Khaya grandifoliola C. DC. (Meliaceae: Sapindales): Ethnobotany, phytochemistry, pharmacological properties, and toxicology

Hydro-ethanolic extract of Khaya grandifoliola attenuates heavy metals-induced hepato-renal injury in rats by reducing oxidative stress and metals-bioaccumulation

People living in developing countries are exposed to hepato-renal injuries induced by heavy metals like lead (Pb), cadmium (Cd), and mercury (Hg) since drinking water supplied is often polluted with a high concentration of those metals. Accordingly, it is necessary to search for antidotes against heavy metals poisoning. Hence, medicinal plants bearing anti-hepatotoxic properties represent a credible option; and such plant is Khaya grandifoliola. However, there is a paucity of knowledge regarding its protective effect on heavy metals-induced hepato-renal toxicity. Thus, this study was designed to assess the protective effect of the hydro-ethanolic stem bark extract of K. grandifoliola (HKG) against hepato-renal injuries induced by chronic consumption of drinking water containing high contents of Pb, Cd, and Hg; in addition to the investigation of the chemical antioxidant properties of HKG. For the antioxidant assays, HKG was tested as a potential inhibitor of lipid peroxidation, reducer of ferric and phosphomolybdenum, and scavenger of hydroxyl and 2,2-Diphenyl-Picryl-Hydrazyl radicals. Its protective effects were evaluated by daily co-treating rats with heavy metals solution (10 mL/kg b.w) containing 0.9, 0.58, and 1.13 ppm respectively for Pb, Cd and Hg and HKG (25 or 100 mg/kg b.w) for five consecutive months; and biochemical parameters associated to liver and kidneys functions, oxidative stress and metals bioaccumulation were assessed. HKG displayed a strong antioxidant capacity (IC50/EC50 range 3.95–17.17 μg/mL) correlated to its polyphenols content and comparable to that of Ascorbic acid. Serum levels of alkaline phosphatase, alanine/aspartate aminotransferase, and creatinine; renal and hepatic content of Cd and Pb, malondialdehyde and glutathione, activities of superoxide dismutase and catalase showed the protective effect of HKG, further evidenced by histopathological analysis. Taking together, these results demonstrated that HKG alleviates heavy metals-induced hepato-renal injuries in rats by reducing oxidative stress and metals-bioaccumulation.

Plants extracts from Cameroon pharmacopeia strongly inhibit the Chikungunya virus infection by targeting entry and replication steps

ETHNOPHARMACOLOGICAL RELEVANCE

Cameroon is one of the sub-Saharan African countries affected by Chikungunya virus (CHIKV). With the absence of approved treatment, this disease represents globally a major public health concern. Several plants are traditionally used in Cameroon for the treatment of virus induced fever and arthralgia. But to date there is no study that validate the efficacy of these plants for the treatment of Chikungunya virus infection.

AIM OF THE STUDY

This study aims to explore the inhition effect, mechanism of action of plant extracts against Chikungunya virus.

MATERIAL AND METHODS

An ethnobotanical survey conducted in some regions of Cameroon, led to the identification of nine medicinal plants used in traditional medicine for the healing of fever-related diseases and arthritis. Crude hydro-ethanolic extracts of each plant were prepared by maceration and their effects against CHIKV infection were investigated. CHIKV S27 strain was used to infection in Vero cell line. The antiviral activities were determined by plaque assay and/or RT-PCR targeting E1 envelope gene of CHIKV. Dose-response studies of the active plants were also determined by flow cytometry and Western blot.

RESULTS

Four extracts, Entada africana Guill et Pers. (E4), Entandrophragma cylindricum Sprague (EI), Khaya grandifoliola C. D.C. Sapindales (E2) and Macaranga hurifolia Beille (E6) showed antiviral activity with the half-maximal inhibitory concentration of 8.29; 8.14; 12.81 and 26.89 μg/mL respectively. All extracts were nontoxic up to the concentration of 100 μg/μL. Entandrophragma cylindricum Sprague (EI), Khaya grandifoliola C. D.C. Sapindales (E2), and Entada africana Guill et Pers. (E4) showed strong inhibition on the entry step of viral infection. At the same time, only Entandrophragma cylindricum Sprague (EI) inhibited the viral titer significantly in replication and intercellular assembly steps. Four plant extracts namely Entandrophragma cylindricum Sprague (EI), Macaranga hurifolia Beille (E6), Phragmentera capitata (Sprengel) Balle (E12), and Detarium microcarpum (E13) were effective against egression step.

CONCLUSIONS

Together, the results of this study showed anti-chikungunya activities of Entandrophragma cylindricum Sprague (EI) and Macaranga hurifolia Beille (E6), with therapeutics perspectives and can be promising sources of the development of anti-CHIKV molecule in future.

Insecticidal Triterpenes in Meliaceae: Plant Species, Molecules, and Activities: Part II (Cipadessa, Melia)

Plant-originated triterpenes are important insecticidal molecules. Research on the insecticidal activity of molecules from Meliaceae plants has always been a hotspot due to the molecules from this family showing a variety of insecticidal activities with diverse mechanisms of action. In this paper, we discussed 116 triterpenoid molecules with insecticidal activity from 22 plant species of five genera (Cipadessa, Entandrophragma, Guarea, Khaya, and Melia) in Meliaceae. In these genera, the insecticidal activities of plants from Entandrophragma and Melia have attracted substantial research attention in recent years. Specifically, the insecticidal activities of plants from Melia have been systemically studied for several decades. In total, the 116 insecticidal chemicals consisted of 34 ring-intact limonoids, 31 ring-seco limonoids, 48 rearranged limonoids, and 3 tetracyclic triterpenes. Furthermore, the 34 ring-intact limonoids included 29 trichilin-class chemicals, 3 azadirone-class chemicals, and 1 cedrelone-class and 1 havanensin-class limonoid. The 31 ring-seco limonoids consisted of 16 C-seco group chemicals, 8 B,D-seco group chemicals, 4 A,B-seco group chemicals, and 3 D-seco group chemicals. Furthermore, among the 48 rearranged limonoids, 46 were 2,30-linkage group chemicals and 2 were 10,11-linkage group chemicals. Specifically, the 46 chemicals belonging to the 2,30-linkage group could be subdivided into 24 mexicanolide-class chemicals and 22 phragmalin-class chemicals. Additionally, the three tetracyclic triterpenes were three protolimonoids. To sum up, 80 chemicals isolated from 19 plant species exhibited antifeedant activity toward 14 insect species; 18 chemicals isolated from 17 plant species exhibited poisonous activity toward 10 insect species; 16 chemicals isolated from 11 plant species possessed growth-regulatory activity toward 8 insect species. In particular, toosendanin was the most effective antifeedant and insect growth-regulatory agent. The antifeedant activity of toosendanin was significant. Owing to its high effect, toosendanin has been commercially applied. Three other molecules, 1,3-dicinnamoyl-11-hydroxymeliacarpin, 1-cinnamoyl-3-methacryl-11-hydroxymeliacarpin, and 1-cinnamoyl-3-acetyl-11-hydroxymeliacarpin, isolated from Meliaazedarach, exhibited a highly poisonous effect on Spodoptera littoralis; thus, they deserve further attention.

Wandering through southwestern Nigeria: An inventory of Yoruba useful angiosperm plants

This paper is a compilation of all known uses of angiosperm plants by the Yoruba people of southwestern Nigeria. Information was gathered from the past experiences of authors and surveys of books, journal articles, dissertations (published and unpublished) and theses using online databases. The review presents 493 angiosperm species (65 monocots and 428 dicots) belonging to 99 families, of which Fabaceae contributed the highest number of useful plants (72 spp.), followed by Euphorbiaceae (31 spp.), Malvaceae (30 spp.), and Asteraceae (25 spp.). Generally, of the identified plants, 418 species are for medicinal purposes, 85 species are utilized as food and beverages, 65 species for other uses including games, food packaging, and arts and crafts while 22 species are used for magical purposes such as success charm, enhancing disappearance, protection from witches and escaping from the repercussion of an act. This study provides baseline ethnobotanical data for future quantitative analyses of useful plants in the region, as indigenous plant knowledge has not been properly explored and documented among the Yoruba people.

Which Plants for What Ailments: A Quantitative Analysis of Medicinal Ethnobotany of Ile-Ife, Osun State, Southwestern Nigeria

Studies on medicinal ethnobotany in rural areas and communities are important for documentation and generation of indigenous knowledge on the medicinal use of plants, as well as identification of new botanicals of pharmacological significance. This paper presents, for the first time, the quantitative ethnobotanical uses of medicinal plants in Ile-Ife, Osun State, Nigeria. The ethnobotanical survey was carried out by conducting semistructured interviews with 70 informants/collaborators. Data were analyzed using various quantitative indices, namely, Ethnobotanical Knowledge Index (EKI), Species Popularity Index (SPI), Relative Frequency of Citation (RFC), Cultural Importance Index (CII), Informant Consensus Factor (FIC), Fidelity Level (FL), and Species Therapeutic Index (STI). A total of 87 plant species belonging to 43 families were documented along with their medicinal uses. Euphorbiaceae is the most implicated family (9%) of the plants documented, and herbs (36%) were the prevalent life form while leaf (46%) was the most used plant part. Fevers are the most common diseases treated with the medicinal plants with 1012 use-reports, followed by skin diseases with 314 use-reports while the most common mode of preparation is decoction (37%). Telfaria occidentalis has the highest SPI and RFC (0.99, 0.99) while Khaya grandifoliola has the highest CII of 1.91. The community has EKI of 0.57 indicating a good knowledge of medicinal plants around them. Species such as Citrus aurantifolia, Khaya grandifoliola, and Ocimum gratissimum have high quantitative indices suggesting that they are effective in the treatment of various diseases in the community and therefore should be considered for pharmacological studies to validate their folkloric usages.