MEDICINAL USES, BIOLOGICAL AND CHEMICAL PROPERTIES OF WILD GRAPE (LANNEA EDULIS): AN INDIGENOUS FRUIT PLANT OF TROPICAL AFRICA

Lannea edulis is a fruit plant widely used as herbal medicine throughout its distributional range in tropical Africa. This study was aimed at providing a critical review of the biological activities, phytochemistry, and medicinal uses of L. edulis. Documented information on the botany, biological activities, medicinal uses, and phytochemistry of L. edulis was collected from several online sources which included BMC, Scopus, SciFinder, Google Scholar, Science Direct, Elsevier, PubMed, and Web of Science. Additional information on the botany, biological activities, phytochemistry, and medicinal uses of L. edulis was gathered from pre-electronic sources such as book chapters, books, journal articles, and scientific publications sourced from the University library. This study showed that the bark, leaves, rootbark, and roots of L. edulis are used as antiabortifacient and herbal medicine to dilate birth canal, dizziness, sore eyes, sexually transmitted diseases, amenorrhea and dysmenorrhea, malaria, bilharzia, and gastrointestinal problems. Ethnopharmacological research revealed that L. edulis extracts and compounds have anthelmintic, anti-human immunodeficiency virus, antihyperglycemic, antihyperlipidemic, antimalarial, antimicrobial, antioxidant, and cytotoxicity activities. Future studies should focus on conducting detailed phytochemical, pharmacological, and toxicological evaluations of L. edulis crude extracts as well as compounds isolated from the species.


Maroyi
are mixed with seeds of Vigna unguiculata (L.) Walp. as remedies for bilharzia and blood in urine [28,52,53]. In Malawi, the bark of L. edulis is mixed with the bark of Bauhinia thonningii Schum. as herbal medicine for bilharzia [54,55]. The leaves of L. edulis are also used as ethnoveterinary medicine in Tanzania [56].

Anthelmintic activities
Mølgaard et al. [100] evaluated the anthelmintic activities of L. edulis leaf and stem extracts against schistosomules of the trematode Schistosoma mansoni and cysticercoids of the cestode of Hymenolepis

Anti-HIV activities
Sigidi et al. [89] evaluated the anti-HIV activities of aqueous root extract of L. edulis using the reverse transcriptase assay. The extract at a concentration of 50 µg/ml and 100 µg/ml showed inhibition of 20% and 30%, respectively [89].

Antimalarial activities
Gessler et al. [ [102] evaluated the antimicrobial activities of the leaf ethanol and aqueous extracts of L. edulis against E. coli and Salmonella spp. using the microdilution method. The extracts exhibited activities against tested pathogens with MIC value of 10 µm/mL [102].

Antioxidant activities
Queiroz et al.  [99]. Munodawafa [83] evaluated the antioxidant activities of methanol leaf extracts of L. edulis using the DPPH free radical scavenging assay with b-carotene as the positive control. The antioxidant activity of the extract was 93.9 % inhibition which was comparable to 98.6 % inhibition exhibited by the positive control [83].

Toxicity activities
Munodawafa [83] and Munodawafa et al. [104] evaluated toxicity of leaf extract of L. edulis using the brine shrimp lethality test with Nerium oleander L. as a positive control. The extract exhibited median LC 50 value of 971 ± 86 µg/mL which was higher than LC 50 value of 141.7 µg/mL exhibited by N. oleander, the positive control [83,104]. Banda [86] and Banda et al. [98] evaluated the toxicity activities of the aqueous leaf extracts of L. edulis aimed at establishing the median lethal dose (LD 50 ) of the extract in male albino rats at doses of 10 mg/kg, 100 mg/kg, 300 mg/kg, 2000 mg/kg, 5000 mg/kg, and 6000 mg/kg. None of the doses caused death or caused rats to exhibit symptoms of toxicity. The LD 50 value of the extract is, therefore, greater than 6000 mg/kg and falls within the nontoxic range [86,98].

CONCLUSION
L. edulis is a well-known medicinal plant in tropical Africa. In many cases, the different plant parts such as bark, leaves, rootbark, and roots