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. 2018 Jul 4:2018:4170372.
doi: 10.1155/2018/4170372. eCollection 2018.

In Vitro Antidiabetic Activity and Mechanism of Action of Brachylaena elliptica (Thunb.) DC

Idowu Jonas Sagbo  1 , Maryna van de Venter  2 , Trevor Koekemoer  2 , Graeme Bradley  1
Affiliations

In Vitro Antidiabetic Activity and Mechanism of Action of Brachylaena elliptica (Thunb.) DC

Idowu Jonas Sagbo et al. Evid Based Complement Alternat Med. .

Abstract

In South Africa, the number of people suffering from diabetes is believed to be rising steadily and the current antidiabetic therapies are frequently reported to have adverse side effects. Ethnomedicinal plant use has shown promise for the development of cheaper, cost-effective antidiabetic agents with fewer side effects. The aim of this study was to investigate the antidiabetic activity and mechanism of action of aqueous leaf extract prepared from Brachylaena elliptica. The potential of the extract for cytotoxicity was evaluated using MTT assay in HepG2 cells. The effects of the plant extract on glucose utilization in HepG2 cells and L6 myotubes, triglyceride accumulation in 3T3-L1, INS-1 proliferation, glucose metabolism in INS-1 cells, and NO production in RAW macrophages were also investigated using cell culture procedures. The inhibitory effects of the extract on the activities of different enzymes including alpha-amylase, alpha-glucosidase, pancreatic lipase, dipeptidyl peptidase IV (DPP-IV), collagenase, and CYP3A4 enzymes were evaluated. The extract also tested against protein glycation using standard published procedure. The plant extract displayed low level of toxicity, where both concentrations tested did not induce 50% cell death. The extract caused a significant increase in glucose uptake in HepG2 liver cells, with efficacy significantly higher than the positive control, berberine. The crude extract also displayed no significant effect on muscle glucose uptake, triglyceride accumulation in 3T3-L1, glucose metabolism in INS-1 cells, alpha-amylase, alpha-glucosidase, DPP-IV, lipase, protein glycation, and collagenase compared to the respective positive controls. The extract displayed a proliferative effect on INS-1 cells at 25 μg/ml when compared to the negative control. The plant also produced a concentration-dependent reduction in NO production in RAW macrophages and also demonstrated weak significant inhibition on CYP3A4 activity. The findings provide evidence that B. elliptica possess antidiabetic activity and appear to exact its hypoglycemic effect independent of insulin.

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Figures

Figure 1
Figure 1
MTT cytotoxicity effect of the aqueous extract of B. elliptica in HepG2 liver cells. Data are expressed as % of control ± SD (n = 4). ∗ indicates a significant increase relative to the untreated control (p < 0.05).
Figure 2
Figure 2
Effect of B. elliptica extract on glucose utilization in HepG2 hepatocytes. Cells were treated for 48 h in the presence or absence of varying concentration of the plant extract. Data expressed as mean ± SD (n = 4). ∗ indicates a significant increase relative to the untreated control (p < 0.05). (#) indicates a significant increase relative to the positive control (berberine) (p < 0.05). No significant increase relative to the metformin (positive control) was noted.
Figure 3
Figure 3
Toxicity of B. elliptica extract to HepG2 cells used for glucose uptake assay. Data represent the mean ± SD (n = 4). ∗ indicates a significant increase relative to the untreated control (p < 0.05).
Figure 4
Figure 4
Effect of B. elliptica extract on glucose utilization in L6 myoblast. Cells were treated for 48 h in the presence or absence of varying concentration of the plant extract. Data expressed as mean ± SD (n= 4). ∗ indicates a significant increase relative to the untreated control (p < 0.05). No significant increase relative to the positive control (insulin) was noted.
Figure 5
Figure 5
Toxicity of B. elliptica extract to L6 myoblast cells used for glucose uptake assay. Data represent the mean ± SD (n = 4). No significant increase relative to the untreated control was noted.
Figure 6
Figure 6
Effect of aqueous extract of B. elliptica on triglyceride accumulation in 3T3-L1 preadipocytes. Two days after confluence preadipocytes were treated for an additional two days with varying concentrations of plant extract or rosiglitazone. Data were expressed as mean ± SD (n= 4). ∗ indicates a significant increase relative to the untreated control (control) (p < 0.05). No significant decrease relative to untreated control was noted.
Figure 7
Figure 7
The effect of B. ilicifolia on MTT reduction in INS-1 cells. Data are expressed as mean ± SD (n = 6). No significant increase relative to the untreated control (with glucose) was noted.
Figure 8
Figure 8
(a) and (b) The effect of aqueous extract of B. elliptica on the proliferation of INS-1 beta cells. INS-1 cells were cultured with or without the plant extract for 48 h, and the total cells and dead cells (cells stained with PI) were then determined using the ImageXpress Micro XLS analysis with a Hoechst 33342 dye for total cell counts and propidium iodide for dead cell counts. Data are expressed as mean ± SD (n= 8). ∗ indicates a significant increase relative to the untreated control (p < 0.05).
Figure 9
Figure 9
The effect of aqueous extract of B. elliptica on NO production by LPS-stimulated RAW macrophage cells. Concurrent MTT assay indicates no significant toxicity under the experimental conditions (data not shown). Data are expressed as mean ± SD (n = 4). ∗ indicates significant decrease relative to the untreated control (p < 0.05). No significant decrease relative to the positive control (aminoguanidine) was noted.
Figure 10
Figure 10
The effect of aqueous extract of B. elliptica on alpha-amylase and alpha-glucosidase activity. EGCG: epigallocatechin gallate. Data expressed as mean ± SD (n = 4). ∗ indicates a significant increase relative to the untreated control (enzyme) (p < 0.05). No significant increase relative to the positive controls (acarbose and epigallocatechin gallate) was noted.
Figure 11
Figure 11
The effect of aqueous extract of B. elliptica on pancreatic lipase activity (%). Data expressed as mean ± SD (n = 4). ∗ indicates a significant increase relative to the untreated control (enzyme) (p < 0.05). No significant increase relative to the positive control (orlistat) was noted.
Figure 12
Figure 12
The effect of aqueous extract of B. elliptica on DPP-IV activity (%). Data expressed as mean ± SD (n= 4). ∗ indicates a significant increase relative to the untreated control (enzyme) (p < 0.05). No significant increase relative to the positive control (diprotin A) was noted.
Figure 13
Figure 13
The effect of aqueous extract of B. elliptica on protein glycation (%). Data expressed as mean ± SD (n = 4). ∗ indicates significant increase relative to the untreated control (control) (p < 0.05). No significant increase relative to the positive control (aminoguanidine) was noted.
Figure 14
Figure 14
The effect of aqueous extract of B. elliptica on collagenase activity (%). Data expressed as mean ± SD (n= 4). ∗ indicates significant increase relative to the untreated control (control) (p < 0.05). No significant increase relative to the positive control (EDTA) was noted.
Figure 15
Figure 15
The effect of aqueous extract of B. elliptica on CYP3A4 activity (%). Data expressed as mean ± SD (n= 4). ∗ indicates a significant increase relative to the untreated control (solvent) (p < 0.05). No significant increase relative to the positive controls (ketoconazole) was noted.
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References

    1. Al-Hourani H. M., Atoum M. F. Body composition, nutrient intake and physical activity patterns in young women during Ramadan. Singapore Medical Journal. 2007;48(10):906–910. - PubMed
    1. Gupta P., Bala M., Gupta S., et al. Efficacy and risk profile of anti-diabetic therapies: Conventional vs traditional drugs—A mechanistic revisit to understand their mode of action. Pharmacological Research. 2016;113:636–674. doi: 10.1016/j.phrs.2016.09.029. - DOI - PubMed
    1. Atanasov A. G., Waltenberger B., Pferschy-Wenzig E. M. Discovery and resupply of pharmacologically active plant-derived natural products: a review. Biotechnology Advances. 2015;33(8):1582–1614. doi: 10.1016/j.biotechadv.2015.08.001. - DOI - PMC - PubMed
    1. Deutschländer M. S. Isolation and identification of a novel anti-diabetic compound [Ph.D. thesis] Department of Plant Science, Faculty of Nature and Agricultural Sciences, University of Pretoria; 2010.
    1. Van Wyk B., VanWyk P. Field Guide to Trees of Southern Africa. Cape Town: Struik Publishers; 1997.

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