Annona muricata, also called soursop, is widespread in many tropical countries, and various parts of the plant have been shown to possess very good pharmacological properties. This work evaluated the chemical composition and antioxidant activities of essential oils obtained from the fruit pulp and leaves of soursop. Essential oils were obtained via hydrodistillation and characterized by gas chromatography-mass spectrometry. Antioxidant potential was evaluated via the phosphomolybdenum, hydrogen peroxide scavenging, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assays. In the leaf essential oil, a total of 31 compounds were identified withδ-cadinene (22.58%) andα-muurolene (10.64%) being the most abundant. Thirty-two compounds were identified in the fruit pulp essential oil with Ç-sitosterol (19.82%) and 2-hydroxy-1-(hydroxymethyl) ethyl ester (13.48%) being present in high amounts. Both essential oils showed very good total antioxidant capacities (49.03 gAAE/100 g and 50.88 gAAE/100 g for fruit pulp and leaf essential oils, respectively). The IC50values from the DPPH assay were 244.8 ± 3.2 μg/mL for leaf essential oil and 512 ± 5.1 μg/mL for the fruit pulp essential oil. At 1 mg/mL, hydrogen peroxide scavenged was below 50% for both leaf and fruit pulp essential oils, indicating moderate activity. These results suggest possible application of the essential oils ofAnnona muricatain food preservation and processing.
The ongoing global pandemic caused by the human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has infected millions of people and claimed hundreds of thousands of lives. The absence of approved therapeutics to combat this disease threatens the health of all persons on earth and could cause catastrophic damage to society. New drugs are therefore urgently required to bring relief to people everywhere. In addition to repurposing existing drugs, natural products provide an interesting alternative due to their widespread use in all cultures of the world. In this study, alkaloids from Cryptolepis sanguinolenta have been investigated for their ability to inhibit two of the main proteins in SARS‐CoV‐2, the main protease and the RNA‐dependent RNA polymerase, using in silico methods. Molecular docking was used to assess binding potential of the alkaloids to the viral proteins whereas molecular dynamics was used to evaluate stability of the binding event. The results of the study indicate that all 13 alkaloids bind strongly to the main protease and RNA‐dependent RNA polymerase with binding energies ranging from ‐6.7 to ‐10.6 kcal/mol. In particular, cryptomisrine, cryptospirolepine, cryptoquindoline, and biscryptolepine exhibited very strong inhibitory potential towards both proteins. Results from the molecular dynamics study revealed that a stable protein‐ligand complex is formed upon binding. Alkaloids from Cryptolepis sanguinolenta therefore represent a promising class of compounds that could serve as lead compounds in the search for a cure for the corona virus disease.
The incidence of antimicrobial resistance among microbial communities is a major threat to global health care and security. Landfills, which are reservoirs for many pharmaceuticals, provide a conducive habitat for antimicrobial-resistant microbes and resistant gene transfer and are therefore a major contributor to the phenomenon of antimicrobial resistance. Hence, this study determined the levels of three widely used antibiotics, metronidazole, penicillin, and amoxicillin, and the occurrence of antimicrobial resistance amongst microbes in soil and leachate samples from active and abandoned landfill sites in Kumasi, Ghana. Soil samples were collected from one active and four abandoned landfills, while leachate specimen was collected only from the active landfill. Sonication and solid-phase extraction (SPE) were used for sample preparation, followed by analysis via an HPLC-PDA method. Isolation and characterization of bacteria were done using standard bacteriological techniques. Antibiotic susceptibility testing was determined following the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Antibiotics were detected at very high concentrations in the specimen collected from both active and abandoned landfill sites. For leachate samples obtained from Dompoase, penicillin was present at the highest concentration (67.42 ± 5.35 μg/mL, ) followed by metronidazole (18.25 ± 7.92 μg/mL) and amoxicillin (10.96 ± 6.93 μg/mL). In general, the levels of antibiotics in soil samples were similar at both active and abandoned landfill sites. Nonetheless, as with leachates, penicillin levels were much higher () than levels of amoxicillin and metronidazole within any particular site. When screened against some antibiotics, Enterobacteriaceae and some Bacillus and Listeria species isolated from the soil and leachate samples proved to be resistant. The high levels of antibiotics coupled with the presence of resistant microbes at these landfills sites call for immediate measures to halt the disposal of pharmaceuticals in the environment so as to avert any possible public health setback.
The presence of five antibiotics (metronidazole, ciprofloxacin, amoxicillin, doxycycline, and chloramphenicol) and four analgesics (diclofenac, ibuprofen, paracetamol, and caffeine) were investigated in water and soil samples from the Sunyani municipality, Ghana. Liquid samples were collected from hospital effluents, sachet drinking water, municipal waterworks, river Tano, and dumpsite leachates, while soil samples were collected from dumpsites and municipal waterworks. All samples were prepared using solid-phase extraction (SPE) and analyzed via an HPLC- PDA method. All antibiotics analyzed, apart from metronidazole, were detected either in soil or water samples. Doxycycline and ciprofloxacin were present in almost all liquid samples. The investigated hospital effluents had antibiotic concentrations of up to 2.93 mg/L for doxycycline and 4.74 mg/L for ciprofloxacin. The highest concentration of any antibiotic found was 8.76 mg/L of amoxicillin in hospital effluents. The maximum concentration of analgesics in liquid samples analyzed was 3.20 mg/L (paracetamol) and 3.00 mg/kg (caffeine) in soil samples. Ecological risk assessment indicated that the pharmaceuticals pose a possible risk to some aquatic organisms. The findings from this study showed the presence of these pharmaceuticals at concentrations that could impact the ecosystem. Consistent monitoring of environmental levels and pursuing the development and implementation of a suitable remediation program is needed.
The use of organochlorine pesticides has been banned worldwide due to their toxicities. However, some farmers use them illegally because of their potency. The aim of this study was to assess the level of organochlorine pesticide (OCP) residues and the potential health risk associated with vegetables, soil, and groundwater obtained from farms in Ayigya, Nsenie, Gyenyase, and Kentinkrono in Kumasi, Ghana. A total of 15 samples were analyzed using a gas chromatograph equipped with an electron capture detector. The highest mean concentration of 184.10 ± 12.11 µg/kg was recorded for methoxychlor in cabbage from Ayigya. Beta-hexachlorocyclohexane (beta-HCH) recorded the lowest mean concentration of 0.20 ± 0.00 µg/kg in cabbage from Ayigya. The combined risk index showed significant health risk to children than adults. The soil samples mainly contained methoxychlor followed by dichlorodiphenyltrichloroethane (DDT), aldrin, and other OCPs. Concentrations of total HCHs, total DDTs, and total OCPs in the soil samples ranged from <0.01 to 49.00, <0.01 to 165.81, and 10−6, posing a potentially serious cancer risk to consumers. Moreover, the hazard quotients (HQs) of aldrin exceeded the threshold value of one, indicating that daily exposure is a potential concern.
Unpleasant side effects associated with prolonged use of current anti-inflammatory drugs have necessitated a need for new drugs with limited side effects. Plants rich in antioxidants have been suggested as potential sources of anti-inflammatory compounds. Thus, the anti-inflammatory and antioxidant activities of extracts of Reissantia indica, Grosseria vignei and Cissus cornifolia—medicinal plants with widespread use in folkloric medicine in Ghana—were evaluated in this study. The phytochemical composition and total phenolic content (TPC) of these extracts were determined using standard methods. Antioxidant potential was screened using the ferric reducing antioxidant activity, nitric oxide and hydrogen peroxide scavenging, and the phosphomolybdenum assays. The anti-inflammatory activities were evaluated using an in vivo assay. Alkaloids, flavonoids, terpenoids, glycosides and coumarins were present in extracts of all three plants. The TPC of Reissantia indica (38.44 µg/g GAE) was twice that of Grosseria vignei (19.12 µg/g GAE) whereas Cissus cornifolia (7.59 µg/g GAE) had the lowest TPC. In all antioxidant tests, activities of the plant extracts varied in the order; Reissantia indica > Grosseria vignei > Cissus cornifolia, which was in agreement with the TPC data. All extracts exhibited potent anti-inflammatory activities, with the dose of extract required to cause half-maximal reduction in edema (ED50) below 80 mg/kg. Reissantia indica was the most potent anti-inflammatory extract with an ED50 of 47.23 mg/kg. The ethanol extracts of Reissantia indica, Grosseria vignei, and Cissus cornifolia thus exhibited potent anti-inflammatory and antioxidant activities and may be important sources of novel antioxidant and anti-inflammatory agents.