Evaluation of trace and toxic heavy metals in selected crude drugs used in khyber Pukhtonkhawa,Pakistan

The present study was conducted for the evaluation of essential trace and toxic heavy metals such as pb,mn,zn,co,cr,cu,fe,ni,k and na in 31 crude drugs commonly used in khyber pukhtonkhawa. these crude drugs were purchased from local venders in peshawar. pb was present in excessive (more than 10 μg /g) concentration in four tested samples while mn concentration exceeded only in two samples. zn concentration exceeded the permissible limit (50 μg /g) in trigonella foenum gracum (102 μg /g) and berberis lyceum (59 μg /g). except glycyrrhiza glabra all these samples of crude drugs exceeded the standard limit for co (0.2 μg /g). twelve crude drugs were within permissible limits of c r(1.5 μg/g). highest concentration of cu was found in berberis lyceum (57 μg/g) followed by trigonella foenum graecum (16 μg/g),glycyrrhiza glabra l. (11 μg/g) and silybum marianum (11 μg/g). the concentrations of remaining metals were in safe range for all tested samples. crude drugs are abundantly used for various ailments,but due to presence of heavy toxic metals,these must be subjected to various pharmacological and toxicological evaluation for their affective and safe use.