The Phytochemistry, Ethnomedicinal and Pharmacology Uses of Justicia carnea Lindl Used in Traditional medicine in Nigeria- A Review

Aim: Justicia carnea has been used in traditional medicine in Nigeria in the treatment and management of various diseases which include inflammation, cancer, malaria, sickle cell disease, gastrointestinal infections, anemia, HIV, diabetes, diarrhea, typhoid, liver diseases, hepatitis, cough, etc. This review is aimed at checking the relationship between the ethnomedicinal uses, the phytochemistry and pharmacological activities of Justicia carnea so as to unveil opportunities for future research.

Methods: A search for relevant information on Justicia carnea was performed on scientific databases (Scopus, Google Scholar, Pubmed, SciFinder, PubChem, Web of Science, and other web sources such as The Plant List, Kew Botanical Garden, and PROTA) and books.

Results: Extracts of the J. carnea have been reported to have been used in various traditional medicines in treating various diseases. Preliminary phytochemical analyses of extracts of the plant revealed the presence of various secondary metabolites such as flavonoids, tannins, saponins, alkaloids, phenols, terpenoids. The presence of these metabolites was responsible for the anti-anemic, anti-cancer, anti-diabetic, and antioxidant properties shown by the plant. The aqueous leaf extract of J. carnea having high phenolic and flavonoids contents was able to show antioxidant capacity and also inhibited α-amylase activity (IC50, 671.43±1.88 μg/mL). Also, both methanol and ethanol leaf extracts showed significant in vivo reduction in blood glucose levels. The ethanol leaf extract at 500 mg/kg and 1000 mg/kg showed a significant increase in Packed Cell Volume, Red blood cell (RBC), Hemoglobin (Hb) and white blood cell (WBC) counts. Aqueous and ethanol leaf extracts of J. carnea have been reported to be relatively safe, though the methanol leaf extract was said to distort both the kidney and liver by showing infiltration of interstitial tissue with inflammatory cells and the portal vein were congested with blood cells, microvesicular steartosis and cytoplasm were replaced with fatty cells with the nuclei being centrally placed respectively.

Conclusion: J. carnea is a potential anti anemic, antioxidant, antidiabetic, hepatoprotective agent, which confirmed its uses in treating hepatitis, sickle cell disease, diabetes etc. Further research on isolation and determination of the activities of the metabolites in vivo and in vitro, establishing their mechanisms of action is necessary.