Cytotoxic and immunopotentiating effects of ethanolic extract of Nigella sativa L. seeds
In-vitro cytotoxic screening of extracts of Nigella sativa L. seeds (Ranunculaceae) indicated cytotoxicity in the ethyl-acetate fraction (EAF) against different classes of cancer cell lines, P388, Molt4, Wehi 164, LL/2, Hep G2, SW620 and J82, as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The ethyl-acetate column chromatographic fraction (CC-5) showed selectivity against Hep G2, Molt4, and LL/2. CC-5 was relatively non-toxic against human umbilical cord endothelial cells at 50 μg/ml. CC-5 had no stimulatory effect on mouse splenocytes as such. CC-5 and water fraction, however, enhanced the proliferative response in the presence of ConA (3 μg/ml), but not LPS (1 and 6 μg/ml). These data indicate that CC-5 possesses a potent cytotoxic effect as well as a potentiating effect on the cellular immune response. The mechanism whereby it produces this needs to be resolved. 
Hypoglycaemic and hypolipidemic effect of ethanolic extract of seeds of Eugenia jambolana in alloxan-induced diabetic rabbits
The hypoglycaemic and hypolipidemic effect of ethanolic extract obtained from seeds of E. jambolana was investigated in alloxan-induced diabetic rabbits. Hypoglycaemic activity was assessed by reduction in fasting blood glucose (FBG) at 90 min and also fall in peak blood glucose during glucose tolerance test (GTT) in sub-diabetic and mild diabetic (MD) rabbits, but in severe diabetic (SD) rabbits by reduction in FBG at 90 min. Ethanolic extract (100 mg/kg body weight) when given orally to sub-diabetic (AR) for 1 day, MD for 7 days and SD for 15 days showed significant fall in FBG at 90 min (12% AR, 18.9% MD and 29% SD) and also produced 16.9% fall in peak blood glucose in AR and 21% in MD rabbits during GTT. When administered daily for 15 days to MD and SD rabbits, significant fall in FBG (41.3% MD, 31.6% SD) and glycosylated haemoglobin (GHb) levels (23.3% MD, 26.6% SD) were observed, while serum insulin level showed significant increase (32.8% MD, 26.9% SD). Liver and muscle glycogen content also increased. The ethanolic extract of seeds also exhibited significant hypolipidemic effect as evident from fall in total serum cholesterol (TC)/high density lipoprotein cholesterol (HDL-c) ratio, serum low density lipoprotein cholesterol (LDL-c) levels and decreased activity of HMG-CoA reductase. The histopathological studies of liver, pancreas and aorta in alcoholic extract treated diabetic groups revealed almost normal appearance. 
Effect of ethanolic extract of Zingiber officinale on dyslipidaemia in diabetic rats
The lipid lowering and antioxidant potential of ethanolic extract of Zingiber officinale Roscoe (family, Zingiberaceae) was evaluated in streptozotocin (STZ)-induced diabetes in rats. Ethanolic extract of Zingiber officinale (200 mg/kg) fed orally for 20 days produced, significant antihyperglycaemic effect (P < 0.01) in diabetic rats. Further, the extract treatment also lowered serum total cholesterol, triglycerides and increased the HDL-cholesterol levels when compared with pathogenic diabetic rats (P < 0.01). STZ-treatment also induced a statistically significant increase in liver and pancreas lipid peroxide levels (P < 0.01) as compared to normal healthy control rats. Zingiber officinale extract treatment lowered the liver and pancreas thiobarbituric acid reactive substances (TBARS) values (P < 0.01) as compared to pathogenic diabetic rats. The results of test drug were comparable to gliclazide (25 mg/kg, orally), a standard antihyperglycaemic agent. The results indicate that ethanolic extract of Zingiber officinale Roscoe can protect the tissues from lipid peroxidation. The extract also exhibit significant lipid lowering activity in diabetic rats. The present study is the first pilot study to assess the potential of Zingiber officinale in diabetic dyslipidaemia. 
Study of Acid-base Indicator Property of Ethanolic Extract of Nerium indicum Flower
A study has been done to investigate the indicator property of ethanolic extract of Nerium indicum. The commonly used synthetics indicators cause environmental pollution and pose hazardous effects in human body. Natural pigments in plants are highly coloured substance and may change with pH variation. The equivalence points of the titrations using flower extract is almost close or coincide with that of phenolphthalein (synthetic indicator). Therefore, use of ethanolic extract of Nerium indicum as an indicator for acid-base titration could be effectively employed as a substitute to the synthetic acid-base indicators. 
Individual and Combined Antibacterial Activity of Crude Extracts from Medicinal Plants Carissa spinarum Linn and Carica papaya Linn
Aim: To assess inhibitory effect of extracts, alone and in combination, from Carissa spinarum Linn (C. spinarum L.) and Carica papaya Linn (C. papaya L.) on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The combined extracts used were C. papaya L leaves petroleum ether extract/C. spinarum L root methanolic extract (CPLP/CSRM), C. spinarum L leaves petroleum ether extract/C. papaya L seed ethanolic extract (CSLP/CPSE), C. spinarum L root ethanolic extract/C. papaya L leaves ethanolic extract (CSRE/CPLE), C. papaya L root ethanolic extract/C. spinarum L bark ethanolic extract (CPRE/CSBE) and C. papaya L leaves methanolic extract/C. spinarum L leaves methanolic extract (CPLM/CSLM).
Study Design: In vitro antibacterial assay.Place and Duration of Study: Samples were collected from Samunge village at Loliondo in Ngorongoro district located in northern Tanzania. Antimicrobial bioassay was carried out at the Department of Molecular Biology and Biotechnology, University of Dar-es-Salaam, between March 2013 and June 2013.
Methodology: The broth micro dilution method was used to determine minimum inhibition concentration (MIC). Fractional inhibitory concentrations were calculated from MICs of individual and combined extracts to determine interactions.
Results: Plant extracts demonstrated MICs ranging from 312 to 5000 μg/ml. The combination of plant extracts against S. aureus resulted into antibacterial activity of CPSE, CPRE, CPLM, CSLM and CPLP extracts to increase by 4-, 2-, 4-, 4-, and 2-fold, respectively. Activity of CSLP, CPLM and CSLM increased by 2-fold against E. coli. Synergy was demonstrated by CPLM/CSLM against S. aureus. Some combinations were additive including CPRE/CSBE, CPLP/CSRM and CSLP/CPSE against S. aureus and CSLP/CPSE, CPRE/CSBE, CPLM/CSLM against E. coli. Nevertheless, antagonism was demonstrated by CSRE/CPLE, CPLP/CSRM against E. coli and CSLP/CPSE and CSRE/CPLE against S. aureus.
Conclusion: This study revealed the importance of using plant-based antibacterial agents in combined therapy to increase efficacy. Extracts of C. spinarum L and C. papaya L could be a source of antibacterial agents when utilized in combination therapy for patients with severe E. coli and staphylococcal infections. These predictors, however, need to be validated to improve their quality. 
 Swamy, S.M.K. and Tan, B.K.H., 2000. Cytotoxic and immunopotentiating effects of ethanolic extract of Nigella sativa L. seeds. Journal of ethnopharmacology, 70(1), pp.1-7.
 Sharma, S.B., Nasir, A., Prabhu, K.M., Murthy, P.S. and Dev, G., 2003. Hypoglycaemic and hypolipidemic effect of ethanolic extract of seeds of Eugenia jambolana in alloxan-induced diabetic rabbits. Journal of Ethnopharmacology, 85(2-3), pp.201-206.
 Bhandari, U. and Pillai, K.K., 2005. Effect of ethanolic extract of Zingiber officinale on dyslipidaemia in diabetic rats. Journal of ethnopharmacology, 97(2), pp.227-230.
 Khalid, K., Idris, M., Muhammad, N. and Bala, A. (2015) “Study of Acid-base Indicator Property of Ethanolic Extract of Nerium indicum Flower”, Journal of Pharmaceutical Research International, 9(1), pp. 1-4. doi: 10.9734/BJPR/2016/20556.
 Rubaka, C., Ndakidemi, P., M. Malebo, H. and Shahada, F. (2014) “Individual and Combined Antibacterial Activity of Crude Extracts from Medicinal Plants Carissa spinarum Linn and Carica papaya Linn”, European Journal of Medicinal Plants, 4(12), pp. 1513-1523. doi: 10.9734/EJMP/2014/10599.