School of Biological Sciences, Vel Tech Dr. RR & Dr. SR Technical University, 40, Avadi-Alamadhi Road, Avadi, Chennai 600062, Research and Development, MARINA LABS, 40, Anna Nedum Pathai, Choolaimedu, Chennai 600094
Email: deepabt06@gmail.com
Received: 14 Jul 2014 Revised and Accepted: 15 Aug 2014
ABSTRACT
Objective: To assess the quality of herbal materials for the presence of heavy metals.
Methods: Herbal materials of around 49 samples from Chennai markets were procured and analysed for the presence of metals like Copper (Cu), Calcium (Ca), Cobalt (Co), Sodium (Na), Nickel (Ni), Magnesium (Mg), Manganese (Mn), Iron (Fe), Chromium (Cr) and Lead (Pb) using AAS, Shimadzu, AA 7000, Japan.
Results: The raw materials of the commercial herbal products were found to contain Manganese, Calcium and Magnesium at greater concentrations, when compared with the other elements analyzed.
Conclusion: The presence of the metals analyzed were found to be within permissible limits in accordance to the American Herbal Products Association (AHPA) and WHO standards. Although the study implies consumption of herbal materials are safe, periodical monitoring of the quality of the herbal materials is recommended.
Keywords: Herbal materials, Heavy metals, Quality Assessment, Atomic Absorption Spectroscopy.
INTRODUCTION
Utilization of plants in medicine is widely followed throughout the world. Traditional medicine which includes Siddha, Ayurveda, Unani, Tibetian and Chinese medicine, use plants to control human ailments. India is not remorse in using plants in her medicinal system [1]. Over 2000 plants have been recommended by World Health Organization (WHO), based on their medicinal attributes [2]. India has officially recognized over 3000 plants for their medicinal value and nearly 6000 plants are used in India’s traditional medical system [3]. However, the concern is about the safety of herbal drugs or raw materials which are freely available in the markets as over the counter (OTC) medicines.
The contaminants of the herbal raw materials or the finished products are widely reported as the major reason to lose the international market, thus affecting the economy. The safety concern is mostly due to the natural contaminants like microbes and heavy metals present in the environment which in turn find their way into the herbal materials. Herbal materials are defined as either whole plants or parts of medicinal plants in the crude state which include herbs, gums, resins and dry powders of herbs [4].
Earlier reports have indicated that herbal medicines contain toxic heavy metals as contaminants which can cause adverse effects like cancer, liver dysfunction, skin eruptions, lung disease, cerebral haemorrhage, alopecia etc. WHO has emphasized to ensure the quality control and safety of herbal products [5].
Metals such as iron, calcium, manganese, cobalt, copper, zinc, nickel, in trace amounts, are essential for human life, as growth supplements. However, large amount of heavy metal accumulation in human body get absorbed and form complexes with proteins, eventually leading to malfunctioning or death of the cells [6].
Non-essential metals such as lead, cadmium are toxic even in trace amounts while few metals (like Chromium and Arsenic) are considered as potential contaminants [7]. The aim of the present study is to ascertain the quality of herbal materials towards the presence of toxic or heavy metals sold in open markets of Chennai, India.
MATERIALS AND METHODS
Sample Collection
A total of 49 raw materials of herbal products were procured from the local markets of Chennai, Tamil Nadu. The samples, belonging to 34 different families, were digested by wet digestion method. The procured material list consisting of vernacular name of the plant and the plant part used in the system of Siddha medicine in India along with its botanical name and family are provided in Table 1.
Analysis of Heavy metals
About 1 g of the sample was accurately weighed and dried in hot air oven at 120° C so as to remove the moisture content. The dried products were digested with Nitric acid (1%) and left at room temperature for 24 h. The digested samples were filtered through Whatman filter paper. The filtrate was used for the experiment [8].
The digested samples were analysed for the quantification of elements like Copper (Cu), Calcium (Ca), Cobalt (Co), Sodium (Na), Nickel (Ni), Magnesium (Mg), Manganese (Mn), Iron (Fe), Chromium (Cr) and Lead (Pb) using AAS, Shimadzu, AA 7000, Japan. Standard solutions of the respective metallic salts (1000 ppm) were used to obtain calibration curve. The operation condition for the acetylene gas flow rate was set to 1.5 L/min and vacuum pressure to 3.5 bar. The quantity of elements present in the herbal drugs was expressed as mean of the elemental concentration ± S.D of three replicates.
RESULTS AND DISCUSSION
A major part of total population in developing countries still uses folklore medicine obtained from plant resources due to its cost effectiveness and accessibility [1]. The safety and quality of herbal drugs have become a major distress for pharmaceutical industries [4]. The phytomedicines of plant species used in homeopathic system have been traced with the presence of Ca, Cr, Cu, Fe, Mg, Ca, K and Zn [9].
The raw materials of the herbal products studied showed the presence of the metals- manganese, calcium, magnesium, copper, lead, iron, nickel, chromium, cobalt and sodium.
The raw materials of the commercial herbal products were found to contain Manganese, Calcium and Magnesium at greater concentrations, when compared with the other elements analysed. The highest concentration of Mn was recorded in Zingiber officinale (499.597±0.0062 ppm/g) while the lowest was recorded in Tribulus terrestris (0.8309±0.0006 ppm/g). Mn deficiency in human causes cardiovascular diseases, immunodeficiency disorders and rheumatic arthritis in adults [10].
Table 1: List of Herbal materials, the part used in medicine, their scientific name and family
| S. No. | Vernacular name of the plant/ Part used in Siddha medicine | Botanical name | Family |
| 1 | Aadhathoda (leaf) | Adhatoda vasica | Acanthaceae |
| 2 | Aaduthinnapalai (leaf) | Aristolochia bracteolata | Aristolochiaceae |
| 3 | Aalam pattai (bark) | Arenga wightii | Arecaceae |
| 4 | Amukkara (leaf) | Withania somnifera | Solanaceae |
| 5 | Arugampul (leaf) | Cynodon dactylon | Poaceae |
| 6 | Ashoka pattai (bark) | Saraca asoca | Fabaceae |
| 7 | Avarampoo (flower) | Cassia auriculata | Fabaceae |
| 8 | Boomi sakkarai kizhangu (tuber) | Maerua arenaria | Capparaceae |
| 9 | Chiriyanangai (leaf) | Andrographis paniculata (a) | Acanthaceae |
| 10 | Chittharathai (rhizome) | Alpinia galanga | Zingiberaceae |
| 11 | Elumbu otti (leaf) | Blepharis maderaspatensis | Acanthaceae |
| 12 | Jaathikai (fruit) | Myristica fragrans | Myristicaceae |
| 13 | Kaasini keerai (leaf) | Cichorium intybus | Asteraceae |
| 14 | Kadukai (fruit) | Terminalia chebula | Combretaceae |
| 15 | Kandang kathiri (leaf) | Solanum xanthocarpum | Solanaceae |
| 16 | Karisalanganni (leaf) | Eclipta prostrata | Asteraceae |
| 17 | Karivepilai (leaf) | Murraya koenigii | Rutaceae |
| 18 | Kichili kizhangu (tuber) | Kaempferia galanga | Zingiberaceae |
| 19 | Korai kizhangu (tuber) | Cyperus rotundus | Cyperaceae |
| 20 | Kuppaimeni (whole plant) | Acalypha indica | Euphorbiaceae |
| 21 | Maasikai (gall) | Quercus infectoria | Fagaceae |
| 22 | Mudakarthan(leaf) | Cardiospermum halicacabum | Sapindaceae |
| 23 | Mukkaratai (leaf) | Boerhavia diffusa | Nyctaginaceae |
| 24 | Murungai pisin (gum) | Moringa oleifera | Moringaceae |
| 25 | Musumusukkai (leaf) | Mukia madarespatana | Cucurbitaceae |
| 26 | Nannari (root) | Hemidesmus indicus | Asclepiadaceae |
| 27 | Veppilai (leaf) | Azadirachta indica | Meliaceae |
| 28 | Neermulli (leaf) | Hygrophila auriculata | Acanthaceae |
| 29 | Nerunjil (fruit) | Tribulus terrestris | Zygophyllaceae |
| 30 | Nilapanai kizhangu (tuber) | Curculigo orchioides | Hypoxidaceae |
| 31 | Nilavembu (leaf) | Andrographis paniculata (b) | Acanthaceae |
| 32 | Orithazh thamarai (whole plant) | Viola odorata | Violaceae |
| 33 | Pakarkai (fruit) | Momordica charantia | Cucurbitaceae |
| 34 | Poduthalai (whole plant) | Phyla nodiflora | Verbanaceae |
| 35 | Punaikalli (leaf) | Mucuna pruriens | Fabaceae |
| 36 | Roja malar (corolla) | Rosa L. | Rosaceae |
| 37 | Seenthil (leaf) | Tinospora cordifolia | Menispermaceae |
| 38 | Sirukurinjan (leaf) | Gymnema sylvestre | Asclepiadaceae |
| 39 | Sukku (rhizome) | Zingiber officinale | Zingiberaceae |
| 40 | Thandrikkai (fruit) | Terminalia belerica | Combretaceae |
| 41 | Thanneervittan kizhangu (tuber) | Asparagus racemosus | Asparagaceae |
| 42 | Thulasi (leaf) | Ocimum sanctum | Lamiaceae |
| 43 | Thumbai (whole plant) | Leucas aspera | Lamiaceae |
| 44 | Thuthuvalai (leaf) | Solanum trilobatum | Solanaceae |
| 45 | Vaazhai thandu (pith) | Musa paradisiaca | Musaceae |
| 46 | Vallarai (leaf) | Centella asiatica | Apiaceae |
| 47 | Vendayam (seed) | Trigonella feonum graecum | Fabaceae |
| 48 | Vettiver (root) | Chrysopogon zizanioides | Poaceae |
| 49 | Vishnu kiranti (whole plant) | Evolvulus alsinoides | Convolvulaceae |
Table 2: Presence of heavy metals in Herbal materials (In ppm/g)
| Species | Cobalt | Lead | Nickel | Sodium | Chromium |
| Acalypha indica | 0.1467±0.01528 | 0.3891±0.0097 | 0.2703±0.0031 | 0.1929±0.0009 | 1.0276±0.0045 |
| Adhatoda vasica | 0.4753±0.00061 | 0.4159±0.0052 | 0.0543±0.004 | 0.0212±0.0005 | 1.1776±0.0043 |
| Alpinia galanga | 0.075±0.0002 | 0.239±0.0096 | 0.2695±0.0045 | 0.3003±0.001 | 0.0776±0.004 |
| Andrographis paniculata (a) | 0.1064±0.00564 | 0.4589±0.0096 | 0.2683±0.0019 | 0.0459±0.0008 | 1.278±0.0038 |
| Andrographis paniculata (b) | 0.0743±0.00503 | 0.459±0.0096 | 0.0348±0.0014 | 0.0151±0.0006 | 1.1754±0.0005 |
| Arenga wightii | 0.476±0.00656 | 0.4791±0.0098 | 0.3044±0.0046 | 0.0118±0.0008 | 1.1768±0.0025 |
| Aristolochia bracteolata | 0.1754±0.00055 | 0.129±0.0096 | 1.6862±0.0047 | 0.2824±0.0014 | 0.8275±0.0041 |
| Asparagus racemosus | 0.5774±0.00257 | 0.4092±0.0099 | 0.4234±0.0191 | 0.1962±0.0007 | 1.2038±0.0036 |
| Azadirachta indica | 0.2504±0.00072 | 0.239±0.0095 | 0.0532±0.0046 | 0.0697±0.0019 | 0 |
Blepharis maderaspatensis |
0.0755±0.00333 | 0.4787±0.0097 | 0 | 0.1488±0.0011 | 0.9046±0.0041 |
| Boerhavia diffusa | 0.1499±0.00021 | 0.3324±0.0151 | 0.0861±0.0044 | 0.0135±0.0011 | 0.3526±0.0038 |
| Cardiospermum halicacabum | 0.1268±0.00197 | 0.469±0.0099 | 0.0334±0.0005 | 0.1327±0.0007 | 1.1031±0.0048 |
| Cassia auriculata | 0.0498±0.00027 | 0.159±0.0096 | 0.3697±0.0048 | 0.0792±0.0001 | 0 |
| Centella asiatica | 0.2253±0.00058 | 0.3587±0.0091 | 0.0371±0.0061 | 0.044±0.0011 | 0.7028±0.0036 |
| Chrysopogon zizanioides | 0.2052±0.00501 | 0.4694±0.0096 | 0.4208±0.0046 | 0.0182±0.0012 | 1.3521±0.0031 |
| Cichorium intybus | 0.1497±0.0007 | 0.2464±0.0057 | 0.0535±0.0044 | 0.0759±0.0011 | 0.1268±0.0027 |
| Curculigo orchioides | 0.4251±0.0022 | 0.4578±0.0078 | 0.3877±0.0045 | 0.0202±0.0008 | 1.2517±0.0025 |
| Cynodon dactylon | 0.4763±0.00513 | 0.4755±0.0049 | 0.1208±0.0046 | 0.0066±0.0006 | 1.1772±0.003 |
| Cyperus rotundus | 0.225±0.003 | 0.3674±0.0071 | 0.5016±0.0023 | 0.0732±0.001 | 0.5275±0.0038 |
| Eclipta prostrata | 0.1746±0.0024 | 0.007±0.0066 | 0.1698±0.0041 | 0.1861±0.0013 | 0.0274±0.0039 |
| Evolvulus alsinoides | 0.3371±0.01269 | 0.429±0.0095 | 0.4182±0.0016 | 0.0421±0.0005 | 1.2554±0.0047 |
| Gymnema sylvestre | 0.5756±0.0006 | 0.4289±0.0096 | 0.2172±0.0005 | 0.2779±0.0008 | 0.6778±0.0043 |
| Hemidesmu sindicus | 0.3303±0.00551 | 0.4586±0.0096 | 0.0833±0.0034 | 0.3026±0.0008 | 1.2531±0.0048 |
| Hygrophila auriculata | 0.125±0.00025 | 0.2987±0.0091 | 0.2702±0.0052 | 0.1336±0.001 | 0.2058±0.0052 |
| Kaempferia galanga | 0.6057±0.00603 | 0.3984±0.0086 | 0.1413±0.0104 | 0.0363±0.0005 | 1.1529±0.0041 |
| Leucas aspera | 0.103±0.00608 | 6.049±0.0096 | 0.3359±0.0047 | 0.0343±0.0002 | 0.1767±0.002 |
| Maerua arenaria | 0.1747±0.00461 | 0.4692±0.0099 | 0.6537±0.0039 | 0.1021±0.0007 | 0.5772±0.003 |
| Momordica charantia | 0.1052±0.00473 | 0.4491±0.0097 | 0.0866±0.0033 | 0.1149±0.0009 | 1.3046±0.0042 |
| Moringa oleifera | 0.6256±0.00053 | 0.4489±0.0094 | 0.1593±0.0121 | 0.1386±0.0006 | 0.7062±0.0054 |
| Mucuna pruriens | 0.0523±0.00252 | 0.3966±0.0061 | 0.6349±0.0021 | 0.0987±0.0005 | 0.9273±0.004 |
| Mukia madarespatana | 0.0513±0.00325 | 0.2784±0.0086 | 0.1195±0.0043 | 0.1891±0.0015 | 0.4525±0.0038 |
| Murraya koenigii | 0.4068±0.00589 | 0.4488±0.0097 | 0.2073±0.0119 | 0.0858±0.0007 | 1.2776±0.004 |
| Musa paradisiaca | 0.2075±0.00736 | 0.4089±0.0096 | 0.3374±0.0036 | 0.2362±0.0005 | 1.2276±0.0042 |
| Myristica fragrans | 0.2052±0.00501 | 0.509±0.0096 | 0.0687±0.0017 | 0.0269±0.001 | 1.2552±0.005 |
| Ocimum sanctum | 0.4787±0.00403 | 0.4588±0.0097 | 0.2048±0.005 | 0.2015±0.0011 | 1.0775±0.0041 |
| Phyla nodiflora | 0.2567±0.00651 | 0.4094±0.0101 | 0.0361±0.003 | 0.1518±0.0006 | 1.152±0.0031 |
| Quercus infectoria | 0.1756±0.00072 | 0.4557±0.0049 | 0.1036±0.0031 | 0.1485±0.0005 | 1.0777±0.0042 |
| Rosa L. | 0.5001±0.00061 | 0.309±0.0096 | 0.1865±0.0056 | 0.1533±0.0004 | 1.2776±0.004 |
| Saraca asoca | 0.5778±0.00314 | 0.4489±0.0098 | 0.4843±0.0049 | 0.0197±0.0006 | 1.2277±0.0043 |
| Solanum trilobatum | 0.3295±0.00409 | 0.4393±0.01 | 0.237±0.0061 | 0.1257±0.0005 | 1.2775±0.0041 |
| Solanum xanthocarpum | 0.125±0.00015 | 0.2894±0.0096 | 0.0168±0.0003 | 0.1001±0.0009 | 0.1553±0.0046 |
| Terminalia belerica | 0.0261±0.00211 | 0.5288±0.0097 | 0.2373±0.0045 | 0.0898±0.0006 | 0.1281±0.0016 |
| Terminalia chebula | 0.1064±0.00553 | 0.449±0.0099 | 0.3201±0.0057 | 0.2446±0.0008 | 1.352±0.0032 |
| Tinospora cordifolia | 0.5514±0.00145 | 0.4089±0.0098 | 0.1343±0.0021 | 0.0437±0.0006 | 1.3055±0.0049 |
| Tribulus terrestris | 0.5254±0.00069 | 0.1892±0.0098 | 0.053±0.0027 | 0.0565±0.0008 | 0.9785±0.0053 |
Trigonella feonum graecum |
0.0756±0.00125 | 0.4786±0.0089 | 0.0844±0.0031 | 0.0212±0.0006 | 1.1234±0.003 |
| Viola odorata | 0.2039±0.00699 | 0.4787±0.0097 | 0.0677±0.0011 | 0.1839±0.001 | 1.2521±0.0031 |
| Withania somnifera | 0.1093±0.00815 | 0.469±0.0096 | 0.3207±0.0047 | 0.096±0.0005 | 1.2522±0.003 |
| Zingiber officinale | 0.0742±0.00312 | 0.4488±0.0095 | 0.3097±0.0176 | 0.0081±0.0005 | 1.3272±0.003 |
| Permisssible limits (AHPA/WHO) | Yet to be established | 10 | 10 | - | 2 |
Table 2 Continued
| Species | Calcium | Copper | Iron | Magnesium | Manganese |
| Acalypha indica | 285.474±0.005 | 47.651±0.0019 | 0.5834±0.0011 | 106.179±0.0008 | 5.00093±0.001 |
| Adhatoda vasica | 218.4032±0.0045 | 37.601±0.0017 | 0.9732±0.0008 | 107.969±0.0012 | 12.754±0.0007 |
| Alpinia galanga | 187.8591±0.003 | 0.7840±0.0017 | 0.9962±0.0009 | 106.0949±0.001 | 294.90±0.0008 |
| Andrographis paniculata (a) | 151.2051±0.0048 | 0.7678±0.0014 | 3.5413±0.0005 | 107.0791±0.001 | 82.296±0.0079 |
| Andrographis paniculata (b) | 132.7456±0.0039 | 35.502±0.0027 | 0.2364±0.0017 | 106.648±0.0011 | 4.6005±0.0011 |
| Arenga wightii | 152.66±0.0045 | 25.934±0.0017 | 1.0251±0.0009 | 106.985±0.0011 | 1.285±0.0005 |
| Aristolochia bracteolata | 164.5598±0.0042 | 0.2341±0.001 | 2.4868±0.0007 | 106.1583±0.0007 | 105.7011±0.0009 |
| Asparagus racemosus | 252.9877±0.004 | 2.9013±0.0016 | 0.8784±0.0011 | 108.653±0.0009 | 4.1007±0.0011 |
| Azadirachta indica | 125.4165±0.0033 | 2.1340±0.0016 | 2.339±0.0011 | 106.506±0.0009 | 53.301±0.0009 |
| Blepharis maderaspatensis | 266.1362±0.2284 | 7.6347±0.0013 | 0.9417±0.0012 | 105.432±0.0009 | 57.601±0.0009 |
| Boerhavia diffusa | 269.3731±0.0025 | 1.0846±0.0013 | 1.2569±0.001 | 108.068±0.0009 | 51.904±0.0066 |
| Cardiospermum halicacabum | 31.80263±0.0039 | 1.8345±0.0013 | 2.151±0.0011 | 107.206±0.0012 | 80.701±0.0009 |
| Cassia auriculata | 50.91603±0.0025 | 2.0677±0.0014 | 1.4119±0.0011 | 105.516±0.0008 | 88.600±0.0007 |
| Centella asiatica | 211.1446±0.0025 | 3.1674±0.0008 | 1.7347±0.0006 | 110.004±0.0065 | 151.60±0.0008 |
| Chrysopogon zizanioides | 211.8745±0.0047 | 1.8673±0.0018 | 4.1393±0.0013 | 108.137±0.0012 | 76.200±0.0016 |
| Cichorium intybus | 202.988±0.0032 | 1.5340±0.0008 | 2.7255±0.0006 | 112.011±0.0006 | 83.501±0.0009 |
| Curculigo orchioides | 245.6691±1.1526 | 51.351±0.0014 | 0.0416±0.0011 | 108.495±0.0016 | 1.3315±0.0009 |
| Cynodon dactylon | 92.6739±0.0046 | 1.8011±0.0018 | 0.0851±0.0008 | 109.337±0.0012 | 1.3468±0.0006 |
| Cyperus rotundus | 284.9887±0.0045 | 28.201±0.0015 | 0.2194±0.0009 | 108.411±0.0011 | 0.993±0.0006 |
| Eclipta prostrata | 298.7874±0.0025 | 1.7340±0.0008 | 3.4685±0.0008 | 111.305±0.0006 | 190.10±0.0008 |
| Evolvulus alsinoides | 236.5878±0.003 | 0.9178±0.0014 | 2.3801±0.0014 | 108.3164±0.001 | 142.20±0.0009 |
| Gymnema sylvestre | 124.5312±0.005 | 32.351±0.0018 | 0.532±0.0014 | 106.532±0.0009 | 2.68546±0.001 |
| Hemidesmus indicus | 217.4548±0.0046 | 1.9014±0.0016 | 2.0313±0.0011 | 107.595±0.0006 | 9.2312±0.0014 |
| Hygrophila auriculata | 216.0732±0.0024 | 0.6507±0.0006 | 0.546±0.0006 | 105.921±0.0008 | 53.1011±0.001 |
| Kaempferia galanga | 283.2172±0.0043 | 73.017±0.0013 | 0.4026±0.0009 | 103.474±0.0014 | 1.9387±0.0009 |
| Leucas aspera | 227.1456±0.0042 | 1.1511±0.0013 | 4.2348±0.0006 | 105.674±0.0008 | 110.70±0.0007 |
| Maerua arenaria | 69.7743±0.0049 | 27.303±0.0046 | 1.1418±0.0012 | 105.737±0.0011 | 45.200±0.0013 |
| Momordica charantia | 162.8173±0.0048 | 0.6676±0.0015 | 2.4917±0.0013 | 107.6483±0.001 | 51.600±0.0012 |
| Moringa oleifera | 77.5598±0.0045 | 37.501±0.0014 | 1.0496±0.001 | 107.322±0.001 | 13.739±0.0007 |
| Mucuna pruriens | 46.58817±0.0047 | 32.351±0.0015 | 0.1076±0.0008 | 107.484±0.0013 | 3.7078±0.0008 |
| Mukia madarespatana | 0.1733±0.0028 | 1.4670±0.0012 | 2.1729±0.001 | 112.105±0.0008 | 128.40±0.0007 |
| Murraya koenigii | 187.7744±0.0048 | 6.2511±0.0014 | 0.9532±0.0011 | 106.648±0.0008 | 62.900±0.0011 |
| Musa paradisiaca | 262.5032±0.0045 | 0.3547±0.0057 | 0.7204±0.0012 | 106.884±0.0011 | 26.0317±0.001 |
| Myristica fragrans | 55.08867±0.0048 | 5.1167±0.0027 | 0.4213±0.0012 | 105.074±0.0009 | 56.101±0.0009 |
| Ocimum sanctum | 199.702±0.0031 | 1.2034±0.0038 | 1.3942±0.0011 | 108.432±0.0009 | 149.500±0.001 |
| Phyla nodiflora | 224.5312±0.005 | 2.6345±0.0017 | 1.3585±0.0012 | 108.206±0.0009 | 2.016±0.0013 |
| Quercus infectoria | 21.70497±0.0043 | 34.351±0.0013 | 0.0074±0.001 | 108.474±0.0012 | 1.90787±0.001 |
| Rosa L. | 61.11713±0.0048 | 34.054±0.0051 | 0.926±0.0014 | 109.374±0.0011 | 1.5467±0.0013 |
| Saraca asoca | 167.9454±0.0036 | 2.9511±0.0017 | 0.2961±0.0013 | 46.2896±0.0016 | 3.0467±0.0013 |
| Solanum trilobatum | 84.21627±0.0031 | 10.017±0.0281 | 2.5189±0.0013 | 107.121±0.0008 | 125.40±0.0007 |
| Solanum xanthocarpum | 191.3164±0.003 | 1.3674±0.0017 | 1.0757±0.0007 | 105.568±0.0008 | 43.699±0.0017 |
| Terminalia belerica | 245.2312±0.0039 | 44.1023±0.002 | 0.1919±0.0008 | 107.184±0.0017 | 3.4777±0.0009 |
| Terminalia chebula | 187.9597±0.004 | 3.3021±0.0019 | 0.7485±0.0016 | 108.105±0.0014 | 41.1012±0.001 |
Tinospora cordifolia |
162.7734±0.004 | 0.93413±0.002 | 0.4508±0.0011 | 108.069±0.0009 | 2.7007±0.0011 |
| Tribulus terrestris | 123.4314±0.0044 | 37.784±0.0016 | 0.2044±0.0013 | 106.521±0.0013 | 0.8390±0.0006 |
| Trigonella feonum graecum | 200.517±0.0049 | 39.018±0.0016 | 2.8623±0.0015 | 108.507±0.0023 | 5.4546±0.0011 |
| Viola odorata | 215.2168±0.004 | 37.101±0.0013 | 0.5988±0.0009 | 106.984±0.0014 | 4.43140±0.001 |
| Withania somnifera | 237.6034±0.0036 | 34.817±0.0014 | 0.6819±0.0012 | 106.168±0.0015 | 12.985±0.0012 |
| Zingiber officinale | 203.8876±0.0031 | 0.9844±0.0014 | 0.8373±0.0012 | 107.542±0.0008 | 499.59±0.0062 |
| Permisssible limits (AHPA/ WHO) | - | 40 | Essential nutrients | - | Yet to be established |
*The results are expressed as mean±SD (ppm/g)’
Higher concentrations of Ca were recorded in Eclipta prostrata (298.7874±0.0025 ppm/g), Acalypha indica (285.4740±0.005 ppm/g) and Cyperus rotundus (284.9887±0.0045 ppm/g).The lowest concentration of Ca metal was detected in Mukia madarespatana (0.1733±0.0028 ppm/g). Ca accumulation in body helps in the metabolism of bones, blood clotting and muscle contraction [11]. Mukia madarespatana had the highest concentration of Mg with 112.056±0.0008 ppm/g and the lowest concentration was in that of Saraca asoca (46.2896±0.0016 ppm/g). This element helps in activation of the enzyme system in citric acid cycle [12]. Similarly, earlier reports related to metal analysis in the herbal cosmetic products showed Mg (2963±90 ppm/g) and Ca (2626±52.37 ppm/g) at maximum levels [13].
The maximum level of Cu metal was present in Kaempferia galanga (73.0178±0.0013 ppm/g). Symptoms of acute copper poisoning include salivation, epigastric pain, nausea, vomiting and diarrhoea, all of which are probably due to the irritant effect of copper on the gastrointestinal mucosa [14]. Jabeen et al [15], reported the range of copper content as 17.6 - 57.3 ppm content in 50 medicinal materials from India.The maximum concentrations of Pb and Fe were detected in Leucas aspera with 6.0490±0.0096 ppm/g and 4.2348±0.0006 ppm/g respectively. Lead is a toxic element to the human system [16] and it causes both acute and chronic poisoning in kidney, liver, vascular and immune system [15]. Haemoglobin possessing iron, enables the transport of oxygen from the lungs to tissues [17], the deficiency of which causes anemia in human beings. Similar results on the presence of Pb and Fe were reported in Nigerian herbal products [18]. Aristolochia bracteolata (1.6862±0.0047 ppm/g) has recorded the highest concentration of Ni. Excessive intake of Ni causes severe allergic reaction, bronchial asthma, dermatitis and eczema [20]. The maximum concentration of Cr was detected in Chrysopogon zizanioides (1.3521±0.0031 ppm/g). Trivalent Chromium plays a vital role in metabolic functions of the body while the hexavalent form is harmful to the human body [19]. The highest concentration of Co (0.6256±0.00053 ppm/g) was recorded in Moringa oleifera. According to Jabeen et al [15], Co was detected at concentration ranging from 3.41±0.60 μg/g to 11.26±0.30μg/g for some herbal plants found in Pakistan. Hemidesmus indicus had the highest concentration of Na (0.3026±0.0008 ppm/g). However, complete absence of Cr was recorded in Azadirachta indica and Cassia auriculata whereas Blepharis maderaspatensis was devoid of Ni. The concentrations of different elements recorded in different herbal materials are listed in Table 2. The limitations on prescribed level of heavy metals in herbal material from different countries like Canada, China, Singapore, Malaysia, Korea and Thailand are already listed by WHO, 2007.
The accumulation of heavy metals in medicinal plants has been reported to be based on various factors such as climatic factors, plant species and air pollution, apart from other environmental factors [21]. The presence of metals in herbal drugs might also be due to phyto-accumulation [22] and other processes involved in formulation and storage of products.
CONCLUSION
Commercially available raw material of the herbal products is used in home remedies for common ailments, worldwide. In the present investigation, greater levels of Mn, Ca and Mg were detected when compared to the other elements. However, the presence of metals analysed were found to be within the permissible limits in accordance to the American Herbal Products Association (AHPA) and WHO standards. Although the study implies consumption of herbal materials are safe, periodical monitoring of the quality of the herbal materials is recommended.
CONFLICT OF INTEREST
No Conflict of Interest lies between Authors.
REFERENCES