Bombax costatum enhances piroxicam's efficacy: Possible involvement of alpha-2 adrenergic receptor, opioidergic and arachidonic pathways.

BACKGROUND: With increasing drug-herb combination and widespread use of Bombax costatum as analgesic in Africa, this research studies effects of Bombax costatum on piroxicam's efficacy and possible mechanisms of antinociception. MATERIALS AND METHODS: In efficacy studies, four groups of mice were respectively treated with 1mL/kg distilled water, 400mg/kg Bombax costatum, 20mg/kg piroxicam and a combination of both. Acetic acid and hot plate were used to induce pain in mice while prostaglandin-E2 and formalin were used to induce inflammation in rats. For mechanistic studies, different groups of mice were treated intraperitoneally with 2mg/kg naloxone, 1mg/kg yohimbine, 20mg/kg propranolol, 5mg/kg glibenclamide and 1mg/kg prazosin respectively. Two other groups were treated orally with 1mL/kg of the vehicle and 400mg/kg Bombax costatum respectively. 60minutes later, 10mL/kg of 0.6% acetic acid was administered via the intraperitoneal route and number of writhes were observed for 10minutes. RESULTS: Concurrent administration of Bombax costatum and piroxicam decreased the number of writhes significantly (P≤0.001), increased reaction time with decreased paw diameter in comparison to control. Additionally, this drug-herb combination showed enhanced anti-nocipective efficacy than when administered singly. Also, pre-treatment with yohimbine and naloxone significantly (P≤0.01) inhibited the antinociceptive activities of Bombax costatum. CONCLUSION: Bombax costatum posses antinociceptive and anti-inflammatory activities and may involve α-2 adrenergic receptor, opioidergic and arachidonic pathways. In addition, Bombax costaum augments the efficacy of piroxicam and could be of clinical benefits if studied on man.

Diurnal efficacy of alpha-lipoic acid/nifedipine/glimepiride combination mitigates diabetic neuropathies in rats.

OBJECTIVES: Time-dependent effects of alpha-lipoic acid/nifedipine/glimepiride combination on diabetic neuropathies were investigated in rats. 7 groups (n=9) of rats were used. MATERIALS AND METHODS: First and second groups were apparently normal and diabetic rats respectively, and were administered 1mL/kg distilled water. The rest of the groups were diabetic and administered 10mg/kg glimepiride at night-time (8:00 pm). Groups 4-7 were administered additional 20mg/kg nifedipine at morning-time (8:00 am), while groups 5-7 were also administered 100mg/kg alpha-lipoic acid (ALA) in the morning, afternoon and night-time respectively (8:00 am, 2:00 pm and 8:00 pm). During the 28 days of oral treatment, paw pressure, tail immersion and motor coordination tests were conducted. The rats were euthanized on the 29th day after a charcoal meal. The small intestines were excised to determine intestinal transit while the brain was collected, homogenised and used to determine levels of oxidative stress. RESULTS: Data show that treatment with ALA at 8:00 am or 2:00 pm significantly (P≤0.01) produced a delay in the onset and improved prognosis of neuropathies. Treatment with ALA at 8:00 pm prevented manifestation of neuropathies throughout the study with positive antioxidant effects. CONCLUSION: Time-dependent ALA treatment in combination with nifedipine and glimepiride should be studied in humans with an approximately similar circadian timing. This may provide additional clinical therapeutic options for diabetic neuropathies.

Bombax Costatum extract abrogates piroxicam-mediated hepatic and gastric toxicities in rats.

OBJECTIVE: Concurrent administration of orthodox drugs and herbs is common in tropical Africa. This study investigates the effect of co-administration of piroxicam and Bombax costatum on hepatic and gastric toxicities and levels of oxidative stress markers. MATERIALS AND METHODS: Twenty male wistar rats were grouped into four. Rats in group one were administered 1mL/kg distilled water as normal control; group two were treated with 400mg/kg of extract; group three were treated with 20mg/kg of piroxicam; while those in group four were treated with both extract and piroxicam at 400mg/kg and 20mg/kg, respectively. All treatments were given orally for 14 days. At the end of the treatment period, the rats were euthanised; blood samples and stomach were collected for determination of hepatic and gastro-toxicity alongside with oxidative stress markers. RESULTS: Treatment with piroxicam alone shows the presence of oxidative stress with marked hepatic and gastric toxicities. Oxidative stress markers, hepatic and gastric toxicity indices after treatment with extract alone and in combination with piroxicam appear like that of the control group. CONCLUSION: Concurrent administration of piroxicam and Bombax costatum prevents piroxicam-induced hepatic and gastric toxicities with a positive effect on antioxidant levels. This may indicate important health benefits of this drug-herb combination.