The anti-inflammatory activity and bioavailability of moringa isothiocyanates
Creators: name: Wolff, Khea Che ́
Publisher: name: No Publisher Supplied
Year: 2023

description: Moringa (Moringa oleifera Lam.) seed extract (MSE) and its main bioactive component, moringa isothiocyanate-1(MIC-1), mitigate inflammation, oxidative stress, diabetes, and cancer in both in vitro and in vivo models. Moringa is a member of the Moringaceae family of 13 known species. All, including Moringa oleifera, are traditionally used as food, medicine, or for industrial purposes. The pods, seeds leaves, bark, and roots are all used. Investigating the therapeutic benefits of MSE and MIC-1 for both oral and topical delivery will help to fill the gap of knowledge in better understanding their potential as botanicals. This thesis provides information necessary to address these benefits, through the following aims: (1) investigate the bioavailability and bioaccessibility of MSE and MIC-1 in vitro and in vivo; (2) evaluate the ability of MSE to attenuate inflammation orally in a collagen-induced arthritis model; (3) evaluate the ability of MSE to reduce inflammation topically in a carrageenan paw edema model; (4) examine the anti-inflammatory effects of MSE and MIC-1in a 12-O-tetradecanoylphorbol-13-acetate (TPA) -induced ear edema model. Chapter 1 provides an introduction to the background and goals of the dissertation including a review of moringa, MSE and MIC-1 in relation to the key subjects discussed in this dissertation such as bioavailability, bioaccessibility and inflammation. Chapter 2 investigated the bioaccessibility using a human intestinal model and bioavailability in rats. Bioaccessibility of MIC-1, using the TNO Intestinal Model (TIM-1), was determined to be 61% and 62% in the fasted and fed states respectively. Bioavailability and pharmacokinetic studies were conducted in Sprague-Dawley rats treated with 50 mg/kg of MIC-1, either intravenously with pure MIC-1, or orally gavaged with MSE or MIC-1. Serum levels of MIC-1 were 6 to 12 times higher in animals dosed intravenously than in animals dosed by gavage with a half-life of about 2 h. Serum levels of MIC-1 dropped to zero between 8 and 24 h for all three treatments. These results suggested that MIC-1 remains largely unmodified during uptake, unlike other isothiocyanates, and has favorable bioaccessibility and bioavailability characteristics for a potential therapeutic agent.Chapter 3 evaluated the ability of MSE to mitigate inflammation, addressing the hypothesis that MSE would attenuate inflammation in a Collagen-Induced Arthritis (CIA) rodent model. Inflammation was induced in rats using an emulsion of Complete Freund’s Adjuvant (CFA) and type II collagen, injected into the tail followed by administration of MSE and MIC-1 with the onset of symptoms. Swelling in the paws of the animals was measured using a plethysmometer. There were no significant reductions in the amount of swelling observed in the animals after treatment with MSE, which provided useful feedback for future experiments, such as the appropriate timing of MSE treatment, from intervention to preventative. Chapter 4 addressed the development of a topical formulation of MSE to evaluate the anti-inflammatory effects in an acute model of inflammation. Various topical formulations were developed and evaluated in a carrageenan paw edema model of acute inflammation. MSE formulations at various doses of 1,2 and 5% were applied directly to the hind paws of rats, 30 min before administering a 1% carrageenan-saline solution. No significant difference was observed when MSE was applied to the paw before the injection of carrageenan, as measured using a plethysmometer. These results led to further investigation into the delivery of MSE and MIC-1, so that those changes can be implemented in future inflammation experiments. Lastly, Chapter 5 elucidated the topical anti-inflammatory effects and mechanisms of action of MSE and MIC-1 using a mouse ear edema model treated with a pro-inflammatory agent, 12-O-tetradecanoylphorbol-13-acetate (TPA). A time-dependent and dose-dependent response was determined by pretreating CD-1 mice with various doses of MSE and MIC-1, dexamethasone, a glucocorticoid as the positive control, or the vehicle control, followed by TPA. The difference in thickness of the ears was measured using a pair of digital Vernier calipers. The most effective doses of MSE and MIC-1 at 2 mg/ear and 0.8 mg/ear respectively were then selected for evaluating the change in weight of the ears using 6 mm biopsy punches. MSE and MIC-1 were both shown to be effective in a dose dependent manner, as assessed by reduction in ear thickness and a 44 % and 48 % decrease in ear punch weight when treated with MSE and MIC-1 respectively. The MSE and MIC-1 treated ears also resulted in a reduction in the levels of cytokine and chemokines, IL-6, MCP-1, and KC. MSE and MIC-1 reduced IL-6 expression by 70 % and 74 %, MCP 1 by 74 % and 73 % and KC by 56 % and 43 % respectively. The anti-inflammatory effect of MSE and MIC-1 was further confirmed by H&amp;E staining, used to assess the thickness in swelling in the ears. MSE significantly reduced the thickness of the ears to 33 % compared to TPA at 47 %. These data validate the anti-inflammatory properties of MSE and MIC-1 involving the inhibition of the NF-кB and Nrf2 pathways.