Phytotherapy in diabetes: Review on potential mechanistic perspectives

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases in which the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (PKB or Akt) pathway is deregulated in response to phosphatase and tensin homolog (PTEN) overexpression. Lactoferrin (LF), a multifunctional iron-binding glycoprotein, is involved in AD pathology; however, direct evidence of its impact upon AD remains unclear. To elucidate LF's role in AD, the possible protective mechanism post-LF administration for 3 months was investigated in AD patients by observing changes in the p-Akt/PTEN pathway. AD patients showed decreased serum acetylcholine (ACh), serotonin (5-HT), antioxidant and anti-inflammatory markers, and decreased expression of Akt in peripheral blood lymphocytes (PBL), as well as PI3K, and p-Akt levels in PBL lysate; all these parameters were significantly improved after daily LF administration for 3 months. Similarly, elevated serum amyloid β (Aβ) 42, cholesterol, oxidative stress markers, IL-6, heat shock protein (HSP) 90, caspase-3, and p-tau, as well as increased expression of tau, MAPK1 and PTEN in AD patients, were significantly reduced upon LF intake. Improvement in the aforementioned AD surrogate markers post-LF treatment was reflected in enhanced cognitive function assessed by the Mini-Mental State Examination (MMSE) and Alzheimer's Disease Assessment Scale-Cognitive Subscale 11-item (ADAS-COG 11) questionnaires as clinical endpoints. These results provide a basis for a possible protective mechanism of LF in AD through its ability to alleviate the AD pathological cascade and cognitive decline via modulation of the p-Akt/PTEN pathway, which affects the key players of inflammation and oxidative stress that are involved in AD pathology.

Diabetes is a major public health concern. In spite of continuous new drug development to treat diabetes, herbal remedies remain a potential adjunct therapy to maintain better glycemic control while also imparting few side-effects. Portulaca oleracea has been traditionally used to manage several diseases due to the anti-oxidant and anti-atherogenic effects it imparts. To better understand the mechanisms associated with potential protective effect of P. oleracea extract against diabetes, alloxan-induced diabetic rats were used in this study. Forty Wistar rats (male, 7–8-wk-old, 140–160 g) were divided into four groups (n = 10/group): Group I (control), Group II (P. oleracea-treated; gavaged with P. oleracea extract daily [at 250 mg/kg] for 4 weeks), Group III (diabetic control; daily IP injection of alloxan [at 75 mg/kg] for 5 days) and Group IV (P. oleracea-pre-treated diabetic; gavaged with P. oleracea extract daily [at 250 mg/kg] for 4 weeks and then daily IP injection of alloxan [at 75 mg/kg] for 5 days). Body weight, food consumption, blood (serum) levels of glucose, C peptide, Hb A1C, insulin, tumor necrosis factor (TNF)-α and interleukin (IL)-6 were determined for all groups. The results indicated that while Hb A1C, serum levels of glucose, TNF-α and IL-6 were all significantly decreased in the P. oleracea-pre-treated diabetic rats, these hosts also had significant increases in C peptide and insulin compared to levels in the counterpart diabetic rats. These results were confirmed by the histopathological assessments which showed marked improvement of the destructive effect on pancreatic islet cells induced by alloxan. P. oleracea extract is a general tissue protective and regeneartive agent, as evidenced by increasing β-cell mass and therefore improved the glucose metabolism. Thus, stimulation of Portulaca oleracea signaling in β- cells may be a novel therapeutic strategy for diabetes prevention.

The current study aims to investigate the antidiabetic efficacy of camel milk-derived lactoferrin and potential involvement of PPAR-γ and SIRT-1 via TLR-4/NFκB signaling pathway in obese diabetic pediatric population. Sixty young obese patients with type 2 diabetes were selected from the Pediatric Endocrine Metabolic Unit, Cairo University and were randomly divided among two age and sex-matched groups so as to receive either standard therapy without lactoferrin in one arm or to be treated with oral lactoferrin capsules (250 mg/day, p.o) for 3 months in the other arm. Both groups were compared to 50 control healthy volunteers. Measurements of HbA1c, lipid profile, antioxidant capacity (SOD, Nrf2), proinflammatory interleukins; (IL-1β, IL-6, IL-18), Cyclin D-1, lipocalin-2, and PPAR-γ expression levels were done at the beginning and 3 months after daily consumption of lactoferrin. The mechanistic involvement of TLR4-SIRT-1-NFκB signaling cascade was also investigated. The antidiabetic efficacy of lactoferrin was confirmed by significant improvement of the baseline levels of HbA1c, BMI and lipid profile of the obese pediatric cohort, which is evidenced by increased PPAR-γ and SIRT-1 expression. Moreover, the anti-inflammatory effect was evident by the significant decrease in serum levels of IL-1β, IL-6, IL-18, TNF-α, lipocalin 2 in type 2 diabetic post-treatment group, which corresponded by decreased NFκB downstream signaling indicators. The antioxidant efficacy was evident by stimulated SOD levels and NrF2 expression; compared with the pre-treatment group (all at P ≤ 0.001). The consumption of high concentrations of lactoferrin explains its hypoglycemic efficacy and counts for its insulin-sensitizing, anti-inflammatory and immunomodulatory effects via TLR4-NFκB-SIRT-1 signaling cascade. Recommendations on regular intake of lactoferrin could ensure better glycemic control, compared to conventional antidiabetics alone.

Background and Objectives: Vitamin D supplementation plays a key effect in lowering cytokine storms among COVID-19 patients by influencing the activity of the renin-angiotensin system and the production of the angiotensin-2 converting enzyme. The study was conducted to explore the effect of high-dose intramuscular vitamin D in hospitalized adults infected with moderate-to-severe SARS-CoV-2 in comparison with the standard of care in the COVID-19 protocol. Materials and Methods: Two groups of patients were compared in this prospective randomized controlled trial as the vitamin D was administered orally to group 1 (alfacalcidol 1 mcg/day) and intramuscularly to group 2 (cholecalciferol 200,000 IU). One hundred and sixteen participants were recruited in total, with fifty-eight patients in each group. Following the Egyptian Ministry of Health’s policy for COVID-19 management, all patients received the same treatment for a minimum of five days. Results: A significant difference was recorded in the length of hospital stay (8.6 versus 6.8 days), need for high oxygen or non-invasive mechanical ventilator (67% versus 33%), need for a mechanical ventilator (25% versus 75%), clinical improvement (45% versus 55%), the occurrence of sepsis (35% versus 65%), and in the monitored laboratory parameters in favor of high-dose vitamin D. Moreover, clinical improvement was significantly associated with the need for low/high oxygen, an invasive/non-invasive mechanical ventilator (MV/NIMV), and diabetes, while mortality was associated with the need for MV, ICU admission, atrial fibrillation, chronic obstructive pulmonary disease, asthma, and the occurrence of secondary infection. Conclusions: Our study showed that high-dose vitamin D was considered a promising treatment in the suppression of cytokine storms among COVID-19 patients and was associated with better clinical improvement and fewer adverse outcomes compared to low-dose vitamin D.