Polyphenolic compounds with anti-tumour potential from Corchorus olitorius (L.) Tiliaceae, a Nigerian leaf vegetable

Pharmacological and phytochemical biodiversity of Corchorus olitorius

Corchorus olitorius L. is a nutritious green leafy vegetable that is eaten as a viscous soup in African and Middle Eastern cultures. The purpose of this review is to highlight the nutritional and nutraceutical potential of this plant. The leaves of C. olitorius are rich providers of minerals as calcium and iron in addition to vitamins B1, B2, folic acid C and E. The leaves contain numerous compounds having several biological effects including antidiabetic and antioxidant properties. Besides, the leaves comprise other phytochemicals such as cardiac glycosides, terpenes, flavonoids, fatty acids, hydrocarbons and phenolics. Various extracts of C. olitorius were shown to exhibit antioxidant, anti-inflammatory, hepatoprotective, antihyperlipidemic, immunostimulant, antitumor, antimicrobial, antidiabetic, analgesic, wound-healing properties and cardioprotective activities.

A Comprehensive Review of C. capsularis and C. olitorious: A Source of Nutrition, Essential Phytoconstituents and Pharmacological Activities

Plant bioactive compounds have gained global significance in terms of both medicinal and economic ramifications due to being easily accessible and are believed to be effective with fewer side effects. Growing relevant clinical and scientific evidence has become an important criterion for accepting traditional health claims of medicinal plants and also supports the traditional uses of Corchorus as folk medicine. C. capsularis and C. olitorius have broad applications ranging from textile to biocomposite, and young leaves and shoots are used as healthy vegetables and have long been used as traditional remedies for fever, ascites, algesia, liver disorders, piles, and tumors in many cultures. This review systematically summarized and emphasized the nutritional attributes, mostly available bioactive compounds, and biological and potential pharmaceutical properties of C. capsularis and C. olitorius, disclosed to users and non-users. Results suggest that various phytochemicals such as cardiac glycosides, phenols, flavonoids, sterols, lipids, and fatty acids were found or analytically identified in different plant parts (leaf, stem, seed, and root), and many of them are responsible for pharmacological properties and their antitumor, anticancer, antioxidant, antinociceptive, anti-inflammatory, analgesic, antipyretic, antiviral, antibacterial, anticonvulsant, antidiabetic and antiobesity, and cardiovascular properties help to prevent and cure many chronic diseases. In addition to their use in traditional food and medicine, their leaves have also been developed for skin care products, and some other possible uses are described. From this review, it is clear that the isolated compounds of both species have great potential to prevent and treat various diseases and be used as functional foods. In conclusion, this comprehensive review establishes a significant reference base for future research into various medical and functional food applications.

Anthelmintic activity and non-cytotoxicity of phaeophorbide-a isolated from the leaf of Spondias mombin L

ETHNOPHARMACOLOGICAL RELEVANCE

Helminthosis (worm infection) is a disease of grazing livestock, with significant economic implications. Increasing resistance to existing synthetic anthelmintics used to control helminthosis and the unwanted presence of residues of the anthelmintics reported in meat and dairy products present a serious global health challenge. These challenges have necessitated the development of novel anthelmintics that could combat drug resistance and exhibit better safety profiles. Spondias mombin L. (Anacardiaceae) is a plant that has been used traditionally as a worm expeller.

AIM OF STUDY

The aim of the work reported herein was to isolate and characterise anthelmintic compound(s) from S. mombin leaf, establishing their bioactivity and safety profile.

MATERIALS AND METHODS

Adult Haemonchus placei motility assay was used to assess anthelmintic bioactivity. Bioassay-guided chromatographic fractionation of acetone extract of S. mombin leaf was carried out on a silica gel stationary phase. The structure of the compound was elucidated using spectroscopy (¹H and ¹³C NMR) and Liquid Chromatography-Mass Spectrometry (LC-ESI-MS). Screening to exclude potential cytotoxicity against mammalian cells (H460, Caco-2, MC3T3-E1) was done using alamar blue (AB) and CellTitreGlo (CTG) viability reagents.

RESULTS

The acetone extract yielded an active fraction 8 (Ethyl acetate: methanol 90:10; anthelmintic LC₅₀: 3.97 mg/mL), which yielded an active sub-fraction (Ethyl acetate: Methanol 95:5; anthelmintic LC₅₀: 53.8 μg/mL), from which active compound 1 was isolated and identified as phaeophorbide-a (LC₅₀: 23.0 μg/mL or 38.8 μM). The compound was not toxic below 200 μM but weakly cytotoxic at 200 μM.

CONCLUSIONS

Phaeophorbide-a (1) isolated from S. mombin leaf extract and reported in the plant for the first time in this species demonstrated anthelmintic activity. No significant toxicity to mammalian cells was observed. It therefore represents a novel anthelmintic pharmacophore as a potential lead for the development of novel anthelmintics.

Potential inhibitors of angiotensin converting enzyme 2 receptor of COVID-19 by Corchorus olitorius Linn using docking, molecular dynamics, conceptual DFT investigation and pharmacophore mapping

A novel coronavirus, previously designated 2019-nCoV, was identified as the cause of a cluster of pneumonia cases in Wuhan, a city in the Hubei Province of China, at the end of 2019. Our objective focuses on the in silico study to screen for an alternative drug that can block the activity of the angiotensin converting enzyme 2 (ACE2), which is a key protein in the physiology of Covid-19, necessary for the entry of the SARS-Cov-2 virus into the host's cells using natural compounds especially phenolic antioxidants, polyphenolics and pharmaceutically phytochemicals derived from the leaves of Corchorus olitorius Linn, appear to be very potential in controlling virus-induced infection. The results of the docking simulation revealed that méthyl-1,4,5-tri-O-caféoyl quinate has a stronger bond, high affinity and gives the best docking scores compared to, the co-crystallized inhibitor (PRD_002214) of the enzyme ACE2, chloroquine, hydroxychloroquine, captopril and simerprevir antiviral drugs. The ADMET properties, Pharmacokinetics and Medicinal Chemistry & P450 site of metabolism prediction, pharmacophore Mapper enzyme revealed that the compound méthyl-1,4,5-tri-O-caféoyl quinate generates a hypothesis which can be applied successfully in biological screening for further experiments. The novel MD computational technique study showed better conformational movements result for the méthyl-1,4,5-tri-O-caféoyl quinate-ACE2 docked complex. Therefore méthyl-1,4,5-tri-O-caféoyl quinate may be considered to be potential inhibitor of the main protease enzyme of virus, but need to be investigated in vivo and in vitro for further drug development process.Communicated by Ramaswamy H. Sarma.

Isolation and Characterisation of Two Quercetin Glucosides with Potent Anti-Reactive Oxygen Species (ROS) Activity and an Olean-12-en Triterpene Glucoside from the Fruit of Abelmoschus esculentus (L.) Moench

Abelmoschus esculentus (Okra) is used in the traditional treatment of cancer, hyperlipidaemia and hyperglycaemia. We, therefore, investigated its composition and potential cytotoxic or antioxidant properties that might underlie its phytotherapeutic applications. Its methanolic fruit extract yielded compounds 1, 2 and 3, identified through NMR, UV and MS analyses as olean-12-en-3-O-β-d-glucopyranoside, isoquercitrin (quercetin glucoside) and 5,7,3',4'-tetrahydroxy-flavonol-3-O-[β-d-glucopyranosyl-(1→6)]-β-d-glucopyranoside (quercetin diglucoside), respectively. Following 48 h exposure, oleanene glucoside was mildly toxic to the HeLa and the MRC5-SV2 cancer cells, isoquercitrin was not toxic except at 100 μg/ml in HeLa, and quercetin diglucoside elicited no toxicity. In a 2',7'-dichlorofluorescein diacetate (DCFDA) assay of intracellular levels of reactive oxygen species (ROS), hydrogen peroxide increased ROS levels, an effect not affected by oleanene glucoside but protected against by isoquercitrin and quercetin diglucoside, with IC₅₀ values, respectively, of 2.7±0.5 μg/ml and 1.9±0.2 μg/ml (3 h post-treatment) and 2.0±0.8 μg/ml and 1.5±0.4 μg/ml (24 h post-treatment.) This is the first report of this oleanene skeleton triterpenoid in the plant. The work provides some insight into why the plant is included in remedies for cancers, cardiovascular complications and diabetes, and reveals it as a potential source of novel therapeutics.

Cornusglucosides A and B, Two New Iridoid Glucosides from the Fruit of Cornus officinalis

Phytochemical study on the fruit of Cornus officinalis Sieb. et Zucc. yielded two new iridoid glucosides, named cornusglucoside A (1) and cornusglucoside B (2). The structures of 1 and 2 were elucidated via comprehensive NMR and HR-ESI-MS data analysis. Additionally, their inhibitory effects on IL-6-induced STAT3 activation were assessed.