The antidiabetic effect of methanolic extract of Holarrhena pubescens seeds is mediated through multiple mechanisms of action.

Holarrhena pubescens is widely used in Indian and Chinese medicine in the treatment of diabetes. The current work determined the oral hypoglycemic and antidiabetic effects of seed extract in rats. The probable mechanism of action was evaluated in-vitro by α - glucosidase inhibition, glucose metabolism in insulinoma (INS-1) cells to reflect secretion of insulin, and protein glycation inhibition. Its potential for herb-drug interaction was evaluated in the cytochrome P450 3A4 (CYP3A4) inhibition assay. The seed extract increased serum insulin levels and reduced serum blood glucose levels in the oral glucose tolerance test. It also reduced the serum glucose levels in streptozocin-induced diabetes. The extract also inhibited α -glucosidase enzyme activity and demonstrated that it can increase the secretion of insulin from INS to 1-rat insulinoma cell line cells in-vitro in a concentration-dependent manner. However, it had a very weak inhibitory effect on protein glycation and it did not affect the activity of CYP3A4. The results of the study showed that H. pubescens seed extract increases insulin secretion and inhibits glucose absorption both in-vivo and in-vitro with a weak protein glycation inhibitory effect. The herb is devoid of CYP3A4 inhibitory effect indicating that it may not have pharmacokinetic interaction with the drug metabolized by this enzyme.

Effect of Moringa oleifera Leaf Extract on Excision Wound Infections in Rats: Antioxidant, Antimicrobial, and Gene Expression Analysis.

The present study investigated the wound healing activity of Moringa oleifera leaf extract on an infected excision wound model in rats. Infection was induced using methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa. An investigation was also done to study the effect of Moringa extract on the vascular endothelial growth factor (VEGF) and transforming growth factor-beta 1 (TGF-ß1) gene expression in vitro using human keratinocytes (HaCaT). The methanol extract of M. oleifera leaves was analyzed for the presence of phytochemicals by LCMS. The antimicrobial activity of the extract was also determined. Wound contraction, days for epithelization, antioxidant enzyme activities, epidermal height, angiogenesis, and collagen deposition were studied. M. oleifera showed an antimicrobial effect and significantly improved wound contraction, reduced epithelization period, increased antioxidant enzymes activity, and reduced capillary density. Effect of the extract was less in wounds infected with P. aeruginosa when compared to MRSA. The VEGF and TGF-ß1 gene expression was increased by M. oleifera.

Moringa oleifera Leaf Extract Promotes Healing of Infected Wounds in Diabetic Rats: Evidence of Antimicrobial, Antioxidant and Proliferative Properties.

Moringa oleifera is known to possess wound healing activity. The present study evaluated the healing properties of methanolic extract of M. oleifera leaves in excision wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) or P. aeruginosa in diabetic rats. An in vitro study was also carried out to determine the gene expression of VEGF and TGF-ß1. Preliminary phytochemical and GC-MS analyses were carried out to determine different chemical constituents present in the extract. M. oleifera was applied locally as an ointment at two different concentrations. Wound contraction, period of epithelization, antioxidant enzyme activities and histological changes were determined. For the gene expression study, HaCaT cell lines were used. The formulation of M. oleifera extract improved wound contraction and decreased the period of epithelization, which was associated with an increase in antioxidant enzyme activities, epithelization, capillary density and collagen formation in MRSA-infected diabetic rats. However, this effect was reduced in diabetic animals infected with P. aeruginosa. An increase in the expression of VEGF and TGF-ß1 was observed in HaCaT cell lines. M. oleifera extract promotes the healing of infected wounds in MRSA-infected diabetic rats but is less effective in the healing of wounds infected with P. aeruginosa in diabetic rats.

Repeat oral dose safety study of standardized methanolic extract of Boswellia sacra oleo gum resin in rats.

The oleo gum resin of Boswellia sacra Fleuck. (Burseraceae) is widely consumed for treatment of several diseases and disorders. To determine the effect of repeated administration of this resin on liver and kidney functions, three different doses of standardized methanolic extract were administered orally to rats for 28 days. Apart from histological studies and determination of biomarkers of hepatotoxicity and nephrotoxicity, other parameters of sub-chronic toxicity such as behavioral change, food consumption and change in body weight were assessed. The extract contained about 36.91% of total boswellic acids; of which 11-keto beta boswellic acid, acetyl-11-keto beta boswellic acid, boswellic acids (α and ß) and acetyl boswellic acid (α and ß) were found to be 5.81%, 1.91%, 21.92% and 7.27% respectively. Oral administration of the extract for 28 consecutive days did not show any sign of behavioral toxicity and did not affect food consumption or weight gain significantly. Determination of biomarkers of hepatic and nephrotoxicity revealed that extract was safe at the tested doses as it did not produce any significant change in the studied biomarkers except producing a dose dependent increase in serum total protein levels. The histological examination supported biochemical findings. To conclude, methanolic extract of Boswellia sacra doen not produce any significant toxicity to liver and kidney up to doses of 100 mg/kg body weight. The results contradict earlier reports that members of boswellia species produce organ toxicity in rats.