Nevirapine induces testicular toxicity in Wistar rats: reversal effect of kolaviron (biflavonoid from Garcinia kola seeds)

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.

Kolaviron, a Garcinia kola biflavonoid complex, protects against ischemia/reperfusion injury: pertinent mechanistic insights from biochemical and physical evaluations in rat brain

The pathophysiology of stroke is characterized by biochemical and physical alterations in the brain. Modulation of such aberrations by therapeutic agents affords insights into their mechanism of action. Incontrovertible evidences that oxidative stress is involved in the pathophysiology of neurologic disorders have brought antioxidative compounds, especially plant phytochemicals, under increasing focus as potential remedies for the prevention and management of neurodegenerative diseases. Kolaviron, a biflavonoid complex isolated from Garcinia kola Heckel (Guttiferae) was evaluated for neuroprotectivity in brains of male Wistar rats submitted to bilateral common carotid artery occlusion-induced global ischemia/reperfusion injury (I/R). Animals were divided into six groups: sham treated, vehicle (I/R), 50 mg/kg kolaviron + I/R, 100 mg/kg kolaviron + I/R, 200 mg/kg kolaviron + I/R and quercetin (20 mg/kg i.p.) + I/R. The common carotid arteries were occluded for 30 min followed by 2 h of reperfusion. Relative brain weight and brain water content were determined and oxidative stress and neurochemical markers were also evaluated. I/R caused significant decreases in glutathione level and the activities of enzymic antioxidants, the sodium pump and acetylcholinesterase while significant increases were recorded in relative brain weight, brain water content, lipid peroxidation and the activities of glutamine synthetase and myeloperoxidase. There was a remarkable ablation of I/R induced oxidative stress, neurochemical aberrations and brain edema in animals pretreated with kolaviron. The results suggested that the protection afforded by kolaviron probably involved regulation of redox and electrolyte homeostasis as well as anti-inflammatory and antiexcitotoxic mechanisms.

Kolaviron and L-ascorbic Acid attenuate chlorambucil-induced testicular oxidative stress in rats

Chlorambucil (4-[4-[bis(2-chloroethyl)amino]phenyl]butanoic acid) is an alkylating agent, indicated in chronic lymphocytic leukaemia. Kolaviron (KV), a biflavonoid complex from Garcinia kola, and L-ascorbic acid (AA) are known to protect against oxidative damage in vivo. This study evaluates the protective capacity of KV and AA on chlorambucil-induced oxidative stress in the testes of rat. Twenty male Wistar rats (180–200 g) were randomized into four groups: I: control, II: chlorambucil (0.2 mg/kg b.w.), III: 0.2 mg/kg chlorambucil and 100 mg/kg KV, and IV: 0.2 mg/kg chlorambucil and 100 mg/kg AA. After 14 days of treatments, results indicated that chlorambucil caused significant reduction (P < 0.05) in testicular vitamin C and glutathione by 32% and 39%, respectively, relative to control. Similarly, activities of testicular GST, SOD, and CAT reduced significantly by 48%, 47%, and 49%, respectively, in chlorambucil-treated rats relative to control. Testicular MDA and activities of ALP, LDH, and ACP were increased significantly by 53%, 51%, 64%, and 70%, respectively, in the chlorambucil-treated rat. However, cotreatment with KV and AA offered protection and restored the levels of vitamin C, GSH, and MDA as well as SOD, CAT, GST, ACP, ALP, and LDH activities. Overall, kolaviron and L-ascorbic acid protected against chlorambucil-induced damage in the testes of the rat.