Antimicrobial activity of South African medicinal plants.

Recently, considerable attention has been focused on dietary and medicinal phytochemicals that inhibit, reverse or retard diseases caused by oxidative and inflammatory processes. Vernonia amygdalina is a perennial herb belonging to the Asteraceae family. Extracts of the plant have been used in various folk medicines as remedies against helminthic, protozoal and bacterial infections with scientific support for these claims. Phytochemicals such as saponins and alkaloids, terpenes, steroids, coumarins, flavonoids, phenolic acids, lignans, xanthones, anthraquinones, edotides and sesquiterpenes have been extracted and isolated from Vernonia amygdalina. These compounds elicit various biological effects including cancer chemoprevention. Garcinia kola (Guttiferae) seed, known as “bitter kola”, plays an important role in African ethnomedicine and traditional hospitality. It is used locally to treat illnesses like colds, bronchitis, bacterial and viral infections and liver diseases. A number of useful phytochemicals have been isolated from the seed and the most prominent of them is the Garcinia bioflavonoids mixture called kolaviron. It has well-defined structure and an array of biological activities including antioxidant, antidiabetic, antigenotoxic and hepatoprotective properties. The chemopreventive properties of Vernonia amygdalina and Garcinia biflavonoids have been attributed to their abilities to scavenge free radicals, induce detoxification, inhibit stress response proteins and interfere with DNA binding activities of some transcription factors.

https://www.mdpi.com/1660-4601/8/6/2533/pdf

Antioxidative and Chemopreventive Properties of Vernonia amygdalina and Garcinia biflavonoid

Ethnobotanical survey of Akwa Ibom State of Nigeria.

http://www.ethnopharmacologia.org/prelude2016/pdf/biblio-a-39-abo.pdf

Ethnobotanical studies of medicinal plants used in the management of diabetes mellitus in South Western Nigeria.

Background
Over three-quarter of the world's population is using herbal medicines with an increasing trend globally. Herbal medicines may be beneficial but are not completely harmless.

This study aimed to assess the extent of use and the general knowledge of the benefits and safety of herbal medicines among urban residents in Lagos, Nigeria.

/pdf/herbal-medicine-use-among-urban-residents-in-lagos-nigeria-2oxnn4ck0s.pdf

Herbal medicine use among urban residents in Lagos, Nigeria

Bioactive sesquiterpene lactones from the leaves of Vernonia amygdalina.

Aqueous and ethanolic extracts of Ocimum gratissimum and xylopia aethiopica were analyzed for their antimicrobial activities against five pathogenic organisms; Staphylococcus aureus, Escherichia coli, Streptococcus fecalis, Pseudomonas aeruginosa and Lactobacilli. Ethanolic extracts of O. gratissimum had a minimum inhibitory concentration (MIC) of 30 mg/ml against S. aureus, E. coli, P. aeruginosa and lactobacilli while for S. fecalis the MIC was 15 mg/ml. Aqueous extracts of O. gratissimum had an MIC of 12.5 mg/ml against S. aureus, E. coli and S. fecalis, while for P. aeruginosa and lactobacilli the MIC was 6.25 and 25 mg/ml, respectively. Ethanolic extracts of X. aethiopica showed an MIC of 10 mg/ml in the five organisms tested. While its aqueous extract gave an MIC of 30 mg/ml for S. aureus and Lactobacilli, and 15 mg/ml for E. coli, P. aeruginosa and S. fecalis. Our findings suggest that the anti-microbial activity of these spices reside in their aqueous fractions and also indicate that very low concentrations are required to achieve antimicrobial effects.

/pdf/an-ethnobotanical-study-of-plants-used-for-the-treatment-of-30m4odcabo.pdf

An ethnobotanical study of plants used for the treatment of diabetes in the Eastern Cape Province, South Africa

Evaluation of antioxidant activity and the fatty acid profile of the leaves of Vernonia amygdalina growing in South Africa

Vernonia amygdalina Del. (Asteraceae) is a plant widely used both for nutritional and medicinal purposes throughout the tropical Africa. The health-promoting ability of this plant species might be related to the antioxidative effect of its constituents. In this study,the antioxidant activity of this plant was evaluated by comparing the reducing capacity and the DPPH radical scavenging of two previously isolated sesquiterpene lactones (vernolide and vernodalol) with the ethanol extract from which the two compounds were isolated. Results indicated that vernolide had a higher reducing power than vernodalol and the ethanol extract. At 0.25 mg=mL, vernolide had an absorbance value of 0.15 while vernolide and the ethanol extract had absorbencies of 0.042 and 0.144, respectively. Catechin (a standard antioxidant compound), however, exhibited a higher reducing power than all the three samples. In the DPPH radical scavenging, both the sesquiterpene lactones and the ethanol extract exhibited appreciable activity. At 0.25 mg=mL, the activity order was ethanol extract > vernodalol > vernolide. At all concentrations, the ethanol extract had higher radical scavenging activity than the sesquiterpene lactones, suggesting a possible synergistic effect of these and any other antioxidant constituents.

https://www.tandfonline.com/doi/pdf/10.1080/13880200701213070

Antioxidant Constituents in Vernonia amygdalina Leaves

Diabetes mellitus is a chronic disease which affects millions of people worldwide. The prevalence of this disease is increasing annually and the number of diabetics is projected to rise above 300 million before 2025. The growing number of diabetics, coupled with the harsh side effects of some synthetic drugs has led to the increasing search for more natural products of plant origin. Vernonia amygdalina Del. (Asteraceae) is one of the plants commonly used for the treatment of diabetes in Africa. This study evaluated the effect of leaf extracts of this plant on glucose utilization in 3T3-L1, C2C12 muscle, and Chang-liver cells. Treatment of the cells with the acetone, methanol, water, and n-hexane/isopropanol extracts of V. amygdalina leaves significantly increased glucose utilization in the C2C12 muscle and Chang-liver cells but showed no effect on the 3T3-L1 cells. The water and n-hexane/isopropanol extracts were the most active in the C2C12 cells with a response of 78.3 and 95.6% above the control, respe...

P. Erasto

Papers

Bioactive sesquiterpene lactones from the leaves of Vernonia amygdalina.

An ethnobotanical study of plants used for the treatment of diabetes in the Eastern Cape Province, South Africa

Evaluation of antioxidant activity and the fatty acid profile of the leaves of Vernonia amygdalina growing in South Africa

Antioxidant Constituents in Vernonia amygdalina Leaves

Effect of leaf extracts of Vernonia amygdalina on glucose utilization in chang-liver, C2C12 muscle and 3T3-L1 cells