Analysis of some selected toxic metals in registered herbal products manufactured in Nigeria

The use of herbal medicine has been on the increase in many developing and industrialized countries and Nigerians in particular has been using herbal medicine for many centuries. The approval of these herbal remedies by regulatory bodies has further encouraged the use of herbal remedies. The safety of these herbal remedies is however poorly understood. This study investigated the concentration of arsenic, cadmium, lead and mercury in twenty registered ready to use herbal products. Twenty brands of herbal remedies were purchased randomly from the Pharmacy shops in Lagos, digested with aquaregia (3:1 HCl: HNO3) and were analysed using atomic absorption spectroscopy (Buck 205 Atomic Absorption Spectrophotometer). There was no detectable lead in any of the 20 herbal samples; however, all the samples contained a detectable amount of one or more of the other metals of interest. The Oral Component Limit (OCL) for arsenic, cadmium and mercury as stated by USP are 1.5, 0.5 and 1.5 μg/g, respectively. All the samples contained arsenic and mercury below the USP OCL, while sixtyfive percent contained cadmium out of which fifty-five percent were above USP OCL. The results obtained from this study suggest a significant risk to consumers’ health considering the toxicity of these heavy metals.Key words: Herbal remedies, toxic heavy metals, atomic absorption spectrophotometry

Evaluation of the concentration of toxic metals in cosmetic products in Nigeria

It has been shown that heavy metals toxicity to humans is as a result of long term or high level exposure to pollutants common in the environment including the air, water, food and numerous consumer products such as the cosmetics and toiletries. In this study, we assessed the levels of toxic metals in different cosmetic products sold at local shops in Lagos, Nigeria. The cosmetic items included thirty creams and twenty lipsticks and lip glosses. These items were purchased from various shops at different locations in Lagos. The cosmetics were analyzed for heavy metals (arsenic, cadmium, lead, mercury and nickel) after digestion with concentrated acids HNO3: H2SO4: HClO4 in ratio 2:2:1. The concentrations of the selected toxic heavy metals were determined in duplicate using a Buck 205 flame atomic absorption spectrophotometer. All the samples analyzed contained a detectable amount of all the metals of interest. The concentration of the heavy metals in the samples ranged from 0.006 to 0.207 ppm. It is obvious from the present study that the use of some cosmetic products exposes users to low concentrations of toxic heavy metals which could constitute potential health risk to users since it has been known that heavy metals can accumulate in the biological system over time and are known to induce skin problems or diseases such as cancer. Further research to better understand the sources of heavy metals in cosmetic products is recommended.Key words: Toxic heavy metals, cosmetics, atomic absorption spectrophotometer, environment

Phytochemical Screening and Antioxidant Activities of Some Selected Medicinal Plants Used for Malaria Therapy in Southwestern Nigeria

Purpose: Oxidative stress has been shown to play an important role in the development of anaemia in malaria. Indeed, increase in total antioxidant status has been shown to be important in recovery from malaria. The antioxidant activities of four medicinal plants traditionally used in the treatment of malaria in southwestern Nigeria were determined. Methods: The ethanolic extracts of the leaves of Carica papaya Linn. [Caricaceae] , stem bark of Magnifera indica Linn. [Anacardiaceae], leaves of Psidium guajava Linn. [Myrtaceae] and the leaves of Vernonia amygdalina Del. [Compositae], were used in the present study. The plant parts commonly used in the locality in malaria therapy were employed in this study. The plants were screened for the presence of phytochemicals and, their effect on 2,2-Diphenyl-1-picryl-hydrazyl radical (DPPH) was used to determine their free radical scavenging activity. Results: Phytochemical screening of the plants showed the presence of flavonoids, terpenoids, saponins, tannins and reducing sugars. M. indica did not contain cardiac glycosides and alkaloids while, P. guajava also showed the absence of alkaloids and anthraquinones. Anthraquinones was similarly absent from V. amygdalina. Concentrations of the plant extracts required for 50% inhibition of DPPH radical scavenging effect (IC50) were recorded as 0.04 mg/ml, 0.313 mg/ml, 0.58 mg/ml, 2.30 mg/ml and 0.054 mg/ml for P. guajava, M. Indica, C. papaya, V. amygdalina and Vitamin C, respectively. Conclusion: All the plants showed potent inhibition of DPPH radical scavenging activity, P. guajava being the most potent. The free radical scavenging (antioxidant) activities of these plants probably contribute to the effectiveness of the above plants in malaria therapy. Keywords: Carica papaya, Magnifera indica, Psidium guajava, Vernonia amygdalina, Antioxidants, Malaria, DPPH, Oxidative stress. Tropical Journal of Pharmaceutical Research Vol. 7 (3) 2008: pp. 1019-102

Evaluation of the chemical constituents and the antimicrobial activity of the volatile oil of Citrus reticulata fruit(Tangerine fruit peel) from South West Nigeria

The volatile oil of tangerine fruit (Citrus reticulata) was extracted by steam distillation and assessed for antibacterial and antioxidant activity. The volatile oil was tested against some Gram-negative organisms (Escherichia coli ATCC 35218, E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella paratyphi, Proteus mirabilis and Citrobacter spp); Gram-positive organisms such as Staphylococcus aureus ATCC 25923, S. aureus, Enterococcus faecalis and a fungus (Candida albicans). The minimum inhibitory concentration (MIC) was determined with concentrations of oil extract ranging from 0.87 to 445 mg/ml. Result of the study showed that the oil has a broad spectrum antibacterial activity. MIC recorded were S. aureus (0.74 mg/ml), S. aureus ATTC 25923 (2.46 mg/ml), E. faecalis (1.26 mg/ml), S. typhi (2.07 mg/ml), K. pneumoniae (0.56 mg/ml), E. coli ATTC 35218 (0.19 mg/ml), E. coli (1.95 mg/ml), P. aeruginosa (0.97 mg/ml), C. albicans (0.68 mg/ml). Antioxidant screening with 2,2-diphenyl-1-picrylhydrazyl (DPPH) was negative. Analysis of the chemical constituent by GC-MS showed the presence of D-limonene as the major constituent. Other constituents found were a-pinene and β-pinene

Evaluation of the concentration of some toxic metals in dietary red palm oil

Palm oil has been part of human diet for more than 5000 years. For generations, it has been revered as both a nutritious food and a valuable medicine. However, care should be taken to evaluate the purity and safety of this nutritional and medicinal agent to the human system. This study investigated the concentration of cadmium, chromium, mercury, lead, arsenic and nickel in twenty-five samples of ready-to consume palm oil that were bought randomly from different markets in Lagos, Nigeria. The samples were digested with aqua-regia (2:1:2 HNO3 :HClO4 :H2 SO4 respectively) and the digested samples were analyzed using Atomic Absorption Spectroscopy. There was no detectable mercury in one of the twenty-five samples analysed. However, all the samples contained a detectable amount of each of the other five metals analysed. The Oral Component Limit (OCL) for cadmium, chromium, mercury, lead, arsenic and nickel as stated by USP are 0.5µg/g, 25 µg/g, 1.5 µg/g, 1 µg/g, 1.5 µg/g and 25 µg/g respectively. The samples contained detectable amounts of the metals although with values below the USP standard OCL. The results obtained from this study suggest that the palm oil samples analysed are save for consumption in terms of the metals of interest analysed

The physicochemical and antibacterial properties of Ciproflaxacin-Mg2* complex

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Evaluation of the concentration of toxic metals in cosmetic products in Nigeria

It has been shown that heavy metals toxicity to humans is as a result of long term or high level exposure to pollutants common in the environment including the air, water, food and numerous consumer products such as the cosmetics and toiletries. In this study, we assessed the levels of toxic metals in different cosmetic products sold at local shops in Lagos, Nigeria. The cosmetic items included thirty creams and twenty lipsticks and lip glosses. These items were purchased from various shops at different locations in Lagos. The cosmetics were analyzed for heavy metals (arsenic, cadmium, lead, mercury and nickel) after digestion with concentrated acids HNO3: H2SO4: HClO4 in ratio 2:2:1. The concentrations of the selected toxic heavy metals were determined in duplicate using a Buck 205 flame atomic absorption spectrophotometer. All the samples analyzed contained a detectable amount of all the metals of interest. The concentration of the heavy metals in the samples ranged from 0.006 to 0.207 ppm. It is obvious from the present study that the use of some cosmetic products exposes users to low concentrations of toxic heavy metals which could constitute potential health risk to users since it has been known that heavy metals can accumulate in the biological system over time and are known to induce skin problems or diseases such as cancer. Further research to better understand the sources of heavy metals in cosmetic products is recommended

Phytochemical Screening and Free Radical Scavenging Activities of the Fruits and Leaves of Allanblackia floribunda Oliv (Guttiferae)

Purpose: To compare the phytochemical constituents in the leaves and fruits of Allanblackia floribunda and determine their free radical scavenging activity. Methods: The fruit and leaves of AF collected from the uncultivated farmlands of Okeigbo, Ondo State, Nigeria, were dried, milled and extracted with methanol. Phytochemical screening was carried out according to standard procedures. Free radical scavenging activity was determined by measuring the decrease in the visible absorbance of 2,2-diphenyl-1-picrylhydrazyl (DPPH) on addition of the plant extract. The mean inhibitory concentration (IC50), which is the concentration of extract needed to decrease the initial absorbance of DPPH by 50% was determined graphically. Total phenolic, flavonoids and proanthocyanidin contents were determined by spectrophotometric methods. Results: Alkaloids, anthraquinones, tannins, saponins, steroids, terpenoids, flavonoids and cardiac glycosides were found to be present in both the fruits and leaves. Only AF fruit contained phlobatannins. IC50 values of 0.01, 0.02 and 0.1 mg/ml were recorded for Vitamin E, AF leaves and AF fruits respectively. Total phenolic, total flavonoid and proanthocyanidin contents were 65, 0.07 and 2.38 mg/g of powdered plant material for AF fruits, and 12, 51.35, 19.5 mg/g of powdered plant material for AF leaves as gallic acid, rutin and catechin equivalents respectively. Conclusion: AF leaves are five times more potent as a free radical scavenger compared to the fruits though the fruit was found to contain a higher phenolic content. Keywords: Free radical scavenger, phenolic content, proanthocyanidin, flavonoids, DPPH, Allanblankia floribunda, tannins, steroids, alkaloids and anthraquinones