Nutritional composition ofGongronema latifoliumandVernonia amygdalina

Moisture Adsorption potentials and energy models of Gongronema latifolium leaves dried in separate environments

Moisture adsorption isotherm potentials and energy models of Gongronema latifolium leaf grits were investigated. Fresh leaves were dried in sun; passive solar dryer and hot air oven, while proximate composition of the dried and fresh leaves were determined using standard laboratory procedure. Equilibrium moisture content (EMC) of the leaf grits was measured using gravimetric static method. Selected mathematical and statistical models were applied on the experimental data to evaluate data fitting. Energy calculations were done based on the mathematical models. The EMCs of the leaf grits directly increased with water activity (aW) at specific temperatures. Adsorption data was better represented by GAB model than others while differential enthalpy decreased as the EMC of the oven sample increased. Differential entropy of all the samples decreased as the EMC increased. The safest monolayer moisture content varied between 7.1036 and 8.0164 gH2O/100 g solid, below 40°C, within relative humidity of 10%-50%. Sun and oven leaf grits adsorbed more moisture than solar sample. Proximate contents of the dried leaves showed higher values for protein and ash. Overall results indicated that the leaf grits when properly packaged could be used as spice or tea powder to manage household nutrient security in addition to the use as therapeutic foods.

A review of the medicinal potentials of plants of the genus Vernonia (Asteraceae)

ETHNOPHARMACOLOGICAL RELEVANCE

The Vernonia genus has about one thousand species and members of the genus are widely used as food and medicine. The aim of this review is to analyze published data on the ethnomedicinal, ethnoveterinary and zoopharmacognostic uses of plants of the Vernonia genus. This will help to identify the state of ethnopharmacological knowledge in regard to this genus and to propose future research priorities.

MATERIALS AND METHODS

The major scientific databases including SciFinder, Sciencedirect, Medline and Google Scholar were queried for information on Vernonia genus using various keyword combinations. The International Plant Name Index was also used to verify the names of species and authors.

RESULTS

A total of 109 Vernonia species were reported in the literature to have medicinal properties. One hundred and five (105) plants were linked to the treatment or management of 44 human diseases or health conditions. Plants of the genus also feature in ethnoveterinary and zoopharmacognostic practices. A total of 12 vernonia species were identified to be used in ethnoveterinary medicine while 2 species are used in self medication practices by chimpanzees and gorillas. In vitro and in vivo research studies reporting the validation of the medicinal properties of some species were also reviewed. One hundred and three bioactive compounds isolated from various Vernonia species were also identified. Vernonia amygdalina was identified as the most frequently used member of the Vernonia genus. The Vernolides, a class of sesquiterpene lactone were identified as the most studied compounds from the genus and show interesting bioactivity in antiplasmodial, antileishmanial, antischistosomial, cytotoxicity, antimicrobial and anti-inflammatory assays.

CONCLUSION

On the basis of results from a combination of in vitro and in vivo efficacy and toxicity studies reported, Vernonia amygdalina holds the most promise for development into a nutraceutical against diabetes and malaria while Vernonia cinerea has potential against cancer and inflammatory conditions. Vernolide A is so far the most promising single agent from a Vernonia species that has potential for development into an anticancer agent. The other Vernonia species and isolated compounds require further studies to ascertain their medicinal potentials.