In vitro and In vivo antimycobacterial, hepatoprotective and immunomodulatory activity of Euclea natalensis and its mode of action

Abstract

Ethnopharmacological relevance: The Natal gwarri or Natal ebony (Euclea natalensis A.DC.) is a deciduous tree found widespread throughout southern Africa, especially in Kwazulu-Natal and the southern cost. It has been widely used by indigenous communities such as the Zulus, Tsongas and Vendas for symptoms related to tuberculosis (TB). The decoctions made from the plant parts are administered for chest diseases to treat complications such as chest pains, bronchitis, pleurisy and asthma. TB is prevalent in immune-compromised patients and it is evident that TB-drugs cause hepatotoxicity. The objective of the present study was therefore to evaluate the antimycobacterial activity of the 2 ethanolic extract of E. natalensis against TB and its hepatoprotective and immunomodulatory activities. Materials and methods:The antimycobacterial, antioxidant, hepatoprotective, immunomodulatory activity and cytotoxicity of the ethanolic extract of the shoots of E. natalensis were determined in vitro. The mechanism of action of the antituberculosis activity was determined by investigating the inhibitory effect on mycothiol disulfide reductase enzyme. Furthermore, the acute, sub-acute toxicity (50-2000 mg/kg) and antimycobacterial effect (300 mg/kg) of E. natalensis shoot extract were investigated in Balb/c mice.Hepatoprotective activity of the extract (50-150 mg/kg) was evaluated on isoniazid and rifampicin (50 mg/kg; i.p.) induced hepatic damage in a rat model. Results:The minimum inhibitory concentration of the extract was found to be 125 µg/ml against Mycobacterium tuberculosis. The extracts fifty percent inhibitory concentration (IC 50 ) against 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical was found to be 22.55 µg/ml. The plant showed a hepatoprotective effect (50% at 12.5 µg/ml) and the ability to increase Thelper 1 cell cytokines; Interleukin 12, Interleukin 2 and Interferon α by up to 12 fold and the ability to decrease the T-helper 2 cell cytokine Interleukin 10 4 fold when compared to baseline cytokine production. No cellular toxicity was observed in primary peripheral blood mononuclear cells (PBMC's) and two secondary cell lines; U937 monocytes and Chang liver cells (a derivative of the HepG2 cell line). During mechanistic studies, the extract showed a 50% inhibition of mycothiol reductase activity at 38.62 µg/ml. During the acute and subacute studies, E. natalensis exhibited no toxic effect and the fifty percent lethal dose (LD 50 ) was established to be above 2000 mg/kg. The extract was able to reduce the mycobacterial load (1.5-fold reduction) in infected mice. Isoniazid and rifampicin caused significant hepatic damage in rats, and the extract was able to reduce the toxicity by 15% and 40% at 50 and 150 mg/kg respectively. Conclusion:The present study supports the traditional usage of the plant against tuberculosis symptoms. The study showed the ability of E. natalensis shoot extract to inhibit mycobacterial growth, stimulate an appropriate immune response and have a hepatic protective effect. Due to the ...

Antibacterial and Anticancer Activity of Ethnomedicinal Plants Used in the Jongilanga Community, Mpumalanga

“…The default docking parameters were employed for the docking study. It includes 100,000 genetic operations on a population size of 100 individuals and mutation rate of 95 as used by various recent studies [14][15][16] . The crystal structure of COX-2 from Homo sapiens was taken from the Protein Data Bank (PDB ID: 5IKR) 17 .…”

Inhibition of mycothione disulphide reductase and mycobacterial biofilm by selected South African plants

“…The mixture was filtered and dried using rotary evaporation (Buchi R-200) in order to obtain a crude dried plant extract. The yield was calculated and the plant extracts were stored in glass polytops at 4ºC (Lall et al, 2016).…”

“…This was demonstrated by the higher biological activity seen in the African species Dorstenia mannii Hook.f., when compared to the related European species (Abegaz et al, 2004 and Ziziphus mucronata Willd., to name but a few. These plants exhibited minimum inhibitory concentrations (MIC) less than 200 µg/ml (Dzoyem et al, 2016;Eldeen and Van Staden, 2007;Green et al, 2010;Lall et al, 2016;Lall and Meyer, 1999).…”

Comparative Investigation of Techniques Used for Mtr Homology Model Refinement

“…The homology model building procedure and validation parameters for the refined Mtr homology model have already been reported by Lall et al [29]. Mtr sequence was retrieved from UniProtKB/TrEMBL database (primary accession number A0A0T9 × 864) [34].…”

“…The Mtr refined homology model obtained through LM and template Gtr (1GER) were subjected to validation parameters. The validation statistics and their comparison with data already published for Mtr homology model by Lall et al [29] is given in Table 1.…”