Ameliorative effect of Kolaviron, an extract of Garcinia kola seeds, on induced hypertension

The role of Kolaviron, a bioflavonoid from Garcinia kola, in the management of cardiovascular diseases: A systematic review

While the cardiovascular effects of Kolaviron (KV) and Garcinia kola (GK) are documented in the literature, a thorough search through literature revealed a fragmentation of information on the effect of KV and GK on cardiovascular diseases (CVDs). This systematic review aims to evaluate and summarize preclinical or clinical evidence on the effect of KV and GK on CVDs. Using the PRISMA guidelines, a systematic literature search was conducted in five medical databases (PubMed, Cochrane, EMBASE, CINAHL, and Web of Science). Inclusion criteria included both in vivo and in vitro studies related to CVDs. Eligible studies included those in which specific clinical parameters, CVD biomarkers, or voltage-gated channel effects were reported. The quality of the included studies was assessed using a modified Collaborative Approach to Meta-Analysis and Review of Animal Data from the Experimental Studies (CAMARADE) checklist. A total of 22 studies were included in this systematic review. The median and mean values of the included studies' quality scores were 6 and 5.864 ± 0.296, respectively. The results from the quality assessment of included studies validate their suitability, usefulness, and fit. Based on this systematic review, the effect of KV and GK on CVDs can be divided into eight emerging trends: (1) Anti-hypertensive/Blood pressure lowering effect; (2) Lipid profile improvement effect (3) Anti-atherosclerotic effect; (4) Anti-thrombotic effect; (5) Cardioprotection; (6) Vasodilatory effect; (7) Antioxidant effects; and (8) Genetic expression and therapeutic target for cardiovascular dysfunction. From this systematic review, it can be concluded that KV is helpful in managing CVD risk factors such as hypertension and high lipids/cholesterol. Several included studies in this review demonstrated the antihypertensive, lipid improvement, antioxidant, and signaling pathway modulation effects of KV. This potentially makes KV a good therapeutic target for the management of CVDs.

Garcinia kola: a critical review on chemistry and pharmacology of an important West African medicinal plant

Garcinia kola Heckel (Clusiaceae) is a tree indigenous to West and Central Africa. All plant parts, but especially the seeds, are of value in local folklore medicine. Garcinia kola is used in treatment of numerous diseases, including gastric disorders, bronchial diseases, fever, malaria and is used to induce a stimulating and aphrodisiac effect. The plant is now attracting considerable interest as a possible source of pharmaceutically important drugs. Several different classes of compounds such as biflavonoids, benzophenones, benzofurans, benzopyran, vitamin E derivatives, xanthones, and phytosterols, have been isolated from G. kola, of which many appears to be found only in this species, such as garcinianin (found in seeds and roots), kolanone (fruit pulp, seeds, roots), gakolanone (stem bark), garcinoic acid, garcinal (both in seeds), garcifuran A and B, and garcipyran (all in roots). They showed a wide range of pharmacological activities (e.g. analgesic, anticancer, antidiabetic, anti-inflammatory, antimalarial, antimicrobial, hepatoprotective and neuroprotective effects), though this has only been confirmed in animal models. Kolaviron is the most studied compound and is perceived by many studies as the active principle of G. kola. However, its research is associated with significant flaws (e.g. too high doses tested, inappropriate positive control). Garcinol has been tested under better conditions and is perhaps showing more promising results and should attract deeper research interest (especially in the area of anticancer, antimicrobial, and neuroprotective activity). Human clinical trials and mechanism-of-action studies must be carried out to verify whether any of the compounds present in G. kola may be used as a lead in the drug development.

Antihypertensive Effect of Kolaviron, a Bioflavonoid From Garcinia kola, in L-NAME Induced Hypertension in Rats

The antihypertensive effect of Kolaviron (KV) has been demonstrated in ethanol- and sucrose-model of hypertension in our previous studies. However, there remains a need to further confirm and validate this effect in other models of hypertension. This study was devised to appraise the antihypertensive action of KV in N(G)-nitro-L-arginine methyl ester (L-NAME) induced experimental format of hypertension. Thirty-six (36) male Wistar rats were divided into 6 groups of 6 animals each. Group I represents the control group while Group II animals received L-NAME 40 mg/kg only. Groups III to V animals received L-NAME 40 mg/kg and 50, 100, and 200 mg/kg KV, respectively. Group VI animals received L-NAME 40 mg/kg and 0.14 mg/kg Lisinopril (LIS). Treatment was done orally for 28 days after which blood pressure was determined via the invasive method. After this, vital organs and blood were retrieved for analysis. KV and LIS elicited significant contraction ( P < .01-.001) in blood pressure producing up to 27%, 24%, and 22% reduction in systolic blood pressure, diastolic blood pressure, and mean arterial pressure, respectively. In addition, KV elicited a notable rise ( P < .05-.001) in catalase, reduced glutathione, and superoxide dismutase in the blood and vital organs. Results from this study further demonstrate and confirm that KV possesses notable blood pressure-lowering effect possibly through its well-documented antioxidant effect. Additional studies are advocated to validate the results from this study and determine the precise mechanism for the antihypertensive action of KV.

Ninety-day oral toxicological profiling of Kolaviron (an extract of Garcinia kola) in male and female rats

There remains an insufficiency of data on the long-term toxicological profile of Garcinia kola Heckel and its extract, Kolaviron (KV), despite several studies on its pharmacological effects. This research was designed to investigate the long-term histopathological, hematological, biochemical, hormonal, reproductive, and oxidative effects of 90 days administration of KV to male and female rats, as well as additional 30 days reversibility study to assess the potential for reversal of induced effects. Fifty-six male and female Wistar rats divided into four groups were treated orally with distilled water/propylene glycol, 20 mg/kg KV, 100 mg/kg KV, and 500 mg/kg KV for 90 days. At the end of 90 days and 30 additional days of reversibility study, 5 ml blood was collected from animals for relevant analyses. Vital organs were harvested for histopathological assessments. In this study, KV did not elicit any adverse effect on histopathological presentations of vital organs which were generally non-abnormal. There was significant increase (p < 0.05) in LEU, MON, EOS%, BAS%, HCT (male animals) and LYM%, EOS%, BAS%, RBC, hemoglobin and MCH (female animals). There was significant diminution (p < 0.05) in cholesterol, triglycerides, LDL, and VLDL levels, with significant increase (p < 0.05) in HDL level in both male and female animals. KV elicited a non-significant increase in sperm count accompanied by a significant increase (p < 0.05) in levels of Follicle stimulating hormone (FSH) and testosterone in male rats. Furthermore, KV elicited significant (p < 0.001-0.05) elevation in the levels of GSH, SOD and CAT, and diminution in the level of MDA. The findings in this study suggest that long-term administration of KV is considerably safe with some variations in response between male and female animals. The possible sustenance of observed effects after cessation of KV administration, lipid lowering, erythropoiesis inducing, and immune system boosting activities of KV were confirmed in this study.

Kolaviron attenuates cardiovascular injury in fructose-streptozotocin induced type-2 diabetic male rats by reducing oxidative stress, inflammation, and improving cardiovascular risk markers

The prevalence of cardiovascular disease among type-2 diabetic patients has become a source of major concern world over. This study explored the protective effect of kolaviron, a bioflavonoid, against oxidative cardiovascular injury in fructose- streptozotocin-induced type 2 diabetic male Sprague Dawley rats. After acclimatization, induction, and confirmation of type-2 diabetes, kolaviron was administered for 28days, after which the animals were anesthetized with Isofor and euthanized. Blood from each rat were collected, and blood samples were then centrifuged for serum and plasma. Cardiac troponin I (cTnI), creatine kinase myocardial band (CK-MB), Creatine phosphokinase (CK), and insulin levels were immediately determined in serum, while remaining samples (serum, plasma, and organs) were stored in the bio-freezer at - 80 °C and 10% formalin for enzyme-link immunosorbent assay (ELISA), biochemical, molecular, and histopathological studies. The results show that type-2 diabetes induction with fructose and streptozotocin led to increased blood glucose levels, decreased insulin levels and cardiac antioxidant enzyme activities, increased malondialdehyde levels, cardiac biomarkers and pro-inflammatory cytokines levels, resulted in abnormal lipid profile, increased blood pressure and angiotensin-converting enzyme (ACE) activity, and decreased plasma endothelial nitric oxide synthase (eNOS) concentration. The histopathological examination of the cardiac tissue revealed severe lesion, hypertrophy, and myofibrils degeneration. However, administration of kolaviron for 28days remarkably improved these conditions. Hence the result from the study validates the potency of kolaviron, and suggests it could serve as an alternative to existing remedy in ameliorating or protecting against cardiovascular injury in type-2 diabetes.