Bitter Kola: Natural Eye Drop for Glaucoma Patients; fact or fiction?

Health Benefits Of Garcinia Kola (Bitter Kola) Health Benefits Of Garcinia Kola (Bitter Kola)

In recent times, Traders carry bitter kola because of their enormous value. Interestingly enough, it would appear we are confusing the term 'science' with 'evidence'. Science is, a way of thinking to allow us to best deduce how the world works around us. Evidence is the product of science (amongst other things). One is a useful tool. One is the product of that useful tool. For instance, Modern medicinal practice is (or should be) 100% science based. It is however, not 100% evidenced backed, likewise, Engineering is 100% science based. Again, it is not 100% evidence backed.

In medicine, the importance of providing an evidence base (a specific kind of output of the scientific method) is of much more importance in other fields like engineering. Why? because in engineering, physics etc the experimental evidence is much easier to produce (in theory) - i.e you could design an experiment (even if only a thought experiment) that could prove/disprove your hypothesis with relative certainty and with little confounds or flaws in experimental design. In medicine, because of the vast amount of confounds and ethical issues (patient A vs patient B are different in thousands of different ways that could affect the validity of the experiment - it is never possible to recruit patients who are identical in every way) we use scientific and mathematical experimental techniques to minimise these confounds - the best of which is a double blind - RCT with good statistical analyses. I provide further details on RCT in this article as you read on.

Thus, in both fields much of what is done is not directly evidence backed, but it is all scientifically backed.


If I was to give a patient 7.5mg of bisoprolol over 5mg of bisoprolol because I wanted to slow their heart rate more, this is not backed by evidence (i.e there is no trial to show 7.5 mg will reduce heart rate over 5mg) but it is backed by science - we know the receptor that bisoprolol acts upon, the inotropic and chronotropic effect this has on the adrenergic system, the volume of distribution of bisoprololetcetc has all been proven. We know that increasing doses of bisoprolol has an inversely proportional relationship to heart rate. We know at what dose the receptor of bisoprolol will be saturated and this relationship no longer holds true. Often there is no need to produce evidence for situations like this. It does not mean that medicine is not scientific. Let's go down to my subject; Bitter kola.

Bitter Kola

Bitter kola also known as Garcinia kola is a specie of flowering plant in the Guttifeae family. It has been used for centuries in "Folk medicine" to treat aliments from fever and cough.According to report from the Center of International Forestry Research, Bitter kola trading is still important to the tribes and villages in Nigeria. It is used by African medicine.The seeds are used for treating cough, fever, head and chest colds, throat infections etc.

Studies as Aphrodisiac

Garcinia kola is claimed to possess aphrodisiac effects and as such is used traditionally in the treatment of erectile dysfunction.

Sexual health is an important component of an individual's quality of life and well-being (WHO, 2002). Sexual dysfunction can, therefore be a very distressing condition for men. It can erode the male essence (NIH, 1992; Monga, 1999).

One form of sexual dysfunction is erectile dysfunction. Erectile dysfunction (ED) is defined as the difficulty in achieving or maintaining an erection sufficient for sexual activity or penetration at least 50% of the time for the last 6 months (Laumann et al., 1999).

Unfortunately, it is a problem often neglected by the health practitioners as they strive to deal with life threatening complications of disease. Successful treatment of ED may improve not only sexual relationships, but also the overall quality of life.

In a research titled 'Effects of ethanolic extract of Garcinia kola on sexual behaviour and sperm parameters in male Wistar rats' authored by Ralebona et al 2012 published in the African Journal of Pharmacy and Pharmacology, a 70% ethanolic extract of G. kola seeds was prepared and used for treating male Wistar rats (n=8 /group); two doses of G. kola (200 and 400 mg/kg body weight) were used for the treatment group, while distilled water was administered to the control group.

All the treatments were orally administered daily for 28 days. On day 28, mounting frequency (MF), intromission frequency (IF) and ejaculation frequency (EF) were quantified during sexual behaviour tests. At termination, body and organ weights, gastric ulceration and cauda epididymal sperm counts were determined. Serum was collected for determination of testosterone levels. Both doses (200 and 400 mg/kg) showed marked aphrodisiac activity with significantly increased sexual behaviour parameters compared to controls. However lower dose of G. kola was more effective than the higher dose.

Testosterone levels were higher in both treatment groups compared to controls. Sperm counts were similar to controls however testes weights were higher in G. kola treated rats compared to controls. Thus these results show that G. kola enhances sexual activity in normal male rats.

Another 2012 study this time by M T Yakubu and A L Quadri titled 'Garcinia Kola Seeds: Is the Aqueous Extract a True Aphrodisiac in Male Wistar Rats'? Published in the Africa Journal of Traditional, Complementary and Alternative Medicine. In this study, the study authors evaluated the effect of aqueous seed extract of G. kola at the doses of 25, 50 and 100 mg/kg body weight on sexual behaviour of male rats. Male rats weighing 215.00 ± 18.58 g were randomized completely into four groups (A-D) of six animals each. Animals in group A received, orally, 0.5 ml of distilled water only while those in groups B, C and D received same volume containing 25, 50 and 100 mg/kg body weight of the seed extract respectively.

Overall, the results revealed that G. kola seeds did not have sex enhancing potential as claimed. Therefore, the acclaimed pro sexual effect of Garcinia kola seeds is scientifically untrue. This study has refuted the claim that one of the rationales for consuming the seeds by the aged population of Nigeria is to enhance sexual invigoration in males. This is the only negative study on bitter kola as aphrodisiac.

In a follow up study led by Rusike et al 2016 published in the first International Journal of Andrology titled 'Dose‐ and time‐dependent effects of Garcinia kola seed extract on sexual behaviour and reproductive parameters in male Wistar rats'.

In this study, the study authors aim to investigate the effects of a crude extract of Garcinia kola on male sexual function after subchronic and chronic treatment periods at different sublethal doses. Adult male Wistar rats were treated orally with 100, 200 and 400 mg kg−1 of a 70% ethanolic extract of G. kola daily for 56 days. Sexual behaviour studies were performed on days 28 and 50. At termination on day 56, organ weights, sperm count, reproductive hormone levels and testicular histology were assessed. Subchronic and chronic treatment of normal male rats with G. kola extract resulted in overall increase in components of libido, erection and ejaculation in treated rats – with lower doses being more efficient than the higher dose. There was a slight reduction in some components of sexual behaviour with prolonged time of treatment. G. kola treatment at all doses resulted in increased testicular weights, increased sperm count with no change in motility and increased serum testosterone levels with no change in gonadotropin levels. Gross testicular histology was not affected by treatment. They concluded that G. kola seed extract possesses potent aphrodisiac activity in male albino rats with resultant increase in sperm count and testosterone levels.

Studies on Glaucoma

Garcinia kola, is found in moist forest and grows as a medium size tree, up to 12 m high. It is cultivated and distributed throughout west and central Africa. Medicinal uses include, purgative, antiparasitic, antimicrobial. The seeds are used in the treatment of bronchitis and throat infections. They are also used to prevent and relieve colic, cure head or chest colds and relieve cough. Also the plant is used for the treatment of liver disorders and as a chewing stick (Iwu 1993). The constituents include-biflavonoids, xanthones and benzophenones. The antimicrobial properties of this plant are attributed to the benzophenone, flavanones. This plant has shown both anti-inflammatory, antimicrobial and antiviral properties. Studies show very good antimicrobial and antiviral properties. In addition, the plant possesses antidiabetic, and antihepatotoxic activities (Iwu 1993).

But is there any evidence that bitter kola can effectively treat glaucoma, a condition which can cause gradual loss of sight, usually due to build-up of pressure within the eye? According to the international medical database PubMed only one randomized controlled trial has been published in a peer-reviewed journal. The study – which was carried out by a team of Nigerian researchers led by Adefule-Ositelu and published in 2010 – compared an extract of bitter kola used as eye drops with timolol eye drops, a drug commonly used for treating glaucoma. The research titled 'Efficacy of Garcinia kola 0.5% Aqueous Eye Drops in Patients with Primary Open-Angle Glaucoma or Ocular Hypertension' was published in Middle East Africa Journal of Ophthalmology. The aim of the study was to evaluate the intraocular pressure (IOP) lowering efficacy of Garcinia kola 0.5% aqueous solution eye drops in patients with newly diagnosed primary open-angle glaucoma or ocular hypertension (POAG/OH).

The investigators employed a randomized, double-masked, multicenter, active-controlled prospective study. Patients who met the inclusion criteria were randomly assigned in equal numbers to receive Timolol 0.5% eye drops as a control medication (A = Group 1 eyes) or Garcinia kola 0.5% eye drops as the study medication (B = Group 2 eyes). All drops were instilled at 6 am and 6 pm daily. In their result, a total of 178 patients were randomly assigned to G. kola and Timolol groups. At baseline there were no differences in mean IOP between groups, based on age, sex, or diagnosis. At the end of the study period (24th week), the mean (± SD) reduction in IOP was 12.93 ± 2.3 mmHg (47.8% ± 0.8% reduction) in G. Kola group and 13.09 ± 2.8 mm Hg (48.2% ± 1.03% reduction) in the Timolol group (P > 0.05). Adverse events were mild in nature with no statistically significant differences between groups (P > 0.05).

They concluded that, Garcinia kola ophthalmic solution significantly reduces IOP as compared to baseline. The IOP lowering effect of both treatments was equivalent

In other words: The results appeared to indicate that the eye drops were as effective as timolol in reducing intra-ocular pressure in patients with glaucoma. Lowering pressure is important to help prevent blindness by reducing further damage to the optic nerve. This is very interesting result as Glaucoma is a leading cause of irreversible blindness. However, others have raised issues concerning the study of this research. For instance, researcher Ike Anya of the fact check questioned the reliability of the study.

According to fact check : A major point of concern is the fact that the paper says the use of the drops was approved for the study by the "Pharmacy Council of Nigeria". "We could find no evidence of the existence of any such body. The Pharmacists Council of Nigeria registers and regulates the practice of pharmacists, not drugs. The regulation of drugs for clinical trials is the responsibility of the National Agency for Food and Drug Administration and Control (NAFDAC). This should have been the body to approve the experimental use of the eye drops, although it has been suggested by a Nigerian lawyer recently that the regulation of clinical trials in the country is not as clear as it should be".

Further, the bitter kola drops are not found on the list of registered drugs displayed on NAFDAC's website. Calls to the numbers listed by the agency online did not connect, so Africa Check was unable to clarify the status of the drug. As such, it is unclear whether it has been licensed and approved for treatment, or whether it was even approved for testing.

Another issue was that the research documents cited in this paper to indicate that garcinia kola was safe in human eyes do not appear to have been designed to look at safety, judging from the abstracts. 'We could not access the original papers', says fact check. One was an in vitro study conducted by A O Adefule-Ositelu et al 2014 published in Nigerian Quarterly Journal of Hospital Medicine titled 'Antifungal Activities of Garcinia Kola Extracts On purulent Human Ocular Discharges in Lagos University Teaching Hospital, Lagos' , meaning that it tested outside a living organism, not on animals or humans. And another also published by A O Adefule-Ositelu et al 2004 titled ' Clinical Evaluation of Ocular Antiviral Effect of Garcinia Kolanut Water Extract in Epidemic HaemorrhagicKeratoconjunctivitis in Lagos' published in the Nigerian Quarterly Journal of Hospital Medicine was a use of garcinia kola eye drops in treating adenokeratoconjunctivitis – popularly called "Apollo" in Nigeria – which was not a randomized controlled trial.

Why a Randomized Controlled Trial matters?

A randomized clinical trial (RCT) is conducted to compare 2 (or more) treatments, or a treatment to a control or comparison group. A randomized controlled trial (or randomized control trial;RCT) is a type of scientific (often medical) experiment that aims to reduce certain sources of bias when testing the effectiveness of new treatments; this is accomplished by randomly allocating subjects to two or more groups, treating them differently, and then comparing them with respect to a measured response. One group-the experimental group-has the intervention being assessed, while the other-usually called the control group-has an alternative condition, such as a placebo or no intervention. The groups are followed under conditions of the trial design to see how effective the experimental intervention was. Treatment efficacy is assessed in comparison to the control. There may be more than one treatment group or more than one control group.

The trial may be blinded, in which information which may influence the participants is withheld until after the experiment is complete. A blind can be imposed on any participant of an experiment, including subjects, researchers, technicians, data analysts, and evaluators. Good blinding may reduce or eliminate some sources of experimental bias. The randomness in the assignment of subjects to groups reduces selection bias and allocation bias, balancing both known and unknown prognostic factors, in the assignment of treatments.[4] Blinding reduces other forms of experimenter and subject biases.

A well-blinded RCT is often considered the gold standard for clinical trials. Blinded RCTs are commonly used to test the efficacy of medical interventions and may additionally provide information about adverse effects, such as drug reactions.

Further omissions

There were further omissions within the paper on glaucoma. For instance, the section describing the masking procedure – the process by which it is ensured the investigators and patients do not know which treatment they are receiving, in order to minimise bias – did not provide information about how similar the characteristics of the two treatments were. If the treatments were distinctly different, and patients knew which they were receiving, that could introduce a bias.

There was no detail in the paper about how the allocation schedule was kept and maintained. An allocation schedule in a randomised controlled trial is the schedule that determines which treatment a trial participant gets. A good study should present that information in order to show that precautions were taken to avoid bias.

In addition, the paper notes "poor drug compliance initially in the majority of subjects", meaning that patients did not take their treatment as planned. "Most subjects exhausted their assigned drug earlier than expected and stopped further treatment a few days prior to the upcoming follow up."However, it does not describe how this was taken into account in the analysis.

The evidence is questionable

The claim, while supported by more research than that surrounding the "cure" for Ebola – for which Professor Adefule-Ositelu has been threatened with prosecution – should be questioned according to fact check. Only one paper appears to document the therapeutic powers of these eye drops. Its reliability is undermined by several omissions. There is no evidence that the drug is registered and approved for use by the proper body.Aside from that single study – which was carried out by a team of Nigerian researchers led by Adefule-Ositelu – Africa Check could find no research confirming whether bitter kola is an effective treatment for glaucoma, they claimed.

Studies on the Prostate

Only one study I chanced on which is a 2016 study by Kalu et al published in the journal Biomed Pharmacotherapy titled 'Effect of kolaviron, a biflavanoid complex from Garcinia kola on some biochemical parameters in experimentally induced benign prostatic hyperplasic rats'. In the study result, the normal rats administered finasteride or kolaviron had decreased prostate weights (P<0.05) compared with the normal control which results were corroborated by histological assay that also showed that treatment with kolaviron (200mg/kg) or finasteride reversed the histoarchitecture of the prostates of the BPH rats. In conclusion, Kolaviron could be useful in the management of BPH.

Other Studies on respiratory disorders.

A 2002 study by Akoachere et al titled 'Antibacterial effect of Zingiberofficinale and Garcinia kola on respiratory tract pathogens' published in East Africa Med Journal investigate the antibacterial activity of Zingiberofficinale (ginger) Garcinia kola (bitter kola) on four respiratory tract pathogens. The extracts exhibited antibacterial activity against the pathogens. Results indicated that extracts of ginger root and bitter kola may contain compounds with therapeutic activity. This is why I added ginger in my Men's Formula for Prostate Health & Immunity, Women's Formula and Nyarkotey Tea for Cardiovascular Health &wellness(for enquiries0241083423)

The plant has also found usefulness in the treatment of stomach ache and gastritis. In fact, Professor Maurice Iwu, the chairman of INEC in a study carried out at the University of Nigeria Nsukka reported the use of the plant for the treatment of jaundice, high fever, and as purgative. They showed that Garcinia Kola extract exhibits a dilatory effect on the alveolar ducts, alveolar sacs and alveoli thereby improves respiratory activities, which may be due to its antioxidant properties in Swiss albino mice.

Garcinia kola has been shown to inhibit smooth muscle activity. It relaxes the smooth muscles of the uterus and the intestine. Although, Garcinia Kola lacks caffeine, its alkaloid and biflavonoids fractions are said to relax the smooth muscles. Historically, plants have provided a source of inspiration for novel drug compounds, as plant derived medicines have made large contributions to human health and well-being. The seeds of Garcinia kola (Gk) forms a major part of the herbal preparation used in traditional African medicine practice for the treatment of various respiratory tract diseases including asthma.

Asthma is a very common chronic disease involving the respiration system. Episodic or chronic wheezing, cough, and feeling of tightness in the chest as a result of bronchoconstriction characterize it. The fundamental cause is still unknown despite intensive research. However, three abnormalities are present: airway obstruction that is at least partially reversible, airway inflammation, and airway hyper responsiveness to a variety of stimuli.

In conclusion, the greatest value of bitter kola extract is prevention and management of diabetic complications of the eye because of it activity on aldose reductase. Other benefits are:

• IMMUNITY: The anti-inflammatory and antioxidant properties makes the body resistant to infections.• IMPOTENCE: Impotence is restored by increasing blood supply to the core area in men who have hardening of the arteries.• HANGOVER: It prevents the alcoholic induced hangover.

It is intriguing that bioflavonoids of Garcinia kola are capable of modulating almost any physiological anomaly. The answer perhaps lies in the role of flavonoids in the evolutionary course of human beings. Humans, over many millennia, have adapted to a diet, which is favourable for their survival and the flavonoid-like structures were part of the physiological system.

Disclaimer: As pertains to all my previous articles, they are for educational purposes and not to be use as substitute to medical advice.

Dr. Raphael NyarkoteyObu, PhD, Is an honorary Professor of Naturopathic Medicine with research interest in Naturopathic & Holistic Urology, Vinnytsia State Pedagogical University, Ukraine. Formulated of FDA approved Men's Formula for Prostate Health, Women's Formula for wellness &Nyarkotey Tea for cardiovascular Health. 0241083423

Source: Dr. Raphael Nyarkotey Obu, RND, PhD.