Possible mechanism of hepatoprotective activity of Azadirachta indica leaf extract: Part II
Hepatoprotective activity of Azadirachta indica leaf extract against paracetamol induced hepatic damage in rats has already been reported. In the present investigation effects of Azadirachta indica leaf extract on blood and liver glutathione, Na+K+-ATPase activity and thiobarbutiric acid reactive substances against paracetamol induced hepatic damage in rats have been studied with a view to elucidate possible mechanism behind its hepatoprotective action. It was interesting to observe that Azadirachta indica leaf extract has reversal effects on the levels of above mentioned parameters in paracetamol hepatotoxicity. Possible mechanism behind the results are discussed. 
Antimicrobial activity of commercial Olea europaea (olive) leaf extract
The aim of this research was to investigate the activity of a commercial extract derived from the leaves of Olea europaea (olive) against a wide range of microorganisms (n = 122). Using agar dilution and broth microdilution techniques, olive leaf extract was found to be most active against Campylobacter jejuni, Helicobacter pylori and Staphylococcus aureus [including meticillin-resistant S. aureus (MRSA)], with minimum inhibitory concentrations (MICs) as low as 0.31–0.78% (v/v). In contrast, the extract showed little activity against all other test organisms (n = 79), with MICs for most ranging from 6.25% to 50% (v/v). In conclusion, olive leaf extract was not broad-spectrum in action, showing appreciable activity only against H. pylori, C. jejuni, S. aureus and MRSA. Given this specific activity, olive leaf extract may have a role in regulating the composition of the gastric flora by selectively reducing levels of H. pylori and C. jejuni. 
Biosynthesis of silver and gold nanoparticles using Chenopodium album leaf extract
This paper reports a facile and rapid biosynthesis of silver and gold nanoparticles from Chenopodium album, an obnoxious weed. The aqueous leaf extract of the herb was used as mild reducing agent for silver and gold nanoparticles (SNPs and GNPs) synthesis from their salt solutions in single-pot process. Quasi-spherical shapes were observed for biosynthesized SNPs and GNPs within range of 10–30 nm, respectively. The UV–VIS spectra gave surface plasmon resonance (SPR) for SNPs and GNPs at 460 and 540 nm, respectively. Influence of leaf extract quantities, metal concentrations, contact time, reaction temperature and pH were evaluated to find their effects on NPs synthesis. The produced nanocrystals of silver and gold were analyzed with transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and fourier transform infrared spectroscopy (FTIR). The stability of NPs was evaluated at different pH with zeta potentiometer without adding any stabilizing agents. 
Effect of Aqueous Leaf Extract of Acalypha wilkesiana on Hematological Parameters in Male Wistar Albino Rats
Aims: The aim of this study is to evaluate the effect of aqueous leaf extract of Acalypha wilkesiana on hematological parameters in male wistar rats.
Study Design: In_vivo.
Place and Duration of Study: Department of Biochemistry, Faculty of Natural Sciences,
Ambrose Alli University, Ekpoma Nigeria, between August 2011 and October 2011.
Methodology: Thirty two male wistar rats of average body weights 167.50g were grouped into four (I-IV), of eight rats each. Group I received distilled water (control), while constituted doses of 2500, 5000 and 10000 mg/kg body weight of the extract were administered once daily for 14 days to animals in group II, III and IV respectively. The effect of administration of this extract on hematological parameters was evaluated.
Results: Results showed that the extract did not exhibit any significant effect (P>0.05) on packed cell volume, hemoglobin, red blood cell count, white blood cell, neutrophil, lymphocytes, platelets, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and erythrocyte sedimentation rate at all the administered doses of the extract. There was a significant reduction in mean corpuscular volume at all doses of the administered extract when compared with the control.
Conclusion: The extract may be considered relatively hematotoxic at a dose of 2500 mg/kg due to its potentials to cause the formation of microcytic RBC’s. 
Methanol Leaf Extract of Persea americana Protects Rats against Cholesterol-Induced Hyperlipidemia
Aim: To investigate anti-hyperlipidemic activity of methanol leaf extract of Persea americana (MEPA) in cholesterol-induced hyperlipidemic rats.
Methodology: The animals were randomly divided into five groups of 5 rats each. Group1 served as the normal control (NC) and received distilled water. Group 2, the cholesterol-induced hyperlipidemic control (CHOL) was given cholesterol diet (20% groundnut oil, 1% cholesterol and 0.5% cholic acid mixed with rat pellet) orally. Groups 3 and 4 received oral administration of cholesterol diet and MEPA at a dose of 20 and 40 mg/kg body weight respectively, while group 5 was treated orally with cholesterol diet and cholestyramine (0.26g/kg body weight). Cholesterol diet, MEPA and cholestyramine were administered daily for a period of eight weeks.
Results: The changes observed in the plasma levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL) and high density lipoprotein (HDL) of hyperlipidemic control rats were reversed by MEPA in a dose-dependent manner. At 20 mg/kg body weight, MEPA significantly (p<0.05) reduced TC, TG and LDL plasma levels by 54.2%, 46.2% and 65.6% respectively, and increased HDL plasma level by 60.0%. At a higher dose of 40 mg/kg, MEPA reduced TC, TG and LDL levels by 60.4%, 69.2% and 87.5% respectively while HDL was increased by 80.0%. There was a significant increase of change in body weight of hyperlipidemic rats compared to the change in normal control. MEPA caused a reduction of change in body weight to nearly that of the normal control. MEPA also dose-dependently caused significant reduction (p<0.05) of plasma lipid peroxidation in the rats. The anti-hyperlipidemic effect of MEPA was comparable to that of the standard drug, cholestyramine.
Conclusion: The results of this study showed that Persea americana could be a source of good alternative remedy for hyperlipidemia. Further studies are needed to fully understand the mechanism of action of the plant. 
 Chattopadhyay, R., 2003. Possible mechanism of hepatoprotective activity of Azadirachta indica leaf extract: part II. Journal of ethnopharmacology, 89(2-3), pp.217-219.
 Sudjana, A.N., D’Orazio, C., Ryan, V., Rasool, N., Ng, J., Islam, N., Riley, T.V. and Hammer, K.A., 2009. Antimicrobial activity of commercial Olea europaea (olive) leaf extract. International journal of antimicrobial agents, 33(5), pp.461-463.
 Dwivedi, A.D. and Gopal, K., 2010. Biosynthesis of silver and gold nanoparticles using Chenopodium album leaf extract. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 369(1-3), pp.27-33.
 Iniaghe, O. M., Egharevba, O. and Oyewo, E. B. (2013) “Effect of Aqueous Leaf Extract of Acalypha wilkesiana on Hematological Parameters in Male Wistar Albino Rats”, Journal of Pharmaceutical Research International, 3(3), pp. 465-471. doi: 10.9734/BJPR/2013/2601.
 Kolawole, O. T., Kolawole, S. O., Ayankunle, A. A. and Olaniran, I. O. (2012) “Methanol Leaf Extract of Persea americana Protects Rats against Cholesterol-Induced Hyperlipidemia”, Journal of Advances in Medicine and Medical Research, 2(2), pp. 235-242. doi: 10.9734/BJMMR/2012/933.