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Covid-19, diabetes, scopoletin, eosinophils

January 12, 2022 - 07:12 -- Pierre Lutgen

A recent communication by WHO raised our interest. Several of our African partners are running pilot trials showing that diabetes can be cured efficiently  by Artemisia afra infusions.

Africa’s sharp increase in diabetes is clashing with the COVID-19 pandemic. Africa’s death rates from COVID-19 infections are significantly higher in patients with diabetes, according to a preliminary analysis which the World Health Organization (WHO) presented  in advance of the World Diabetes Day on 14 November. COVID-19 is delivering a clear message: fighting the diabetes epidemic in Africa is in many ways as critical as the battle against the current pandemic,” said Dr, WHO Regional Director for Africa. “The COVID-19 pandemic will eventually subside, but Africa is projected in the coming years to experience the highest increase in diabetes globally. We must act now … and support the millions of Africans unaware they are suffering from this silent killer.

       Matshidiso Moeti, COVID-19 more deadly in Africans with diabetes. Brazzaville, 11 Nov 2021.

More details are given in a paper published in The Lancet. WHO has found that COVID-19 is four times deadlier in people with diabetes in Africa than it is for Africans without diabetes. WHO calculated case fatality rates from COVID-19 by comorbidity, across 13 nations in sub-Saharan Africa with a cumulative population of 270 million. The overall case fatality rate was 2·5%. But for patients with diabetes, it was 10·2%.

Although the death toll for COVID-19 in Africa is only 0,01%, the concentration of all medical and financial means on this disease has been massively destructive for African economies and health-care systems. Diabetes care in Africa is largely paid for by patients themselves. But the pandemic has deprived people of work. 32 million people across sub-Saharan Africa have been pushed into extreme poverty. In the second quarter of 2020, in South Africa alone, 2·2 million people lost their jobs. “A lot of African patients have been trying to stretch out their medication, so that it lasts longer, which has affected how well their diabetes has been controlled”, explained Barango, WHO, Harare.

   Burki T. COVID-19 and diabetes in Africa: a lethal combination. Lancet Diabetes Endocrinol. 2022 Jan;10(1):23. doi: 10.1016/S2213-8587(21)00315-6. Epub 2021 Nov 29. PMID: 34856175; PMCID: PMC8629492.

The link between diabetes and Covid-19 had already been described in a Chinese paper in March 2020.

     Guo W, Li M, Dong Y, Zhou H, Zhang Z, Tian C, Qin R, Wang H, Shen Y, Du K, Zhao L, Fan H, Luo S, Hu D. Diabetes is a risk factor for the progression and prognosis of COVID-19. Diabetes Metab Res Rev. 2020 Mar 31:e3319. doi: 10.1002/dmrr.3319.

A recent study, based on the retrospective analysis of the clinical record of 4252 hospitalized patients with a positive SARS-Cov-2 PCR test, found that a higher percentage of eosinophils was predictive of higher odds of survival.

       Glickman, J.W., Pavel, A.B., Guttman‐Yassky, E. and Miller, R.L. (2021), The role of circulating eosinophils on COVID‐19 mortality varies by race/ethnicity. Allergy.

The frequent relapse of patients who have suffered after a Covid-19 hospitalisation or in those who have been fully vaccinated, has stimulated a new field of research. There is a big controversy regarding the cause of re-positive episodes and the infectivity of re-positive cases. A study from China has shown that during relapse the eosinophil count becomes very low.

      Li X, Yin D, Yang Y, et al. Eosinophil: A Nonnegligible Predictor in COVID-19 Re-Positive Patients. Front Immunol. 2021;12:690653.  2021 Jul 29. doi:10.3389/fimmu.2021.690653

In a weblog in February 202, we described the link between eosinopenia and Covid-19. One possible explanation for the low incidence of Covid-19 in Africa is that malaria and helminthic infections significantly raise the level of eosinophils in the general population. An number of scientific papers alsoconfirm that diabetes causes an increased risk in the mortality and severity of COVID-19. However, the mechanism is not entirely clear. Understanding the relationship between COVID-19 and diabetes could advance therapeutic measures, but there is a scarcity of data on the matter. We quote hereunder several papers described in our weblog.

         Pierre Lutgen.  Covid-19, Malaria, Diabetes, Obesity and Eosinophils. February 8, 2021

A recent study from India confirms that diabetes and eosinopenia are associated with severity of the Covid disease. Eosinophils are 4 times lower in severe cases.

       Anurag A, Jha PK, Kumar A. Differential white blood cell count in the COVID-19: A cross-sectional study of 148 patients. Diabetes Metab Syndr. 2020;14(6):2099-2102. doi:10.1016/j.dsx.2020.10.029

Eosinophils also play a major role in diabetes. A higher peripheral eosinophil percentage was  associated with decreased risk of T2D and insulin resistance in middle aged and elderly Chinese.

       Zhu L, Su T, Xu M, et al. Eosinophil inversely associates with type 2 diabetes and insulin resistance in Chinese adults. PLoS One. 2013;8(7):e67613. Published 2013 doi:10.1371/journal.pone.0067613

An  investigation in India showed that  scopoletin at 1mg/kg dose is very helpful in diabetes and its complication. It showed a significant anti-hyperglycemic and anti-hyperlipidemic activity in Streptozotocin induced diabetic rats.. Glimepiride (0.11mg/kg) was used as reference standard for the activity comparison. Scopoletin showed significant reduction in blood glucose level in streptozotocin induced diabetic rats that is comparable to Glimepiride,

      Anchal Verma, Priyanka Dewangan. Hypoglycemic and Hypolipidemic Activity of Scopoletin in Streptozotocin Induced Diabetic Rats. Int. J. Pharm. Sci. Rev. Res., 22(1), Sep – Oct 2013; nᵒ 17, 79-83

     Raible DG, Mohanty JG, Jaffe JS,. Hydrogen peroxide release from human eosinophils on fibronectin: scopoletin enhances eosinophil activation. Free Radic Biol Med. 2000 Jun 1;28(11):1652-60. doi: 10.1016/s0891-5849(00)00279-3. PMID: 10938462

Scopoletin, a derivative of coumarin, is a benzopyrone in nature, and present in various plants. Artemisia afra is very rich in scopoletin as it was already discovered in 1922.

     Goodson JA. The Constituents of the Flowering Tops of Artemisia afra, Jacq. Biochem J. 1922;16(4):489-493. doi:10.1042/bj0160489