CHAPTER TWO: LITERATURE REVIEW

2.1 Introduction

In this chapter, we will look at what other people have already written or studied about the use
of herbal medicine in treating type 2 diabetes. We will talk about diabetes itself, what herbal
medicine is, how people use herbs, and what researchers have said about the use of herbal
medicine in Africa and Cameroon. We will also look at the problems and risks of using herbs.

2.2 Overview of Type 2 Diabetes

Type 2 diabetes is a long-term disease where the body cannot use insulin properly. Insulin is a
hormone that helps sugar move from the blood into the body’s cells. When this does not
happen correctly, blood sugar becomes too high. This can lead to serious health problems like
heart disease, kidney failure, and nerve damage [1].

The number of people with diabetes is growing around the world. The International Diabetes
Federation said that in 2021, more than 537 million people had diabetes, and this number is
expected to reach 783 million by 2045 [2]. In Africa, the number is also going up fast because
people are eating more processed foods, not exercising, and living in cities [3].

2.3 Diabetes in Cameroon

In Cameroon, about 5.8% of adults live with diabetes [4]. Many of them do not know they have
it until they develop problems. In rural and semi-urban areas like Bamenda 3 Health District,
access to hospitals, doctors, and medicines is limited. Also, many people cannot afford diabetes
drugs or regular checkups. Because of this, many turn to traditional medicine, especially herbs
[5].

2.4 Herbal Medicine: Meaning and Use

Herbal medicine is a type of traditional medicine made from plants. It includes leaves, roots,
barks, seeds, and flowers. These plant parts are prepared and used to treat different diseases.
In many African countries, including Cameroon, people have used herbs for hundreds of years
to treat health problems [6].
Many people believe that herbs are more natural, cheaper, and safer than modern drugs. Herbs
are often prepared at home as tea, powder, or juice. In some cases, people get herbs from
traditional healers [7].

2.5 Common Herbs Used for Diabetes

Some herbs are believed to help reduce blood sugar levels. In Cameroon and other African
countries, commonly used herbs for diabetes include:

Vernonia amygdalina (bitter leaf)

Moringa oleifera (moringa)

Allium sativum (garlic)

Azadirachta indica (neem)

Psidium guajava (guava leaves)

Ocimum gratissimum (African basil) [8]

Studies show that these plants have some ability to reduce blood sugar in animals or humans.
For example, Moringa and bitter leaf may help the body use insulin better [9,10].

2.6 Benefits of Herbal Medicine in Diabetes

Some research suggests that herbal medicine can help lower blood sugar levels and improve
health in people with diabetes. A study in Nigeria showed that diabetic patients who used bitter
leaf had lower blood sugar than those who did not [11]. Herbal medicine may also help reduce
other problems like high blood pressure or poor digestion.

Many people say herbs are cheaper, easy to get, and do not have many side effects—especially
compared to hospital drugs that can be expensive or difficult to find [12].
2.7 Risks and Challenges of Herbal Medicine

Even though many people use herbs, there are some problems. First, many herbs have not
been fully tested to see how safe or effective they are. Some may not work at all, or they may
even be harmful [13].

Also, herbal medicine can interact badly with hospital medicine. For example, mixing herbs with
drugs like metformin or insulin could make blood sugar drop too low [14]. Some herbs may also
cause liver or kidney damage if used for a long time or in the wrong dose [15].

Another problem is that most patients do not tell their doctors that they are using herbs. This
makes it hard for health workers to give the best care [16].

2.8 Herbal Medicine Use in Cameroon

In Cameroon, traditional medicine is common, especially in rural and semi-urban areas. A study
by Tsabang et al. found that over 60% of diabetic patients use herbal medicine [5]. Most people
say they use herbs because they are cheap, effective, and available.

In Bamenda 3 Health District, there are many traditional healers, and people often trust them
more than hospitals. However, the use of herbs is not well documented, and there is very little
local research to guide safe use.

2.9 Knowledge Gaps

Although herbal medicine is widely used in Cameroon, there is not enough scientific
information about which herbs work best, how they should be used, and what side effects they
might have. There is also limited research in specific areas like Bamenda 3, where many people
mix herbs with hospital drugs.

This study will help fill that gap by collecting information from patients in Bamenda 3 on how
they use herbal medicine to manage type 2 diabetes.

2.10 Summary

Type 2 diabetes is growing in Cameroon and around the world. Many people use herbal
medicine to manage their condition because it is cheaper and easier to access than hospital
drugs. However, herbal treatments are not always tested or safe, and there is limited research
about how they are used, especially in Bamenda 3. This study will explore how diabetic patients
in this area use herbal medicine, which herbs they use, and what benefits or problems they
experience.
References

1. American Diabetes Association. Standards of Medical Care in Diabetes—2023. Diabetes Care.

2. International Diabetes Federation. IDF Diabetes Atlas. 10th ed. Brussels: IDF; 2021.

3. Mbanya JC, Motala AA, Sobngwi E, Assah FK, Enoru ST. Diabetes in sub-Saharan Africa.
Lancet. 2010;375(9733):2254–66.

4. World Health Organization. Diabetes country profiles: Cameroon [Internet]. WHO; 2022
[cited 2025 May 14]. Available from: https://www.who.int/data/gho/data/themes/topics/topic-
details/GHO/diabetes

5. Tsabang N, Yedjou CG, Tsambang T, Tchounwou PB. Assessment of the usage of traditional
medicine in the treatment of diabetes in Cameroon. Med Aromat Plants. 2011;1(2):1–6.

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World Health Organ. 2008;86(8):594–9.

7. Ekor M. The growing use of herbal medicines: Issues relating to adverse reactions and
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8. Sofowora A. Medicinal Plants and Traditional Medicine in Africa. 3rd ed. Ibadan: Spectrum
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9. Goyal BR, Agrawal BB, Goyal RK, Mehta AA. Phytopharmacology of Moringa oleifera Lam.: An
overview. Nat Prod Radiance. 2007;6(4):347–53.

10. Akah PA, Okafor CL. Blood sugar lowering effect of Vernonia amygdalina Del. in an
experimental rabbit model. Phytother Res. 1992;6(3):171–3.

11. Osinubi AA. Effects of Vernonia amygdalina and Gongronema latifolium on blood glucose in
rats. Afr J Tradit Complement Altern Med. 2006;3(1):94–102.

12. Fakeye TO, Adebisi A, Tijani A. Use of herbal medicines among pregnant women in an urban
setting in Nigeria. BMC Complement Altern Med. 2009;9:53.

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14. Izzo AA, Ernst E. Interactions between herbal medicines and prescribed drugs. Drugs.
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15. Teschke R, Eickhoff A. Herbal hepatotoxicity in traditional and modern medicine: actual key
issues and new encouraging steps. Front Pharmacol. 2015;6:72.

16. Hughes GD, Aboyade OM, Clark BL, Puoane TR. The prevalence of traditional herbal
medicine use among hypertensives living in South African communities. BMC Complement
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