Bitter kola boosts libido, beats osteoarthritis, researchers confirm By Chukwuma Muanya

Photo: Bitter Cola (Garcinia Kola)

It may sound absurd but it is true. Nigerian scientists have confirmed in clinical settings and in animal models that eating moderate quantities of bitter cola does not just enhance sexual activity but have clinically significant analgesic/anti-inflammatory effects in knee osteoarthritis patients. CHUKWUMA MUANYA writes.

CAN eating at least a piece of bitter kola (Garcinia kola) daily be the treatment for low libido, low sperm count, erectile dysfunction and knee osteoarthritis?

Results of a study published in African Journal of Pharmacy and Pharmacology have confirmed that bitter kola possesses sexual enhancing effects on male rats as evidenced by the increased mounting (MF) and intromission (IF) frequencies with increased number of subsequent ejaculations over the 20 min observation period.

The study is titled “Effects of ethanolic extract of Garcinia kola on sexual behaviour and sperm parameters in male Wistar rats.”

Another study published in Journal of Orthopaedic Surgery and Research by medical doctors, pharmacists and nurses at Obafemi Awolowo University Teaching Hospital (OAUTH) concluded: “Garcinia kola appeared to have clinically significant analgesic/anti-inflammatory effects in knee osteoarthritis patients. Garcinia kola is a potential osteoarthritis disease activity modifier with good mid term outcome. Further studies are required for standardization of dosages and to determine long-term effects.”

The study is titled “Clinical effects of Garcinia kola in knee osteoarthritis.”

Botanically known as Garcinia kola, bitter kola belongs to the plant family Guttifereae. In Nigeria it is called oje in Bokyi, edun or efiari in Efik, efrie in Ejagham-Ekin, cida goro in Hausa, efiat in Ibibio, emiale in Icheve, igoligo in Idoma, aku-ilu or ugolo in Ibo, akaan in Ijo-Izon, okain in Isekiri, and orogbo in Yoruba.

Yet another study on bitter kola published recently in Science Journal of Microbiology showed that seed and leaf of bitter kola have antibacterial activity on clinical isolates of Staphylococcus aureus, Escherichia coli, Salmonella typhi and Streptococcus pyogenes.

Phytochemical screening of the extracts revealed the presence of some bioactive components like alkaloids, saponins, tannins, anthraquinones and cardiac glycosides. These components determine the antibacterial activity of the seed and leaf extracts. The results from this study, provides scientific evidence that Garcinia kola has the capability of inhibiting the growth of pathogenic micro-organisms; thus it will be useful in tropical medicine for the treatment of microbial infections.

The researchers wrote: “G. kola has been shown to be a popular treatment for diarrhea and fever. The seed extract is antiseptic and is active mostly against gram-positive bacteria. While the leaf, is active mostly against gram-negative bacteria. It is also very efficacious for hepatitis.

“In West Africa, is now being harnessed as a cure for the Ebola virus infections and also against flu. The stem, bark and the seeds are used for acute fever, inflammation of the respiratory tract and throat infections. Historically, Nigerians used Garcinia kola as an aphrodisiac.

“The seeds are also chewed to relieve hoarseness of voice, sore throat and cough. In folk medicine the seed is used for the treatment of liver disorder. It is also used in the treatment of dysentery and diarrhea. The leaves are used for stomachache and pains and is also anti helmithic. They also serve as good remedy for typhoid fever.”

Erectile dysfunction (ED) is defined as the difficulty in achieving or maintaining an erection sufficient for sexual activity or penetration at least 50 per cent of the time for the last six months.

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.

Osteoarthritis is the most common form of joint disease, affecting the knee more than other joints. Several factors play a role in osteoarthritis risk; these include age, gender, genetics, behavioral influences and ethnicity.

Trauma is a recognised predisposing factor to development of osteoarthritis of the knee (KOA) associated with raised intra osseous pressure and death of the chondrocytes. Osteoarthritis of the knees reduces the ability to avoid obstacles and supporting epidemiologic studies have found osteoarthritis to be a risk factor for falls. The pain associated with osteoarthritis of the knees increased the propensity to trip on an obstacle and underscores the importance of treating pain associated with osteoarthritis.

The South African researchers from Walter Sisulu University, Mthatha, South Africa investigated the effects of oral administration of ethanolic extract of G. kola on male sexual behaviour, testosterone levels and sperm parameters.

A 70 per cent ethanolic extract of G. kola seeds was prepared and used for treating male Wistar rats in a group of eight; 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.

Meanwhile, the OAUTH researchers used prospective randomized, placebo controlled, double blind, clinical trial approved by the institutional medical ethics review board and written informed consent obtained from each patient.

All KOA patients presenting at the OAUTH complex were recruited into the study. The patients were grouped into four (A = Placebo, B = Naproxen, C = Garcinia kola, D = Celebrex). The drugs and placebo were given twice a day per oral route. Each dose consisted of 200 mg of G. kola, Naproxen (500 mg), Celebrex (200 mg) and Ascorbic acid (100 mg). The primary outcome measure over six weeks study period was the change in mean WOMAC pain visual analogue scales (VAS). Secondary outcome measures included the mean change in joint stiffness and physical function (mobility/walking).

The South African researchers wrote: “The present study confirmed that G. kola possesses sexual enhancing effects on male rats as evidenced by the increased MF and intromission IF frequencies with increased number of subsequent ejaculations over the 20 min observation period. These parameters are considered to be a measure of both libido and potency and indicative of improved sexual arousal and performance. Thus our results show that G. kola treatment increases both libido and potency in normal rats.”

It has been shown that drugs, which enhance sexual function may act via an increase in circulating testosterone levels, the male sex hormone responsible, among other functions, in enhancing sexual function via central and peripheral effects.

Indeed testosterone supplementation has been shown to improve libido and intensifying orgasm and ejaculation.

The researchers noted: “In this study, G. kola treatment resulted in increased testosterone levels, which may account for the enhanced sexual activity. The mechanisms for increased total testosterone levels may be via central influences to increase gonadotropins or locally via increase in the number of Leydig cells or their sensitivity to luteinising hormone (LH). Further studies to elucidate mechanisms are required.

“There was a significant increase in testicular weights with no change in the weights of accessory reproductive organs and epididymal sperm count. Increase in spermatogenesis is usually accompanied by increased testicular weight since the bulk of testicular weight is made up of seminiferous tubules that house spermatids and spermatozoa.

“Despite the increased testosterone levels there was maintenance of accessory organ weights. Normal accessory organ structure and function is maintained by circulating androgens. The actual duration of increase in the levels of testosterone was not determined in our study; therefore, the accessory organs may have not experienced the increased testosterone long enough for weight change. Threshold levels of required testosterone might be different for the different accessory organ functions.

“Furthermore, despite the increased testicular weight, G. kola had no effect on epididymal sperm count after 28 days of treatment. One complete spermatogenic cycle takes 58 days in the rat. Since our study was less than 58 days, spermatogonia exposed to G. kola treatment had not been deposited into the epididymis for observation. A longer study is therefore necessary to make meaningful observations on the effects of treatment on epididymal sperm counts.

“The body and vital organ weights were not altered after treatment with G. kola extract. Monitoring of organ weights gives information on general wellbeing of the animal.”

According to the researchers, these results show that G. kola treatment over 28 days did not affect organ weights, since they remained similar to those of the controls. “Furthermore, acute toxicity and ulcerogenicity studies confirm nontoxic effects of G. kola,” they noted.

The researchers concluded: “G. kola treatment at two doses showed enhanced libido and potency in male rats after treatment for 28 days. Furthermore, G. kola treatment enhances testosterone secretion and increases testicular weights.”

According to the OAUTH study, the efficacy of G. kola, naproxen and celebrex was apparent for the KOA patients within the six weeks of therapy. G. kola’s onset of action was relatively fast with better improvement when compared with the placebo. The Garcinia kola positive analgesic/anti-inflammatory effect were significant in KOA patients.

The researchers said this may be a useful alternative in patients with osteoarthritis who have not responded to first-line treatment with acetaminophen and in whom non steroidal anti-inflammatory drugs (NSAIDs) are contraindicated, ineffective, or poorly tolerated. “As serious adverse effects are associated with oral NSAIDs, only limited use can be recommended.”

The researchers wrote: “G. kola is known to contain high content of bioflavonoid compounds with a general anecdotal effect in folk medicine in Africa. Active oxygen and free radicals are related to various physiological and pathological events, such as inflammation. There is always a relationship between oxidation, infections, inflammatory reactions, and biological membrane of cells.

“It has been reported to prevent accumulation of lipid per oxidation products and protect biomembranes against oxidative damage by acting as antioxidant. It also acts as scavenger of free radicals and reactive oxygen species which are not treated by traditional NSAIDs drugs or selective COX-2 inhibitors. When free radicals and reactive oxygen species accumulate in the joint could trigger additional inflammatory processes in KOA.

“The scavenging activity of flavonoids of G. kola seeds on super oxide anion radicals (O2) generated non-enzymically was comparable with butylated hydroxytoluene. The reducing power shows that flavonoids of G. kola seeds are electron donors and could react with free radicals to convert them to stable products thereby terminating radical chain reaction involved in knee osteoarthritis inflammatory process.

“Garcinia kola may be acting as antioxidant to either inhibit or slow down the progression of symptomatic knee osteoarthritis. It could also act as a scavenger to remove the particles that have been observed on the surfaces of human articular cartilage following trauma and osteoarthritis. The particles contained calcium and phosphorus, which were identified only in structurally abnormal cartilage.

“Bitter kola has been known to protect against the oxidation of lipoprotein, presumably through the mechanisms involving metal chelating and antioxidant activity. The relief of pain experienced by subjects on G. kola could be associated with either removal of the free radicals and or revascularization of the subchondria bone through the anti-atherogenic effect. This pathway is not clear at this stage of the study. It may be through activation of the cytokines selective inhibition of inducible nitric oxide synthase, which has been shown to reduce the progression of experimental osteoarthritis in vivo.

“The bitter kola is believed to have aphrodisiac properties probably related to its vasodilator effects on the genitalia smooth muscles. Reduction of intraosseous/subchondria pressures could be the other pathway for the reduction of knee pain experienced by patients on G. kola. The ability to lower intraocular pressure was earlier noted in glaucoma patients.

“The preliminary crude observation was confirmed scientifically in animals and human glaucoma’s patients. The vasodilatation induced could improve the subchondria blood circulation in knee osteoarthritis. The G. kola extract has been shown to have antithrombotic activities. The effect of G. kola on chondrocyte nutrition is not clearly elucidated at present. This will form the fulcrum of future studies.”

According to the Useful Plants of West Tropical Africa by H. M. Bukhill, its principal application is for chew-sticks. In Liberia they are said to whiten the teeth. In Ghana it is the smaller trees, which tend to be felled for this purpose and the wood is cut and split into pencil-sized pieces. It is bundles of these, which are a common market commodity throughout the Region, for the chew-sticks of this species are considered superior to any other.

The roots are also used, sometimes in preference, and in the Ibadan area of S Nigeria they are thought to prevent dental caries. Tests have, however, shown no anti-biotic activity. In Sierra Leone the root is chewed to clean the mouth.

In Igbo (Nigeria) pharmacology extracts of stems, roots and seeds have shown strong anti-hepatotoxic and hepatotropic activity. Petroleum ether and acetone extracts were found to be markedly anti-microbial.

The powdered bark is applied in Nigeria to malignant tumours, cancers, etc., and the gum is taken internally for gonorrhoea, and externally to seal new wounds. In Congo a bark-decoction is taken for female sterility and to ease child-birth, the intake being daily till conception is certain and then at half quantity throughout the term.

The bark is added to that of Sarcocephalus latifolius (Rubiaceae), a tisane of which has a strong reputation as a diuretic, urinary decongestant and for chronic urethral discharge. The bark is also thought to be galactogenic, whilst in Ghana the bark is used with Piper guineense (Piperaceae) and sap from a plantain stalk (Musaceae) to embrocate the breast for mastitis.

In Ivory Coast a decoction of the bark is taken to induce the expulsion of a dead foetus, and seed and bark are taken to treat stomach-pains. Bark and leaves are used in Congo for pulmonary and gastro-intestinal troubles. Root and bark are administered in Sierra Leone as a tonic to men ‘to make their organs work well’ and in that country too bark is added to palm-wine to improve its potency.

Bark is administered in Ivory Coast as an aphrodisiac. In S Nigeria a cold-water extract of root-bark with salt administered to cases of ukwala (cough) and agboor (vomiting), identified as bronchial asthma or cough, and vomiting, is said to promote improvement. The bark is used in tanning in Ghana, and during the 1939–45 War thousands of tons were exported as a tanning material.

Tannins, a reducing sugar and traces of an alkaloid have been detected in the bark; flavonins are also present, the whole being extremely bitter, resinous and astringent. The leaves have a bitter taste. They are used in Congo as a deterrant to fleas.

A leaf-infusion is purgative. The fruits are edible, orange-sized, and contain a yellow pulp surrounding four seeds. The fruits are eaten in Nigeria as a cure for general aches in the head, back, etc., and as a vermifuge.

Igbo medicine-men prescribe the fruit for arthritic conditions. Wild animals go for them and the elephant is particularly partial, coming from afar to trees in season. The residue after chewing is white. They are eaten raw and not in prepared food. They have medicinal attributes. Mastication will relieve coughs, hoarseness, and bronchial and throat troubles. They are taken dry as a remedy for dysentery. They are said to provide an antidote against Strophanthus poisoning. They are vermifugal.

In Senegal, on Mt. Nimba, Liberia, in Ivory Coast and in Congo they are considered aphrodisiac. In Liberia the seeds are chopped up and steeped in water or better still in beer, while in Congo they enter into many medico-magical remedies taken with palm-wine ‘to cleanse the stomach and to give strength in love’.

In Nigeria the simple act of mastication of the seeds is held to be as effective. The active principle, or principles, in the nut remain enigmatic. Caffeine, which is present in the true kola, is absent. A trace of alkaloid has been reported in Nigerian materials, but absent in other samples. Tannins are present which may contain the anti-bacterials morellin and guttiferin. The seeds have been shown to have four fluorescent substances of an undetermined nature. Activity may also lie in resins, which are as yet unidentified.

Source: The Guardian News


Publish Date: 

Sunday, 6 October 2013