimicrobial studies. Ketoconazole 4000 µg/mL and tioconazole cream 1% were used as reference standards while normal saline was used as control. The fungicidal activity kinetics of the plant extract was carried out using selected concentrations of the plant extract against the most sensitive organism (Candida albicans). For the in vivo studies, 25 albino rats weighing between 180-200 g were divided into 5 groups, anesthesized (thiopental sodium 50 mg/kg), infected with overnight culture of Candida albicans and incubated at 37 degrees C for three days to allow for growth of the microorganisms. Each of the five groups was treated on the third day of incubation with different concentrations of the formulated simple ointment (200 mg/mL, 100 mg/kg, 50 mg/mL), tioconazole cream 1% (reference standard) and normal saline control, respectively. The alkaloidal extract exhibited greater zones of inhibition with Candida glabrata and Trichophyton tonsurans while Candida albicans and Trichophyton interdigitali also showed some sensitivity. There was no surviving organism at the end of 240 min at 100 mg/mL concentration with 10(-4) dilution factor. Treatment of the infected rats with the formulated simple ointments (200, 100 and 50 mg/mL) showed that 50 mg/mL ointment had a better percentage reduction in the fungal loads at the end of the experiment when compared with the 200 mg/mL simple ointment as well as the standard tioconazole 1% cream and normal saline treated rats, respectively. The alkaloidal fraction of Enantia chlorantha stem bark as well as the formulated ointment exhibited significant in vitro and in vivo antifungal activities against different species of Candida, dermatophytes and plant fungi.

Cyclotide discovery in Gentianales revisited--identification and characterization of cyclic cystine-knot peptides and their phylogenetic distribution in Rubiaceae plants.

Cyclotides are a unique class of ribosomally synthesized cysteine-rich miniproteins characterized by a head-to-tail cyclized backbone and three conserved disulfide-bonds in a knotted arrangement. Originally they were discovered in the coffee-family plant Oldenlandia affinis (Rubiaceae) and have since been identified in several species of the violet, cucurbit, pea, potato, and grass families. However, the identification of novel cyclotide-containing plant species still is a major challenge due to the lack of a rapid and accurate analytical workflow in particular for large sampling numbers. As a consequence, their phylogeny in the plant kingdom remains unclear. To gain further insight into the distribution and evolution of plant cyclotides, we analyzed ∼300 species of >40 different families, with special emphasis on plants from the order Gentianales. For this purpose, we have developed a refined screening methodology combining chemical analysis of plant extracts and bioinformatic analysis of transcript databases. Using mass spectrometry and transcriptome-mining, we identified nine novel cyclotide-containing species and their related cyclotide precursor genes in the tribe Palicoureeae. The characterization of novel peptide sequences underlines the high variability and plasticity of the cyclotide framework, and a comparison of novel precursor proteins from Carapichea ipecacuanha illustrated their typical cyclotide gene architectures. Phylogenetic analysis of their distribution within the Psychotria alliance revealed cyclotides to be restricted to Palicourea, Margaritopsis, Notopleura, Carapichea, Chassalia, and Geophila. In line with previous reports, our findings confirm cyclotides to be one of the largest peptide families within the plant kingdom and suggest that their total number may exceed tens of thousands.

Combination studies of Eucalyptus torelliana F. Muell. leaf extracts and clarithromycin on Helicobacter pylori.

Helicobacter pylori is a Gram-negative bacillus that is associated with the development of gastritis and peptic ulcer disease (PUD). In Nigeria, leaf extracts of Eucalyptus torelliana F. Muell. are used in traditional medicine to treat PUD and other gastrointestinal ailments. The additive and synergistic effects of E. torelliana leaf extracts, in combination with clarithromycin, were investigated using two types of H. pylori strains (ATCC 43629, ATCC 43579) and four clinical isolates of H. pylori (Ed, A2, G1-1, 5514) in the checkerboard assay and the fractional inhibitory concentration (FIC) index. A time-kill study was also performed on the strain ATCC 43579. The results showed that the E. torelliana extract inhibited the growth of all H. pylori strains, and the addition of one of the isolated active compounds, namely compound 2 (a substituted pyrenyl ester) enhanced the activity of clarithromycin. The minimum inhibitory concentration values of clarithromycin and the botanical compound were reduced twofold (from 0.125 to 0.0625 µg/mL and > 100 to 50 µg/mL respectively). A 100% reduction in CFU/mL of H. pylori ATCC 43579 was observed with the combination of 0.25 µg/mL clarithromycin and 100 µg/mL and 200 µg/mL compound 2 after 3 h of exposure. The results of the investigation showed that the combination of botanical compounds and antibiotics may be beneficial in the treatment of H. pylori infections.

Moringa oleifera Seed at the Interface of Food and Medicine: Effect of Extracts on Some Reproductive Parameters, Hepatic and Renal Histology.

The lipid-rich Seed of Moringa oleifera has been promoted as an effective water clarifier. Aside its vital nutritional application as an emerging food additive, the seed has continued to gain a wider acceptance in various global ethnomedicines for managing several communicable and lifestyle diseases, howbeit, its potential toxic effect, particularly on fertility and pregnancy outcomes has remained uninvestigated; the effect of Moringa oleifera seed (MOSE) aqueous-methanol extracts on fertility and pregnancy outcome, was investigated in vivo using female Wistar rats that were divided into 50, 100, 300 and 500 mg per kilogram body weight. Group six was given Moringa oleifera seed treated water ad-libitum (ad-libitum group). Organs harvested for histological assessment included ovary, uterus, liver and kidney. In addition to HPLC fingerprint and a preliminary peptide detection, we determined the physico-chemical characteristics and mineral content of MOSE using standard methods. Data were analyzed with significance at p ≤ 0.05. There was no significant difference in the estrus cycle, mating index, gestation survival index, gestation index, fertility index and sex ratio among all groups. Gestation length was reduced in some groups. While the male pup birth weight was comparable among the different groups, female pups birth weights were significantly reduced in 50 and 100 mg groups. Anogenital distance indices of female pups in ad libitum group were significantly increased. Pathologies were observed in liver and kidneys of dams while kidneys of pups presented a dose dependent reduction in the number of glomeruli. There were no observed pathological changes in the ovary and uterus. This study showed for the first time in rodents, that the lipid-rich MOSE is unsafe to the kidney of rodents while the lipid-free MOSE appears to be safe at doses up to 300 mg/kg body weight. Findings from this study suggested that the female pups were masculinized. In conclusion, the lipid-rich seed extracts of MOSE appear to be unsafe during pregnancy, induce hepatic and renal toxicity while the lipid-free MOSE excludes inherent toxicity as the hydrophobic part has been linked to toxicity as observed in this study due to the developmental programming effect on female offspring in rodents.

Anti-sickling activities of two isolated compounds from the root of Combretum racemosum P. beauv. (Combretaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Evaluation of plants such as Combretum racemosum with claimed traditional use in the management of sickle cell anaemia in Nigeria and other parts of West Africa could serve as a useful research strategy in the search for potential anti-sickling drugs and templates. AIM OF THE STUDY: This study aimed at evaluating the antisickling potential of C. racemosum by activity-guided purification and isolation of its active constituents. MATERIALS AND METHODS: Crude methanol extract of the root of C. racemosum and the fractions obtained by partitioning with chloroform, ethyl acetate, and aqueous were investigated for anti-sickling activity against sodium metabisulphite induced sickling of sickle cell haemoglobin (HbSS). Repeated chromatographic separations were conducted on the most active chloroform fraction to purify and isolate bioactive compounds for further tests for anti-sickling activity. The characterization of the isolated compounds was done by mass spectrometry (FD+MS) and nuclear magnetic resonance (1HNMR) spectroscopy. RESULTS: The chloroform fraction (FA) (% sickled erythrocyte ranged from 3.0 to 34.1) exhibited better anti-sickling activity than aqueous (% sickled erythrocyte ranged from 38.9 to 51.5) as well as the crude methanol (% sickled erythrocyte ranged from 19.1 to 30.4). Hence, the phytochemical investigation was focused on the chloroform fraction, which led to the identification of two ellagic acid derivatives (3,3',4'-tri-O-methyl ellagic acid (A) and 3,3'-di-O- methyl ellagic acid (B). The two isolated compounds possessed good, comparable anti-sickling activities with compound A exhibiting a slightly better in vitro activity. CONCLUSION: This paper reports for the first time anti-sickling principles from C. racemosum and therefore, provided some justification for the ethnomedicinal use of the plant in the management of sickle cell disease.

Two new phytoecdysteroids from Sphenocentrum jollyanum Pierre root.

The crude methanol extract of Sphenocentrum jollyanum root exhibited 98% and 80% antimicrobial activity against Aspergillus fumigatus Pinh and Vancomycin resistant enterococcus (VRE) at a concentration of 200 µg/mL, with IC50 11.45 and 12.95 µg/mL, respectively. The ethyl acetate fraction of methanol extract showed in-vitro antimicrobial activity against A. fumigatus Pinh at 83% with IC50 of <8 µg/mL. The phytochemical investigation of ethyl acetate fraction yielded six compounds, which were identified by their NMR, IR and MS spectral analyses as two new phytoecdysteroidal glycosides Sphenocentroside A (1), and Sphenocentroside B (2), and four known phytoecdysteroids: polypodoaurein (3), polypodine B (4), ecdysterone (5), and 20, 26-dihydroxyecdysone (6).

Ethnobotanical survey of Rinorea dentata (Violaceae) used in South-Western Nigerian ethnomedicine and detection of cyclotides.

ETHNOPHARMACOLOGICAL RELEVANCE: People living in the tropical rain forest of South-Western Nigeria use Rinorea dentata (P. Beauv.) Kuntze (Violaceae) in ethno-veterinary medicine to facilitate parturition. There are no evidence-based pharmacological investigations for the uterotonic activity of this plant. AIMS OF STUDY: (i) Collection of data about the ethnopharmacological uses of R. dentata and evaluation of its uses and applications in health care; (ii) determining potential uterotonic effects in vitro, and (iii) chemical characterization of R. dentata, which is a member of the Violaceae family known to express circular cystine-knot peptides, called cyclotides. MATERIALS AND METHODS: The ethnopharmacological use of R. dentata in settlement camps within the area J4 of Omo forest has been investigated by semi-structured questionnaires and open interviews. Use index analysis has been performed by seven quantitative statistical models. Respondents' claim on the beneficial ethno-veterinary application of the plant to aid parturition has been investigated in vitro by myometrial contractility organ bath assays. The bioactive plant extract was screened by chemical derivatization and mass spectrometry-based peptidomics using reversed-phase HPLC fractionation and MALDI-TOF/TOF analysis. RESULTS: Based on the survey analysis, medicinal preparations of R. dentata have been used for anti-microbial and anti-malaria purpose in humans, and for aiding parturition in farm animals. The latter application was mentioned by one out of six respondents who claimed to use this plant for any medicinal purpose. The plant extract exhibited a weak uterotonic effect using organ bath studies. The plant contains cyclotides and the peptide riden A has been identified by de novo amino acid sequencing using mass spectrometry. CONCLUSION: Few dwellers around the settlement camps of the tropical forest of Omo (Nigeria) use R. dentata for various health problems in traditional veterinary and human medicine. The weak uterotonic effect of the cyclotide-rich extract is in agreement with the low use value index obtained for this plant. Cyclotides have been reported in the genus Rinorea confirming the ubiquitous expression of these stable bioactive plant peptides within the family of Violaceae.

Uterine contractility of plants used to facilitate childbirth in Nigerian ethnomedicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Pregnant women in Nigeria use plant preparations to facilitate childbirth and to reduce associated pain. The rationale for this is not known and requires pharmacological validation. AIM OF STUDY: Obtain primary information regarding the traditional use of plants and analyze their uterine contractility at cellular level. MATERIALS AND METHODS: Semi-structured, open interviews using questionnaires of traditional healthcare professionals and other informants triggered the collection and identification of medicinal plant species. The relative traditional importance of each medicinal plant was determined by its use-mention index. Extracts of these plants were analyzed for their uterotonic properties on an in vitro human uterine cell collagen model. RESULT: The plants Calotropis procera, Commelina africana, Duranta repens, Hyptis suaveolens, Ocimum gratissimum, Saba comorensis, Sclerocarya birrea, Sida corymbosa and Vernonia amygdalina were documented and characterized. Aqueous extracts from these nine plants induced significant sustained increases in human myometrial smooth muscle cell contractility, with varying efficiencies, depending upon time and dose of exposure. CONCLUSION: The folkloric use of several plant species during childbirth in Nigeria has been validated. Seven plants were for the first time characterized to have contractile properties on uterine myometrial cells. The results serve as ideal starting points in the search for safe, longer lasting, effective and tolerable uterotonic drug leads.