Garcinia kola: a new look at an old adaptogenic agent

Molecular docking, pharmacophore modelling, MD simulation and in silico ADMET study reveals bitter cola constituents as potential inhibitors of SARS-CoV-2 main protease and RNA dependent-RNA polymerase

A mini survey was employed in the search of herbs and spices which people believe could prevent them from contracting COVID-19. Phytochemicals which have been earlier implicated for the bioactivity of the afore-mentioned herbs and spices were identified through literature search. The phytochemicals were then subjected to pharmacore modelling, molecular docking and molecular dynamics simulation in order to identify phytochemicals that could serve as inhibitors of 3-Chymotryprin-like protease and RNA dependent-RNA polymerase of SARS-CoV-2. The drug-likeness and toxicity profile of the phytochemicals were afterwards predicted via ADMET studies. The mini survey showed ginger, garlic, bitter cola, as the lead-herbs which could find application in anti- COVID-19 therapy. Literature search revealed 27 phytochemicals were implicated for bioactivity of these herbs. Of these 27 phytoconstituents that were docked with 3-chymotrypsin-like protease and RNA dependent-RNA polymerase, the constituents of bitter cola had lower docking scores than other phytochemicals. MD simulation results showed that Garcinia biflavonoid I displayed less comformational changes and the better binding free energy. Also, the garcinia biflavonoids had relatively safe ADMET predictions. Hence, Garcinia biflavonoids and some other constituents of bitter cola could be further modified so as to obtain safe pharmaceutical intervention for the COVID-19 challenge.Communicated by Ramaswamy H. Sarma.

Biphenyls in Clusiaceae: Isolation, structure diversity, synthesis and bioactivity

Clusiaceae plants contain a wide range of biologically active metabolites that have gotten a lot of interest in recent decades. The chemical compositions of these plants have been demonstrated to have positive effects on a variety of ailments. The species has been studied for over 70 years, and many bioactive compounds with antioxidant, anti-proliferative, and anti-inflammatory properties have been identified, including xanthones, polycyclic polyprenylated acylphloroglucinols (PPAPs), benzophenones, and biphenyls. Prenylated side chains have been discovered in many of these bioactive substances. To date, there have been numerous studies on PPAPs and xanthones, while no comprehensive review article on biphenyls from Clusiaceae has been published. The unique chemical architectures and growing biological importance of biphenyl compounds have triggered a flurry of research and interest in their isolation, biological evaluation, and mechanistic studies. In particular, the FDA-approved drugs such as sonidegib, tazemetostat, daclatasvir, sacubitril and trifarotene are closely related to their biphenyl-containing moiety. In this review, we summarize the progress and development in the chemistry and biological activity of biphenyls in Clusiaceae, providing an in-depth discussion of their structural diversity and medicinal potential. We also present a preliminary discussion of the biological effects with or without prenyl groups on the biphenyls.

Comparison between the Biological Active Compounds in Plants with Adaptogenic Properties (Rhaponticum carthamoides, Lepidium meyenii, Eleutherococcus senticosus and Panax ginseng)

BACKGROUND

In the 1960s, research into plant adaptogens began. Plants with adaptogenic properties have rich phytochemical compositions and have been used by humanity since ancient times. However, it is not still clear whether the adaptogenic properties are because of specific compounds or because of the whole plant extracts. The aim of this review is to compare the bioactive compounds in the different parts of these plants.

METHODS

The search strategy was based on studies related to the isolation of bioactive compounds from Rhaponticum carthamoides, Lepidium meyenii, Eleutherococcus senticosus, and Panax ginseng. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

RESULTS

This review includes data from 259 articles. The phytochemicals isolated from Rhaponticum carthamoides, Lepidium meyenii, Eleutherococcus senticosus, and Panax ginseng were described and classified in several categories.

CONCLUSIONS

Plant species have always played an important role in drug discovery because their effectiveness is based on the hundreds of years of experience with folk medicine in different nations. In our view, there is great potential in the near future for some of the phytochemicals found in these plants species to become pharmaceutical agents.

Identification of potential histone deacetylase inhibitory biflavonoids from Garcinia kola (Guttiferae) using in silico protein-ligand interaction

Overactivity of histone deacetylases (HDACs) is the underlying cause of some cancers, thus, inhibiting their overactivities is a rational treatment option. However, endeavors to employ current anti-HDACs agents in cancer treatment have yielded limited success. Consequently, there is need to explore anti-HDACs natural products, especially from plants sources, because of the intimate relationship plant products and drug discovery have enjoyed over the centuries. To identify possible HDACs inhibitors, Garcinia kola (Guttiferae) seed-derived compounds were screened in silico for HDAC-inhibitory tendencies because of their reported anticancer potentials. Fifteen G. kola-derived compounds and givinostat were docked with five selected HDACs using AutodockVina, while the binding interactions of the compounds with high binding affinities for the five HDACs were viewed with Discovery Studio Visualizer BIOVIA, 2016. Results indicated that four of the compounds studied, including amentoflavone, Garcinia biflavonoid 1, Garcinia biflavonoid 2 and kolaflavanone have higher binding propensity for all the five HDACs relative to givinostat, the standard HDAC inhibitor. This study indicated that inhibition of HDAC might be another key mechanism accountable for the bioactivities of G. kola and its intrinsic compounds. The results from this study implied that the compounds could be further investigated as drugable HDAC inhibitors with potential pharmacological applications in the treatment of cancers.

Garcinoic Acids and a Benzophenone Derivative from the Seeds of Garcinia kola and Their Antibacterial Activities against Oral Bacterial Pathogenic Organisms

In this study, three new garcinoic acid dimers, δ,δ-bigarcinoic acid (1), δ,δ-bi-O-garcinoic acid (2), and γ,δ-bi-O-garcinoic acid (3), and a new benzophenone derivative, (8E)-4-geranyl-3,5-dihydroxybenzophenone (4), as well as seven known compounds (5-11) were isolated from the seeds of Garcinia kola. The structures of the new compounds were elucidated using MALDI-TOF-MS and spectroscopic data, including 1D and 2D NMR and electronic circular dichroism spectra. All of the isolated compounds were evaluated for their antimicrobial activity against two oral pathogens, Porphyromonas gingivalis and Streptococcus sobrinus. Among them, 4 and δ-garcinoic acid (6) exhibited antimicrobial activity against both of these microorganisms (MICs of 31.3-62.5 μM for P. gingivalis and 15.6-31.3 μM for S. sobrinus). These results indicate that some chemical constituents in G. kola seeds have potential application in the prevention of oral diseases.

Antilisterial Effect of Rosa damascena and Nymphaea alba in Mus musculus

The present study was proposed to investigate the toxicological and prophylactic potential of ethanolic extracts of Rosa damascena and Nymphaea alba and their mixture in albino mice. For toxicity study, three different doses of plant extracts were orally administrated to three groups of mice for 14 successive days. Blood biochemistry and histological examinations of liver and kidney revealed that these extracts had no harmful effects up to 1000 mg/kg. To determine the prophylactic effects of Rosa damascena, Nymphaea alba, and their mixture, an infection model of Listeria monocytogenes was established in a pilot study. Establishment of infection was confirmed by changes in haematological parameters and reisolation of Listeria monocytogenes from different tissues. Results showed that these extracts alone or in combination could restrict the growth of Listeria monocytogenes in different organs. Neutrophils were high in positive control group but remained in normal range in all treated groups. Listeria monocytogenes was recovered in low numbers from animals treated with extract of single plant but was negligible in group treated with mixture of extract of plants. Platelets count was increased in treated groups as compared to control. Results confirmed that these extracts are potent source of antimicrobial compounds and that they have synergistic effect in combined form.

Screening of some medicinal plants from cameroon forβ-Lactamase inhibitory activity

In efforts to find new bioactive beta-lactamase inhibitors, this study investigated 16 Cameroonian plants belonging to 10 families which were evaluated for anti-beta-lactamase activity. The investigation showed that extracts 2, 6, 3 and 5 of the 16 plants investigated presented interesting in vitro beta-lactamase inhibition (over 90%), respectively, of the beta-lactamases TEM-1, OXA-10, IMP-1 and P99. These extracts were from Mammea africana (all beta-lactamases), Garcinia lucida, G. kola (OXA-10, IMP-1 and P99), Bridelia micrantha (OXA-10, P99), Ochna afzelii (OXA-10, P99), Prunus africana (IMP-1) and Adenia lobata (TEM-1). After elimination of tannins (according to the European Pharmacopoeia) the extracts from B. micrantha, G. lucida and M. africana were tested further for their anti-beta-lactamase activity. The extracts from B. micrantha and G. lucida exhibited potent inhibitory activity, respectively, of beta-lactamase OXA-10 (IC(50) = 0.02 mg/mL) and P99 (IC(50) = 0.01 mg/mL). The anti-beta-lactamase activity of M. africana extract was weak. The isolation and the structural elucidation of the active constituents of G. lucida and B. micrantha will provide useful leads in the development of beta-lactamase inhibitors.